Subscriber access provided by - Access paid by the | UCSB Libraries
Bioactive Constituents, Metabolites, and Functions
Valine supplementation in a reduced protein diet regulates growth performance partially through modulation of plasma amino acids profile, metabolic responses, endocrine and neural factors in piglets xiao ya zhang, Xiangfang Zeng, xutong liu, hongmin jia, pingli he, Shiyan Qiao, and Xiangbing Mao J. Agric. Food Chem., Just Accepted Manuscript • DOI: 10.1021/acs.jafc.8b01113 • Publication Date (Web): 10 Mar 2018 Downloaded from http://pubs.acs.org on March 13, 2018
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 35
Journal of Agricultural and Food Chemistry
1
Valine supplementation in a reduced protein diet regulates growth performance
2
partially through modulation of plasma amino acids profile, metabolic responses,
3
endocrine and neural factors in piglets
4 5
Xiaoya Zhang,†, § Xutong Liu,† Hongmin Jia,† Pingli He,† Xiangbing Mao,‡ Shiyan Qiao† and
6
Xiangfang Zeng†,*
7
†
8
China
9
‡
10
State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing 100193,
Animal Nutrition Institute, Sichuan Agricultural University, Sichuan, Chengdu 611130,
China
11 12 13 14 15 16 17 18 19 20
1
ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
21 22
ABSTRACT: The objective of this study was to investigate whether valine (Val)
23
supplementation in a reduced protein (RP) diet regulates growth performance associated with
24
the changes in plasma amino acids (AAs) profile, metabolism, endocrine and neural system in
25
piglets. Piglets or piglets with a catheter in the precaval vein were randomly assigned to two
26
treatments, including two RP diets with standardized ileal digestible (SID) Val: Lysine (Lys)
27
ratio of 0.45 and 0.65, respectively. The results indicated that piglets in the higher Val:Lys
28
ratio treatment had higher average daily feed intake (ADFI) (P < 0.001), average daily gain
29
(ADG) (P = 0.001), and feed conversion ratio (FCR) (P = 0.004) and lower plasma urea
30
nitrogen (P = 0.032) and expression of gastric cholecystokinin (CCK) and hypothalamic
31
pro-opiomelanocortin (POMC). Plasma AAs profiles including postprandial plasma essential
32
AAs (EAAs) profile, and in serum, muscle and liver involved in metabolism of AAs and fatty
33
acids were significantly different between two treatments. In conclusion, Val influenced
34
growth performance associated with metabolism of AAs and fatty acids and endocrine and
35
neural system in piglets.
36
KEYWORDS: amino acids profile, cholecystokinin, growth performance, metabolites,
37
pro-opiomelanocortin, piglets, feed intake, valine
2
ACS Paragon Plus Environment
Page 2 of 35
Page 3 of 35
Journal of Agricultural and Food Chemistry
38
INTRODUCTION
39
Branched chain amino acids (BCAAs) valine (Val) is an important nutrient for
40
animals and humans and plays crucial roles in growth,1 metabolism homoeostasis
41
including lipid and protein metabolism modulation,2 energy homoeostasis,3 cell
42
function and immunity.4 High amount of dietary Val supplementation has no
43
detrimental effect on laying productivity or immune function in laying hens.5
44
Optimum dietary Val supplementation increases body weight gain (BWG) and feed
45
conversion ratio (FCR), which is due to the specific response of Val and not related
46
with the increase in total nitrogen.6 Val deprivation markedly decreases blood glucose
47
level, partially because of downregulation of glucose-6-phosphatase expression.7
48
Besides, dietary Val deficiency impairs intestinal physical barrier function and
49
intestinal immune function through decreasing tight junction protein expression and
50
anti-inflammatory cytokines in fishes.8 Under Val deprivation status, monocytes were
51
not able to differentiate into mature dendritic cells as well as a decrease in
52
phospho-S6 kinase and CD83 expression.9 Val has the capacity to increase
53
macrophage phagocytosis in mice, ultimately reducing the load of pathogens through
54
stimulation of PI3K/Akt1 pathway and the increase in NO production.10
55
Val, the fifth limiting AA for growing pigs fed corn-soybean meal-based diets,11
56
is commonly added to the low protein (LP) diets. Our previous data showed that Val
57
supplementation to the LP diet (16.9% crude protein (CP)) had a comparable effect in
58
improving growth performance of weaned pigs, compared with the standard protein
59
diet (20.9% CP). 12 While dietary Val deficiency appeared to reduce the average daily
60
feed intake (ADFI), resulting in a subsequent reduction in growth of weaned pigs.13
3
ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
61
The feed intake in animals and humans is regulated by the hypothalamic signaling
62
pathways14 and endocrine system.15,16 Nevertheless, there is lack of evidence that
63
whether Val modulates feed intake through endocrine and neural system in RP diet.
64
Moreover, BCAA deficiency is demonstrated to cause disturbances in nutrients
65
metabolism.17 However, the metabolic changes in different organs and the
66
corresponding contributions to feed intake and growth is still unclear in response to
67
BCAA supplementation in RP diet.
68
Therefore, the objective of this study was to investigate whether Val
69
supplementation in a RP diet influenced growth performance through changes in
70
plasma AAs concentrations, expression of endocrine factors and metabolic profile of
71
serum, muscle and liver in piglets.
72
MATERIALS AND METHODS
73
The animal handling procedures used in this study were in accordance with the
74
Chinese Guidelines for Animal Welfare and were approved by the China Agricultural
75
University Animal Care and Use Committee (Beijing, China).
76
Animals, Experimental Design and Sampling. In order to investigate the
77
different changes of metabolites in serum, liver and muscle, plasma amino acids
78
concentrations, as well as neural and endocrine system factors in two levels of Val
79
treatments, twelve healthy piglets (Duroc x Landrace x Large White) with similar
80
initial body weight (18.9 ± 2.3 kg) were randomly assigned to one of two dietary
81
standardized ileal digestible (SID) Val: Lys ratios (0.45 and 0.65) for 14 days, based
82
on body weight and sex. The diets were formulated based on corn and soybean meal
83
(16.9 % CP, Table 1). The other essential amino acids (EAAs) were balanced to meet
4
ACS Paragon Plus Environment
Page 4 of 35
Page 5 of 35
Journal of Agricultural and Food Chemistry
84
or exceed the recommendations of the National Research Council (NRC, 2012).
85
Piglets had free access to feed and water throughout the experiment. Piglets were
86
weighed on the morning of day 1 and 14 in the fasted state (overnight fasting) to
87
calculate average daily gain (ADG). Feed intake was recorded daily during the
88
experiment to calculate ADFI and FCR. On the morning of days 14 (overnight fasting
89
state), blood samples from all piglets were collected into 10 mL heparinized
90
vacutainer tubes and vacuum blood collection tubes (Becton Dickinson Vacutainer
91
Systems, Franklin Lakes, NJ) via the jugular vein, respectively. Blood was
92
centrifuged at 1,000 × g for 15 min at 4℃ within 2 h after sampling. An aliquot of
93
plasma was stored at -20℃ until AA analysis. Serum was obtained after
94
centrifugation and stored at -80℃ until use. Thereafter, all the piglets were killed by
95
electrocution. Mucosa of the gastric fundus were stripped at the middle of the bottom
96
position of the stomach and duodenal mucosa at a point 2 cm from the pylorus was
97
also collected. Samples from hypothalamus, liver and longissimus dorsi muscle were
98
also collected. All samples were stored at -80℃.
99
To investigate the differences of postprandial amino acid profiles in two levels of
100
Val treatments, six healthy piglets (Duroc x Landrace x Large White) with similar
101
initial body weight (15.7 ± 0.8 kg) were surgically fitted with a catheter in the
102
precaval vein and assigned to one of the same two dietary treatments as in Exp. 1
103
based on body weight and sex. After a 7-d recovery period from the surgery, blood
104
samples were collected from the catheters every 2 days in a 6-d experiment. At 07:50
105
h collected blood sampling, piglets were fed their respective diets (12 g/kg BW0.75)
5
ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
106
and for each piglet, all feed was ingested within 10 min.18 After that, blood samples
107
were taken every 20 min during the first hour and every 1 hour during the following 3
108
h (total of 6 time points). Blood was stored in heparinized tubes (Becton Dickinson
109
Vacutainer Systems, Franklin Lakes, NJ) kept on ice and centrifuged at 1,000 × g for
110
15 min at 4℃ within 2 h after sampling. An aliquot of plasma was stored at -20℃
111
until AA analysis.
112
In both experiments, all the piglets were housed in the Metabolism Laboratory of
113
the Ministry of Agriculture Feed Industry Centre (China Agricultural University,
114
Beijing, China). All the piglets were housed individually in stainless steel metabolic
115
cage (1.4 m x 0.7 m x 0.6 m) equipped with a water nipple and a feed trough in an
116
environmentally controlled room (22 ± 2℃).
117
Chemical Analysis. Analysis of dietary CP content (Table 1) was conducted
118
according to the method of the Association of Official Analytical Chemists (AOAC)
119
(2003). For the analysis of most AAs, diets were hydrolyzed in 6 N HCl at 110℃ for
120
24 h (AOAC, 2003). The content of sulfur AAs was determined after performic acid
121
oxidation followed by acid hydrolysis and tryptophan content was determined after
122
alkaline hydrolysis (AOAC, 2003). AA analysis was conducted by High Performance
123
Liquid Chromatography (Hitachi L-8800 Amino Acid Analyzer, Tokyo, Japan).
124
Plasma AA content was using an Ion-Exchange Chromatography (S-433D
125
Amino Acid Analyzer, Sykam, Germany).46 Plasma urea nitrogen was determined
126
using a blood urea nitrogen color test kit (Nanjing Jiancheng Bioengineering Institute,
127
Nanjing, China).
6
ACS Paragon Plus Environment
Page 6 of 35
Page 7 of 35
Journal of Agricultural and Food Chemistry
128
RNA Extraction and RT-PCR Analysis. Total RNA was extracted from the
129
gastric, duodenal and hypothalamic tissues using Trizol Reagent (Invitrogen Life
130
Technologies, Carlsbad, CA) according to the manufacturer’s instruction. RNA
131
concentrations were measured using a Nanodrop. First-strand cDNA was synthesized
132
using a PrimeScript 1st Strand cDNA Synthesis Kit (Takata, Ostu, Japan, Cat: 6110A).
133
Primers were designed using Oligo 7.0 Software (Table 2). Real-time PCR was
134
performed using an Applied Biosystems 7500 Real-Time PCR System (Foster City,
135
CA, USA) with SYBR Green PCR Master Mix (Takara, Japan) in 10 µL reaction with
136
1/20 (for β-actin) or 1/10 (for target gene) of the first-strand cDNA. The PCR
137
program was set for the denaturation at 95℃ for 10 min, followed by 40 cycles of 94℃
138
for 15 s, 55℃ for 20 s, and 72℃ for 30 s. Each sample was measured in triplicate.
139
Relative gene expression was calculated according to the △△Ct method using
140
β-actin as the reference gene.
141
Non-Targeted Metabolic Fingerprinting Analysis. Serum samples (200 µL)
142
were deproteinized and metabolites were extracted with ice-cold acetonitrile and
143
methanol mixture (1:1, v: v) at 1:4 sample: extract solution ratio. After vortexing, the
144
samples were centrifuged at 13000 rpm for 10 min at 4℃. Then 500 µL of the
145
supernatants were removed and evaporated to dryness in a vacuum concentrator. The
146
residues were resuspended in 100 µL of methanol: water (1:1), vortexed and
147
centrifuged again at 13000 rpm for 10 min at 4℃. The supernatants were transferred
148
to sample vials for HPLC-QTOF-MS analysis.
149
Muscle and liver samples were initially crushed and extracted using ice-cold
7
ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
150
extraction mix (methanol : water, 8: 2, v/v). The samples were vortexed and then
151
stand on dry ice for 4 h. The aqueous fractions were centrifuged at 13000 rpm for 10
152
min at 4℃ and the supernatant were removed. The mixture of the precipitate and 400
153
L methanol were vortexed for 1 min. After standing on dry ice for 30 min, the
154
samples were centrifuged again at 13000 rpm for 10 min at 4℃ and the supernatants
155
were combined with the supernatant from the first extraction. The supernatants were
156
evaporated to dryness in a vacuum concentrator. The residues were resuspended in
157
100 mL of methanol: water (1:1) solution, vortexed, and centrifuged again at 13000
158
rpm for 10 min at 4℃. The supernatants were transferred to sampler vials for LC-MS
159
analysis.
160
Metabolomics Profiling. Isolating the substances in 5 µL of the extracted
161
sample were performed by the Agilent 1290 Infinity HPLC system, coupled to an
162
Agilent 6520 quadrupole-time of flight mass spectrometer (QTOF-MS) with a heated
163
electrospray ionization (ESI) source. An Agilent Eclipse Plus C18 column (2.1×100
164
mm, 1.8 µm) was also used. The column temperature was set at 35℃ and the flow
165
rate was 0.3 mL/min with solvent A (0.1% formic acid water solution) and solvent B
166
(0.1% formic acid acetonitrile solution). Gradients were used from 5-30% solvent B
167
from 0 to 6 min; 95% solvent B from 6 to 9 min; 95% solvent B from 9 to 14 min; 5%
168
solvent B from 14 to 18 min before the loading of the next sample. The temperature
169
of the drying gas process was set at 350℃. The flow rate of desolvation was set at 12
170
L/min. And the nebulizer pressure was at 60 psig. The capillary voltages were set at
171
3500V, with fragmentor voltages of 150 V. Data acquisition were up to 2 spectra/s in
8
ACS Paragon Plus Environment
Page 8 of 35
Page 9 of 35
Journal of Agricultural and Food Chemistry
172
a full scan mode. The metabolites were collided straight into MS at a rate of 4
173
spectra/s. The precursor ions and their isotopes were selected by quadrupole of 4.0
174
a.m.u..
175
Data Processing. Molecular feature extraction from the raw data were
176
performed by Masshunter Profinder software (version B.06.00, Agilent Technologies,
177
Inc., Santa Clara, USA). Data were processed using algorithm followed by data
178
reduction. The data were corrected by chromatographic dimension and time
179
normalization. The window-wise summing of 0.15 min and 2 mDa produced m/z
180
values. Serum and tissues’ metabolic differences in two treatments were analyzed
181
using ANOVA. Significant changed metabolites were selected through P < 0.05 and a
182
fold change > 1.5 and then used the METLIN software to generate formulas.
183
Statistical Analysis. Statistical analysis of Exp.1 was performed using MIXED
184
procedure in SAS (SAS 9.3 software, SAS Inst. Inc., Cary, NC). The model included
185
diet as fixed effects and piglets as a random effect. Polynomial contrasts were
186
conducted to determine linear and quadratic effects of increasing SID Val:Lys ratios.
187
The data in Exp. 2 were analyzed using repeated measures of MIXED Procedure, and
188
the model included diet, time and their interaction. An alpha of P < 0.05 was the
189
criterion for statistical significance.
190
RESULTS
191
Growth Performance. Dietary Val levels affected growth performance of piglets
192
(Table 3). Piglets fed SID Val:Lys ratio of 0.45 had lower ADG (P = 0.001) and
193
ADFI (P < 0.001), and poorer FCR (P = 0.004), compared with piglets fed SID
9
ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
194
Val:Lys ratio of 0.65 treatment.
195
Plasma Concentrations of Urea Nitrogen and Amino Acids. In Exp. 1, plasma
196
urea nitrogen decreased (P = 0.032) with increased dietary SID Val: Lys ratio (Table
197
3). Plasma Val increased (P = 0.004) with the addition of dietary Val. For other
198
plasma EAAs, methionine (P = 0.017) and threonine (P = 0.001) decreased with an
199
increase in SID Val:Lys ratio (Table 4). For plasma nonessential AA (NEAAs),
200
asparagine (P = 0.007) and glutamine (P = 0.012) were significantly lower with the
201
addition of Val (Table 4).
202
The postprandial plasma profiles for the piglets fed the diets with SID Val:Lys
203
ratio of 0.45 and 0.65 are shown in the Fig.3. The plasma profiles of these five
204
essential amino acids isoleucine, leucine, methionine and threonine displayed
205
variations over two groups at 40 min time point (P < 0.05). 2, 3 or 4 h after feeding,
206
Val concentration was higher (P < 0.05) in piglets fed the diet with SID Val:Lys ratio
207
of 0.65. Other NEAAs were not different among the two treatments.
208
Relative Gene Expression of Endocrine Factors in Stomach, Duodenum, and
209
Hypothalamus. Compared with dietary SID Val:Lys ratio of 0.45, the expression of
210
gastric CCK was lower (P = 0.032) in pigs fed the diet with dietary SID Val:Lys ratio
211
of 0.65 (Fig. 2). Dietary Val level had no impact on duodenal CCK level as well as
212
gastric and duodenal ghrelin level (Fig. 2). The expression of hypothalamic POMC
213
was lower (P = 0.045) in pigs fed the diet with a SID Val:Lys ratio of 0.65 compared
214
with that in dietary Val:Lys ratio of 0.45 group (Fig.1). Hypothalamic neuropeptide Y
215
level was not affected by dietary Val content (Fig.1).
10
ACS Paragon Plus Environment
Page 10 of 35
Page 11 of 35
Journal of Agricultural and Food Chemistry
216
Metabolic Profiles in Plasma, Liver, and Muscle. Serum metabolome in pigs
217
fed diets with SID Val: Lys ratio of 0.45 and 0.65 were differentially expressed (Table
218
5). To identify which variables accounted for such a distinct separation, we calculated
219
the P value and fold change (FC), defined as the SID Val: Lys ratio of 0.45 to 0.65
220
group for a given expression profile. Taken these two variables into account, we
221
identified 14 metabolites shown in Table 5. Intriguingly, 10 of the metabolites
222
detected were found to be upregulated in the SID Val: Lys ratio of 0.45, while 3 were
223
downregulated. In muscle, 7 metabolites were shown in Table 6. 5 of the metabolites
224
detected were found to be upregulated in the SID Val: Lys ratio 0.45 group, while 2
225
were downregulated. In liver, 7 metabolites were shown in Table 7. 5 of the
226
metabolites detected were found to be upregulated in the SID Val: Lys ratio 0.45
227
group, while 2 were downregulated.
228
DISCUSSION
229
Our results indicated that with Val supplementation to the LP diets, feed intake
230
and FCR improved compared to the Val-deficient diets. As a result, piglets growth
231
performance was different between the two treatments. These results are consistent to
232
a previous experiment in which piglets fed a LP diet showed positive response to Val
233
supplementstion.19 This raises the question how piglets react to the change of Val
234
levels in LP diet.
235
Plasma urea nitrogen can be considered as a marker of protein utilization
236
efficiency.20 Because of an imbalance of EAAs available for tissue protein synthesis,
237
excess AAs can serve as metabolic molecules in different metabolic pathways.21 Also,
11
ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
238
excess AAs cannot be stored, therefore, undergo the urea production22. The present
239
results showed that plasma urea nitrogen was higher in the Val deficient group than
240
the Val supplemented group, which means that Val deficiency in LP diets breaks
241
down the balance among AAs causing body’s metabolic changes.
242
Therefore, we measured the content of metabolites in serum, liver and muscle
243
between the dietary SID Val: Lys ratio of 0.45 and 0.65. Results of present study
244
demonstrated that dietary Val supplementation decreased serum concentrations of
245
N-stearoyl valine and N-(Ammonioacetyl) glycylglycine and increased serum
246
concentrations of ketoisovaleric acid which are related to BCAA metabolism.
247
Research has shown that when rats were fed a Val-deficient diets, plasma
248
concentrations of Val, Leu and Ile decreased significantly.18 These results suggested
249
that a Val-deficient diet activated Leu and Ile catabolism. BCAAs are circulated in the
250
whole body acting as nutrient signals that involve in protein metabolism.23 We can
251
also see that the concentration of Nalpha-Methylhistidine decreased significantly in
252
the dietary SID Val: Lys ratio of 0.65 revealing that the ratio of protein proteolysis
253
decreased.
254
Muscle can acutely sense and identify deficiencies in AAs because it storages
255
the largest protein and turns over protein to AAs.24 Val deficiency can result in the
256
elevation of threonine in muscle.17,25 Study has shown that the excess dietary
257
threonine can lower protein synthesis in tissues causing the growth and development
258
failure.25 Our results indicated that L-Homoserine, intermediate product of the
259
biosynthesis of threonine, increased in SID Val: Lys ratio of 0.45 treatment, which
12
ACS Paragon Plus Environment
Page 12 of 35
Page 13 of 35
Journal of Agricultural and Food Chemistry
260
means that Val deficiency actives threonine metabolism process and may result in a
261
significant reduction in tissue protein synthesis.
262
Data on liver metabolites suggested coordinate regulation of nutrient
263
metabolism that favors fatty acids metabolism and protein synthesis in piglets. Our
264
results indicated that oleoylethylamide (OEA) was much higher in SID Val: Lys ratio
265
of 0.45 treatment. OEA belongs to the monounsaturated fatty that is released by
266
enterocytes26,27 and further combines with peroxisome proliferator-activated
267
receptor-alpha (PPAR-α) to enable fat oxidation in the liver.28 OEA might be
268
responsible for reduced satiety and hyperphagia.26 Therefore, the differences in
269
metaboliscs between two Val levels in LP diets remain us that some metabolics may
270
be essential elements of the physiology and metabolic system regulating food intake
271
and then affecting growth performance.
272
In the current study, increasing Val content decreased the expression of CCK in
273
the gastric fundus. CCK, endocrine hormone secreted from gastrointestinal tract, is
274
primarily released from the upper small intestine29 and may be transported to the
275
blood as important signals to disturb regulation of neurons in the hypothalamic.30-33
276
Neuropeptide Y (NPY) and pro-opiomelanocortin (POMC) neurons are located in the
277
arcuate nucleus of the hypothalamus which are related to the feeding behaviors. In our
278
study, the expression of POMC was decreased in the SID Val: Lys ratio of 0.65
279
treatment. This supports the fact that the expression of PMOC neurons can be
280
activated by CCK, which is important in the regulation of satiety31.
281
On the other hand, the AAs imbalance that results from a Val deficient diet
13
ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
282
might be a signaling transferred to the hypothalamus to induce the suppression of feed
283
intake.35Our data indicated that postprandial plasma leucine, and isoleucine
284
concentration were higher at 40 min time point in the SID Val: Lys ratio of 0.45 RP
285
diet then decreased rapidly. These results indicated that the body can rapidly detected
286
the Val deficiency. BCAAs share the same enzymes that be utilized to compete for
287
transamination and oxidative decarboxylation catalyzed. With higher Val diets, the
288
activity of enzyme complex can be simulated causing catabolism of Leu and Ile37,
289
therefore, the leucine, and isoleucine concentration was lower than the SID Val: Lys
290
ratio of 0.45 RP diet. And that AAs imbalance would be a critical factor in the
291
regulation of some metabolic pathway, which can result in a reduction in feed intake.
292
Our data indicated that in Val deficiency treatment, plasma Val content was lower,
293
and methionine, threonine, asparagine and glutamine were significantly higher. Study
294
has shown that Val deficiency elevated plasma threonine levels, which is thought to
295
be a body protection mechanism.36,37 Threonine can be as amino radicals in the body
296
which is less toxic than ammonia, whose concentration would be increased
297
significantly when dietary Val is deficient as protein proteolysis is increased.24
298
In conclusion, LP diets supplemented with crystalline Val increased feed intake
299
and growth performance, partly through the modulation of metabolic profiles in serum,
300
liver and muscle, endocrine factors and the AAs profiles during the postprandial
301
period which may act as signals for neural system.
302
AUTHOR INFORMATION
303
Corresponding Authors
14
ACS Paragon Plus Environment
Page 14 of 35
Page 15 of 35
Journal of Agricultural and Food Chemistry
304
*(X.Z.)
Phone:
+86
10-62733588.
Fax:
+86
10-62733688.
E-mail:
305
[email protected].
306
Funding
307
This study was supported by the Beijing Advanced Innovation Center for Food
308
Nutrition and Human Health, China Agricultural University and the Modern
309
Agro-Industry Technology Research System of Beijing. The authors thank the
310
Dacheng Group (Changchun, China) and Health and Nutrition of Evonik Industries
311
(AG Germany) for providing the crystalline amino acids.
312
Notes
313
The authors declare no competing financial interest.
314 315
ABBREVIATIONS USED
316
RP: reduced protein; Val, valine; SID, standardized ileal digestible; Lys, Lysine;
317
ADFI, average daily feed intake; ADG, average day gain; G:F, gain: feed; CCK,
318
cholecystokinin; POMC, pro-opiomelanocortin; MS, mass spectrometer; BCAA,
319
branched-chain amino acids; AA, amino acids; BWG, body weight gain; FCR, feed
320
conversion ratio; NEAA, nonessential amino acids; NPY, Neuropeptide Y; AGRP,
321
agouti-related protein; CART, cocaine- and amphetamine-regulated transcript; FC,
322
fold change; AOAC, Association of Official Analytical Chemists; QTOF-MS,
323
quadrupole-time of flight mass spectrometer; ESI, electrospray ionization; mTOR,
324
mammalian target of rapamycin; BCAT, branched chain aminotransferase; BCKDH,
325
branched chain α-keto acid dehydrogenase; CP, crude protein.
15
ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
326
REFERENCES
327
(1) Ren, M.; Zhang, S.H.; Zeng, X.F.; Liu, H.; Qiao, S.Y. Branched-chain amino acids
328
are beneficial to maintain growth performance and intestinal immune-related
329
function in weaned piglets fed protein restricted diet. Asian-Australas. J. Anim.
330
Sci. 2015, 28, 1742-1750.
331
(2) Duan, Y.H.; Guo, Q.P.; Wen, C.Y.; Wang, W.L.; Li, Y.H.; Tan, B.E.; Yin, Y.L. Free
332
amino acid profile and expression of genes related to protein metabolism in
333
skeletal muscle of growing pigs fed low- protein diets supplemented with
334
branched-chain amino acids. J. Agric. Food Chem. 2016, 64, 9390-9400.
335 336
(3) Wu, G.Y. Amino acids: Metabolism, functions, and nutrition. Amino Acids. 2009, 37, 1-17.
337
(4) Tavernari, F.C.; Lelis, G. R.; Vieira, R. A.; Rostagno, H. S.; Albino, L. F. T.; Neto,
338
A.R. O. Valine needs in starting and growing Cobb (500) broilers. Poultry Sci.
339
2013, 92, 151-157.
340
(5) Azzam, M. M. M.; Dong, X. Y.; Dai, L.; Zou, X.T. Effect of excess dietary
341
L-valine on laying hen performance, egg quality, serum free amino acids, immune
342
function and antioxidant enzyme activity. Brit. Poultry. Sci. 2015, 56, 72-78.
343
(6) Thornton, S.A.; Corzo, A.; Pharr, G.T.; Dozier, W.A.; Miles, D.M.; Kidd, M.T.
344
Valine requirements for immune and growth responses in broilers from 3 to 6
345
weeks of age. Brit. Poultry. Sci. 2006, 47, 190-199.
346
(7) Xiao, F.; Yu, J.; Guo, Y.; Deng,J.; Li, K.; Du, Y.; Chen, S.; Zhu, J.; Sheng, H.; Guo,
347
F. Effects of individual branched-chain amino acids deprivation on insulin
16
ACS Paragon Plus Environment
Page 16 of 35
Page 17 of 35
Journal of Agricultural and Food Chemistry
348
sensitivity and glucose metabolism in mice. Metabolism. 2014, 63, 841-850.
349
(8) Luo, J. B.; Feng, L.; Jiang, W. D.; Liu, Y.; Wu, P.; Jiang, J.; Kuang, S. Y.; Tang, L.;
350
Zhang, Y. A.; Zhou, X. Q. The impaired intestinal mucosal immune system by
351
valine deficiency for young grass carp (Ctenopharyngodon idella) is associated
352
with decreasing immune status and regulating tight junction proteins transcript
353
abundance in the intestine. Fish Shellfish Immun. 2014, 40, 197-207.
354
(9) Kakazu, E.; Kanno, N.; Ueno, Y.; Shimosegawa, T. Extracellular branched-chain
355
amino
acids,
especially
valine,
regulate
maturation
and
356
monocyte-derived dendritic cells. J. Immunol. 2007, 179, 7137-7146.
function
of
357
(10) Chen, X. H.; Liu S. R.; Peng B., Li D.; Cheng Z. X.; Zhu J. X.; Zhang S.; Peng Y.
358
M.; Li H.; Zhang T. T.; Peng X. X. Exogenous l-Valine Promotes Phagocytosis to
359
Kill Multidrug-Resistant Bacterial Pathogens. Front. Immuno. 2017, 8, 207.
360
(11) Figueroa, J.L.; Lewis, A.J.; Miller, P.S.; Fischer, R.L.; Diedrichsen, R.M.; Growth,
361
carcass traits, and plasma amino acid concentrations of gilts fed low-protein diets
362
supplemented with amino acids including histidine, isoleucine, and valine. J. Anim.
363
Sci. 2003, 81, 1529-1537.
364
(12) Zhang, S.H.; Qiao, S.Y.; Ren, M.; Zeng, X.F.; Ma, X.; Wu, Z.L.; Thacker, P.; Wu,
365
G.Y. Supplementation with branched-chain amino acids to a low-protein diet
366
regulates intestinal expression of amino acid and peptide transporters in weanling
367
pigs. Amino Acids. 2013, 45, 1191-1205.
368
(13) Gloaguen, M.; Floc'h, Le.N.; Brossard, L.; Barea, R.; Primot, Y.; Corrent, E.;
369
Milgen, J.Van. Response of piglets to the valine content in diet in combination
17
ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
370
with the supply of other branched-chain amino acids. Animal. 2011, 5, 1734-1742.
371
(14) Chen, H.Y.; Trumbauer, M.E.; Chen, A.S. Orexigenic action of peripheral ghrelin
372
is mediated by neuropeptide Y and agouti-related protein. Endocrinology. 2004,
373
145, 2607-12.
374 375
(15) Geary N. Endocrine controls of eating: CCK, leptin, and ghrelin. Physiol. Behav. 2004, 81, 719-33.
376
(16) Inui, A.; Asakawa, A.; Bowers, C.Y.; Mantovani, G.; Laviano, A.; Meguid, M.M.
377
Ghrelin, appetite, and gastric motility: the emerging role of the stomach as an
378
endocrine organ. FASEB. J. 2004,18, 439-56.
379
(17) Nagao, K.; Bannai, M.; Seki, S.; Mori, M.; Takahashi, M. Adaptational
380
modification of serine and threonine metabolism in the liver to essential amino
381
acid deficiency in rats. Amino Acids. 2009, 36, 555-62.
382
(18) Gloaguen, M.; Floc'h, Le.N.; Corrent, E.; Primot, Y.; Milgen, J.Van. Providing a
383
diet deficient in valine but with excess leucine results in a rapid decrease in feed
384
intake and modifies the postprandial plasma amino acid and α-keto acid
385
concentrations in pigs. J.Anim.Sci. 2012, 90, 3135-3142.
386
(19) Mavromichalis, I.; Webel, D. M.; Emmert, J. L.; Moser, R. L.; Baker, D. H.
387
Limiting order of amino acids in a low-protein corn-soybean meal-based diet for
388
nursery pigs. J. Anim. Sci. 1998, 76, 2833-2837.
389
(20) Coma J.; Carrion, D.; Zimmerman, D.R. Use of plasma urea nitrogen as a rapid
390
response criterion to determine the lysine requirement of pigs. J.Anim.
391
Sci. 1995, 73, 472-481.
18
ACS Paragon Plus Environment
Page 18 of 35
Page 19 of 35
Journal of Agricultural and Food Chemistry
392
(21) Linder, M. C. Nutrition and metabolism of proteins. Nutritional Biochemistry and
393
Metabolism with Clinical Applications. Appleton & Lange, Stamford, CT. 1991.
394
87-109.
395
(22) Wang. X.; Wei, H.; Cao, J.; Li, Zh; He, P. Metabolomics analysis of muscle from
396
piglets fed low protein diets supplemented with branched chain amino acids usin.g
397
HPLC-high-resolution MS. Electrophoresis. 2015, 36, 2250-2258.
398
(23) Tetsuya, Takimoto.; Chie. Furuta.; Hitoshi, Murakami.; Makoto, Bannai.
399
Anorexia and Valine-Deficient Diets. Branched Chain Amino Acids in Clinical
400
Nutrition. 2015, DOI 10.1007/978-1-4939-1923-9_14.
401
(24) Wang, X.; Qiao, S.Y.; Yin, Y.l.; Yue, L.Y.; Wang, Z.Y.; Wu, G.Y. A Deficiency or
402
Excess of Dietary Threonine Reduces Protein Synthesis in Jejunum and Skeletal
403
Muscle of Young Pigs. J. Nutr. 2007, 137, 1442-1446.
404
(25) Dipasquale.
P.;
Romano,
A.;
Cianci,
S.;
Righetti,
L.;
Gaetani,
S.
405
Oleoylethanolamide: a new player in energy metabolism control. Role in food
406
intake. Drug Discov Today Dis Mech. 2010, 7, e169-e174.
407
(26) Sarro-Ramírez,
A.;
Sánchez-López,
D.;
Tejeda-Padrón,
A.;
Frías,
C.;
408
Zaldívar-Rae, J. Murillo-Rodríguez E. Brain molecules and appetite: the case of
409
oleoylethanolamide. Cent Nerv Syst Agents Med Chem. 2013, 13, 88-91.
410 411 412 413
(27) Sihag, J.; Jones, P. J. H. Oleoylethanolamide: The role of a bioactive lipid amide in modulating eating behaviour
obesity reviews 2017, DOI: 10.1111/obr.12630
(28) Reidelberger, R.D. Cholecystokinin and control of food intake. J.Nutr. 1994, 124 (Suppl.), 1327S-1333S.
19
ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
414
(29) Wang, L.X.; Barachina, M.D.; Martinez, V.; Wei, J.Y.; Tache, Y. Synergistic
415
interaction between CCK and leptin to regulate food intake. Regul. Peptides. 2000,
416
92, 79-85.
417 418 419 420
(30) Furuse, M. Release and endogenous actions of the gastrin/cholecystokinin (CCK) family in the chicken. J. Exp. Zool. 1999, 283, 448-454. (31) Otsuki, M. Pathophysiological role of cholecystokinin in humans. J. Gastroen Hepatol. 2000, 15 (Suppl.), D71-D83.
421
(32) Ebenezer, I.S.; Riva, C.De.La.; Baldwin, B.A. Effects of the CCK receptor
422
antagonist MK-329 on food intake in pigs. Physiol. Behav. 1990, 47, 145-148.
423
(33) Wei, F.; Kate, L. J.; Ellacott, I.G. H.; Takahashi, K.J.; Yu, P.X.; Roger, D. C.
424
Cholecystokinin-mediated suppression of feeding involves the brainstem
425
melanocortin system. Nat. Neuroscie. 2004, 7, 4-7.
426 427
(34) Gietzen, D.W.; Hao, S.; Anthony, T.G. Mechanisms of food intake repression in indispensable amino acid deficiency. Annu. Rev. Nutr. 2007, 27, 63-78.
428
(35) Shikata, N.; Maki, Y.; Noguchi, Y. Multi-layered network structure of amino acid
429
(AA) metabolism characterized by each essential AA-deficient condition. Amino
430
Acids. 2007, 33, 113-21.
431 432
(36) Schutz, Y.; Protein turnover, ureagenesis and gluconeogenesis. Int. J. Vitam. Nutr. Res. 2011, 81,101-7.
433
(37) Wiltafsky, M. K.; Pfaffl, M. W.; Roth, F. X.; The effects of branched-chain amino
434
acid interactions on growth performance, blood metabolites, enzyme kinetics and
435
transcriptomics in weaned pigs. Br. J. Nutr. 2010,103, 964-976.
20
ACS Paragon Plus Environment
Page 20 of 35
Page 21 of 35
Journal of Agricultural and Food Chemistry
436
Table 1.
437
as-fed)
Ingredient composition and calculated nutrient content of the basal diet (%
treatment (SID Val to Lys ratio) item 0.45
0.65
69.60 4.00 9.00 3.00 8.00 1.00 0.60 1.20 0.30 0.50 0.84 0.30 0.37 0.10 0.00 0.22 0.30 0.23 0.12 0.32
69.53 4.00 9.00 3.00 8.00 1.00 0.60 1.20 0.30 0.50 0.84 0.30 0.37 0.10 0.23 0.22 0.30 0.23 0.12 0.16
16.89 1.22 0.73 0.80 0.22 0.58 2490 1.15 0.70 0.75 0.20 0.52
16.90 1.24 0.74 0.80 0.23 0.80 2490 1.15 0.70 0.75 0.20 0.75
ingredient composition (%) corn soybean meal peanut meal fish meal whey powder soybean oil limestone dicalcium phosphate salt vitamin-mineral premix1 L-Lysine HCl DL-Methionine L-Threonine L-Tryptophan L-Valine L-Isoleucine L-Leucine L-Phenylalanine L-Histidine L-Alanine calculated nutrition content (%) crude protein Lys Met + Cys Thr Trp Val NE (MJ/kg)2 SID3 Lys SID Met + Cys SID Thr SID Trp SID Val
21
ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
438
1
439
vitamin A acetate; vitamin D, 3,000.00 IU as vitamin D3; vitamin E, 64.00 IU as DL-α-tocopheryl
440
acetate; vitamin K3, 3.00 mg; vitamin B1, 1.50 mg; vitamin B2, 5.50 mg; vitamin B6, 3.00 mg as
441
pyridoxine hydrochloride; vitamin B12, 12.00 µg; nicotinic acid, 40.00 mg; pantothenic acid, 15.00
442
mg as calcium pantothenate; folic acid, 0.80 mg; biotin, 100.00 µg; choline chloride, 0.55 g; Fe,
443
100.00 mg as as Ferrous sulfate monohydrate; Cu (CuSO4·5H2O), 150.00 mg; Zn, 100.00 mg as
444
zinc sulfate; Mn, 40.00 mg as zinc sulfate; I, 0.30 mg as calcium iodate; Se, 0.30 mg as sodium
445
selenite. 2NE: net energy (MJ/kg). NE content was calculated using energy values for the
446
ingredients obtained from the NRC (2012). 3SID: standardized ileal digestible. SID values for the
447
diets were estimated by multiplying the analyzed AA levels by the SID of the corresponding AA
448
in those feedstuffs obtained from the NRC (2012).
Vitamin-mineral premix provided the following per kilogram of diet: vitamin A, 9,000.00 IU as
22
ACS Paragon Plus Environment
Page 22 of 35
Page 23 of 35
449
Journal of Agricultural and Food Chemistry
Table 2. The primer sequences for quantitative Real Time-PCR gene
primer sequence 5'-3'
product length (bp)
Tm (ºC)
accession No.
238
60.00
KU_672525
268
61.80
AH_013312
118
60.80
NM_214237
269
60.80
XM_008686403
267
58.90
XM_021085834
TGCGGGACATCAAGGAGAAG β-actin
AGTTGAAGGTGGTCTCGTGG GGAGTCCAAGAAGCCAGCAG
ghrelin
ACAGAGGTGGCTGGTCTCAG GGCCAGATACATCCAGCAGG
cholecystokinin
CATCCAGCCCATGTAGTCCC ACCCTCGCCCTGTCCCTGCT
neuropeptide Y
ATGTGGTGATGGGAAATGAG CGGTGAAGGTGTATCCCAAC
Pro-opiomelanocortin
AGGTCATGAAGCCGCCGTAG
23
ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
Page 24 of 35
450
Table 3. Effect of dietary standardized ileal digestible (SID) Val to Lys ratios on the performance and plasma urea nitrogen concentrations of
451
piglets1 treatment (SID Val to Lys ratio) item
452
1
453
2
SEM2
P
0.45
0.65
ADG (g/d)
341a
713b
47.00