Loss of renal tubular G9a benefits acute kidney injury by lowering focal lipid accumulation via CES1.

Surgery-induced renal ischemia and reperfusion (I/R) injury and nephrotoxic drugs like cisplatin can cause acute kidney injury (AKI), for which there is no effective therapy. Lipid accumulation is evident following AKI in renal tubules although the mechanisms and pathological effects are unclear. Here, we report that Ehmt2-encoded histone methyltransferase G9a is upregulated in patients and mouse kidneys after AKI. Renal tubular specific knockout of G9a (Ehmt2Ksp ) or pharmacological inhibition of G9a alleviates lipid accumulation associated with AKI. Mechanistically, G9a suppresses transcription of the lipolytic enzyme Ces1; moreover, G9a and farnesoid X receptor (FXR) competitively bind to the same promoter regions of Ces1. Ces1 is consistently observed to be downregulated in the kidney of AKI patients. Pharmacological inhibition of Ces1 increases lipid accumulation, exacerbates renal I/R-injury and eliminates the beneficial effects on AKI observed in Ehmt2Ksp mice. Furthermore, lipid-lowering atorvastatin and an FXR agonist alleviate AKI by activating Ces1 and reducing renal lipid accumulation. Together, our results reveal a G9a/FXR-Ces1 axis that affects the AKI outcome via regulating renal lipid accumulation.

Histone demethylase UTX aggravates acetaminophen overdose induced hepatotoxicity through dual mechanisms.

Acetaminophen (APAP) overdose is a major cause of acute liver failure, while the underlying mechanisms of APAP hepatotoxicity are not fully understood. Recently, emerging evidence suggests that epigenetic enzymes play roles in APAP-induced liver injury. Here, we found that Utx (ubiquitously transcribed tetratricopeptide repeat, X chromosome, also known as KDM6A), a X-linked histone demethylase which removes the di- and tri-methyl groups from histone H3K27, was markedly induced in the liver of APAP-overdosed female mice. Hepatic deletion of Utx suppressed APAP overdose-induced hepatotoxicity in female but not male mice. RNA-sequencing analysis suggested that Utx deficiency in female mice upregulated antitoxic phase II conjugating enzymes, including sulfotransferase family 2 A member 1 (Sult2a1), thus reduces the amount of toxic APAP metabolites in injured liver; while Utx deficiency also alleviated ER stress through downregulating transcription of ER stress genes including Atf4, Atf3, and Chop. Mechanistically, Utx promoted transcription of ER stress related genes in a demethylase activity-dependent manner, while repressed Sult2a1 expression through mediating H3K27ac levels independent of its demethylase activity. Moreover, overexpression of Sult2a1 in the liver of female mice rescued APAP-overdose induced liver injury. Together, our results indicated a novel UTX-Sult2a1 axis for the prevention or treatment of APAP-induced liver injury.

Histone demethylase UTX is a therapeutic target for diabetic kidney disease.

KEY POINTS: Diabetic kidney disease (DKD) is a major complication of diabetes. We found that UTX (ubiquitously transcribed tetratricopeptide repeat on chromosome X, also known as KDM6A), a histone demethylase, was upregulated in the renal mesangial and tubular cells of diabetic mice and DKD patients. In cultured renal mesangial and tubular cells, UTX overexpression promoted palmitic acid-induced elevation of inflammation and DNA damage, whereas UTX knockdown or GSK-J4 treatment showed the opposite effects. We found that UTX demethylase activity-dependently regulated the transcription of inflammatory genes and apoptosis; moreover, UTX bound with p53 and p53-dependently exacerbated DNA damage. Administration of GSK-J4, an H3K27 demethylase inhibitor, ameliorated the diabetes-induced renal abnormalities in db/db mice, an animal model of type 2 diabetes. These results revealed the possible mechanisms underlying the regulation of histone methylation in DKD and suggest UTX as a potential therapeutic target for DKD. ABSTRACT: Diabetic kidney disease (DKD) is a microvascular complication of diabetes and the leading cause of end-stage kidney disease worldwide without effective therapy available. UTX (ubiquitously transcribed tetratricopeptide repeat on chromosome X, also known as KDM6A), a histone demethylase that removes the di- and tri-methyl groups from histone H3K27, plays important biological roles in gene activation, cell fate control and life span regulation in Caenorhabditis elegans. In the present study, we report upregulated UTX in the kidneys of diabetic mice and DKD patients. Administration of GSK-J4, an H3K27 demethylase inhibitor, ameliorated the diabetes-induced renal dysfunction, abnormal morphology, inflammation, apoptosis and DNA damage in db/db mice, comprising an animal model of type 2 diabetes. In cultured renal mesanglial and tubular cells, UTX overexpression promoted palmitic acid induced elevation of inflammation and DNA damage, whereas UTX knockdown or GSK-J4 treatment showed the opposite effects. Mechanistically, we found that UTX demethylase activity-dependently regulated the transcription of inflammatory genes; moreover, UTX bound with p53 and p53-dependently exacerbated DNA damage. Collectively, our results suggest UTX as a potential therapeutic target for DKD.

Chemical constituents from Sophora tonkinensis and their glucose transporter 4 translocation activities.

Bioassay-guided phytochemical investigation of the EtOAc fraction (ST-EtOAc) from the roots of Sophora tonkinensis resulted in the isolation of a new compound 6aR,11aR-1-hydroxy-4-isoprenyl-maackiain (1), along with 12 known compounds (2-13). The structure of the new compound was established by 1D and 2D NMR, MS data and circular dichroism analysis. Polyprenylated flavonoids 6-9 and 11-13 increased GLUT-4 translocation by the range of 1.35-2.75 folds. Sophoranone (8) exerted the strongest activity with 2.75 folds GLUT-4 translocation enhancement at the concentration of 10µM. This is the first report of the GLUT-4 translocation activity of the plant Sophora tonkinensis.

Depsidone and xanthones from Garcinia xanthochymus with hypoglycemic activity and the mechanism of promoting glucose uptake in L6 myotubes.

Garcinia xanthochymus is a widely used folk medicine in southwestern China. Previous studies indicated it possesses potential anti-diabetic activities both in vitro (Fu et al., 2014; Nguyen et al., 2017) and in vivo (Shivanand et al., 2017). To discover bioactive ingredients from it and unveil their mechanism of action against diabetes, the present study was designed to isolate constituents from extract of G. xanthochymus, determine their structures, screen their activities and investigate mechanism of action of the active substances. Twenty compounds including a new depsidone named garciniadepsidone A (20) and 19 known xanthones were obtained. All of them were screened to discover the active compounds with anti-diabetic activities. Finally, three xanthones including 12b-hydroxy-des-d-garcigerrin (5), 1,2,5,6-tretrahydroxy-4-(1,1-dimethyl-2-propenyl)-7-(3-methyl-2-butenyl) xanthone (13) and 1,5,6-trihydroxy-7,8-di(3-methyl-2-butenyl)-6',6'-dimethylpyrano (2',3':3,4) xanthone (18) were found to be able to significantly stimulate the glucose uptake in the skeleton muscle cells. The effects of the three compounds were comparable to those of insulin and metformin. Based on molecular mechanistic study, it was found that both of compound 5 and 13 promoted glucose uptake by activating phosphatidylinositol-3 kinase (PI3K)/the serine/threonine kinase protein kinase B (PKB/Akt) signaling pathway and AMP-activated protein kinase (AMPK) signaling pathway, resulting in the translocation of GLUT4 in L6 myotubes without affecting the expression of GLUT4. Compound 5 and 13 have great potential to be developed as promising leads to target diabetes.

Chloroquine Increases Glucose Uptake via Enhancing GLUT4 Translocation and Fusion with the Plasma Membrane in L6 Cells.

BACKGROUND/AIMS: Chloroquine can induce an increase in the cellular uptake of glucose; however, the underlying mechanism is unclear. METHODS: In this study, translocation of GLUT4 and intracellular Ca2+ changes were simultaneously observed by confocal microscope in L6 cells stably over-expressing IRAP-mOrange. The GLUT4 fusion with the plasma membrane (PM) was traced using HA-GLUT4-GFP. Glucose uptake was measured using a cell-based glucose uptake assay. GLUT4 protein was detected by Western blotting and mRNA level was detected by RT-PCR. RESULTS: We found that chloroquine induced significant increases in glucose uptake, glucose transporter GLUT4 translocation to the plasma membrane (GTPM), GLUT4 fusion with the PM, and intracellular Ca2+ in L6 muscle cells. Chloroquine-induced increases of GTPM and intracellular Ca2+ were inhibited by Gallein (Gßx03B3; inhibitor) and U73122 (PLC inhibitor). However, 2-APB (IP3R blocker) only blocked the increase in intracellular Ca2+ but did not inhibit GTPM increase. These results indicate that chloroquine, via the Gßx03B3;-PLC-IP3-IP3R pathway, induces elevation of Ca2+, and this Ca2+ increase does not play a role in chloroqui-ne-evoked GTPM increase. However, GLUT4 fusion with the PM and glucose uptake were significantly inhibited with BAPTA-AM. This suggests that Ca2+ enhances GLUT4 fusion with the PM resulting in glucose uptake increase. CONCLUSION: Our data indicate that chloroquine via Gßx03B3;-PLC-IP3-IP3R induces Ca2+ elevation, which in turn promotes GLUT4 fusion with the PM. Moreover, chloroquine can enhance GLUT4 trafficking to the PM. These mechanisms eventually result in glucose uptake increase in control and insulin-resistant L6 cells. These findings suggest that chloroquine might be a potential drug for improving insulin tolerance in diabetic patients.

Regulation of the Function and Expression of EpCAM.

The epithelial cell adhesion molecule (EpCAM) is a single transmembrane protein on the cell surface. Given its strong expression on epithelial cells and epithelial cell-derived tumors, EpCAM has been identified as a biomarker for circulating tumor cells (CTCs) and exosomes and a target for cancer therapy. As a cell adhesion molecule, EpCAM has a crystal structure that indicates that it forms a cis-dimer first and then probably a trans-tetramer to mediate intercellular adhesion. Through regulated intramembrane proteolysis (RIP), EpCAM and its proteolytic fragments are also able to regulate multiple signaling pathways, Wnt signaling in particular. Although great progress has been made, increasingly more findings have revealed the context-specific expression and function patterns of EpCAM and their regulation processes, which necessitates further studies to determine the structure, function, and expression of EpCAM under both physiological and pathological conditions, broadening its application in basic and translational cancer research.

Tet1 deficiency exacerbates oxidative stress in acute kidney injury by regulating superoxide dismutase.

Rationale: Increased methylation of key genes has been observed in kidney diseases, suggesting that the ten-eleven translocation (Tet) methyl-cytosine dioxygenase family as well as 5mC oxidation may play important roles. As a member of the Tet family, the role of Tet1 in acute kidney injury (AKI) remains unclear. Methods: Tet1 knockout mice, with or without tempol treatment, a scavenger of reactive oxygen species (ROS), were challenged with ischemia and reperfusion (I/R) injury or unilateral ureteral obstruction (UUO) injury. RNA-sequencing, Western blotting, qRT-PCR, bisulfite sequencing, chromatin immunoprecipitation, immunohistochemical staining, and dot blot assays were performed. Results: Tet1 expression was rapidly upregulated following I/R or UUO injury. Moreover, Tet1 knockout mice showed increased renal injury and renal cell death, increased ROS accumulation, G2/M cell cycle arrest, inflammation, and fibrosis. Severe renal damage in injured Tet1 knockout mice was alleviated by tempol treatment. Mechanistically, Tet1 reduced the 5mC levels in an enzymatic activity-dependent manner on the promoters of Sod1 and Sod2 to promote their expression, thus lowering injury-induced excessive ROS and reducing I/R or UUO injury. Conclusions: Tet1 plays an important role in the development of AKI by promoting SOD expression through a DNA demethylase-dependent mechanism.

A renal YY1-KIM1-DR5 axis regulates the progression of acute kidney injury.

Acute kidney injury (AKI) exhibits high morbidity and mortality. Kidney injury molecule-1 (KIM1) is dramatically upregulated in renal tubules upon injury, and acts as a biomarker for various renal diseases. However, the exact role and underlying mechanism of KIM1 in the progression of AKI remain elusive. Herein, we report that renal tubular specific knockout of Kim1 attenuates cisplatin- or ischemia/reperfusion-induced AKI in male mice. Mechanistically, transcription factor Yin Yang 1 (YY1), which is downregulated upon AKI, binds to the promoter of KIM1 and represses its expression. Injury-induced KIM1 binds to the ECD domain of death receptor 5 (DR5), which activates DR5 and the following caspase cascade by promoting its multimerization, thus induces renal cell apoptosis and exacerbates AKI. Blocking the KIM1-DR5 interaction with rationally designed peptides exhibit reno-protective effects against AKI. Here, we reveal a YY1-KIM1-DR5 axis in the progression of AKI, which warrants future exploration as therapeutic targets.

Tubular Elabela-APJ axis attenuates ischemia-reperfusion induced acute kidney injury and the following AKI-CKD transition by protecting renal microcirculation.

Rationale: Ischemia-reperfusion injury (I/R) is a common cause of acute kidney injury (AKI). Post-ischemic recovery of renal blood supply plays an important role in attenuating injury. Exogenous application of elabela (ELA) peptides has been demonstrated by us and others to alleviate AKI, partly through its receptor APJ. However, the endogenous role of ELA in renal I/R remains unclear. Methods: Renal tubule specific ELA knockout (ApelaKsp KO) mice challenged with bilateral or unilateral I/R were used to investigate the role of endogenous ELA in renal I/R. RNA-sequencing analysis was performed to unbiasedly investigate altered genes in kidneys of ApelaKsp KO mice. Injured mice were treated with ELA32 peptide, Nω-hydroxy-nor-L-arginine (nor-NOHA), prostaglandin E2 (PGE2), Paricalcitol, ML221 or respective vehicles, individually or in combination. Results: ELA is mostly expressed in renal tubules. Aggravated pathological injury and further reduction of renal microvascular blood flow were observed in ApelaKsp KO mice during AKI and the following transition to chronic kidney disease (AKI-CKD). RNA-seq analysis suggested that two blood flow regulators, arginine metabolizing enzyme arginase 2 (ARG2) and PGE2 metabolizing enzyme carbonyl reductases 1 and 3 (CBR1/3), were altered in injured ApelaKsp KO mice. Notably, combination application of an ARG2 inhibitor nor-NOHA, and Paricalcitol, a clinically used activator for PGE2 synthesis, alleviated injury-induced AKI/AKI-CKD stages and eliminated the worst outcomes observed in ApelaKsp KO mice. Moreover, while the APJ inhibitor ML221 blocked the beneficial effects of ELA32 peptide on AKI, it showed no effect on combination treatment of nor-NOHA and Paricalcitol. Conclusions: An endogenous tubular ELA-APJ axis regulates renal microvascular blood flow that plays a pivotal role in I/R-induced AKI. Furthermore, improving renal blood flow by inhibiting ARG2 and activating PGE2 is an effective treatment for AKI and prevents the subsequent AKI-CKD transition.

Mecp2 protects kidney from ischemia-reperfusion injury through transcriptional repressing IL-6/STAT3 signaling.

Rationale: Ischemia-reperfusion (IR) induced acute kidney injury (AKI) causes serious clinical problems associated with high morbidity and mortality. Mecp2 is a methyl-CpG binding protein, its mutation or deletion causes a neurodevelopment disease called Rett syndrome. Notably, some Rett syndrome patients present urological dysfunctions. It remains unclear whether and how Mecp2 affects AKI. Methods: Renal tubular cell specific Mecp2 deletion mice challenged with IR injury were used to investigate the effects of Mecp2 on renal tubular damage, function, cell death, fibrosis and inflammation. Cultured renal epithelial cell lines were transfected with wildtype or different domain-deletion mutants of Mecp2 to study the effects of Mecp2 on Il-6/STAT3 signaling. Results: Our results indicated rapidly upregulated Mecp2 upon acute in vivo and in vitro renal injury. Notably, increased tubular MeCP2 staining was also found in the renal sections of AKI patients. Furthermore, ablation of Mecp2 aggravated renal injury, and promoted renal cell death, inflammation, and fibrosis. Mechanistically, through its transcriptional repression domain, Mecp2 bound to the promoter of proinflammatory cytokine Il-6 to negatively regulate its expression, thus inhibiting STAT3 activation. Conclusions: A novel protective role of Mecp2 against AKI via repressing the Il-6/STAT3 axis was suggested.

Renal UTX-PHGDH-serine axis regulates metabolic disorders in the kidney and liver.

Global obesity epidemics impacts human health and causes obesity-related illnesses, including the obesity-related kidney and liver diseases. UTX, a histone H3K27 demethylase, plays important roles in development and differentiation. Here we show that kidney-specific knockout Utx inhibits high-fat diet induced lipid accumulation in the kidney and liver via upregulating circulating serine levels. Mechanistically, UTX recruits E3 ligase RNF114 to ubiquitinate phosphoglycerate dehydrogenase, the rate limiting enzyme for de novo serine synthesis, at Lys310 and Lys330, which leads to its degradation, and thus suppresses renal and circulating serine levels. Consistently, phosphoglycerate dehydrogenase and serine levels are markedly downregulated in human subjects with diabetic kidney disease or obesity-related renal dysfunction. Notably, oral administration of serine ameliorates high-fat diet induced fatty liver and renal dysfunction, suggesting a potential approach against obesity related metabolic disorders. Together, our results reveal a metabolic homeostasis regulation mediated by a renal UTX-PHGDH-serine axis.

Vitamin C Inhibits the Metabolic Changes Induced by Tet1 Insufficiency Under High Fat Diet Stress.

SCOPE: DNA methylation contributes to obesity, but the role of the DNA demethylase ten-eleven translocation protein 1 (Tet1) in obesity remains unclear. Vitamin C is a cofactor for the Tet family of proteins, but whether vitamin C can be used to treat obesity via Tet1 awaits clarification. METHODS AND RESULTS: Tet1+/+ and Tet1+/- mice are fed a high fat diet (HFD). Higher weight gain and more severe hepatic steatosis, accompanied by reduced 5-hydromethylcytosine (5hmC) levels, are found in the white adipose tissue and liver of Tet1+/- mice. Accumulated lipids are observed in palmitic acid or oleic acid treated primary hepatocytes derived from Tet1+/- mice, which are rescued by Tet1 overexpression or vitamin C treatment. Bisulfite sequencing reveals higher DNA methylation levels on lipolysis related genes in the liver of Tet1+/- mice. Notably, oral intake of vitamin C normalizes DNA methylation levels, promotes lipolysis, and decreases obesity in HFD-fed Tet1+/- mice. CONCLUSIONS: The results reveal a novel function of Tet1 in obesity and provide a new mechanism for the beneficial role of vitamin C in metabolic diseases through enhanced Tet1 activity.

Kidney injury molecule-1 is a potential receptor for SARS-CoV-2.

COVID-19 patients present high incidence of kidney abnormalities, which are associated with poor prognosis and mortality. The identification of SARS-CoV-2 in the kidney of COVID-19 patients suggests renal tropism of SARS-CoV-2. However, whether there is a specific target of SARS-CoV-2 in the kidney remains unclear. Herein, by using in silico simulation, coimmunoprecipitation, fluorescence resonance energy transfer, fluorescein isothiocyanate labeling, and rational design of antagonist peptides, we demonstrate that kidney injury molecule-1 (KIM1), a molecule dramatically upregulated upon kidney injury, binds with the receptor-binding domain (RBD) of SARS-CoV-2 and facilitates its attachment to cell membrane, with the immunoglobulin variable Ig-like (Ig V) domain of KIM1 playing a key role in this recognition. The interaction between SARS-CoV-2 RBD and KIM1 is potently blockaded by a rationally designed KIM1-derived polypeptide AP2. In addition, our results also suggest interactions between KIM1 Ig V domain and the RBDs of SARS-CoV and MERS-CoV, pathogens of two severe infectious respiratory diseases. Together, these findings suggest KIM1 as a novel receptor for SARS-CoV-2 and other coronaviruses. We propose that KIM1 may thus mediate and exacerbate the renal infection of SARS-CoV-2 in a 'vicious cycle', and KIM1 could be further explored as a therapeutic target.

WD Repeat Domain 1 Deficiency Inhibits Neointima Formation in Mice Carotid Artery by Modulation of Smooth Muscle Cell Migration and Proliferation.

The migration, dedifferentiation, and proliferation of vascular smooth muscle cells (VSMCs) are responsible for intimal hyperplasia, but the mechanism of this process has not been elucidated. WD repeat domain 1 (WDR1) promotes actin-depolymerizing factor (ADF)/cofilin-mediated depolymerization of actin filaments (F-actin). The role of WDR1 in neointima formation and progression is still unknown. A model of intimal thickening was constructed by ligating the left common carotid artery in Wdr1 deletion mice, and H&E staining showed that Wdr1 deficiency significantly inhibits neointima formation. We also report that STAT3 promotes the proliferation and migration of VSMCs by directly promoting WDR1 transcription. Mechanistically, we clarified that WDR1 promotes the proliferation and migration of VSMCs and neointima formation is regulated by the activation of the JAK2/STAT3/WDR1 axis.

Aloperine Relieves Type 2 Diabetes Mellitus via Enhancing GLUT4 Expression and Translocation.

Aloperine (ALO), a quinolizidine alkaloid isolated from Sophora alopecuroides L. used in the traditional Uygur medicine, induced a significant increase in cellular glucose uptake of L6 cells, suggesting it has the potential to relieve hyperglycemia. Therefore, we investigated the effects of ALO on type 2 diabetes mellitus (T2DM) through in vitro and in vivo studies. The translocation of glucose transporter 4 (GLUT4) and changes in intracellular Ca2+ levels were real-time monitored in L6 cells using a laser scanning confocal microscope and related protein kinase inhibitors were used to explore the mechanism of action of ALO. Furthermore, high fat diet combined with low-dose streptozotocin (STZ) was used to induce T2DM in rats, and ALO was given to the stomach of T2DM rats for 4 weeks. In vitro results showed that ALO-induced enhancement of GLUT4 expression and translocation were mediated by G protein-PLC-PKC and PI3K/Akt pathways and ALO-enhanced intracellular Ca2+ was involved in activating PKC via G protein-PLC-IP3R-Ca2+ pathway, resulting in promoted GLUT4 plasma membrane fusion and subsequent glucose uptake. ALO treatment effectively ameliorated hyperglycemia, glucose intolerance, insulin resistance and dyslipidemia, alleviated hepatic steatosis, protected pancreatic islet function and activated GLUT4 expression in insulin target tissues of T2DM rats. These findings demonstrated that ALO deserves attention as a potential hypoglycemic agent.

PEGylated and Acylated Elabela Analogues Show Enhanced Receptor Binding, Prolonged Stability, and Remedy of Acute Kidney Injury.

Acute kidney injury (AKI), mostly caused by renal ischemia-reperfusion (I/R) injury and nephrotoxins, is characterized by rapid deterioration in renal-functions without effective drug treatment available. Through activation of a G protein-coupled receptor APJ, a furin-cleaved fragment of Elabela (ELA[22-32], E11), an endogenous APJ ligand, protects against renal I/R injury. However, the poor plasma stability and relatively weak APJ-binding ability of E11 limit its application. To address these issues, we rationally designed and synthesized a set of E11 analogues modified by palmitic acid (Pal) or polyethylene glycol; improved plasma stability and APJ-binding capacity of these analogues were achieved. In cultured renal tubular cells, these analogues protected against hypoxia-reperfusion or cisplatin-caused injury. For renal I/R-injured mice, these analogues showed improved reno-protective effects than E11; notably, Pal-E11 showed therapeutic effects at 24 h post I/R injury. These results present ELA analogues as potential therapeutic options in managing AKI.

Clinical Characteristics and Outcomes of Patients With Diabetes and COVID-19 in Association With Glucose-Lowering Medication.

OBJECTIVE: Diabetes is one of the most distinct comorbidities of COVID-19. Here, we describe the clinical characteristics of and outcomes in patients with diabetes in whom COVID-19 was confirmed or clinically diagnosed (with typical features on lung imaging and symptoms) and their association with glucose-lowering or blood pressure-lowering medications. RESEARCH DESIGN AND METHODS: In this retrospective study involving 904 patients with COVID-19 (136 with diabetes, mostly type 2 diabetes), clinical and laboratory characteristics were collected and compared between the group with diabetes and the group without diabetes, and between groups taking different medications. Logistic regression was used to explore risk factors associated with mortality or poor prognosis. RESULTS: The proportion of comorbid diabetes is similar between cases of confirmed and of clinically diagnosed COVID-19. Risk factors for higher mortality of patients with diabetes and COVID-19 were older age (adjusted odds ratio [aOR] 1.09 [95% CI 1.04, 1.15] per year increase; P = 0.001) and elevated C-reactive protein (aOR 1.12 [95% CI 1.00, 1.24]; P = 0.043). Insulin usage (aOR 3.58 [95% CI 1.37, 9.35]; P = 0.009) was associated with poor prognosis. Clinical outcomes of those who use an ACE inhibitor (ACEI) or angiotensin II type-I receptor blocker (ARB) were comparable with those of patients who do not use ACEI/ARB among COVID-19 patients with diabetes and hypertension. CONCLUSIONS: C-reactive protein may help to identify patients with diabetes who are at greater risk of dying during hospitalization. Older patients with diabetes were prone to death related to COVID-19. Attention needs to be paid to patients with diabetes and COVID-19 who use insulin. ACEI/ARB use showed no significant impact on patients with diabetes and hypertension who have COVID-19.

Fat-Specific Knockout of Mecp2 Upregulates Slpi to Reduce Obesity by Enhancing Browning.

Abnormalities of methyl-CpG binding protein 2 (Mecp2) cause neurological disorders with metabolic dysfunction; however, its role in adipose tissues remains unclear. Here, we report upregulated Mecp2 in white adipose tissues (WAT) of obese humans, as well as in obese mice and during in vitro adipogenesis. Normal chow-fed adipocyte-specific Mecp2 knockout mice (Mecp2 Adi KO mice) showed a lean phenotype, with downregulated lipogenic genes and upregulated thermogenic genes that were identified using RNA sequencing. Consistently, the deficiency of Mecp2 in adipocytes protected mice from high-fat diet (HFD)-induced obesity and inhibited in vitro adipogenesis. Furthermore, Mecp2 Adi KO mice showed increased browning under different stimuli, including cold treatment. Mechanistically, Mecp2 bound to the promoter of secretory leukocyte protease inhibitor (Slpi) and negatively regulated its expression. Knockdown of Slpi in inguinal WAT of Mecp2 Adi KO mice prevented cold-induced browning. Moreover, recombinant SLPI treatment reduced the HFD-induced obesity via enhancing browning. Together, our results suggest a novel non-central nervous system function of Mecp2 in obesity by suppressing browning, at least partially, through regulating adipokine Slpi.

Dandelion Chloroform Extract Promotes Glucose Uptake via the AMPK/GLUT4 Pathway in L6 Cells.

The number of patients with type 2 diabetes mellitus (T2DM) is increasing rapidly worldwide. Glucose transporter 4 (GLUT4) is one of the main proteins that transport blood glucose into the cells and is a target in the treatment of T2DM. In this study, we investigated the mechanism of action of dandelion chloroform extract (DCE) on glucose uptake in L6 cells. The glucose consumption of L6 cell culture supernatant was measured by a glucose uptake assay kit, and the dynamic changes of intracellular GLUT4 and calcium (Ca2+) levels were monitored by laser scanning confocal microscopy in L6 cell lines stably expressing IRAP-mOrange. The GLUT4 fusion with the plasma membrane (PM) was traced via myc-GLUT4-mOrange. GLUT4 expression and AMP-activated protein kinase (AMPK), protein kinase B (PKB/Akt), protein kinase C (PKC), and phosphorylation levels were determined by performing western blotting. GLUT4 mRNA expression was detected by real-time PCR. DCE up-regulated GLUT4 expression, promoted GLUT4 translocation and fusion to the membrane eventually leading to glucose uptake, and induced AMPK phosphorylation in L6 cells. The AMPK inhibitory compound C significantly inhibited DCE-induced GLUT4 expression and translocation while no inhibitory effect was observed by the phosphatidylinositol 3-kinase (PI3K) inhibitor Wortmannin and PKC inhibitor Gö6983. These data suggested that DCE promoted GLUT4 expression and transport to the membrane through the AMPK signaling pathway, thereby stimulating GLUT4 fusion with PM to enhance glucose uptake in L6 cells. DCE-induced GLUT4 translocation was also found to be Ca2+-independent. Together, these findings indicate that DCE could be a new hypoglycemic agent for the treatment of T2DM.