Differential responses to UCP1 ablation in classical brown versus beige fat, despite a parallel increase in sympathetic innervation.

In the cold, the absence of the mitochondrial uncoupling protein 1 (UCP1) results in hyper-recruitment of beige fat, but classical brown fat becomes atrophied. Here we examine possible mechanisms underlying this phenomenon. We confirm that in brown fat from UCP1-knockout (UCP1-KO) mice acclimated to the cold, the levels of mitochondrial respiratory chain proteins were diminished; however, in beige fat, the mitochondria seemed to be unaffected. The macrophages that accumulated massively not only in brown fat but also in beige fat of the UCP1-KO mice acclimated to cold did not express tyrosine hydroxylase, the norepinephrine transporter (NET) and monoamine oxidase-A (MAO-A). Consequently, they could not influence the tissues through the synthesis or degradation of norepinephrine. Unexpectedly, in the cold, both brown and beige adipocytes from UCP1-KO mice acquired an ability to express MAO-A. Adipose tissue norepinephrine was exclusively of sympathetic origin, and sympathetic innervation significantly increased in both tissues of UCP1-KO mice. Importantly, the magnitude of sympathetic innervation and the expression levels of genes induced by adrenergic stimulation were much higher in brown fat. Therefore, we conclude that no qualitative differences in innervation or macrophage character could explain the contrasting reactions of brown versus beige adipose tissues to UCP1-ablation. Instead, these contrasting responses may be explained by quantitative differences in sympathetic innervation: the beige adipose depot from the UCP1-KO mice responded to cold acclimation in a canonical manner and displayed enhanced recruitment, while the atrophy of brown fat lacking UCP1 may be seen as a consequence of supraphysiological adrenergic stimulation in this tissue.

Hinokiflavone resists HFD-induced obesity by promoting apoptosis in an IGF2BP2-mediated Bim m6A modification dependent manner.

Obesity has emerged as a major health risk on a global scale. Hinokiflavone (HF), a natural small molecule, extracted from plants like cypress, exhibits diverse chemical structures and low synthesis costs. Using high-fat diet-induced obese mice models, we found that HF suppresses obesity by inducing apoptosis in adipose tissue. Adipocyte apoptosis helps maintain tissue health by removing aging, damaged, or excess cells in adipose tissue, which is crucial in preventing obesity and metabolic diseases. We found that HF can specifically bind to insulin-like growth factor 2 mRNA binding protein 2 to promote the stability of N6-methyladenosine-modified Bim, inducing mitochondrial outer membrane permeabilization. Mitochondrial outer membrane permeabilization leads to Caspase9/3-mediated adipocyte mitochondrial apoptosis, alleviating obesity induced by a high-fat diet. The proapoptotic effect of HF offers a controlled means for weight loss. This study reveals the potential of small molecule HF in developing new therapeutic approaches in drug development and biomedical research.

Deubiquitinase UCHL1 regulates estradiol synthesis by stabilizing voltage-dependent anion channel 2.

Lack of estradiol production by granulosa cells blocks follicle development, causes failure of estrous initiation, and results in an inability to ovulate. The ubiquitin-proteasome system plays a critical role in maintaining protein homeostasis and stability of the estrous cycle, but knowledge of deubiquitination enzyme function in estradiol synthesis is limited. Here, we observe that the deubiquitinase ubiquitin C-terminal hydrolase 1 (UCHL1) is more significant in estrous sows and high litter-size sows than in nonestrous sows and low-yielding sows. Overexpression of UCHL1 promotes estradiol synthesis in granulosa cells, and interference with UCHL1 has the opposite effect. UCHL1 binds, deubiquitinates, and stabilizes voltage-dependent anion channel 2 (VDAC2), promoting the synthesis of the estradiol precursor pregnenolone. Cysteine 90 (C90) of UCHL1 is necessary for its deubiquitination activity, and Lys45 and Lys64 in VDAC2 are essential for its ubiquitination and degradation. In vivo, compared with WT and sh-NC-AAV groups, the estrus cycle of female mice is disturbed, estradiol level is decreased, and the number of antral follicles is decreased after the injection of sh-UCHL1-AAV into ovarian tissue. These findings suggest that UCHL1 promotes estradiol synthesis by stabilizing VDAC2 and identify UCHL1 as a candidate gene affecting reproductive performance.

YTHDF2 promotes DNA damage repair by positively regulating the histone methyltransferase SETDB1 in spermatogonia†.

Genomic integrity is critical for sexual reproduction, ensuring correct transmission of parental genetic information to the descendant. To preserve genomic integrity, germ cells have evolved multiple DNA repair mechanisms, together termed as DNA damage response. The RNA N6-methyladenosine is the most abundant mRNA modification in eukaryotic cells, which plays important roles in DNA damage response, and YTH N6-methyladenosine RNA binding protein 2 (YTHDF2) is a well-acknowledged N6-methyladenosine reader protein regulating the mRNA decay and stress response. Despite this, the correlation between YTHDF2 and DNA damage response in germ cells, if any, remains enigmatic. Here, by employing a Ythdf2-conditional knockout mouse model as well as a Ythdf2-null GC-1 mouse spermatogonial cell line, we explored the role and the underlying mechanism for YTHDF2 in spermatogonial DNA damage response. We identified that, despite no evident testicular morphological abnormalities under the normal circumstance, conditional mutation of Ythdf2 in adult male mice sensitized germ cells, including spermatogonia, to etoposide-induced DNA damage. Consistently, Ythdf2-KO GC-1 cells displayed increased sensitivity and apoptosis in response to DNA damage, accompanied by the decreased SET domain bifurcated 1 (SETDB1, a histone methyltransferase) and H3K9me3 levels. The Setdb1 knockdown in GC-1 cells generated a similar phenotype, but its overexpression in Ythdf2-null GC-1 cells alleviated the sensitivity and apoptosis in response to DNA damage. Taken together, these results demonstrate that the N6-methyladenosine reader YTHDF2 promotes DNA damage repair by positively regulating the histone methyltransferase SETDB1 in spermatogonia, which provides novel insights into the mechanisms underlying spermatogonial genome integrity maintenance and therefore contributes to safe reproduction.

Kojic acid inhibits pig sperm apoptosis and improves capacitated sperm state during liquid preservation at 17°C.

The parameters of sperm apoptosis and capacitation during liquid storage at 17°C can indicate the quality of pig sperm and the potential development of early embryos. However, the effect of kojic acid (KA) on semen preservation and its mechanism has not been fully understood. In this study, we discovered that adding KA to the diluent improved the antioxidant capacity of sperm mitochondria, maintained the normal structure of sperm mitochondria, and reduced sperm apoptosis. Western blot analysis revealed that KA prevented the release of Cytochrome c from mitochondria to the cytoplasm, reduced the expression of pro-apoptosis proteins cleaved Caspase-3 and cleaved Caspase-9, and increased the expression of the antiapoptosis protein Bcl-XL. Furthermore, KA also enhanced the motility parameters, oxidative phosphorylation level, adenosine triphosphate level, and protein tyrosine phosphorylation of capacitated sperm, while preserving the acrosome integrity and plasma membrane integrity of capacitated sperm. In conclusion, this study offers new insights into the molecular mechanism of how KA inhibits porcine sperm apoptosis and improves capacitated sperm parameters. Additionally, it suggests that KA can serve as an alternative to antibiotics.

Heterosis formation mechanism, prediction methods, and their application and prospect in pig production.

Heterosis is the phenomenon that the hybrid offspring outperform two-parent population. Hybridisation has been widely used in plant and animal production as it effectively improves the growth and developmental performance, reproductive performance and disease resistance of the offspring. Hybridization can effectively improve the growth and development performance, reproductive performance and disease resistance of offspring, so it is widely used in animal and plant production. Researchers have used cross-breeding techniques to cultivate excellent new agricultural and animal husbandry strains and supporting lines such as super-excellent Chaoyou 1000 hybrid rice, Xiaoyan No.6 hybrid wheat, Dumeng sheep, and Shanxia black pigs. However, there are still some urgent problems in the current hybrid dominance research: the existing hybrid dominance theory can only partially explain the phenomenon of plant and animal hybrid dominance, and the theory of animal hybrid dominance is less researched, and the accuracy of the existing hybrid dominance prediction methods is limited. China is the world's largest pork production and consumption country. Heterosis can effectively improve the production performance of pigs, and its application in the pig industry has important economic and research value. However, the existing research on pig hybrid production is in its infancy and needs to be further studied. In this review, we summarize the existing heterosis theory, heterosis prediction methods, and their application in pig production, to provide a reference for the application of heterosis in pig breeding.

LncIMF2 promotes adipogenesis in porcine intramuscular preadipocyte through sponging MiR-217.

Intramuscular fat is positively related to meat quality including tenderness, flavor, and juiciness. Long noncoding RNA (LncRNA) plays a vital role in regulating adipogenesis. However, it is largely unknown about lncRNAs associated with porcine intramuscular adipocyte adipogenesis. In the present study, we focus on a novel LncRNA, which is named lncIMF2, associated with adipogenesis by our previous RNA-sequence analysis and bioinformatics analysis. We demonstrated LncIMF2 knockdown inhibited the proliferation of porcine intramuscular adipocytes while expression of cell cycle-related genes was decreased. Besides, we found LncIMF2 knockdown inhibited expression of adipogenic differentiation marker genes including PPARγ (Peroxisome proliferator-activated reporter gamma) and ATGL (Adipose triglyceride lipase). Similarly, overexpression of LncIMF2 promotes proliferation and differentiation of porcine intramuscular preadipocytes. Moreover, we proved that IncIMF2 acts as a molecular sponge for MicroRNA-217 (miR-217), which has been found associated with adipogenesis, thereby affecting the expression of the miR-217 target gene. Collectively, our findings will contribute to a deeper understanding of the role of LncRNA in pig IMF deposition for the improvement of meat quality.

Lnc-ORA interacts with microRNA-532-3p and IGF2BP2 to inhibit skeletal muscle myogenesis.

Skeletal muscle is one of the most important organs of the animal body. Long noncoding RNAs play a crucial role in the regulation of skeletal muscle development via several mechanisms. We recently identified obesity-related lncRNA (lnc-ORA) in a search for long noncoding RNAs that influence adipogenesis, finding it impacted adipocyte differentiation by regulating the PI3K/protein kinase B/mammalian target of rapamycin pathway. However, whether lnc-ORA has additional roles, specifically in skeletal muscle myogenesis, is not known. Here, we found that lnc-ORA was significantly differentially expressed with age in mouse skeletal muscle tissue and predominantly located in the cytoplasm. Overexpression of lnc-ORA promoted C2C12 myoblast proliferation and inhibited myoblast differentiation. In contrast, lnc-ORA knockdown repressed myoblast proliferation and facilitated myoblast differentiation. Interestingly, silencing of lnc-ORA rescued dexamethasone-induced muscle atrophy in vitro. Furthermore, adeno-associated virus 9-mediated overexpression of lnc-ORA decreased muscle mass and the cross-sectional area of muscle fiber by upregulating the levels of muscle atrophy-related genes and downregulating the levels of myogenic differentiation-related genes in vivo. Mechanistically, lnc-ORA inhibited skeletal muscle myogenesis by acting as a sponge of miR-532-3p, which targets the phosphatase and tensin homolog gene; the resultant changes in phosphatase and tensin homolog suppressed the PI3K/protein kinase B signaling pathway. In addition, lnc-ORA interacted with insulin-like growth factor 2 mRNA-binding protein 2 and reduced the stability of myogenesis genes, such as myogenic differentiation 1 and myosin heavy chain. Collectively, these findings indicate that lnc-ORA could be a novel underlying regulator of skeletal muscle development.

Adipose-specific BMP and activin membrane-bound inhibitor (BAMBI) deletion promotes adipogenesis by accelerating ROS production.

With the improvement of people's living standards, the number of obese patients has also grown rapidly. It is reported that the level of oxidative stress in obese patients has significantly increased, mainly caused by the increase in reactive oxygen species (ROS) levels in adipose tissue. Studies have shown that the use of siRNA to interfere with bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI) expression could promote adipocyte differentiation, and under hypoxic conditions, BAMBI could act as a regulator of HIF1α to regulate the polarity damage of epithelial cells. In view of these results, we speculated that BAMBI may regulate adipogenesis by regulating the level of ROS. In this study, we generated adipose-specific BAMBI knockout mice (BAMBI AKO) and found that compared with control mice, BAMBI AKO mice showed obesity when fed with high-fat diet, accompanied by insulin resistance, glucose intolerance, hypercholesterolemia, and increased inflammation in adipose tissue. Interestingly, adipose-specific deficiency of BAMBI could cause an increase in the expression level of Nox4, thereby promoting ROS production in cytoplasm and mitochondria and the DNA-binding activity of C/EBPß and ultimately promoting adipogenesis. Consistently, our findings indicated that BAMBI may be a reactive oxygen regulator to affect adipogenesis, thereby controlling obesity and metabolic syndrome.

Resveratrol improves estrus disorder induced by bisphenol A through attenuating oxidative stress, autophagy, and apoptosis.

Bisphenol A (BPA), as a widely used plasticizer, is easily absorbed by animals and humans. It has certain toxic effects on various tissues, including liver, heart, kidney, testis, and ovary. The toxic effects of BPA on animal reproduction have aroused widespread concern, but its regulatory mechanism and antidote in female animals estrus cycle remain unclear. In this study, the results displayed that BPA destroyed the normal estrus cycle of mice through decreasing the levels of progesterone and estradiol. Furthermore, BPA significantly increased the levels of oxidative stress, autophagy, and apoptosis in ovaries and granulosa cells. Interestingly, we found that the natural antioxidant resveratrol rescued estrus disorder and impaired estradiol secretion, reduced the abnormal reactive oxygen species accumulation, autophagy, and apoptosis in BPA exposed ovarian tissues. Moreover, transmission electron microscopy showed that resveratrol reduced BPA-induced autophagic vesicles formation and flow cytometry showed that resveratrol inhibited the increase of apoptotic cells induced by BPA on granulosa cells. Therefore, the supplement of resveratrol could restore BPA-induced estrus disorder by protecting ovarian granulosa cells. Overall, resveratrol is a potential drug to alleviate BPA-induced estrous cycle disorders and ovarian damage.

Boar seminal plasma improves sperm quality by enhancing its antioxidant capacity during liquid storage at 17°C.

The objective of this study was to investigate the effects of different levels of seminal plasma (SP) on boar sperm quality, antioxidant capacity and bacterial concentrations during liquid storage at 17°C. Boar sperm was diluted with Beltsville Thawing Solution (BTS) consisting of 0, 25, 50 and 75% (v/v) of SP. Total motility, progressive motility and dynamic parameters were assessed by the computer assisted sperm analysis (CASA) system. Acrosome and plasma membrane integrity were measured by FITC-PNA/DAPI and SYBR-14/PI staining, respectively. In addition, total antioxidant capacity (T-AOC), malondialdehyde (MDA) content, and reactive oxygen species (ROS) levels were detected using commercial assay kits. Bacterial concentrations were assessed by turbidimetric assay. Our results showed that 25% SP markedly improved total motility, progressive motility, sperm dynamic parameters, acrosome integrity compared with 0, 50 and 75% SP (P < 0.05). In addition, 25% SP significantly increased T-AOC but decreased MDA content and ROS levels compared with 0, and 75% SP (P < 0.05). Moreover, 25% SP significantly decreased the bacterial concentrations in extended semen compared with 50% and 75% SP, however, which was higher than with 0% SP (P < 0.05). These results suggest that 25% SP can promote boar sperm quality through enhancing its antioxidant capacity during liquid storage.

Astaxanthin improves preserved semen quality at 17°C by enhancing sperm antioxidant and motility properties.

Porcine sperm is rich in polyunsaturated fatty acids; therefore, it is highly susceptible to oxidative damage during storage. Inhibition of oxidative stress during preservation is essential for maintaining sperm motility. Astaxanthin is a potent antioxidant used in the cosmetic and pharmaceutical industries. This study aimed to explore the effect of supplementing astaxanthin as an extender of porcine semen preservation dilutions at 17°C. Various concentrations of astaxanthin were added to diluted porcine semen at 17°C. We performed computer-assisted semen analysis, evaluation of plasma membrane integrity and acrosome integrity, and measurement of total antioxidant activity, malondialdehyde (MDA) content, reactive oxygen species levels, superoxide dismutase (SOD) activity, catalase (CAT) activity, glutathione peroxidase (GSH-PX) activity and sperm motility parameters. Compared with the control group, the addition of 0.25 µg/ml astaxanthin group significantly improved sperm motility parameters stored on the fifth day; these were increased levels of sperm SOD, GSH-PX and CAT (p < .05), increased sperm adenosine trisphosphate and lactate dehydrogenase levels and decreased sperm MDA levels (p < .05). These findings suggest that adding 0.25 µg/ml of astaxanthin improves the quality of porcine semen stored at 17°C. Our findings provide theoretical support for developing new protective agents critical for preserving pig semen at 17°C.

Deciphering the miRNA transcriptome of Rongchang pig longissimus dorsi at weaning and slaughter time points.

MicroRNA (miRNA) is essential for the process of gene posttranscriptional regulation in skeletal muscle of many species, such as mice, cattle and so on. However, a little number of miRNAs have been reported in the muscle development of Chinese native pig breeds. In this study, the longissimus dorsi transcripts of Chinese native Rongchang pig at weaning and slaughter time points were analysed for miRNA-seq. The results showed that 19 novel and 186 known miRNAs involved in the Rongchang pig skeletal muscle development were identified. Based on these findings, we further confirmed that porcine miR-127, miR-299 and miR-432-5p were obviously down-expressed in adult pig (287 days of age), while miR-7134-3p and 664-5p were significantly up-expressed in weaning pig (35 days of age). In other words, these miRNAs could be the potential molecular markers and play vital roles in the muscle development process. Moreover, we found miR-127 could inhibit the proliferation and myogenesis of porcine satellite cells in longissimus dorsi muscle. Our findings will provide deep insight into miRNA function for pork quality research with Chinese indigenous pig breeds.

Boar sperm quality and oxidative status as affected by rosmarinic acid at 17 °C.

Peroxidation damage induces sublethal injury to boar sperm during preservation. Rosmarinic acid (RA) has already been verified to efficiently protect cells from oxidant-induced injury and to produce significant effect on cryopreservation of semen. Through our experiments, we aim at investigating whether RA has a positive effect on the preservation of pig semen at room temperature. The semen collected from sexually mature Large White boars were preserved at 17 °C in Beltsville thawing solution (BTS) supplied. The boar sperm were exposed to 0, 25, 50, 75, 100, 125 and 150 µM RA in vitro and the sperm functions were examined. The sperm motility, the acrosome and plasma membrane integrity, the catalase activity (CAT), the total antioxidative capacity (T-AOC) activity and the malondialdehyde content (MDA) were examined at 0, 1, 3 and 5 days. The BTS diluent containing RA improved the sperm quality during the process of liquid preservation compared with the control treatment. After 5 days of liquid preservation, the addition of RA at 100 µM produced an optimal effect on the survival time as well as on the maintenance of motility, acrosome and plasma membrane integrity; T-AOC activity; CAT activity; and the MDA content. Besides, our results in the reproductive experiments showed that the addition of RA at 100 µM to the BTS diluent increased the pregnancy rate. These results suggest that the proper concentration of RA in boar semen extenders possibly improves the artificial insemination efficiency by reducing the sperm damage and the subsequent dysfunction during liquid preservation in swine production systems.

MicroRNA-664-5p promotes myoblast proliferation and inhibits myoblast differentiation by targeting serum response factor and Wnt1.

MicroRNAs (miRNAs) are noncoding RNAs that regulate gene expression at the post-transcriptional level and are involved in the regulation of the formation, maintenance, and function of skeletal muscle. Using miRNA sequencing and bioinformatics analysis, we previously found that the miRNA miR-664-5p is significantly differentially expressed in longissimus dorsi muscles of Rongchang pigs. However, the molecular mechanism by which miR-664-5p regulates myogenesis remains unclear. In this study, using flow cytometry, 5-ethynyl-2'-deoxyuridine staining, and cell count and immunofluorescent assays, we found that cell-transfected miR-664-5p mimics greatly promoted proliferation of C2C12 mouse myoblasts by increasing the proportion of cells in the S- and G2-phases and up-regulating the expression of cell cycle genes. Moreover, miR-664-5p inhibited myoblast differentiation by down-regulating myogenic gene expression. In contrast, miR-664-5p inhibitor repressed myoblast proliferation and promoted myoblast differentiation. Mechanistically, using dual-luciferase reporter gene experiments, we demonstrated that miR-664-5p directly targets the 3'-UTR of serum response factor (SRF) and Wnt1 mRNAs. We also observed that miR-664-5p inhibits both mRNA and protein levels of SRF and Wnt1 during myoblast proliferation and myogenic differentiation, respectively. Furthermore, the activating effect of miR-664-5p on myoblast proliferation was attenuated by SRF overexpression, and miR-664-5p repressed myogenic differentiation by diminishing the accumulation of nuclear ß-catenin. Of note, miR-664-5p's inhibitory effect on myogenic differentiation was abrogated by treatment with Wnt1 protein, the key activator of the Wnt/ß-catenin signaling pathway. Collectively, our findings suggest that miR-664-5p controls SRF and canonical Wnt/ß-catenin signaling pathways in myogenesis.

MiR-127 attenuates adipogenesis by targeting MAPK4 and HOXC6 in porcine adipocytes.

MicroRNAs (miRNAs) have critical roles during adipogenesis; however, their precise functions are not completely understood. Porcine miRNA expression profiles show that miR-127 is dramatically downregulated with age in adipose tissue. We aimed to identify the precise functions and mechanisms of miR-127 in proliferation and adipogenesis. Preadipocytes were cultured under conditions to induce proliferation or differentiation and the effect of miR-127 overexpression on these processes, and the associated bioinformatically predicted target genes, were assessed using luciferase assays, quantitative real-time PCR, western blot analysis, and cell staining techniques. miR-127 increased proliferation by promoting cell cycling, whereas it suppressed differentiation, which was accompanied by reduced lipid accumulation. miR-127 targeted mitogen-activated protein kinase 4 and homeobox C6 (HOXC6) to activate preadipocyte proliferation. During differentiation, miR-127 targeted HOXC6 to attenuate adipogenesis. These findings identify miR-127 as an inhibitor of porcine adipogenesis, which may inform future strategies to reduce porcine fat deposition and treat human obesity.

MicroRNA-323-3p promotes myogenesis by targeting Smad2.

Skeletal muscle is an important and complex organ with multiple biological functions in humans and animals. Proliferation and differentiation of myoblasts are the key steps during the development of skeletal muscle. MicroRNA (miRNA) is a class of 21-nucleotide noncoding RNAs regulating gene expression by combining with the 3'-untranslated region of target messenger RNA. Many studies in recent years have suggested that miRNAs play a critical role in myogenesis. Through high-throughput sequencing, we found that miR-323-3p showed significant changes in the longissimus dorsi muscle of Rongchang pigs in different age groups. In this study, we discovered that overexpression of miR-323-3p repressed myoblast proliferation and promoted differentiation, whereas the inhibitor of miR-323-3p displayed the opposite results. Furthermore, we predicted Smad2 as the target gene of miR-323-3p and found that miR-323-3p directly modulated the expression level of Smad2. Then luciferase reporter assays verified that Smad2 was a target gene of miR-323-3p during the differentiation of myoblasts. These findings reveal that miR-323-3p is a positive regulator of myogenesis by targeting Smad2. This provides a novel mechanism of miRNAs in myogenesis.

Lentivirus-mediated CTRP6 silencing ameliorates diet-induced obesity in mice.

The C1q/TNF-related protein 6 (CTRP6) is an adipokine involved in diverse biological processes. Formerly, we identified that CTRP6 regulates adipocyte differentiation, fatty acid oxidation and triglyceride accumulation in vitro. However, the effects of CTRP6 on adiposity in vivo have not yet been defined. This study aimed to confirm the involvement of CTRP6 in adipose accumulation and brown adipogenesis by intraperitoneal injection of the CTRP6-shRNA lentivirus into mice (CL mice). CL mice were significantly thinner than the control mice after feeding with a high fat diet (HFD), independent of food intake quantity. These HFD-fed CL mice displayed lower white and brown adipocyte sizes, and serum leptin levels, but an increase in serum adiponectin and insulin sensitivity relative to control mice. Additionally, the brown fat markers, such as UCP1, PRDM16, PGC1α and Cidea were found to be upregulated in the white and brown adipose tissue of the CL mice. These markers were also upregulated in a primary culture of mouse white and brown adipocytes treated with the CTRP6-shRNA lentivirus. Mechanistically, the knockdown of CTRP6 increased p38MAPK phosphorylation, but decreased expression of proteins involved in the Hedgehog signaling pathway (Sufu, Gli2 and Gli3). CTRP6 knockdown also upregulated expression of mitochondrial metabolic factors NRF-1, TFAM, CPT1 and Cyt C. Data from the current study show that CTRP6 knockdown protects against diet-induced obesity and promotes brown adipogenesis by the p38MAPK/Hh signaling pathway in conjunction with the upregulation of brown fat markers and mitochondrial metabolic factors.

MAT2A promotes porcine adipogenesis by mediating H3K27me3 at Wnt10b locus and repressing Wnt/ß-catenin signaling.

Methionine adenosyltransferase (MAT) is a critical biological enzyme and that can catalyze L-met and ATP to form S-adenosylmethionine (SAM), which is acted as a biological methyl donor in transmethylation reactions involving histone methylation. However, the regulatory effect of methionine adenosyltransferase2A (MAT2A) and its associated methyltransferase activity on adipogenesis is still unclear. In this study, we investigate the effect of MAT2A on adipogenesis and its potential mechanism on histone methylation during porcine preadipocyte differentiation. We demonstrated that overexpression of MAT2A promoted lipid accumulation and significantly up-regulated the levels of adipogenic marker genes including PPARγ, SREBP-1c, and aP2. Whereas, knockdown of MAT2A or inhibition MATII enzyme activity inhibited lipid accumulation and down-regulated the expression of the above-mentioned genes. Mechanistic studies revealed that MAT2A interacted with histone-lysine N-methyltransferase Ezh2 and was recruited to Wnt10b promoter to repress its expression by promoting H3K27 methylation. Additionally, MAT2A interacted with MafK protein and was recruited to MARE element at Wnt10b gene. The catalytic activity of MAT2A as well as its interacting factor-MAT2B, was required for Wnt10b repression and supplying SAM for methyltransferases. Moreover, MAT2A suppressed Wnt10b expression and further inhibited Wnt/ß-catenin signaling to promote adipogenesis.

Adiponectin AS lncRNA inhibits adipogenesis by transferring from nucleus to cytoplasm and attenuating Adiponectin mRNA translation.

Adiponectin (AdipoQ) is an adipocyte-derived hormone with positive function on systemic glucose and lipid metabolism. Long noncoding RNA (lncRNA) is emerging as a vital regulator of adipogenesis. However, AdipoQ-related lncRNAs in lipid metabolism have not been explored. Here, AdipoQ antisense (AS) lncRNA was first identified, and we further found that it inhibited adipogenesis. The half-life of AdipoQ AS lncRNA was 10 h, whereas that of AdipoQ mRNA was 4 h. During adipogenic differentiation, AdipoQ AS lncRNA translocated from nucleus to cytoplasm. AdipoQ AS lncRNA and AdipoQ mRNA formed an RNA duplex. Moreover, AdipoQ AS lncRNA delivered via injection of adenovirus expressing AdipoQ AS lncRNA decreases white adipose tissue (WAT), brown adipose tissue (BAT) and liver triglycerides (TG) in mice consuming a high fat diet (HFD). Interestingly, the non-overlapping region of AdipoQ AS lncRNA improved serum glucose tolerance and insulin sensitivity in HFD mice, but not AdipoQ AS lncRNA. In conclusion, AdipoQ AS lncRNA transfer from nucleus to cytoplasm inhibits adipogenesis through formation of an AdipoQ AS lncRNA/AdipoQ mRNA duplex to suppress the translation of AdipoQ mRNA. Taken together, we suggest that AdipoQ AS lncRNA is a novel therapeutic target for obesity-related metabolic diseases.