GSK3 regulation Wnt/ß-catenin signaling affects adipogenesis in bovine skeletal muscle fibro/adipogenic progenitors.

Clarifying the cellular origin and regulatory mechanisms of intramuscular fat (IMF) deposition is crucial for improving beef quality. Here, we used single-nucleus RNA sequencing to analyze the structure and heterogeneity of skeletal muscle cell populations in different developmental stages of Yanbian cattle and identified eight cell types in two developmental stages of calves and adults. Among them, fibro/adipogenic progenitors (FAPs) expressing CD29 (ITGA7)pos and CD56 (NCAM1)neg surface markers were committed to IMF deposition in beef cattle and expressed major Wnt ligands and receptors. LY2090314/XAV-939 was used to activate/inhibit Wnt/ß-catenin signal. The results showed that the blockade of Glycogen Synthase Kinase 3 (GSK3) by LY2090314 promoted the stabilization of ß-catenin and reduced the expression of genes related adipogenic differentiation (e.g., PPARγ and C/EBPα) in bovine FAPs, confirming the anti-adipogenic effect of GSK3. XAV-939 inhibition of the Wnt/ß-catenin pathway promoted the lipid accumulation capacity of FAPs. Furthermore, we found that blocking GSK3 enhanced the paracrine effects of FAPs-MuSCs and increased myotube formation in muscle satellite cells (MuSCs). Overall, our results outline a single-cell atlas of skeletal muscle development in Yanbian cattle, revealed the role of Wnt/GSK3/ß-catenin signaling in FAPs adipogenesis, and provide a theoretical basis for further regulation of bovine IMF deposition.

Bta-miR-330 promotes bovine intramuscular pre-adipocytes adipogenesis via targeting SESN3 to activate the Akt-mTOR signaling pathway.

Consumers are more inclined to choose beef with a high intramuscular fat content (IMF), which regulated by lots of factors. It is very significant to find a miRNA that plays a key role in the accumulation of IMF. In our study, we found that bta-miR-330 was highly expressed in Japanese black cattle and differentially expressed at intramuscular pre-adipocytes differentiation processes. Furthermore, we transfected the bta-miR-330 mimic & inhibitor in intramuscular pre-adipocytes. The results showed that bta-miR-330 inhibits the proliferation but promotes the adipogenesis of intramuscular pre-adipocytes. Subsequently, our study showed that bta-miR-330 binds to SESN3, which inhibits the adipogenesis of intramuscular pre-adipocytes. Moreover, we established the mechanism that bta-miR-330 promotes the adipogenesis of intramuscular pre-adipocytes by targeting SESN3 to activate the Akt-mTOR signaling pathway. Overall, our results revealed that bta-miR-330-SESN3-Akt-mTOR axis plays an important role in adipogenesis of intramuscular pre-adipocytes, which provides a molecular basis for increasing IMF content in beef cattle.

Mazabraud's syndrome in female patients: Two case reports.

BACKGROUND: Mazabraud's syndrome (MS) is a rare and slowly progressive benign disease characterized by the concurrent presence of fibrous dysplasia of bone and intramuscular myxoma, and is thought to be associated with mutations of the GNAS gene. To date, only about 100 cases of MS have been reported in the literature, but its standard treatment strategy remains unclear. CASE SUMMARY: We report two cases of MS in young women who underwent different treatments based on their symptoms and disease manifestations. The first patient, aged 37, received internal fixation and intravenous bisphosphonate for a pathological fracture of the right femoral neck, excision of a right vastus medialis myxoma was subsequently performed for pain control, and asymptomatic psoas myxomas were monitored without surgery. Genetic testing confirmed a GNAS gene mutation in this patient. The second patient, aged 24, underwent right vastus intermedius muscle myxoma resection, and conservative treatment for fibrous dysplasia of the ilium. These patients were followed-up for 17 months and 3 years, respectively, and are now in a stable condition. CONCLUSION: Various treatments have been selected for MS patients who suffer different symptoms. The main treatment for myxomas is surgical resection, while fibrous dysplasia is selectively treated if the patient experiences pathological fracture or severe pain. However, given the documented instances of malignant transformation of fibrous dysplasia in individuals with MS, close follow-up is necessary.

The importance of psoas muscle on low back pain: a single-center study on lumbar spine MRI.

Background: Low back pain (LBP) is the most frequent indication to magnetic resonance imaging (MRI) examinations of the lumbosacral spine. The individual role of soft tissues, including muscles, on LBP is not fully understood and the contribution of each MRI-derived parameter of soft tissues status on the intensity of LBP has not been investigated in detail. Methods: The study design was observational retrospective, single center carried out at a University Hospital. Images were acquired using a using a 1.5 Tesla scanner. Patients completed a symptom questionnaire and rated their pain intensity using the Visual Analogue Scale (VAS). The VAS scores ​​were categorized as mild, moderate, and severe using cutoff values of 3.8 and 5.7, based on the literature. Biometric data, including weight and height, were also recorded to calculate the body mass index (BMI). The ratios between intramuscular fat infiltration and net muscle area were also calculated. Patient sample included 94 patients with LBP underwent MRI of the lumbosacral spine. Results: The stepwise analysis revealed that increasing psoas net area was associated with lower VAS levels (odds ratio [OR]: 0.94: 95% confidence interval [CI]: 0.90-0.98; p=.005), and an increase of one square centimeter of total psoas area resulted in a greater probability of reporting a mild (+1.21%; 95% CI: 0.37, 2.05%) or a moderate VAS (+0.40%; 95% CI: -0.02, 0.82%), Furthermore, a more severe VAS was associated with a higher BMI (OR: 1.13; 95% CI: 1.00-1.27). Conclusion: Our study demonstrates a relationship between LBP and MRI parameters of paravertebral and psoas muscles status. The psoas muscle is extremely important for spine stabilization and is linked to clinical symptoms of patients affected by LBP. These findings could contribute to future studies and improve treatment options in patients with LBP, possibly reducing the impact on disability, quality of life and socioeconomical burden.

A Rare Presentation of Cysticercosis in the Sternocleidomastoid Muscle.

Cysticercosis is a rare condition associated with the development of cysticercus (larval form) of Taenia solium (pork tapeworm), within an intermediate host. Accidental ingestion of infectious eggs is most likely the cause of humans becoming intermediate hosts. The most common site for larval cysts is the central nervous system followed by vitreous humor of the eye, striated muscle, and, in rare cases, subcutaneous and other tissues. Isolated muscular involvement with nonspecific symptoms makes this condition challenging to diagnose. We present an unusual case of cysticercus in the sternocleidomastoid muscle diagnosed with ultrasonography and contrast-enhanced scans, which was subsequently treated with surgical excision and a short course of anthelmintics.

Hidden in Muscles: A Case Study of Intramuscular Lipoma.

This case report presents a 64-year-old male with a giant intramuscular lipoma on the right lumbar region's latissimus dorsi muscle. The patient presented with painless swelling, which gradually increased over six years. Magnetic resonance imaging (MRI) confirmed the presence of the lipoma, prompting surgical intervention. The surgical procedure involved meticulous dissection and complete excision of the tumor. Histopathological examination validated the diagnosis. Comparative analyses with similar cases highlighted variations in surgical approaches and the challenges in managing intramuscular lipomas. This case emphasizes the importance of considering intramuscular lipomas in soft tissue mass differentials and the significance of comprehensive management strategies for optimal patient outcomes.

Transcriptome analysis reveals the effects of Schizochytrium sp. on the meat quality attributes of Tan lambs.

Schizochytrium sp., a feed additive, positively affects the quality of animal meat. In this study, the molecular mechanisms through which dietary Schizochytrium sp. affects the meat quality characteristics of Tan lambs were investigated using transcriptomic techniques. The findings demonstrate that the lambs supplemented with Schizochytrium sp. had a larger loin eye area and a higher average daily gain and intramuscular fat content (P < 0.05). They also had lower drip loss (at 24 and 48 h) and shear force (P < 0.05). Further, 745 genes were differentially expressed between lambs supplemented with Schizochytrium and the control group. Moreover, KEGG pathway analysis showed that the ECM-receptor interaction pathway, which is related to muscle generation and intramuscular fat deposition, was significantly enriched in the lambs administered a diet containing Schizochytrium sp. Herein, we identified some pivotal genes linked to muscular system development and lipid metabolism. Thus, using Schizochytrium sp. may boost the meat quality of Tan lambs by modifying the expression of genes related to hub pathways. The results supply a new basis to determine the molecular mechanisms through which Schizochytrium sp. supplementation regulates the meat quality characteristics of sheep.

The Attitudes of Healthcare Professionals in an Autonomous Community in Spain towards Paediatric Influenza Vaccination.

In the 2022-2023 influenza season, three autonomous communities anticipated the document approved by the Public Health Commission recommending influenza vaccination for all children aged 6 to 59 months. The primary objective of this study was to evaluate the attitude of healthcare professionals towards the first universal vaccination campaign in our region, as well as the acceptability of the vaccines used and their attitude towards pilot school vaccination. This was a cross-sectional, survey-based, descriptive study. All healthcare professionals involved in the campaign were invited to participate. Overall, 91.9% of surveyed professionals thought that influenza vaccination from 6 to 59 months was important or very important, and 89.8% had previous experience regarding the intramuscular vaccine. Healthcare professionals rated the intranasal vaccine significantly more positively, but there were no differences when asking about each vaccine without comparison. The inhaled vaccine was preferred by 97.5% for the following campaign. Pilot school vaccination had a 75% acceptance rate. The inhaled vaccine was preferred by most professionals, and pilot school vaccination was highly accepted and independently associated with the importance of vaccination as considered by physicians, being a medical doctor, and participation in the pilot programme.

A rare case of Ganglion cyst in the thigh in a 44-year-old woman: A case report and literature review.

INTRODUCTION AND SIGNIFICANCE: Ganglion cysts in the thigh area are uncommon, typically occurring in the wrist and ankle. These cysts are usually painless but may compress nearby structures, causing discomfort. Ultrasound is a valuable tool to differentiate ganglion cysts from hematomas and lipomas. It also helps identify the fluid-filled cyst walls. Treatment typically involves surgical removal, with complete resection being the goal. CASE PRESENTATION: We present a case of a woman who experienced a gradual increase in size of a lump in her groin area. The lump was later diagnosed and completely removed. Histological analysis revealed the presence of a ganglion cyst. CLINICAL DISCUSSION: Clinical examination is crucial for diagnosing superficial ganglion cysts. It allows us to assess their separation from the skin and connection to deeper structures. It's important to consider ganglion cysts as part of the differential diagnosis for cystic lesions in the groin area during routine medical practice. This can help avoid unnecessary and expensive tests like MRI scans in some cases. CONCLUSION: Developing a thorough differential diagnosis for uncommon lesions in specific anatomical areas is essential in clinical practice. This aids in choosing appropriate diagnostic methods and surgical intervention, if necessary, to prevent recurrence of the condition.

Metabolic and microbial mechanisms related to the effects of dietary wheat levels on intramuscular fat content in finishing pigs.

The current study aimed to investigate the metabolic and microbial mechanisms behind the effects of dietary wheat levels on intramuscular fat (IMF) content in the psoas major muscle (PM) of finishing pigs. Thirty-six barrows were arbitrarily assigned to two groups and fed with diets containing 25% or 55% wheat. Enhancing dietary wheat levels led to low energy states, resulting in reduced IMF content. This coincided with reduced serum glucose and low-density lipoprotein cholesterol levels. The AMP-activated protein kinase α2/sirtuin 1/peroxisome proliferator-activated receptor-γ coactivator 1α pathway may be activated by high-wheat diets, causing downregulation of adipogenesis and lipogenesis genes, and upregulation of lipolysis and gluconeogenesis genes. High-wheat diets decreased relative abundance of Lactobacillus and Coprococcus, whereas increased SMB53 proportion, subsequently decreasing colonic propionate content. Microbial glycolysis/gluconeogenesis, d-glutamine and D-glutamate metabolism, flagellar assembly, and caprolactam degradation were linked to IMF content. Metabolomic analysis indicated that enhancing dietary wheat levels promoted the protein digestion and absorption and affected amino acids and lipid metabolism. Enhancing dietary wheat levels reduced serum glucose and colonic propionate content, coupled with strengthened amino acid metabolism, contributing to the low energy states. Furthermore, alterations in microbial composition and propionate resulted from high-wheat diets were associated with primary bile acid biosynthesis, arachidonic acid metabolism, steroid hormone biosynthesis, and biosynthesis of unsaturated fatty acids, as well as IMF content. Colonic microbiota played a role in reducing IMF content through modulating the propionate-mediated peroxisome proliferators-activated receptor signaling pathway. In conclusion, body energy and gut microbiota balance collectively influenced lipid metabolism.

Orthopedic Manifestations of Disseminated Cryptococcal neoformans Infection in an Immunocompromised Patient: a Case Report.

Introduction: Cryptococccus neoformans is a fungus which typically presents in immunocompromised hosts, commonly presenting as meningoencephalitis. There have been very few documented incidents of intramuscular manifestations of this pathogen. Case Report: We report on a case of a 45-year-old caucasian male with disseminated Cryptococcus neoformans who developed cryptococcal intramuscular abscesses of all extremities and osteomyelitis of the left upper limb. Clinical treatment and surgical debridement of the forearm was performed. Persistent infection resulted in a left humeral amputation and ultimately the patient's death. This is one of the few documented intramuscular abscesses of Cryptococcus neoformans. Conclusion: Orthopedic manifestations of cryptococcal infections are rare; however, awareness and prompt diagnosis may improve outcomes.

Comparison of Wrinkle Patterns Generated by Intradermal and Intramuscular Botulinum Toxin Injections by Clinical Evaluation.

Purpose: Botulinum toxin has played a remarkable role in management of forehead wrinkles. Most used is intramuscular technique due to its deposition into the muscles, however, with adverse effects like brow ptosis. This study has been designed for the evaluation of efficacy for intradermal v/s intramuscular route of botulinum toxin injections for forehead wrinkles using clinical correlation. Methods: This study included a clinical trial of 32 facial halves divided equally into intradermal and intramuscular injection technique groups, receiving total dose of 8 U. Results were assessed by clinical examination upto 2 weeks and 4 weeks with parameters; objective wrinkle rate, eyebrow height, eyebrow movement, pain, and satisfaction after treatment. Result: Results showed least mean for objective wrinkle rate in intramuscular group, showing statistically significant improvement. Overall improvement in eyebrow height and eyebrow movement were slightly more for intramuscular group. Pain was lesser for intradermal group, whereas satisfaction of patient of patient post treatment is similar for both the groups. Conclusion: Among intradermal and intramuscular botulinum toxin injection technique, the effect and potency were better for intramuscular technique, whereas the patient comfort and compliance were better for intradermal technique.

Identification of porcine fast/slow myogenic exosomes and their regulatory effects on lipid accumulation in intramuscular adipocytes.

BACKGROUND: Pork quality is affected by the type of muscle fibers, which is closely related to meat color, tenderness and juiciness. Exosomes are tiny vesicles with a diameter of approximately 30-150 nm that are secreted by cells and taken up by recipient cells to mediate communication. Exosome-mediated muscle-fat tissue crosstalk is a newly discovered mechanism that may have an important effect on intramuscular fat deposition and with that on meat quality. Various of adipose tissue-derived exosomes have been discovered and identified, but the identification and function of muscle exosomes, especially porcine fast/slow myotube exosomes, remain unclear. Here, we first isolated and identified exosomes secreted from porcine extensor digitorum longus (EDL) and soleus (SOL), which represent fast and slow muscle, respectively, and further explored their effects on lipid accumulation in longissimus dorsi adipocytes. RESULTS: Porcine SOL-derived exosomes (SOL-EXO) and EDL-derived exosomes (EDL-EXO) were first identified and their average particle sizes were approximately 84 nm with double-membrane disc- shapes as observed via transmission electron microscopy and scanning electron microscopy. Moreover, the intramuscular fat content of the SOL was greater than that of the EDL at 180 days of age, because SOL intramuscular adipocytes had a stronger lipid-accumulating capacity than those of the EDL. Raman spectral analysis revealed that SOL-EXO protein content was much greater than that of EDL-EXO. Proteomic sequencing identified 72 proteins that were significantly differentially expressed between SOL-EXO and EDL-EXO, 31 of which were downregulated and 41 of which were upregulated in SOL-EXO. CONCLUSIONS: Our findings suggest that muscle-fat tissue interactions occur partly via SOL-EXO promoting adipogenic activity of intramuscular adipocytes.

Trimodal wireless intramuscular device detects muscle pressure, flow, and oxygenation changes in porcine model of lower extremity compartment syndrome.

PURPOSE: Compartment syndrome remains difficult to diagnose early in its clinical course. Pressure transducer catheters have been used to directly measure intracompartmental pressure (ICP), but this method is unreliable, with a false positive rate of 35%. We have previously used intramuscular near infrared spectroscopy to detect changes in tissue oxygen saturation (StO2) in response to increasing ICP using a novel implantable probe. However, measuring StO2 may not be sufficient to identify CS in the clinical setting. The pathophysiology of CS consists of increased ICP, leading to decreased tissue perfusion, and resulting in reduced tissue oxygenation. More clinically useful information may come from the integration of multiple data streams to aid in the diagnosis of CS. In this study, we present a novel, intramuscular probe capable of simultaneous measurement of ICP, StO2, and microvascular blood flow in a porcine model of ACS. METHODS: Proof of concept for this device is demonstrated in a porcine lower extremity balloon compression model of ACS. Pressure was maintained for 20 min (short-term) or 3 h (long-term) before the balloon volume was removed. RESULTS: In both short- and long-term experiments, as ICP increased with increasing balloon volume, the novel multimodal sensor simultaneously and reliably detected pressure elevation and corresponding reversible reductions in microvascular flow rate and tissue oxygenation. CONCLUSION: This novel trimodal device simultaneously measured the elevated ICP, decreased perfusion, and tissue ischemia of evolving ACS, substantiating our basic understanding of CS pathophysiology.

Short-term mortality prediction in acute pulmonary embolism: Radiomics values of skeletal muscle and intramuscular adipose tissue.

BACKGROUND: Acute pulmonary embolism (APE) is a potentially life-threatening disorder, emphasizing the importance of accurate risk stratification and survival prognosis. The exploration of imaging biomarkers that can reflect patient survival holds the potential to further enhance the stratification of APE patients, enabling personalized treatment and early intervention. Therefore, in this study, we develop computed tomography pulmonary angiography (CTPA) radiomic signatures for the prognosis of 7- and 30-day all-cause mortality in patients with APE. METHODS: Diagnostic CTPA images from 829 patients with APE were collected. Two hundred thirty-four features from each skeletal muscle (SM), intramuscular adipose tissue (IMAT) and both tissues combined (SM + IMAT) were calculated at the level of thoracic vertebra 12. Radiomic signatures were derived using 10 times repeated three-fold cross-validation on the training data for SM, IMAT and SM + IMAT for predicting 7- and 30-day mortality independently. The performance of the radiomic signatures was then evaluated on held-out test data and compared with the simplified pulmonary embolism severity index (sPESI) score, a well-established biomarker for risk stratification in APE. Predictive accuracy was assessed by the area under the receiver operating characteristic curve (AUC) with a 95% confidence interval (CI), sensitivity and specificity. RESULTS: The radiomic signatures based on IMAT and a combination of SM and IMAT (SM + IMAT) achieved moderate performance for the prediction of 30-day mortality on test data (IMAT: AUC = 0.68, 95% CI [0.57-0.78], sensitivity = 0.57, specificity = 0.73; SM + IMAT: AUC = 0.70, 95% CI [0.60-0.79], sensitivity = 0.74, specificity = 0.54). Radiomic signatures developed for predicting 7-day all-cause mortality showed overall low performance. The clinical signature, that is, sPESI, achieved slightly better performance in terms of AUC on test data compared with the radiomic signatures for the prediction of both 7- and 30-day mortality on the test data (7 days: AUC = 0.73, 95% CI [0.67-0.79], sensitivity = 0.92, specificity = 0.16; 30 days: AUC = 0.74, 95% CI [0.66-0.82], sensitivity = 0.97, specificity = 0.16). CONCLUSIONS: We developed and tested radiomic signatures for predicting 7- and 30-day all-cause mortality in APE using a multicentric retrospective dataset. The present multicentre work shows that radiomics parameters extracted from SM and IMAT can predict 30-day all-cause mortality in patients with APE.

Efficacy and advantage of immunotherapy for melanoma via intramuscular co-expression of plasmid-encoded PD-1 and CTLA-4 scFvs.

Immunotherapy, in the shape of immune checkpoint inhibitors (ICIs), has completely changed the treatment of cancer. However, the increasing expense of treatment and the frequency of immune-related side effects, which are frequently associated with combination antibody therapies and Fc fragment of antibody, have limited the patient's ability to benefit from these treatments. Herein, we presented the therapeutic effects of the plasmid-encoded PD-1 and CTLA-4 scFvs (single-chain variable fragment) for melanoma via an optimized intramuscular gene delivery system. After a single injection, the plasmid-encoded ICI scFv in mouse sera continued to be above 150 ng/mL for 3 weeks and reached peak amounts of 600 ng/mL. Intramuscular delivery of plasmid encoding PD-1 and CTLA-4 scFvs significantly changed the tumor microenvironment, delayed tumor growth, and prolonged survival in melanoma-bearing mice. Furthermore, no significant toxicity was observed, suggesting that this approach could improve the biosafety of ICIs combination therapy. Overall, the expression of ICI scFvs in vivo using intramuscular plasmid delivery could potentially develop into a reliable, affordable, and safe immunotherapy technique, expanding the range of antibody-based gene therapy systems that are available.

Comparative Analgesic Efficacy of Intramuscular Dexamethasone, Ketorolac, Tramadol, and Butorphanol with Regard to Postoperative Pain After Mandibular Third Molar Surgery.

Surgical removal of the third molar often resulted in postoperative pain which affected the quality of life of the patients. Pharmacological management of pain includes NSAIDS or steroids. The present study compared four drugs, viz. Group 1 (4 mg dexamethasone injection); Group 2 (30 mg ketorolac); Group 3 (50 mg tramadol injection); and Group 4 (1 mg butorphanol injection) in the management of postoperative pain after third molar surgery. We observed that in comparison with the first and third postoperative pain between groups, it revealed the lowest mean pain score in the butorphanol group, followed by dexamethasone and tramadol group and the highest mean score in the ketorol group (P value <0.0001). We conclude that butorphanol with low dosage can be effectively used for reducing postoperative discomfort after surgery.

Lower Pregnancy and Live Birth Rates with Vaginal Endometrin Plus Intramuscular Progesterone Every Third Day Versus Intramuscular Progesterone Alone in Programmed Frozen Embryo Transfers: A Retrospective Case-control Study.

This study aimed to determine whether the use of vaginal Endometrin plus intramuscular progesterone on every third day (VIM) in programmed frozen embryo transfer (FET) is associated with lower pregnancy and live birth rates compared to daily intramuscular progesterone (IM). FET data from a single program were collected between November 2018 and December 2021. A total of 903 FETs were analyzed, including 504 FETs in the IM group, and 399 FETs in the VIM group. Inclusion criteria were women undergoing FETs with either 50 mg daily IM progesterone only (control) or 200 mg Endometrin twice daily plus 50 mg IM progesterone on every third day, with the transfer of a single day 5 or 6 frozen embryo. There were no significant differences in patient age at time of FETs, BMI, endometrial thickness, blastocyst quality, or infertility diagnosis between the groups. The VIM had significantly lower positive hCG and clinical pregnancy rates compared to the IM (60.2% vs 72.0% and 40.6% vs 56.7%, respectively, P = 0.0002 and P < 0.0001). The live birth rate was 36.1% in the VIM, compared to 49.4% in the IM (P < 0.0001). These findings also remained significant when excluding FETs with donor egg (35.9% vs 50.1%, P < 0.0001). This study demonstrated that VIM in FET cycles yields significantly lower pregnancy and live birth rates compared to IM along. IM progesterone alone may be preferable to combined Endometrin and IM progesterone in patients undergoing programmed frozen embryo transfers.

Single-nucleus RNA sequencing and lipidomics reveal characteristics of transcriptional and lipid composition in porcine longissimus dorsi muscle.

BACKGROUND: Global per capita meat consumption continues to rise, especially pork. Meat quality is influenced by the content of intramuscular fat (IMF) as a key factor. The longissimus dorsi muscle of Dahe pigs (DHM, IMF: 7.98% ± 1.96%) and Dahe black pigs (DHBM, IMF: 3.30% ± 0.64%) was studied to explore cellular heterogeneity and differentially expressed genes (DEGs) associated with IMF deposition using single-nucleus RNA sequencing (snRNA-seq). The lipid composition was then analyzed using non-targeted lipidomics. RESULTS: A total of seven cell subpopulations were identified, including myocytes, fibroblast/fibro/adipogenic progenitors (FAPs), satellite cells, endothelial cells, macrophages, pericytes, and adipocytes. Among them, FAPs and adipocytes were more focused because they could be associated with lipid deposition. 1623 DEGs in the FAPs subpopulation of DHBM were up-regulated compared with DHM, while 1535 were down-regulated. These DEGs enriched in the glycolysis/gluconeogenesis pathway. 109 DEGs were up-regulated and 806 were down-regulated in the adipocyte subpopulation of DHBM compared with DHM, which were mainly enriched in the PPAR signaling pathway and fatty acid (FA) biosynthesis. The expression level of PPARG, ABP4, LEP, and ACSL1 genes in DHM was higher than that in DHBM. Lipidomics reveals porcine lipid composition characteristics of muscle tissue. A total of 41 lipid classes and 2699 lipid species were identified in DHM and DHBM groups. The top ten relative peak areas of lipid classes in DHM and DHBM were triglyceride (TG), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), diglyceride (DG), cardiolipin (CL), ceramides (Cer), Simple Glc series (Hex1Cer), sphingomyelin (phSM), and phosphatidylinositol (PI). The relative peak areas of 35 lipid species in DHM were lower than DHBM, and 28 lipid species that were higher. There was a significant increase in the TG fatty acyl chains C6:0, C17:0, and C11:4, and a significant decrease in C16:0, C18:1, C18:2, and C22:4 in DHBM (p < 0.05). CONCLUSIONS: C16:0 FA may downregulate the expression level of PPARG gene, which leads to the downregulation of fat metabolism-related genes such as ACSL, PLIN2, and FABP4 in DHBM compared with DHM. This may be the reason that the lipid deposition ability of Dahe pigs is stronger than that of Dahe black pigs, which need further investigation.

Preliminary studies on the molecular mechanism of intramuscular fat deposition in the longest dorsal muscle of sheep.

BACKGROUND: Intramuscular fat content is an important index reflecting the quality of mutton, which directly affects the flavor and tenderness of mutton. Livestock and poultry intramuscular fat content is influenced by genetics, nutritional level, and environmental factors. Key regulatory factors play a crucial role in intramuscular fat deposition. However, there is a limited amount of research on the identification and function of key genes involved in intramuscular fat content deposition specifically in sheep. RESULTS: Histological differences in the longest dorsal muscle of the small-tailed frigid sheep increased in diameter and decreased in several muscle fibers with increasing monthly age; The intramuscular fat content of the longest dorsal muscle of the small-tailed cold sheep varied with age, with a minimum of 1 month of age, a maximum of 6 months of age, and a minimum of 12 months of age. Transcriptomic sequencing and bioinformatics analysis revealed a large number of differential genes in the longest dorsal muscles of little-tailed billy goats of different months of age, which were enriched in multiple GO entries and KEGG pathways. Among them, the pathway associated with intramuscular fat was the AMPK signaling pathway, and the related genes were PPARGC1A and ADIPOQ; Immunohistochemical studies showed that PPARGC1A and ADIPOQ proteins were expressed in connective tissues, cell membranes, and, to a lesser extent, the cytoplasm of the longest dorsal muscle of the little-tailed frigid sheep; Real-time PCR and Western Blot validation showed that PPARGC1A and ADIPOQ were both expressed in the longest dorsal muscle of the little-tailed frigid sheep at different ages, and there were age differences in the amount of expression. The ADIPOQ gene was negatively correlated with the intramuscular fat content of the longest dorsal muscle, and the PPARGC1A gene was positively correlated with the intramuscular fat content of the longest dorsal muscle; As inferred from the above results, the ADIPOQ gene was negatively correlated with the intramuscular fat content of the longest dorsal muscle (r = -0.793, P < 0.05); and the PPARGC1A gene was positively correlated with the intramuscular fat content of the longest dorsal muscle r = 0.923, P < 0.05). CONCLUSIONS: Based on the above results, it can be inferred that the ADIPOQ gene is negatively correlated with the intramuscular fat content of the longest back muscle (r = -0.793, P < 0.05); the PPARGC1A gene is positively correlated with the intramuscular fat content of the longest back muscle (r = 0.923, P < 0.05).