Changes in thyroid hormones predict weight regain in patients with obesity who undergo metabolic surgery.

AIM: To investigate the relationship between thyroid function and weight regain in patients with obesity after metabolic surgery. METHODS: This retrospective study enrolled 162 patients who underwent metabolic surgery. Correlations between decreases in thyroid hormone levels and changes in weight, waist circumference (WC) and the Chinese visceral adiposity index (CVAI) were assessed. Binary logistic regression and receiver operating characteristic (ROC) curves were used to identify predictors and clinically useful cut-off values, respectively. RESULTS: The levels of thyroid-stimulating hormone (TSH) and free triiodothyronine (FT3) decreased markedly at 1 year after surgery, as did weight, body mass index (BMI), triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, WC and CVAI. Decreases in TSH and FT3 after metabolic surgery were associated with changes in weight, BMI and CVAI. Binary logistic regression and ROC curve analyses confirmed that decreases in TSH can predict good weight loss after metabolic surgery to some extent. Finally, binary logistic regression and ROC curve analyses confirmed that changes in TSH can predict weight regain after metabolic surgery. CONCLUSIONS: Changes in TSH and FT3 after metabolic surgery were correlated with changes in weight and CVAI. Changes in thyroid hormones can predict weight regain in patients with obesity who underwent metabolic surgery.

Salt-Induced Hepatic Inflammatory Memory Contributes to Cardiovascular Damage Through Epigenetic Modulation of SIRT3.

BACKGROUND: High salt intake is the leading dietary risk factor for cardiovascular diseases. Although clinical evidence suggests that high salt intake is associated with nonalcoholic fatty liver disease, which is an independent risk factor for cardiovascular diseases, it remains elusive whether salt-induced hepatic damage leads to the development of cardiovascular diseases. METHODS: Mice were fed with normal or high-salt diet for 8 weeks to determine the effect of salt loading on liver histological changes and blood pressure, and salt withdrawal and metformin treatment were also conducted on some high-salt diet-fed mice. Adeno-associated virus 8, global knockout, or tissue-specific knockout mice were used to manipulate the expression of some target genes in vivo, including SIRT3 (sirtuin 3), NRF2 (NF-E2-related factor 2), and AMPK (AMP-activated protein kinase). RESULTS: Mice fed with a high-salt diet displayed obvious hepatic steatosis and inflammation, accompanied with hypertension and cardiac dysfunction. All these pathological changes persisted after salt withdrawal, displaying a memory phenomenon. Gene expression analysis and phenotypes of SIRT3 knockout mice revealed that reduced expression of SIRT3 was a chief culprit responsible for the persistent inflammation in the liver, and recovering SIRT3 expression in the liver effectively inhibits the sustained hepatic inflammation and cardiovascular damage. Mechanistical studies reveal that high salt increases acetylated histone 3 lysine 27 (H3K27ac) on SIRT3 promoter in hepatocytes, thus inhibiting the binding of NRF2, and results in the sustained inhibition of SIRT3 expression. Treatment with metformin activated AMPK, which inhibited salt-induced hepatic inflammatory memory and cardiovascular damage by lowering the H3K27ac level on SIRT3 promoter, and increased NRF2 binding ability to activate SIRT3 expression. CONCLUSIONS: This study demonstrates that SIRT3 inhibition caused by histone modification is the key factor for the persistent hepatic steatosis and inflammation that contributes to cardiovascular damage under high salt loading. Avoidance of excessive salt intake and active intervention of epigenetic modification may help to stave off the persistent inflammatory status that underlies high-salt-induced cardiovascular damage in clinical practice.

TRPC5 deletion in the central amygdala antagonizes high-fat diet-induced obesity by increasing sympathetic innervation.

Transient receptor potential channel 5 (TRPC5) is predominantly distributed in the brain, especially in the central amygdala (CeA), which is closely associated with pain and addiction. Although mounting evidence indicates that the CeA is related to energy homeostasis, the possible regulatory effect of TRPC5 in the CeA on metabolism remains unclear. Here, we reported that the expression of TRPC5 in the CeA of mice was increased under a high-fat diet (HFD). Specifically, the deleted TRPC5 protein in the CeA of mice using adeno-associated virus resisted HFD-induced weight gain, accompanied by increased food intake. Furthermore, the energy expenditure of CeA-specific TRPC5 deletion mice (TRPC5 KO) was elevated due to augmented white adipose tissue (WAT) browning and brown adipose tissue (BAT) activity. Mechanistically, deficiency of TRPC5 in the CeA boosted nonshivering thermogenesis under cold stimulation by stimulating sympathetic nerves, as the ß3-adrenoceptor (Adrb3) antagonist SR59230A blocked the effect of TRPC5 KO on this process. In summary, TRPC5 deletion in the CeA alleviated the metabolic deterioration of mice fed a HFD, and these phenotypic improvements were correlated with the increased sympathetic distribution and activity of adipose tissue.

Asprosin induces vascular endothelial-to-mesenchymal transition in diabetic lower extremity peripheral artery disease.

BACKGROUND: Altered adipokine secretion in dysfunctional adipose tissue facilitates the development of atherosclerotic diseases including lower extremity peripheral artery disease (PAD). Asprosin is a recently identified adipokine and displays potent regulatory role in metabolism, but the relationship between asprosin and lower extremity PAD remains uninvestigated. METHODS: 33 type 2 diabetes mellitus (T2DM) patients (DM), 51 T2DM patients with PAD (DM + PAD) and 30 healthy normal control (NC) volunteers were recruited and the blood samples were collected for detecting the circulatory asprosin level and metabolomic screening. RNA sequencing was performed using the aorta tissues from the type 2 diabetic db/db mice and human umbilical vein endothelial cells (HUVECs) were treated with asprosin to determine its impact on the endothelial-to-mesenchymal transition (EndMT). RESULTS: The circulating levels of asprosin in DM + PAD group were significantly higher than that of NC group and the DM group. Circulating asprosin level was remarkably negatively correlated with ankle-brachial index (ABI), even after adjusting for age, sex, body mass index (BMI) and other traditional risk factors of PAD. Logistic regression analysis revealed that asprosin is an independent risk factor for PAD and receiver-operator characteristic (ROC) curve determined a good sensitivity (74.5%) and specificity (74.6%) of asprosin to distinguish PAD. Data from metabolomics displayed a typical characteristics of de novo amino acid synthesis in collagen protein production by myofibroblasts in patients with PAD and activation of TGF-ß signaling pathway appeared in the aortic tissue of db/db mice. Asprosin directly induces EndMT in HUVECs in a TGF-ß-dependent manner as TGF-ß signaling pathway inhibitor SB431542 erased the promotional effect of asprosin on EndMT. CONCLUSIONS: Elevated circulatory asprosin level is an independent risk factor of lower extremity PAD and might serve as a diagnostic marker. Mechanistically, asprosin directly induces EndMT that participates in vascular injury via activation of TGF-ß signaling pathway. Trial registration This trial was registered at clinicaltrials.gov as NCT05068895.

Achieving blood pressure targets and antihypertensive effects through metabolic surgery in type 2 diabetes patients with hypertension.

AIMS: The effect of metabolic surgery compared with that of conventional therapy on target blood pressure (BP)and defined daily dose (DDD) of antihypertensive drugs in type 2 diabetes (T2DM) patients with hypertension remains unclear. This study aimed to investigate the differences in target BP and DDD between metabolic surgery and conventional treatment in T2DM patients with hypertension. MATERIALS AND METHODS: This was a prospective study of 535 diabetes patients who underwent metabolic surgery (n = 112) and medical treatment (n = 423). Changes in the target BP from baseline to every follow-up were analysed. RESULTS: Metabolic surgery decreased both office systolic and diastolic BP (DBP) and also significantly reduced ambulatory systolic BP (SBP; 132 ± 2 vs. 119 ± 1 mmHg, p < 0.0001), but not DBP (78 ± 1 vs. 76 ± 1 mmHg, p = 0.177). Patients maintained their SBP at <120 mmHg after 2 years (50% vs. 1.9%, p < 0.0001). Moreover, the rate of achieving the target SBP of 130 and 140 mmHg was also significantly higher in the surgery group, and this started from the initial 6 months after commencing treatment to the end of follow-up. The dosage (DDD: 1.44 ± 0.65 vs. 0.32 ± 0.05, p < 0.001) of antihypertensive medication was significantly decreased after metabolic surgery. Furthermore, metabolic surgery, but not medical treatment, markedly improved the risks of atherosclerotic cardiovascular disease. CONCLUSIONS: Metabolic surgery can effectively achieve the BP target and reduce the usage of antihypertensive medications as well as improve multiple metabolic dysfunction in T2DM patients with hypertension. This study provides an alternative approach to antagonize the metabolic related hypertension.

Determination of adrenal hypersecretion in primary Aldosteronism without aldosterone-production adenomas.

BACKGROUND: Primary aldosteronism (PA) is highly prevalent in hypertensive population. Adrenal vein sampling (AVS) is the only procedure to assess adrenal aldosterone hypersecretion in PA. PA patients without aldosterone-producing adenomas (APA) frequently have unilateral aldosterone hypersecretion (UAH). These patients could bear inappropriate adrenalectomy without AVS. This study aims to identify which clinical characteristics should be recommended to perform AVS in these PA patients. METHODS: This study was performed from January 2018 to July 2019 at a center for hypertension and metabolic diseases. Adrenal computed tomography (CT) scan, biochemical evaluation, and AVS were performed. RESULTS: Total 141 patients were included in this study. Aldosterone to renin ratio (ARR) after confirmatory test is highly associated with adrenal laterality. The specificity of ARR > 10 (ng/dL)/(mU/L) after confirmatory test is 100%. After confirmatory test, patients with ARR > 10 (ng/dL)/(mU/L) had higher plasma aldosterone concentration and incidences of ischemic heart diseases and renal damage(p < 0.05). CONCLUSIONS: After confirmatory tests, ARR > 10 (ng/dL)/(mU/L) indicates adrenal laterality, with increasingly cardiorenal damage in PA patients without APA. Thus, AVS should be recommended in these patients before surgery. TRIAL REGISTRATION: NCT03398785 , Date of Registration: December 24, 2017.

The role of adipose TRP channels in the pathogenesis of obesity.

The prevalence of obesity is continuously increasing worldwide. Transient receptor potential (TRP) channels constitute a family of nonselective cation channels that are ubiquitously expressed in mammalian tissues, including adipose tissue. Although TRP channels might be regarded as therapeutic targets for obesity due to the inhibitory effects of their agonists on body weight and adiposity, the exact role of TRP channels in the development of obesity by modulating the function of adipose tissue has not been systemically reviewed. Multiple TRP channels are present in adipocytes and are involved in diverse aspects of cellular function, including differentiation and maturation of white adipose tissue (WAT), browning of WAT and thermogenesis of brown adipose tissue (BAT). Most of these functions are mediated by alterations in intracellular Ca2+ levels or subcellular Ca2+ signaling pathway. TRP channels influence intracellular Ca2+ dynamics through directly mediating Ca2+ entry (TRPVs and others) or store-operated mechanisms (TRPCs). Intracellular Ca2+ displays a biphasic effect on regulation adipocyte behaviors depending on the differentiation stage, which may account for the different roles of individual TRP channels in regulation of adiposity. This review emphasizes the contribution of TRP channels to obesity and provide an in-depth discussion on the complexity of their mechanism of actions.

Activation of TRPV1 channel by dietary capsaicin improves visceral fat remodeling through connexin43-mediated Ca2+ influx.

BACKGROUND: The prevalence of obesity has dramatically increased worldwide and has attracted rising attention, but the mechanism is still unclear. Previous studies revealed that transient receptor potential vanilloid 1 (TRPV1) channels take part in weight loss by enhancing intracellular Ca2+ levels. However, the potential mechanism of the effect of dietary capsaicin on obesity is not completely understood. Ca2+ transfer induced by connexin43 (Cx43) molecules between coupled cells takes part in adipocyte differentiation. Whether TRPV1-evoked alterations in Cx43-mediated adipocyte-to-adipocyte communication play a role in obesity is unknown. MATERIALS AND METHODS: We investigated whether Cx43 participated in TRPV1-mediated adipocyte lipolysis in cultured 3T3-L1 preadipocytes and visceral adipose tissues from humans and wild-type (WT) and TRPV1-deficient (TRPV1-/-) mice. RESULTS: TRPV1 and Cx43 co-expressed in mesenteric adipose tissue. TRPV1 activation by capsaicin increased the influx of Ca2+ in 3T3-L1 preadipocytes and promoted cell lipolysis, as shown by Oil-red O staining. These effects were deficient when capsazepine, a TRPV1 antagonist, and 18 alpha-glycyrrhetinic acid (18α-GA), a gap-junction inhibitor, were administered. Long-term chronic dietary capsaicin reduced the weights of perirenal, mesenteric and testicular adipose tissues in WT mice fed a high-fat diet. Capsaicin increased the expression levels of p-CaM, Cx43, CaMKII, PPARδ and HSL in mesenteric adipose tissues from WT mice fed a high-fat diet, db/db mice, as well as obese humans, but these effects of capsaicin were absent in TRPV1-/- mice. Long-term chronic dietary capsaicin decreased the body weights and serum lipids of WT mice, but not TRPV1-/- mice, fed a high-fat diet. CONCLUSION: This study demonstrated that capsaicin activation of TRPV1-evoked increased Ca2+ influx in Cx43-mediated adipocyte-to-adipocyte communication promotes lipolysis in both vitro and vivo. TRPV1 activation by dietary capsaicin improves visceral fat remodeling through the up-regulation of Cx43.

Diabetes mellitus is associated with early chronic venous disorder of the lower extremities in Chinese patients with cardiometabolic risk factors.

BACKGROUND: Metabolic syndrome has received great attention because it poses a potential cardiovascular hazard, which increases the risk of lower extremity atherosclerosis. However, the relationship between the components of metabolic syndrome and the onset of chronic venous disorder of the lower extremities remains unexplained. METHODS: This study investigated the characteristics of cardiometabolic risk factors of early chronic venous disorder of the lower extremities in subjects with cardiometabolic risk. The characteristics of risk factors and diabetes-related complications in diabetic patients with early chronic venous disorder of the lower extremities were also investigated. In addition, the association between early chronic venous disorder and atherosclerosis of the lower extremities was analysed. The study examined 782 subjects with cardiometabolic risk factors, including obesity, hypertension, diabetes mellitus and dyslipidaemia. Lower extremity venous function was measured by digital photoplethysmography. RESULTS: Women had a higher prevalence of early chronic venous disorder than did men (p < 0.01). Male subjects with early chronic venous disorder had a higher systolic blood pressure than those with normal venous function (p < 0.01), and female subjects with early chronic venous disorder had a higher fasting plasma glucose level than did controls (p < 0.05). The prevalence of diabetes mellitus is also significantly higher in female patients with early chronic venous disorder (p = 0.000). Diabetic patients with early chronic venous disorder not only had higher fasting plasma glucose and total cholesterol levels but also had more serious macrovascular complications than the control group. The independent risk factors of early chronic venous disorder in female subjects with cardiometabolic risks were age and fasting plasma glucose in men it was only age Women face a two times greater risk than men. The independent risk factors of early chronic venous disorder in diabetic patients were age, gender, HbA1c and triglyceride levels Women had an almost 12 times greater risk of early chronic venous disorder than men. Among the diabetic patients, the prevalence of early chronic venous disorder did not differ by ankle-brachial index. CONCLUSION: Female subjects with cardiometabolic risk factors or female diabetic patients face a greater risk of early chronic venous disorder than do male subjects. Diabetic patients with early chronic venous disorder had more serious macrovascular complications than did the controls, and the early venous function was found to be correlated with the blood glucose level and triglyceride status.

Rationality and implication of catheter-based adrenal ablation for bilateral primary aldosteronism.

Mineralocorticoid receptor antagonists (MRAs) for bilateral primary aldosteronism (PA) are the mainstay option recommended by guidelines, but poor compliance occurs due to numerous side effects. We aimed to examine whether catheter-based adrenal ablation could be an alternative treatment for bilateral PA.644 PA patients were included from a total of 6054 hypertensive patients. Adrenal CT scan and adrenal venous sampling (AVS) were both performed for PA subtype classification. Clinical and biochemical outcomes were assessed at 6 months after treatment according to the Primary Aldosteronism Surgical Outcome (PASO) criteria.93 patients with PA were recruited to be treated by adrenal ablation, including 25 bilateral PA and 68 unilateral PA according to AVS results. Office SBP and DBP significantly decreased from baseline levels, serum potassium levels increased and ARR significantly decreased (p < 0.01) in both the bilateral and unilateral groups. In the bilateral group, complete, partial and absent clinical success was achieved in 6 (24.0%), 11 (44.0%) and 8(32.0%) patients, respectively. In the unilateral group, complete, partial and absent clinical success was achieved in 12 (17.6%), 37 (54.4%), and 19 (27.9%) patients, respectively. The numbers of patients achieving complete, partial, and absent biochemical success were 15 (60.0%), 6 (24.0%), and 4 (16.0%), respectively, in the bilateral group versus 37 (54.4%), 9 (13.2%), and 22 (32.3%), respectively, in the unilateral group. In conclusion, we provide evidence for the beneficial outcomes of unilateral adrenal ablation for patients with bilateral PA. Our findings provide insight into an alternative option for patients with bilateral excess aldosterone.

Sodium-glucose exchanger 2 inhibitor canagliflozin promotes mitochondrial metabolism and alleviates salt-induced cardiac hypertrophy via preserving SIRT3 expression.

INTRODUCTION: Excess salt intake is not only an independent risk factor for heart failure, but also one of the most important dietary factors associated with cardiovascular disease worldwide. Metabolic reprogramming in cardiomyocytes is an early event provoking cardiac hypertrophy that leads to subsequent cardiovascular events upon high salt loading. Although SGLT2 inhibitors, such as canagliflozin, displayed impressive cardiovascular health benefits, whether SGLT2 inhibitors protect against cardiac hypertrophy-related metabolic reprogramming upon salt loading remain elusive. OBJECTIVES: To investigate whether canagliflozin can improve salt-induced cardiac hypertrophy and the underlying mechanisms. METHODS: Dahl salt-sensitive rats developed cardiac hypertrophy by feeding them an 8% high-salt diet, and some rats were treated with canagliflozin. Cardiac function and structure as well as mitochondrial function were examined. Cardiac proteomics, targeted metabolomics and SIRT3 cardiac-specific knockout mice were used to uncover the underlying mechanisms. RESULTS: In Dahl salt-sensitive rats, canagliflozin showed a potent therapeutic effect on salt-induced cardiac hypertrophy, accompanied by lowered glucose uptake, reduced accumulation of glycolytic end-products and improved cardiac mitochondrial function, which was associated with the recovery of cardiac expression of SIRT3, a key mitochondrial metabolic regulator. Cardiac-specific knockout of SIRT3 not only exacerbated salt-induced cardiac hypertrophy but also abolished the therapeutic effect of canagliflozin. Mechanistically, high salt intake repressed cardiac SIRT3 expression through a calcium-dependent epigenetic modifications, which could be blocked by canagliflozin by inhibiting SGLT1-mediated calcium uptake. SIRT3 improved myocardial metabolic reprogramming by deacetylating MPC1 in cardiomyocytes exposed to pro-hypertrophic stimuli. Similar to canagliflozin, the SIRT3 activator honokiol also exerted therapeutic effects on cardiac hypertrophy. CONCLUSION: Cardiac mitochondrial dysfunction caused by SIRT3 repression is a critical promotional determinant of metabolic pattern switching underlying salt-induced cardiac hypertrophy. Improving SIRT3-mediated mitochondrial function by SGLT2 inhibitors-mediated calcium handling would represent a therapeutic strategy against salt-related cardiovascular events.

Quantitative model for assessment of lower-extremity perfusion in patients with diabetes.

BACKGROUND: Although diabetic and atherosclerotic vascular diseases have different pathophysiological mechanisms, the screening methods currently used for diabetic lower-extremity vascular diseases are mainly based on the evaluation methods used for atherosclerotic vascular diseases. Thus, assessment of microvascular perfusion is of great importance in early detection of lower-extremity ischemia in diabetes. PURPOSE: This cross-sectional study aimed to develop a quantitative model for evaluating lower-extremity perfusion. METHODS: We recruited 57 participants (14 healthy participants and 43 diabetes patients, of which 16 had lower-extremity arterial disease [LEAD]). All participants underwent technetium-99 m sestamibi (99mTc-MIBI) scintigraphy and ankle-brachial index (ABI) examination. We derived two key perfusion kinetics indices named activity perfusion index (API) and basal perfusion index (BPI). This study was registered in ClinicalTrials.gov (URL: https://www. CLINICALTRIALS: gov, NCT02752100). RESULTS: The estimated limb perfusion values in our lower-extremity perfusion assessment (LEPA) model showed excellent consistency with the actual measured data. Diabetes patients showed reduced lower-extremity perfusion in comparison with the control group (BPI: 106.21 ± 11.99 vs. 141.56 ± 17.38, p < 0.05; API: 12.34 ± 3.27 vs. 14.56 ± 3.12, p < 0.05). Using our model, the reductions in lower-extremity perfusion could be detected early in approximately 96.30% of diabetes patients. Patients with LEAD showed more severe reductions in lower-extremity perfusion than diabetes patients without LEAD (BPI: 47.85 ± 20.30 vs. 106.21 ± 11.99, p < 0.05; API: 7.06 ± 1.70 vs. 12.34 ± 3.27, p < 0.05). Discriminant analysis using API and BPI could successfully screen all diabetes patients with LEAD with a sensitivity of 100% and specificity of 80.77%. CONCLUSIONS: We established a LEPA model that could successfully assess lower-extremity microvascular perfusion in diabetes patients. This model has important application value for the recognition of early-stage LEAD in patients with diabetes.

Catheter-based adrenal ablation: an alternative therapy for patients with aldosterone-producing adenoma.

Unilateral adrenalectomy is the standard treatment for patients with aldosterone-producing adenoma (APA), but it lacks an option for patients with APA who refuse or are not suitable for surgery. In this study, we studied whether catheter-based adrenal ablation for APA is comparable to adrenalectomy. A total of 2185 hypertensive patients were screened, and 112 patients with APA were recruited and counselled on the treatment options. Fifty-two patients opted for catheter-based adrenal ablation, and 60 opted for adrenalectomy. Clinical and biochemical outcomes were assessed at 6 months after treatment. Factors associated with hypertension remission and the advantages and limitations of this approach were evaluated. According to the primary aldosteronism surgical outcome (PASO) criteria, complete and partial clinical success was achieved in 21 (40.4%) and 23 (44.2%) patients in the ablation group vs. 33 (55.0%) and 23 (38.3%) patients in the adrenalectomy group, respectively. Complete and partial biochemical success was achieved in 30 (57.7%) and 17 (32.7%) patients in the ablation group vs. 51 (85.0%) and 5 (8.3%) patients in the adrenalectomy group, respectively. The complete clinical success rate was not (P > 0.05), but the complete biochemical success rate was significantly different between the two groups (P < 0.01). Factors associated with adrenal ablation-mediated hypertension remission were hypertension duration and serum potassium level at baseline. Compared with surgery, adrenal ablation requires a shorter operating time and time to resume physical activity. Catheter-based adrenal ablation may be an alternative and feasible option for APA patients unwilling to receive surgical treatment.

Mitochondrial dysfunction caused by SIRT3 inhibition drives proinflammatory macrophage polarization in obesity.

OBJECTIVE: Metabolic reprogramming is a main feature of proinflammatory macrophage polarization, a process that leads to inflammation in dysfunctional adipose tissue. Therefore, the study aim was to explore whether sirtuin 3 (SIRT3), a mitochondrial deacetylase, participates in this pathophysiological process. METHODS: Macrophage-specific Sirt3 knockout (Sirt3-MKO) mice and wild-type littermates were treated with a high-fat diet. Body weight, glucose tolerance, and inflammation were evaluated. Bone marrow-derived macrophages and RAW264.7 cells were treated with palmitic acid to explore the mechanism of SIRT3 on inflammation. RESULTS: The expression of SIRT3 was significantly repressed in both bone marrow-derived macrophages and adipose tissue macrophages in mice fed with a high-fat diet. Sirt3-MKO mice exhibited accelerated body weight and severe inflammation, accompanied with reduced energy expenditure and worsened glucose metabolism. In vitro experiments showed that SIRT3 inhibition or knockdown exacerbated palmitic acid-induced proinflammatory macrophage polarization, whereas SIRT3 restoration displayed opposite effects. Mechanistically, SIRT3 deficiency resulted in hyperacetylation of succinate dehydrogenase that led to succinate accumulation, which suppressed the transcription of Kruppel-like factor 4 via increasing histone methylation on its promoter, thus evoking proinflammatory macrophages. CONCLUSIONS: This study emphasizes an important preventive role of SIRT3 in macrophage polarization and implies that SIRT3 is a promising therapeutic target for obesity.

Cx43 acts as a mitochondrial calcium regulator that promotes obesity by inducing the polarization of macrophages in adipose tissue.

Metabolic reprogramming of macrophages initiates the polarization of pro-inflammatory macrophages that exacerbates adipocyte dysfunction and obesity. The imbalance of mitochondrial Ca2+ homeostasis impairs mitochondrial function and promotes inflammation. Connexin 43 (Cx43), a ubiquitous gap junction protein, has been demonstrated to regulate intracellular Ca2+ homeostasis. Here we explored whether macrophage Cx43 affects the obesity process by regulating the polarization of macrophage. HFD treatment induced obesity and exacerbated macrophages infiltration with upregulation of macrophages Cx43. Macrophage-specific knockout of Cx43 reduced HFD-induced obesity by alleviating inflammation in adipose tissue, with less pro-inflammatory M1 macrophage infiltration. Consistently, inhibition or knockdown of Cx43 improved palmitic acid (PA) induced mitochondrial dysfunction, as indicated by improved oxidative phosphorylation (OXPHOS), reduced formation of mitochondria-associated membranes (MAM) and mitochondrial Ca2+ overload. Mechanistically, Cx43 interacted with the mitochondrial Ca2+ uniporter (MCU) and knockdown of Cx43 alleviated PA-induced succinate dehydrogenase (SDH) oxidation by lowering MCU-mediated mitochondrial Ca2+ uptake, which then, promoting the polarization of pro-inflammatory M1 macrophages. Thus, this study identified Cx43 as a mitochondrial Ca2+ regulator that aggravates obesity via promoting macrophages polarized to M1 pro-inflammatory phenotype and suggests that Cx43 might be a promising therapeutic target antagonizing obesity.

TRPV1 activation prevents nonalcoholic fatty liver through UCP2 upregulation in mice.

Nonalcoholic fatty liver is characterized by the fatty deformation and lipid deposition of hepatic parenchymal cells that are associated with cardiometabolic diseases. In this study, we report the effect of capsaicin on its receptor, transient receptor potential vanilloid 1 (TRPV1) cation channel, in preventing fatty liver formation. Functional TRPV1 has been detected in hepatocytes and liver tissues. TRPV1 activation by capsaicin reduced lipid accumulation and triglyceride level in the liver from wild-type (WT) mice. However, these effects were absent in the liver from TRPV1(-/-) mice. Chronic dietary capsaicin increased the hepatic uncoupling protein 2 (UCP2) expression in WT but not in TRPV1(-/-) mice (P < 0.01). We conclude that TRPV1 long-time activation might prevent high-fat diet-induced fatty liver in mice through upregulation of hepatic UCP2. Dietary capsaicin may represent a promising intervention in populations at high risk for fatty liver.

Atorvastatin attenuates TNF-α-induced increase of glucose oxidation through PGC-1α upregulation in cardiomyocytes.

Recent studies have shown that atorvastain has anti-inflammatory effect and can prevent cardiac hypertrophy. The development of cardiac hypertrophy and dysfunction is associated with an increase in cardiac glucose utilization. In this study, we investigated the effect of atorvastatin on glucose oxidation in tumor necrosis factor α (TNF-α)-stimulated cardiomyocytes (H9c2 cells) and the potential role of peroxisome proliferation-activated receptor coactivator 1α (PGC-1α) in this effect. Exposure of H9c2 cells to TNF-α inhibited the expressions of PGC-1α, pyruvate dehydrogenase kinase 4, and carnitine palmityl transferase 1 and induced a significant increase in glucose oxidation rate. However, the effects of TNF-α were significantly reversed by atorvastatin. Selective silence of PGC-1α in H9c2 cells resulted in the downregulation of pyruvate dehydrogenase kinase 4 and carnitine palmityl transferase 1 and further increased the TNF-α-induced glucose oxidation. Interestingly, the effect of atorvastatin on PGC-1α was almost abolished by mevalonate and partially by farnesol but not by geranylgeraniol. In conclusion, atorvastatin inhibits TNF-α-induced glucose oxidation through PGC-1α upregulation in cardiomyocytes, which might be associated with the regulation of isoprenoid metabolites.

Adult-onset Still's disease: how to make a diagnosis in an atypical case.

Adult-onset Still's disease (AOSD) is a complicated multi-systemic inflammatory disease, the main features of which are high spiking fever, evanescent rash, polyarthralgia, lymphadenopathy, hepatosplenomegaly and leukocytosis. The pathogenesis and etiology of AOSD are still unknown. We report a case of atypical AOSD presenting with only arthralgia, fever, lymphadenopathy, slightly elevated serum C-reactive protein and ferritin levels and a slightly elevated erythrocyte sedimentation rate; these signs and symptoms did not fulfill the proposed diagnostic criteria of both Cush and Yamaguchi. After exclusion of other likely diagnoses, a diagnosis of atypical AOSD was made, and a low dose of corticosteroids was effective in resolving all of the patient's symptoms. More clinical practice and research are needed to determine pathogenesis and etiology of AOSD and to amend the diagnostic criteria to include such atypical cases.

Assessment of sublingual microcirculation for the screening of diabetic nephropathy.

OBJECTIVE: To investigate the potential of employing sublingual microcirculation as an early noninvasive screening technique for diabetic nephropathy (DN). RESEARCH DESIGN AND METHODS: We recruited 89 patients with type 2 diabetes mellitus (T2DM) and 41 healthy subjects in this cross-sectional observational study. All participants underwent fluorescein fundus angiography, vibration perception testing, 10 g (Semmes-Weinstein) monofilament examination, nerve conduction velocity, and 24-h urine microalbumin determination. HbA1c, fasting plasma glucose, blood lipid, and estimated glomerular filtration rate(eGFR) were measured. Sublingual microcirculatory images were captured using side-stream dark-field (SDF) microcirculation microscopy, and total and perfused vascular density (TVD and PVD) were calculated. RESULTS: The sublingual microcirculatory parameters denoting microvascular density and perfusion were negatively correlated with both fasting plasma glucose (TVD, r = - 0.316, P < 0.001; PVD, r = - 0.350, P < 0.001; PPV, r = - 0.279, P = 0.001) and HbA1c (TVD, r = - 0.367, P < 0.001; PVD, r = - 0.423, P < 0.001; PPV, r = - 0.399, P < 0.001). Diabetes patients already had a reduction in sublingual microcirculation compared with healthy control, and more severe reductions in TVD (7.07 ± 1.64 vs. 9.67 ± 1.94 mm/mm2, P < 0.001) and PVD (5.88 ± 1.82 vs. 8.64 ± 2.46 mm/mm2, P < 0.001) were found in those diabetes patients developed microvascular complications. Sublingual microcirculation impairment was accompanied with higher urinary albumin creatinine ratio (UACR). Receiver operating characteristic (ROC) analysis showed that TVD (area under the curve, AUC = 0.890 [0.836 0.944], P < 0.001) and PVD (AUC = 0.883 [0.826, 0.940], P < 0.001) could be indicators for DN screening. We derived a combined predictor index (CPI) considering both TVD and PVD for screening DN, and both the AUC (0.892, [0.838 0.945], P < 0.001) and cutoff point of 11.30 mm/mm2 showed great improvement (sensitivity: 95.5%, specificity: 67.4%). CONCLUSIONS: Diabetes patients experienced impaired sublingual microcirculation, which was closely correlated with UACR. Sublingual microcirculation monitoring could be used for the noninvasive early detection of DN.