Cold has been a long-term survival challenge in the evolutionary process of mammals. In response to cold stress, in addition to brown adipose tissue (BAT) dissipating energy as heat through glucose and lipid oxidation to maintain body temperature, cold stimulation can strongly activate thermogenesis and energy expenditure in beige fat cells, which are widely distributed in the subcutaneous layer. However, the effects of cold stimulation on other tissues and systemic lipid metabolism remain unclear. Our previous research indicated that, under cold stress, BAT not only produces heat but also secretes numerous exosomes to mediate BAT-liver crosstalk. Whether subcutaneous fat has a similar mechanism is still unknown. Therefore, this study aimed to investigate the alterations in lipid metabolism across various tissues under cold exposure and to explore whether subcutaneous fat regulates systemic glucose and lipid metabolism via exosomes, thereby elucidating the regulatory mechanisms of lipid metabolism homeostasis under physiological stress. RT-qPCR, Western blot, and H&E staining methods were used to investigate the physiological changes in lipid metabolism in the serum, liver, epididymal white adipose tissue, and subcutaneous fat of mice under cold stimulation. The results revealed that cold exposure significantly enhanced the thermogenic activity of subcutaneous adipose tissue and markedly increased exosome secretion. These exosomes were efficiently taken up by hepatocytes, where they profoundly influenced hepatic lipid metabolism, as evidenced by alterations in the expression levels of key genes involved in lipid synthesis and catabolism pathways. This study has unveiled a novel mechanism by which subcutaneous fat regulates lipid metabolism through exosome secretion under cold stimulation, providing new insights into the systemic regulatory role of beige adipocytes under cold stress and offering a theoretical basis for the development of new therapeutic strategies for obesity and metabolic diseases.
Animals ; Lipid Metabolism/physiology* ; Mice ; Exosomes/metabolism* ; Cold Temperature ; Subcutaneous Fat/physiology* ; Thermogenesis/physiology* ; Adipose Tissue, Brown/metabolism* ; Male

Obesity is a worldwide health problem. An imbalance in energy metabolism is an important cause of obesity and related metabolic diseases. Our previous studies showed that inhibition of miR-429 increased the protein level of uncoupling protein 1 (UCP1) in beige adipocytes; however, whether local inhibition of miR-429 in subcutaneous adipose tissue affects diet-induced obesity and related metabolic disorders remains unclear. The aim of this study was to investigate the effect of local overexpression of miR-429 sponge in subcutaneous adipose tissue on obesity and related metabolic disorders. The control adeno-associated virus (AAV) or AAV expressing the miR-429 sponge was injected into mouse inguinal white adipose tissue. Seven days later, the mice were fed a high-fat diet for 10 weeks to induce obesity. The effects of the miR-429 sponge on body weight, adipose tissue weight, plasma glucose and lipid levels, and hepatic lipid content were explored. The results showed that the overexpression of miR-429 sponge in subcutaneous white adipose tissue reduced body weight and fat mass, decreased fasting blood glucose and plasma cholesterol levels, improved glucose tolerance, and alleviated hepatic lipid deposition in mice. Mechanistic investigation showed that the inhibition of miR-429 significantly upregulated the expression of UCP1 in adipocytes and adipose tissue. These results suggest that local inhibition of miR-429 in subcutaneous white adipose tissue ameliorates obesity and related metabolic disorders potentially by upregulating UCP1, and miR-429 is a potential therapeutic target for the treatment of obesity and related metabolic disorders.
Animals ; MicroRNAs/physiology* ; Obesity/metabolism* ; Mice ; Adipose Tissue, White/metabolism* ; Metabolic Diseases ; Subcutaneous Fat/metabolism* ; Male ; Uncoupling Protein 1/metabolism* ; Diet, High-Fat ; Mice, Inbred C57BL

Objective To study the correlation between the abdominal wall subcutaneous fat thickness and heart weight, so as to provide reference for prediction methods of normal range of heart weight that is suitable for autopsy in China. Methods The forensic pathology autopsy cases accepted by Center for Medicolegal Expertise of Sun Yat-sen University from 1998 to 2017 were collected. Then the exclusion criteria were determined, and according to them the total case group was selected, and the 6 disease groups and the normal group were further selected from the total case group. The rank sum test was used to compare the heart weight of the normal group and the disease groups to determine the influence of diseases on heart weight. Then the Spearman rank correlation analysis of abdominal wall subcutaneous fat thickness and heart weight in different genders and different ages in the total case group and the normal group was conducted to get the correlation coefficient （r_s）. Results In the total case group, correlation between abdominal wall subcutaneous fat thickness and heart weight was shown in males of all ages （P<0.05）; while in females, the correlation had no statistical significance （P>0.05） in 15-<20 age and 50-<60 age, but was statistically significant （P<0.05） in other age groups. For the males in the normal group, r_s was respectively 0.411, 0.541 and 0.683 in the 15-<40 age, the 40-<60 age, and the ≥60 age. For the females, r_s was respectively 0.249 and 0.317 in the 15-<40 age and the 40-<60 age. The correlation in the ≥60 age had no statistical significance（P>0.05）. Conclusion In the general population and the normal population, abdominal wall subcutaneous fat thickness is correlated with the heart weight of males. It is of significance to include the abdominal wall subcutaneous fat thickness in the prediction of normal range of heart weight for males in China.
Abdominal Wall/diagnostic imaging* ; China ; Female ; Heart/diagnostic imaging* ; Humans ; Male ; Middle Aged ; Reference Values ; Subcutaneous Fat/diagnostic imaging*

BACKGROUND: Obesity is a fundamental factor in metabolic disorders such as hyperlipidemia, insulin resistance, fatty liver, and atherosclerosis. However, effective preventive measures are still lacking. This study aimed to investigate different surgical protocols for removing partial adipose tissue before the onset of obesity and determine whether, and by which protocol, preliminary adipose removal could exert potent preventive effects against diet-induced metabolic disorders. METHODS: Male low-density lipoprotein receptor (LDL-R) knockout (KO) mice were randomly divided into four groups and subjected to epididymal fat removal (Epi-FR) surgery, subcutaneous fat removal (suQ-FR) surgery, both subcutaneous and epididymal fat removal (Epi + suQ-FR) surgery, or sham-operation. After 1 week of recovery, all mice were given a high-fat diet (HFD) for 10 weeks to induce metabolic disorders. RESULTS: In the Epi-FR group and the sham-operated group, the mean numbers of the residual subcutaneous fat were 28.59 mg/g and 18.56 mg/g, respectively. The expression of relative genes such as Pparg, Cebpa, Dgat2, Fabp4 and Cd36 in the residual subcutaneous fat increased 2.62, 3.90, 3.11, 2.06, 1.78 times in the Epi-FR group compared with that in the sham-operated group. Whereas in the other fat-removal groups, the residual fat depots had no significant change in either size or gene expression, as compared with those of the sham-operated group. Plasma lipid and glucose levels and insulin sensitivity, as detected by the glucose tolerance test, were not significantly alleviated in the three fat removal groups. Liver mass or lipid content was not attenuated in any of the three fat removal groups. The atherosclerosis burdens in the entire inner aorta and aortic root did not decrease in any of the three fat removal groups. CONCLUSIONS Our data suggest that removal of epididymal adipose or subcutaneous adipose alone or in combination before the onset of obesity did not protect against hyperlipidemia, insulin resistance, fatty liver, or atherosclerosis in LDL-R KO mice fed with a HFD. Hence, adipose removal possibly does not represent a potential approach in preventing obesity-related metabolic disorders in the obesity-susceptible population.
Adipose Tissue ; Animals ; Diet, High-Fat/adverse effects* ; Insulin Resistance ; Liver ; Male ; Mice ; Mice, Inbred C57BL ; Obesity ; Subcutaneous Fat

abdominal muscle and fat areas on computed tomography (CT) images.MATERIALS AND METHODS: A fully convolutional network-based segmentation system was developed using a training dataset of 883 CT scans from 467 subjects. Axial CT images obtained at the inferior endplate level of the 3rd lumbar vertebra were used for the analysis. Manually drawn segmentation maps of the skeletal muscle, visceral fat, and subcutaneous fat were created to serve as ground truth data. The performance of the fully convolutional network-based segmentation system was evaluated using the Dice similarity coefficient and cross-sectional area error, for both a separate internal validation dataset (426 CT scans from 308 subjects) and an external validation dataset (171 CT scans from 171 subjects from two outside hospitals).RESULTS: The mean Dice similarity coefficients for muscle, subcutaneous fat, and visceral fat were high for both the internal (0.96, 0.97, and 0.97, respectively) and external (0.97, 0.97, and 0.97, respectively) validation datasets, while the mean cross-sectional area errors for muscle, subcutaneous fat, and visceral fat were low for both internal (2.1%, 3.8%, and 1.8%, respectively) and external (2.7%, 4.6%, and 2.3%, respectively) validation datasets.CONCLUSION: The fully convolutional network-based segmentation system exhibited high performance and accuracy in the automatic segmentation of abdominal muscle and fat on CT images.]]>
Abdominal Muscles ; Adipose Tissue ; Artificial Intelligence ; Dataset ; Intra-Abdominal Fat ; Learning ; Muscle, Skeletal ; Muscles ; Sarcopenia ; Spine ; Subcutaneous Fat ; Tomography, X-Ray Computed

Therapeutic angiogenesis is an important strategy to rescue ischemic tissues in patients with critical limb ischemia having no other treatment option such as endovascular angioplasty or bypass surgery. Studies indicated so far possibilities of therapeutic angiogenesis using autologous bone marrow mononuclear cells, CD34⁺ cells, peripheral blood mononuclear cells, adipose-derived stem/progenitor cells, and etc. Recent studies indicated that subcutaneous adipose tissue contains stem/progenitor cells that can give rise to several mesenchymal lineage cells. Moreover, these mesenchymal progenitor cells release a variety of angiogenic growth factors including vascular endothelial growth factor, fibroblast growth factor, hepatocyte growth factor and chemokine stromal cell-derived factor-1. Subcutaneous adipose tissues can be harvested by less invasive technique. These biological properties of adipose-derived regenerative cells (ADRCs) implicate that autologous subcutaneous adipose tissue would be a useful cell source for therapeutic angiogenesis in humans. In this review, I would like to discuss biological properties and future perspective of ADRCs-mediated therapeutic angiogenesis.
Angioplasty ; Bone Marrow ; Extremities ; Fibroblast Growth Factors ; Hepatocyte Growth Factor ; Humans ; Intercellular Signaling Peptides and Proteins ; Ischemia ; Mesenchymal Stromal Cells ; Stem Cell Transplantation ; Stem Cells ; Subcutaneous Fat ; Vascular Endothelial Growth Factor A

OBJECTIVES: To identify trends in percentage body fat (PBF) in adolescents to determine gender-specific classification thresholds for being overweight and obese. METHODS: A cross-sectional study of 899 adolescents (11 to 14.5 years) from Hanoi and Nam Dinh was conducted in Vietnam. PBF, subcutaneous fat and percentage of lean mass were measured directly using OMRON HBF 375 scales to measure bioelectrical impedance. RESULTS: PBF decreased in boys with increasing age (p < 0.001). The difference in PBF between boys and girls, significantly increased with age after 12.5 years (p < 0.001). There was a stronger correlation between PBF and fat content (Pearson's r = 0.860, p < 0.0001) than that between (BMI) and fat content (Pearson's r = 0.521, p < 0.0001). The prevalence of being overweight or obese in girls was similar when determined by PBF or BMI. Hanoi had higher rates of adolescents being overweight or obese compared with Nam Dinh. CONCLUSION: PBF provides a more accurate body assessment for being overweight or obese in adolescents compared with BMI.
Adipose Tissue ; Adolescent ; Body Mass Index ; Classification ; Cross-Sectional Studies ; Electric Impedance ; Female ; Humans ; Obesity ; Overweight ; Prevalence ; Subcutaneous Fat ; Vietnam ; Weights and Measures

Sparganosis is a parasitic infestation caused by sparganum, a plerocercoid tapeworm larva of the genus Spirometra. Since the first case of human sparganosis reported in 1908, sparganosis has been a global disease, and is common in China, Japan, and Southeast Asian countries. Consumption of raw snakes, frogs, fish, or drinking contaminated beverages are sources of human infections. Human sparganosis usually manifests in subcutaneous fat in areas such as the abdomen, genitourinary tract, and limbs. Breast sparganosis cases are rare, representing less than 2% of total cases of human infections. Complete surgical extraction of the sparganum is the treatment of choice. Because of the rarity of the disease, clinical suspicion is vital to reach the diagnosis of breast sparganosis. Here we report 2 rare cases of breast sparganosis presenting with a painless breast lump, both treated with surgical excision and sparganum extraction.
Abdomen ; Asian Continental Ancestry Group ; Beverages ; Breast ; Cestoda ; China ; Diagnosis ; Drinking ; Extremities ; Humans ; Japan ; Larva ; Snakes ; Sparganosis ; Sparganum ; Spirometra ; Subcutaneous Fat

Patients with diabetes mellitus (DM) often suffer from diverse skin disorders, which might be attributable to skin barrier dysfunction. To explore the role of lipid alterations in the epidermis in DM skin disorders, we quantitated 49 lipids (34 ceramides, 14 free fatty acids (FFAs), and cholesterol) in the skin epidermis, liver, and kidneys of db/db mice, a Type 2 DM model, using UPLC-MS/MS. The expression of genes involved in lipid synthesis was also evaluated. With the full establishment of hyperglycemia at the age of 20 weeks, remarkable lipid enrichment was noted in the skin of the db/db mice, especially at the epidermis and subcutaneous fat bed. Prominent increases in the ceramides and FFAs (>3 fold) with short or medium chains ( Animals ; Ceramides ; Diabetes Mellitus ; Diabetes Mellitus, Type 2 ; Epidermis ; Fatty Acids, Nonesterified ; Humans ; Hyperglycemia ; Kidney ; Liver ; Mice ; Receptors, Cytoplasmic and Nuclear ; Skin ; Stearoyl-CoA Desaturase ; Subcutaneous Fat

OBJECTIVE: Abnormal body composition is an important modifiable risk factor in lung transplantation. Therefore, precise quantification of different body components, including muscle and fat, may play an important role in optimizing outcomes in lung transplant patients. The purpose of the study was to investigate the prognostic significance of muscle and subcutaneous fat mass measured on chest CT with regard to lung transplantation survival and other post-transplant outcomes. MATERIALS AND METHODS: The study population included 45 consecutive adult lung transplant recipients (mean age of 47.9 ± 12.1 years; 31 males and 14 females) between 2011 and 2017. Preoperative cross-sectional areas of muscle and subcutaneous fat were semi-automatically measured on axial CT images at the level of the 12th thoracic vertebra (T12). Additional normalized indexed parameters, adjusted for either height or weight, were obtained. Associations of quantitative parameters with survival and various other post-transplant outcomes were evaluated. RESULTS: Of the 45 patients included in the present study, 10 mortalities were observed during the follow-up period. Patients with relative sarcopenia (RS) classified based on height-adjusted muscle area with a cut-off value of 28.07 cm²/m² demonstrated worse postoperative survival (log-rank test, p = 0.007; hazard ratio [HR], 6.39:1) despite being adjusted for age, sex, and body mass index (HR, 8.58:1; p = 0.022). Weight-adjusted parameters of muscle area were negatively correlated with duration of ventilator support (R = −0.54, p < 0.001) and intensive care unit (ICU) stay (R = −0.33, p = 0.021). CONCLUSION: Patients with RS demonstrate worse survival after lung transplantation that those without RS. Additionally, quantitative parameters of muscles measured at the T12 level on chest CT were associated with the duration of post-lung transplant ventilator support and duration of stay in the ICU.
Adult ; Body Composition ; Body Mass Index ; Cohort Studies ; Follow-Up Studies ; Humans ; Intensive Care Units ; Lung ; Lung Transplantation ; Male ; Mortality ; Muscles ; Retrospective Studies ; Risk Factors ; Sarcopenia ; Spine ; Subcutaneous Fat ; Thorax ; Tomography, X-Ray Computed ; Transplant Recipients ; Ventilators, Mechanical