Therapeutic applications and challenges in myostatin inhibition for enhanced skeletal muscle mass and functions.

Myostatin, a potent negative regulator of skeletal muscle mass, has garnered significant attention as a therapeutic target for muscle dystrophies. Despite extensive research and promising preclinical results, clinical trials targeting myostatin inhibition in muscle dystrophies have failed to yield substantial improvements in muscle function or fitness in patients. This review details the mechanisms behind myostatin's function and the various inhibitors that have been tested preclinically and clinically. It also examines the challenges encountered in clinical translation, including issues with drug specificity, differences in serum myostatin concentrations between animal models and humans, and the necessity of neural input for functional improvements. Additionally, we explore promising avenues of research beyond muscle dystrophies, particularly in the treatment of metabolic syndromes and orthopedic disorders. Insights from these alternative applications suggest that myostatin inhibition may hold the potential for addressing a broader range of pathologies, providing new directions for therapeutic development.

Uses of Papaya Leaf and Seaweed Supplementations for Controlling Glucose Homeostasis in Diabetes.

Studies from laboratory animal models and complementary medical practices have implied that nutrients from special plants or herbs contain antidiabetic, antioxidant, anti-obese, anti-hypertensive, and anti-inflammatory properties. Seaweed and tropical papaya, which are widely available in Asian and Pacific countries, have been used as home remedies for centuries. The bioactive extracts from these plants contain vitamins A, C, B and E complexes, as well as polysaccharides, phenolic compounds, essential fatty acids, flavonoids, saponins, fucoidan, and phlorotannin. In this review, the authors examine the pathogenesis of diabetes characterized by hyperglycemia due to the dysregulation of glucose homeostasis, antidiabetic/antihyperglycemic seaweed or/and papaya derived bioactive phytochemicals and their proposed mechanisms of action in the management of Type 2 Diabetes Mellitus (T2DM). The authors also propose combining papaya and seaweed to enhance their antidiabetic effects, leveraging the advantages of herb-to-herb combination. Papaya and seaweed have demonstrated antidiabetic effects through in vitro assays, cellular models, and animal studies despite the limited clinical trials. Nutraceuticals with antidiabetic effects, such as secondary metabolites isolated from seaweed and papaya, could be combined for a synergistic effect on T2DM management. However, the application of these compounds in their purified or mixed forms require further scientific studies to evaluate their efficacy against diabetes-related complications, such as hyperlipidemia, elevated free radicals, pro-inflammatory molecules, insulin insensitivity, and the degeneration of pancreatic beta cells.

Targeted overexpression of PPARγ in skeletal muscle by random insertion and CRISPR/Cas9 transgenic pig cloning enhances oxidative fiber formation and intramuscular fat deposition.

Peroxisome proliferator-activated receptor gamma (PPARγ) is a master regulator of adipogenesis and lipogenesis. To understand its roles in fiber formation and fat deposition in skeletal muscle, we successfully generated muscle-specific overexpression of PPARγ in two pig models by random insertion and CRISPR/Cas9 transgenic cloning procedures. The content of intramuscular fat was significantly increased in PPARγ pigs while had no changes on lean meat ratio. PPARγ could promote adipocyte differentiation by activating adipocyte differentiating regulators such as FABP4 and CCAAT/enhancer-binding protein (C/EBP), along with enhanced expression of LPL, FABP4, and PLIN1 to proceed fat deposition. Proteomics analyses demonstrated that oxidative metabolism of fatty acids and respiratory chain were activated in PPARγ pigs, thus, gathered more Ca2+ in PPARγ pigs. Raising of Ca2+ could result in increased phosphorylation of CAMKII and p38 MAPK in PPARγ pigs, which can stimulate MEF2 and PGC1α to affect fiber type and oxidative capacity. These results support that skeletal muscle-specific overexpression of PPARγ can promote oxidative fiber formation and intramuscular fat deposition in pigs.

Characterization of the whole transcriptome of spleens from Chinese indigenous breed Ningxiang pig reveals diverse coding and non-coding RNAs for immunity regulation.

The spatio-temporal expression patterns of RNA and comparisons between different developmental stages have been one of the useful techniques for studying animal physiology and functional gene regulations. A Chinese indigenous breed Ningxiang pig is known for its quality meat production, disease resistance and slow growth performances in pig industry. To gain a better understanding of pig immunity and disease resistance, we comprehensively analyzed the whole transcriptome of the spleens from three important developmental nodes of Ningxiang pig at 30, 90 and 210 days of age. By three ways of comparisons (30vs 90 days, 30 vs 210 days and 90 vs 210 days), a total of 364to 865 differentially expressed mRNAs, 37 to 98 differentially expressed miRNAs,220 to 278 lncRNAs, and 96 to 113 circRNAs were identified. Further analysis of expression patterns, potential function and interactions with miRNAs identified the potential non-coding RNAs related to immunomodulation such as ssc-miRNA-150, ssc-miRNA-497, MSTRG24160, MSTRG18646. The results revealed that miRNAs and circRNAs may have evolved to regulate a large set of biological processes of spleen function in Ningxiang pigs, and circRNAs play a role of miRNA sponges. The results from study is the first report of whole transcriptome analysis of Ningxiang pig spleen and provide new insights into the expression changes of RNAs during the spleen development, which contribute to the phenotypic formation of immunity and disease resistancesin Chinese indigenous pig breeds.

Enhanced Muscle Fibers of Epinephelus coioides by Myostatin Autologous Nucleic Acid Vaccine.

Epinephelus coioides is a fish species with high economic value due to its delicious meat, high protein content, and rich fatty acid nutrition. It has become a high-economic fish in southern parts of China and some other Southeast Asian countries. In this study, the myostatin nucleic acid vaccine was constructed and used to immunize E. coioides. The results from body length and weight measurements indicated the myostatin nucleic acid vaccine promoted E. coioides growth performance by increasing muscle fiber size. The results from RT-qPCR analysis showed that myostatin nucleic acid vaccine upregulated the expression of myod, myog and p21 mRNA, downregulated the expression of smad3 and mrf4 mRNA. This preliminary study is the first report that explored the role of myostatin in E. coioides and showed positive effects of autologous nucleic acid vaccine on the muscle growth of E. coioides. Further experiments with increased numbers of animals and different doses are needed for its application to E. coiodes aquaculture production.

Roles of transcription factor SQUAMOSA promoter binding protein-like gene family in papaya (Carica papaya) development and ripening.

SQUAMOSA promoter binding protein-like (SPL) family plays vital regulatory roles in plant growth and development. The SPL family in climacteric fruit Carica papaya has not been reported. This study identified 14 papaya SPLs (CpSPL) from papaya genome and analyzed their sequence features, phylogeny, intron/exon structure, conserved motif, miR156-mediated posttranscriptional regulation, and expression patterns. 14 CpSPLs were clustered into 8 groups, and two distinct expression patterns were revealed for miR156-targeted and nontargeted CpSPLs in different tissues and fruit development stages. The expression changes of CpSPLs in ethephon and 1-MCP treated fruit during ripening suggested that the CpSPLs guided by CpmiR156 play crucial roles in ethylene signaling pathway. This study sheds light on the new function of SPL family in fruit development and ripening, providing insights on understanding evolutionary divergence of the members of SPL family among plant species.

Enhanced skeletal muscle growth in myostatin-deficient transgenic pigs had improved glucose uptake in stretozotocin-induced diabetes.

The size of skeletal muscle mass plays a significant role in glucose uptake in healthy and diabetic human subjects. Previously, we have generated myostatin-deficient (MSTN-/-) transgenic pigs via animal cloning technology. MSTN-/- pigs had dramatic phenotype with individual muscle mass increase by 100% over their wild-type controls, which provides a unique large animal model to investigate how enhanced skeletal muscles are beneficial to glucose update in diabetes. We employed intravenous administration of stretozotocin (STZ) to male MSTN-/- and wild-type pigs (100 mg/kg body weight). One month later, blood glucose and insulin concentrations and pancreas histology were examined, STZ-induced diabetes occurred in both MSTN transgenic and wild-type pigs. Histology of pancreas, analysis of pAKT and Glut4 transporter proteins by Western blotting, and real-time qPCR for MSTN gene expression were used in the study. The STZ-treated pigs had increased levels of fasting plasma glucose and insulin levels in comparison with animals receiving sodium citrate buffer, their pancreas also had reduced beta cells and slight increases in lymphocyte. There are significant lower concentrations of fasting plasma glucose and insulin in MSTN-/- pigs than that of wild-type pigs after STZ administration. Detections of pAKT and Glut4 transporter proteins by Western blotting in muscle tissue indicates significant elevations of both proteins in MSTN-/- pigs compared with the wild-type pigs. The results from this pig model suggest that enhanced skeletal muscle by manipulation of myostatin function can improve glucose uptake even in the status of diabetes.

Differential Transcriptome Analysis of Early Postnatal Developing Longissimus Dorsi Muscle from Two Pig Breeds Characterized in Divergent Myofiber Traits and Fatness.

Meat quality traits (MQTs) are very important in the porcine industry, which are mainly determined by skeletal muscle fiber composition, extra-muscular and/or intramuscular fat content. To identify the differentially expressed candidate genes affecting the meat quality traits, first we compared the MQTs and skeletal muscle fiber characteristics in the longissimus dorsi muscle (LDM) of the Northeast Min pig (NM) and the Changbaishan wild boar (CW) with their body weight approaching 90 kg. The significant divergences in the skeletal muscle fiber phenotypes and fatness traits between the two porcine breeds established an ideal model system for further identifying potential key functional genes that dominated MQTs. Further, a transcriptome profile analysis was performed using the Illumina sequencing method in early postnatal developing LDM from the two breeds at the ages of 42 days. Comparative analysis between these two cDNA libraries showed that there were 17,653 and 22,049 unambiguous tag-mapped sense transcripts detected from NM and CW, respectively. 4522 differentially expressed genes (DEGs) were revealed between the two tissue samples, of them, 4176 genes were found as having been upregulated and 346 genes were identified as having been downregulated in the NM library. By pathway enrichment analysis, a set of significantly enriched pathways were identified for the DEGs, which are potentially involved in myofiber development, differentiation and growth, lipogenesis and lipolysis in porcine skeletal muscle. The expression levels of 30 out of the DEGs were validated by real-time quantitative reverse transcriptase PCR (qRT-PCR) and the observed result was consistent noticeably with the Illumina transcriptome profiles. The findings from this study can contribute to future investigations of skeletal muscle growth and development mechanism and to establishing molecular approaches to improve meat quality traits in pig breeding.

Comparative Characterization of the Complete Mitochondrial Genomes of the Three Apple Snails (Gastropoda: Ampullariidae) and the Phylogenetic Analyses.

The apple snails Pomacea canaliculata, Pomacea diffusa and Pomacea maculate (Gastropoda: Caenogastropoda: Ampullariidae) are invasive pests causing massive economic losses and ecological damage. We sequenced and characterized the complete mitochondrial genomes of these snails to conduct phylogenetic analyses based on comparisons with the mitochondrial protein coding sequences of 47 Caenogastropoda species. The gene arrangements, distribution and content were canonically identical and consistent with typical Mollusca except for the tRNA-Gln absent in P. diffusa. An identifiable control region (d-loop) was absent. Bayesian phylogenetic analysis indicated that all the Ampullariidae species clustered on the same branch. The genus Pomacea clustered together and then with the genus Marisa. The orders Architaenioglossa and Sorbeoconcha clustered together and then with the order Hypsogastropoda. Furthermore, the intergenic and interspecific taxonomic positions were defined. Unexpectedly, Ceraesignum maximum, Dendropoma gregarium, Eualetes tulipa and Thylacodes squamigerus, traditionally classified in order Hypsogastropoda, were isolated from the order Hypsogastropoda in the most external branch of the Bayesian inference tree. The divergence times of the Caenogastropoda indicated that their evolutionary process covered four geological epochs that included the Quaternary, Neogene, Paleogene and Cretaceous periods. This study will facilitate further investigation of species identification to aid in the implementation of effective management and control strategies of these invasive species.

Characterization of the Complete Mitochondrial Genome Sequences of Three Croakers (Perciformes, Sciaenidae) and Novel Insights into the Phylogenetics.

The three croakers (Nibea coibor, Protonibea diacanthus and Argyrosomus amoyensis, Perciformes, Sciaenidae) are important commercial species inhabiting the Eastern Indian Ocean and Western Pacific. Molecular data employed in previous research on phylogenetic reconstruction have not been adequate and complete, and systematic and comprehensive phylogenetic relationships for these fish are unresolved. We sequenced the complete mitochondrial genomes of the three croakers using next-generation sequencing for the first time. We analyzed the composition and phylogenies between 19 species in the family Sciaenidae using the mitochondrial protein coding sequences of 204 species in the Series Eupercaria. We present the characterization of the complete mitochondrial genome sequences of the three croakers. Gene arrangement and distribution of the three croakers are canonically identical and consistent with other vertebrates. We found that the family Sciaenidae is an independent branch that is isolated from the order Perciformes and does not belong to any extant classification. Therefore, this family is expected to belong to a new classification at the order level and needs further analysis. The evolution of Sciaenidae has lagged far behind the Perciformes differentiation. This study presents a novel insight into the phylogenetics of the family Sciaenidae from the order Perciformes and facilitates additional studies on the evolution and phylogeny of Series Eupercaria.

Functional verification of a porcine myostatin propeptide mutant.

Myostatin is a member of TGF-ß superfamily that acts as a key negative regulator in development and growth of embryonic and postnatal muscles. In this study, the inhibitory activities of recombinant porcine myostatin propeptide and its mutated form (at the cleavage site of metalloproteinases of BMP-1/TLD family) against murine myostatin was evaluated in vivo by intraperitoneal injection into mice. Results showed that both wild type and mutated form of porcine propeptide significantly inhibited myostatin activity in vivo. The average body weight of mice receiving wild type propeptide or its mutated form increased by 12.5 % and 24.14%, respectively, compared to mice injected with PBS, implying that the in vivo efficacy of porcine propeptide mutant is greater than its wild type propeptide. Transgenic mice expressing porcine myostatin propeptide mutant were generated to further verify the results obtained from mice injected with recombinant porcine propeptide mutant. Compared with wild type (non-transgenic) mice, relative weight of gastrocnemius, rectusfemoris, and tibialis anterior increased by 22.14 %, 34.13 %, 25.37%, respectively, in transgenic male mice, and by 19.90 %, 42.47 %, 45.61%, respectively, in transgenic female mice. Our data also demonstrated that the mechanism by which muscle growth enhancement is achieved by these propeptides is due to an increase in fiber sizes, not by an increase in number of fiber cells.

RNA sequencing identifies upregulated kyphoscoliosis peptidase and phosphatidic acid signaling pathways in muscle hypertrophy generated by transgenic expression of myostatin propeptide.

Myostatin (MSTN), a member of the transforming growth factor-ß superfamily, plays a crucial negative role in muscle growth. MSTN mutations or inhibitions can dramatically increase muscle mass in most mammal species. Previously, we generated a transgenic mouse model of muscle hypertrophy via the transgenic expression of the MSTN N-terminal propeptide cDNA under the control of the skeletal muscle-specific MLC1 promoter. Here, we compare the mRNA profiles between transgenic mice and wild-type littermate controls with a high-throughput RNA sequencing method. The results show that 132 genes were significantly differentially expressed between transgenic mice and wild-type control mice; 97 of these genes were up-regulated, and 35 genes were down-regulated in the skeletal muscle. Several genes that had not been reported to be involved in muscle hypertrophy were identified, including up-regulated myosin binding protein H (mybph), and zinc metallopeptidase STE24 (Zmpste24). In addition, kyphoscoliosis peptidase (Ky), which plays a vital role in muscle growth, was also up-regulated in the transgenic mice. Interestingly, a pathway analysis based on grouping the differentially expressed genes uncovered that cardiomyopathy-related pathways and phosphatidic acid (PA) pathways (Dgki, Dgkz, Plcd4) were up-regulated. Increased PA signaling may increase mTOR signaling, resulting in skeletal muscle growth. The findings of the RNA sequencing analysis help to understand the molecular mechanisms of muscle hypertrophy caused by MSTN inhibition.

The formation of brown adipose tissue induced by transgenic over-expression of PPARγ2.

Brown adipose tissue (BAT) is specialized to dissipate energy as heat, therefore reducing fat deposition and counteracting obesity. Brown adipocytes arise from myoblastic progenitors during embryonic development by the action of transcription regulator PRDM16 binding to PPARγ, which promotes BAT-like phenotype in white adipose tissue. To investigate the capability of converting white adipose tissue to BAT or browning by PPARγ in vivo, we generated transgenic mice with over-expressed PPARγ2. The transgenic mice showed strong brown fat features in subcutaneous fat in morphology and histology. To provide molecular evidences on browning characteristics of the adipose tissue, we employed quantitative real-time PCR to determine BAT-specific gene expressions. The transgenic mice had remarkably elevated mRNA level of UCP1, Elovl3, PGC1α and Cebpα in subcutaneous fat. Compared with wild-type mice, UCP1 protein levels were increased significantly in transgenic mice. ATP concentration was slightly decreased in the subcutaneous fat of transgenic mice. Western blotting analysis also confirmed that phosphorylated AMPK and ACC proteins were significantly (P<0.01) increased in the transgenic mice. Therefore, this study demonstrated that over-expression of PPARγ2 in skeletal muscle can promote conversion of subcutaneous fat to brown fat formation, which can have beneficial effects on increasing energy metabolisms and combating obesity.

Supplementation of papaya leaf juice has beneficial effects on glucose homeostasis in high fat/high sugar-induced obese and prediabetic adult mice.

Prediabetes is characterized by a cluster of glycemic parameters higher than normal but below the threshold of type 2 diabetes mellitus (T2DM). In recent years, phytochemical-rich plant extracts have gained popularity as therapeutic agents for metabolic disorders. This study investigated the effects of papaya leaf (PL) juice supplementation on blood glucose levels in diet-induced obese and prediabetic adult mice. B65JL F1 mice (n = 20) at 12-14 months old were fed a high fat/sugar diet (HFHS) for 120 days. Mice were switched to restricted rodent chow of 3 g feed/30 g body weight/day, supplemented with 3 g/100 mL PL juice for 30 days. HFHS diet remarkably increased fasting plasma glucose levels from 114 ± 6.54 mg/dL to 192.7 ± 10.1 mg/dL and body weight from 32.5 ± 1.6 to 50.3 ± 4.1 g. HFHS diet results in hyperglycemia, insulin resistance, hyperlipidemia, and liver steatosis. The combination of PL juice and restricted diet significantly reduced body weight and fasting blood glucose levels to 43.75 ± 1.4 g and 126.25 ± 3.2 mg/dl, respectively. Moreover, PL juice with a restricted diet significantly improved lipid profile: cholesterol from 204 to 150 mg/dL, LDL-c from 110.4 to 50 mg/dL, and triglyceride from 93.7 to 60 mg/dL. Additionally, PL juice combined with a restricted diet significantly reduced adiposity, reversed fatty liver, and restored skeletal muscle Glut4 and phosphorylated (p-AKT (ser473). This study demonstrated that supplementation of PL juice with a restricted diet was more effective than a restricted diet alone in reversing major symptoms related to prediabetic and obesity conditions.

Lysine Distinctively Manipulates Myogenic Regulatory Factors and Wnt/Ca2+ Pathway in Slow and Fast Muscles, and Their Satellite Cells of Postnatal Piglets.

Muscle regeneration, representing an essential homeostatic process, relies mainly on the myogenic progress of resident satellite cells, and it is modulated by multiple physical and nutritional factors. Here, we investigated how myogenic differentiation-related factors and pathways respond to the first limiting amino acid lysine (Lys) in the fast and slow muscles, and their satellite cells (SCs), of swine. Thirty 28-day-old weaned piglets with similar body weights were subjected to three diet regimens: control group (d 0-28: 1.31% Lys, n = 12), Lys-deficient group (d 0-28: 0.83% Lys, n = 12), and Lys rescue group (d 0-14: 0.83% Lys; d 15-28: 1.31% Lys, n = 6). Pigs on d 15 and 29 were selectively slaughtered for muscular parameters evaluation. Satellite cells isolated from fast (semimembranosus) and slow (semitendinosus) muscles were also selected to investigate differentiation ability variations. We found Lys deficiency significantly hindered muscle development in both fast and slow muscles via the distinct manipulation of myogenic regulatory factors and the Wnt/Ca2+ pathway. In the SC model, Lys deficiency suppressed the Wnt/Ca2+ pathways and myosin heavy chain, myogenin, and myogenic regulatory factor 4 in slow muscle SCs but stimulated them in fast muscle SCs. When sufficient Lys was attained, the fast muscle-derived SCs Wnt/Ca2+ pathway (protein kinase C, calcineurin, calcium/calmodulin-dependent protein kinase II, and nuclear factor of activated T cells 1) was repressed, while the Wnt/Ca2+ pathway of its counterpart was stimulated to further the myogenic differentiation. Lys potentially manipulates the differentiation of porcine slow and fast muscle myofibers via the Wnt/Ca2+ pathway in opposite trends.

Muscle-specific transgenic expression of porcine myostatin propeptide enhances muscle growth in mice.

Myostatin is a well-known negative regulator of skeletal muscle growth. Inhibition of myostatin activity results in increased muscle mass. Myostatin propeptide, as a myostatin antagonist, could be applied to promote meat production in livestock such as pigs. In this study, we generated a transgenic mouse model expressing porcine myostatin propeptide under the control of muscle-specific regulatory elements. The mean body weight of transgenic mice from a line expressing the highest level of porcine myostatin propeptide was increased by 5.4 % (P = 0.023) and 3.2 % (P = 0.031) in males and females, respectively, at 8 weeks of age. Weight of carcass, fore limb and hind limb was respectively increased by 6.0 % (P = 0.038), 9.0 % (P = 0.014), 8.7 % (P = 0.036) in transgenic male mice, compared to wild-type male controls at the age of 9 weeks. Similarly, carcass, fore limb and hind limb of transgenic female mice was 11.4 % (P = 0.002), 14.5 % (P = 0.006) and 14.5 % (P = 0.03) respectively heavier than that of wild-type female mice. The mean cross-section area of muscle fiber was increased by 17 % (P = 0.002) in transgenic mice, in comparison with wild-type controls. These results demonstrated that porcine myostatin propeptide is effective in enhancement of muscle growth. The present study provided useful information for future study on generation of transgenic pigs overexpressing porcine myostatin propeptide for improvement of muscle mass.

Genome Variation Map of Domestic Qinghai-Tibet Plateau Yaks by SLAF-Seq Reveals Genetic Footprint during Artificial Selection.

The yak (Bos grunniens) was domesticated in the high-altitude QTP. Research about their genetic diversity and population structure is limited. In this study, we resequenced the genome of 494 domestic yaks using Specific-Locus Amplified Fragment Sequencing (SLAF-seq). The survey was conducted on six populations sampled from isolated locations in China in order to analyze their structure and genetic diversity. These six domestic populations were clearly grouped into two independent clusters, with Jinchuan, Changtai, and Jiulong showing a tight genetic relationship with the wild yak. Nerve development pathways were enriched with GO enrichment analysis of 334 domesticated genes. Major genomic regions associated with the differentiation of domestic yaks were detected. These findings provide preliminary information on the yak genome variability, useful to understand the genomic characteristics of different populations in QTP.

Integrating proteomics and metabolomics to elucidate the molecular network regulating of inosine monophosphate-specific deposition in Jingyuan chicken.

Inosine monophosphate (IMP) plays a significant role in meat taste, yet the molecular mechanisms controlling IMP deposition in muscle tissues still require elucidation. The present study systematically and comprehensively explores the molecular network governing IMP deposition in different regions of Jingyuan chicken muscle. Two muscle groups, the breast and leg, were examined as test materials. Using nontargeted metabolomic sequencing, we screened and identified 20 metabolites that regulate IMP-specific deposition. We maintained regular author and institution formatting, used clear, objective, and value-neutral language, and avoided biased or emotional language. We followed a consistent footnote style and formatting features and used precise word choice with technical terms where appropriate. Out of these, 5 were identified as significant contributors to the regulation of IMP deposition. We explained technical term abbreviations when first used and ensured a logical flow of information with causal connections between statements. The results indicate that PGM1, a key enzyme involved in synthesis, is higher in the breast muscle compared to the leg muscle, which may provide an explanation for the increased deposition of IMP in the breast muscle. We aimed for a clear structure with logical progression, avoided filler words, and ensured grammatical correctness. The activity of key enzymes (PKM2, AK1, AMPD1) involved in this process was higher in the breast muscle than in the leg muscle. In the case of IMP degradation metabolism, the activity of its participating enzyme (PurH) was lower in the breast muscle than in the leg muscle. These findings suggest that the increased deposition of IMP in Jingyuan chickens' breast muscle may result from elevated metabolism and reduced catabolism of key metabolites. In summary, a metaomic strategy was utilized to assess the molecular network regulation mechanism of IMP-specific deposition in various segments of Jingyuan chicken. These findings provide insight into genetic improvement and molecular breeding of meat quality traits for top-notch broilers.

Effects of age on subcutaneous adipose tissue proteins in Chinese indigenous Ningxiang pig by TMT-labeled quantitative proteomics.

Adipose tissue not only affects meat quality and animal productivity, but also participates in inflammation and immunity. Ningxiang pig is famous for their excellent meat quality, disease resistance and tolerance of roughage. It is not yet well known how proteins in adipose tissue is dynamically regulated during the growth of Ningxiang pig. This report studies the proteomic changes in subcutaneous adipose tissue in Ningxiang pigs to gain a better understanding of the molecular mechanism of fat development during the growth period. By TMT-labeled quantitative proteomic analysis of subcutaneous adipose tissue of 9 purebred Ningxiang pigs of different ages, we identified 2533 unique proteins and 716 differentially abundant proteins (DAPs), of which more than half of the DAPs were concentrated in the 90d-210d period. Retrograde endocannabinoid signaling was only significantly enriched in DAPs of N90d vs N30d, Alcoholism and Graft-versus-host disease were only significantly enriched in DAPs of N210d vs N90d. Proteins related to dilated cardiomyopathy was found to be an important pathway in fat development and lipid metabolism. A variety of novel DAPs involved in maintaining mitochondrial function and cell viability, such as NDUFS6, SDHB, COX5A, ATP5D and TNNT1, which play a role in controlling the prediction networks, may indirectly regulate the development and functional maintenance of adipocytes. SIGNIFICANCE: These age-dependent DAPs discovered in this study may help expand the understanding of the molecular mechanisms of the development, function maintenance and transformation of adipose tissue in Ningxiang pig for developing new strategies for improving meat quality and pig breeding in the future.

Transgenic overexpression of bone morphogenetic protein 11 propeptide in skeleton enhances bone formation.

Bone morphogenetic protein 11 (BMP11) is a key regulatory protein in skeletal development. BMP11 propeptide has been shown to antagonize GDF11 activity in vitro. To explore the role of BMP11 propeptide in skeletal formation in vivo, we generated transgenic mice with skeleton-specific overexpression of BMP11 propeptide cDNA. The mice showed a transformation of the seventh cervical vertebra into a thoracic vertebra in our previous report. Presently, further characterizations of the transgenic mice indicated that ossification in calvatia was dramatically enhanced in transgenic fetuses at 16.5 dpc in comparison with their wild-type littermates. At 10 weeks of age, bone mineral content and bone mineral density were significantly (P<0.05) higher in transgenic mice than that in their wild-type littermates based on dual energy X-ray absorptiometry analysis. The relative trabecular bone volume measured by histological analysis was dramatically increased in transgenic mice compared with their wild-type littermates. The enhanced bone formations in the transgenic mice appear to result from increase osteoblast activities as the expressions of four osteoblast markers - α1 type 1 collagen, osteocalcin, alkaline phosphatase and phex were significantly higher in transgenic fetuses than that in their wild-type littermates. These results suggest that over-expression of BMP11 propeptide stimulates bone formation by increasing osteoblast cell functions.