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SUMMARYTo discover new drugs to combat coronavirus disease 2019 (COVID-19), an understanding of the molecular basis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is urgently needed. Here, for the first time, we report the crucial role of cathepsin L (CTSL) in patients with COVID-19. The circulating level of CTSL was elevated and was positively correlated with disease course and severity in COVID-19 patients. Correspondingly, SARS-CoV-2 pseudovirus infection increasedCTSLexpression in human cell lines and humanACE2transgenic mice, whileCTSLoverexpression, in turn, enhanced pseudovirus infection. CTSL functionally cleaved the SARS-CoV-2 spike protein and enhanced virus entry, as evidenced by CTSL overexpression and knockdownin vitroand application of CTSL inhibitor drugsin vivo. Furthermore, amantadine, a licensed anti-influenza drug, significantly inhibited CTSL activity and prevented SARS-CoV-2 pseudovirus infection. Therefore, CTSL is a promising target for new anti-COVID-19 drug development.

Identification of key regulators of energy homeostasis holds important therapeutic promise for metabolic disorders, such as obesity and diabetes. ACE2 cleaves angiotensin II (Ang II) to generate Ang-(1-7) which acts mainly through the Mas1 receptor. Here, we identify ACE2 pathway as a critical regulator in the maintenance of thermogenesis and energy expenditure. We found that ACE2 is highly expressed in brown adipose tissue (BAT) and that cold stimulation increases ACE2 and Ang-(1-7) levels in BAT and serum. Ace2 knockout mice (Ace2-/y) and Mas1 knockout mice (Mas1-/-) displayed impaired thermogenesis. Mice transplanted with brown adipose tissue from Mas1-/- display metabolic abnormalities consistent with those seen in the Ace2 and Mas1 knockout mice. In contrast, impaired thermogenesis of Leprdb/db obese diabetic mice and high-fat diet-induced obese mice were ameliorated by overexpression of Ace2 or continuous infusion of Ang-(1-7). Activation of ACE2 pathway was associated with improvement of metabolic parameters, including blood glucose, lipids, and energy expenditure in multiple animal models. Consistently, ACE2 pathway remarkably enhanced the browning of white adipose tissue. Mechanistically, we showed that ACE2 pathway activated Akt/FoxO1 and PKA pathway, leading to induction of UCP1 and activation of mitochondrial function. Our data propose that adaptive thermogenesis requires regulation of ACE2 pathway and highlight novel potential therapeutic targets for the treatment of metabolic disorders.

Aim PAX6 is a transcription factor involved in embryonic development of many organs, including the eyes and the pancreas. Mutations of PAX6 gene is the main cause of a rare disease, congenital aniridia (CA). This case-control study aims to investigate the effects of PAX6 mutations on glucose metabolism and insulin secretion in families with CA. Methods Twenty-one families with CA were screened by Sanger sequencing. Patients with PAX6 mutations and CA (cases) and age-matched healthy family members (controls) were enrolled. Oral glucose tolerance test (OGTT) were performed to detect diabetes or impaired glucose tolerance (IGT). Insulin and proinsulin secretion were evaluated. Results Among 21 CA families, heterozygous PAX6 mutations were detected in five families. Among cases (n=10) from the five families, two were diagnosed with newly identified diabetes and another two were diagnosed with IGT. Among controls (n=12), two had IGT. The level of HbA1c were 36 ± 4 mmol/mol (5.57 ± 0.46 %) and 32 ± 5 mmol/L (5.21 ± 0.54 %) in the cases and the controls, respectively (P = 0.049). More importantly, levels of proinsulin in the cases were significantly higher than that of the controls, despite similar levels of total insulin. The areas under the curve (AUCs) of proinsulin in the cases (6425 ± 4390) were significantly higher than that of the controls (3709 ± 1769) (P = 0.032). Conclusion PAX6 may participate in the production of proinsulin to insulin and heterozygous PAX6 mutations may be associated with glucose metabolism in CA patients.

Background. The pathogenesis Graves’ Orbitopathy (GO) is not yet fully understood. Here, we conducted a pathway analysis based on genome-wide DNA methylation data of Chinese GO patients to explore GO-related pathways and potential feature genes. Methods. Six GO patients and 6 age-matched control individuals were recruited, and a genome-scale screen of DNA methylation was measured using their peripheral blood sample. After extracting the differentially methylated regions (DMRs), we classified DMRs into three clusters with respect to median absolute deviation (MAD) for GO and control group, respectively. Then the extract tests were performed to identify significant pathways by comparing the counts of genes in each cluster between GO and control group in a pathway. For each significant pathway, we calculated the Methylation-based Inference of Regulatory Activity (MIRA) score to infer the regulatory activity of genes involved in the pathway. Furthermore, we took the significant pathways as the subsets and applied Random forests (RF) method to extract GO-related feature genes. Results. We identified four potential significant pathways associated with the occurrence and development of GO disease. There were Toxoplasmosis, Axon guidance, Focal adhesion, and Proteoglycans in cancer (p Conclusion. Our study suggested pathway analyses can help understand the potential relationships between the DNA methylation level of some certain genes and their regulation in Chinese GO patients.

Mitochondrial metabolism plays an essential role in the regulation of insulin release and glucose homeostasis. Evidence demonstrated that the angiotensin-converting enzyme 2 (ACE2) participates in the regulation of glucose metabolism, however, its role in mitochondrial metabolism remains unclear. The purpose of our study was to determine if ACE2 can regulate mitochondrial function in pancreatic β-cells. We found that ACE2 over-expression restored glucose-stimulated insulin secretion (GSIS) and mitochondrial membrane potential (MMP) in the presence of H2O2 in INS-1 cells. PCR array demonstrated that ACE2 over-expression up-regulated 67 mitochondria-related genes in INS-1 cells. In pancreatic islets, ACE2 ablation attenuated intracellular calcium influx with a decrease in GSIS. Ace2−/y mice islets exhibited impaired mitochondrial respiration and lower production of ATP, along with decreased expression of genes involved in mitochondrial oxidation. In islets from db/db mice, ACE2 over-expression increased intracellular calcium influx and restored impaired mitochondrial oxidation, potentially causing an increase in GSIS. These results shed light on the potential roles of ACE2 in mitochondrial metabolism, moreover, may improve our understanding of diabetes.

AimsBicarbonate is involved in many human essential metabolic processes, but little is known about the association between serum bicarbonate and glucose metabolism. This study aims to investigate the association between serum bicarbonate and the risk of progressing to impaired fasting glucose (IFG)/diabetes mellitus (DM).SettingThe data were obtained from a large-scale prospective cohort study in a single health centre in Beijing.ParticipantsA total of 5318 participants aged 18–70 years who underwent health examinations annually with baseline fasting plasma glucose (FPG) ranging from 3.9 to 5.5 mmol/L, without a history of either diabetes or concomitant chronic diseases, were enrolled in this 6-year observational study.Primary outcome measuresA logistic regression analysis was used to calculate ORs for progressing to IFG/DM by the category of baseline serum bicarbonate. In addition, an analysis of the receiver operating characteristic (ROC) curve for predicting IFG was performed.ResultsOf the 5318 participants, 210 developed IFG after a median 2.2 years of follow-up. After adjusting for sex, age, FPG, body mass index, systolic blood pressure, serum creatinine, serum alanine aminotransferase and low-density lipoprotein cholesterol at baseline, the participants in the first (OR 4.18, 95% CI 2.42 to 7.21; pConclusionsLower serum bicarbonate is associated with higher risk of the development of IFG/DM.

The purpose of this study was to investigate the effect of moxifloxacin on HERG channel protein and glucose metabolism. HERG expression was investigated using immunohistochemistry. The whole-cell patch clamp method was used to examine the effect of moxifloxacin on HERG channel currents. A glucose tolerance test was used to analyze the effects of moxifloxacin on blood glucose and insulin concentrations in mice. Results show that HERG protein was expressed in human pancreatic β-cells. Moxifloxacin inhibited HERG time-dependent and tail currents in HEK293 cells in a concentration-dependent manner. The IC50 of moxifloxacin inhibition was 36.65 μmol/L. Moxifloxacin (200 mg/kg) reduced blood glucose levels and increased insulin secretion in wild-type mice at 60 min after the start of the glucose tolerance test. In contrast, moxifloxacin did not significantly alter blood glucose and insulin levels in HERG knockout mice. Serum glucose levels increased and insulin concentrations decreased in HERG knockout mice when compared to wild-type mice. The moxifloxacin-induced decrease in blood glucose and increase in insulin secretion occurred via the HERG protein; thus, HERG protein plays a role in insulin secretion.

To observe the effect of twirling-reducing needling on changes of profile of differentially-expressed genes in the hypothalamus in rats with stress-induced prehypertension (SI-PHT), so as to explore its mechanism under-lying improvement of prehypertension.Wistar male rats were randomly divided into blank control group (After modeling, the systolic pressure levels were remarkably increased from the 3Twirling-reducing needling of acupuncture can lower blood pressure in prehypertension rats, which may be related to its effects in regulating expression of Acsm 3, Cgα, CryαB, Tshβ genes and in activating AITD pathway.

Summary: Glucose-stimulated insulin secretion from islet β cells is mediated by KATP channels. However, the role of non-KATP K+ channels in insulin secretion is largely unknown. Here, we show that a non-KATP K+ channel, KCNH6, plays a key role in insulin secretion and glucose hemostasis in humans and mice. KCNH6 p.P235L heterozygous mutation co-separated with diabetes in a four-generation pedigree. Kcnh6 knockout (KO) or Kcnh6 p.P235L knockin (KI) mice had a phenotype characterized by changing from hypoglycemia with hyperinsulinemia to hyperglycemia with insulin deficiency. Islets from the young KO mice had increased intracellular calcium concentration and increased insulin secretion. However, islets from the adult KO mice not only had increased intracellular calcium levels but also had remarkable ER stress and apoptosis, associated with loss of β cell mass and decreased insulin secretion. Therefore, dysfunction of KCNH6 causes overstimulation of insulin secretion in the short term and β cell failure in the long term. : Yang et al. show that KCNH6 plays a key role in insulin secretion and glucose hemostasis in humans and mice. Dysfunction of KCNH6 results in a hyperinsulinemia phenotype in the short term and hypoinsulinemia and diabetes in the long term. Keywords: maturity-onset diabetes of the young, MODY, monogenic diabetes, type 2 diabetes, islet, insulin secretion, KCNH6, KCNH2, KATP, Cas9

OBJECTIVE The predictive value of microalbuminuria (MAU) for kidney damage is limited in type 2 diabetes (T2D). We studied whether a urine proteome specific for sight-threatening proliferative diabetic retinopathy (PDR) is an indicator to predict chronic renal insufficiency (CRI) in patients with T2D. RESEARCH DESIGN AND METHODS A shotgun urine proteomic analysis was performed in patients with MAU and PDR (case subjects) and in patients with MAU and a duration of T2D for >10 years but without any degree of retinopathy (control subjects). In the cohort study, 210 patients with T2D with an estimated glomerular filtration rate (eGFR) ≥80 mL/min/1.73 m2 were followed for a median of 5.3 years. Urine proteins specific for PDR were used for predicting CRI (eGFR RESULTS The top two urine proteins with the highest difference in ratio of case subjects to control subjects were haptoglobin (8.7 times; P < 0.0001) and α-2-macroglobulin (5.7 times; P < 0.0001). In the cohort study, patients with baseline urinary haptoglobin ≥20 ng/min (haptoglobinuria) had a higher incidence of CRI than those without (hazard ratio [95% CI] 3.27 [1.41–7.58]; P = 0.006). The overall CRI rate was 3.2% for patients without haptoglobinuria or MAU, 9.5% for those with MAU, and 13.3% for those with haptoglobinuria. The highest rate for CRI (22.4%) was in patients with both MAU and haptoglobinuria (P < 0.001). CONCLUSIONS Urine haptoglobin, which is specific for PDR, is a novel biomarker and complement to urine albumin for predicting kidney damage in patients with T2D.

Background Previous works indicated that the stress on the endoplasmic reticulum (ER) affected nonalcoholic fatty liver disease (NAFLD). However, there is no clear evident on the effect of the regulation of ER stress by angiotensin-converting enzyme 2 (ACE2) on the prevention of NAFLD. Methods HepG2 cells were treated with thapsigargin (Tg) or palmitic acid (PA). We analysed ACE2 expression using Western-blotting analyses. ER stress-related proteins were detected in ACE2 knockout mice and Ad-ACE2-treated db/db mice by immunofluorescence or Western-blotting analyses. In ACE2-overexpression HepG2 cells, the triglyceride (TG), total cholesterol (TC), and glycogen content were detected by assay kits. Meanwhile, the expression of hepatic lipogenic proteins (ACCα, SREBP-1c, FAS, and LXRα), enzymes for gluconeogenesis (PEPCK, G6Pase, and IRS2), and IKKβ/NFκB/IRS1/Akt pathway were analysed by Western-blotting analyses. Results ACE2 was significantly increased in Tg/PA-induced cultured hepatocytes. Additionally, ACE2 knockout mice displayed elevated levels of ER stress, while Ad-ACE2-treated db/db mice showed reduced ER stress in liver. Furthermore, activation of ACE2 can ameliorate ER stress, accompanied by decreased TG content, increased intracellular glycogen, and downregulated expression of hepatic lipogenic proteins and enzymes for gluconeogenesis in Tg/PA-induced hepatocytes. As a consequence of anti-ER stress, the activation of ACE2 led to improved glucose and lipid metabolism through the IKKβ/NFκB/IRS1/Akt pathway. Conclusions This is the first time documented that ACE2 had a notable alleviating role in ER stress-induced hepatic steatosis and glucose metabolism via the IKKβ/NFκB/IRS1/Akt-mediated pathway. This study may further provide insight into a novel underlying mechanism and a strategy for treating NAFLD.

To study the characteristics of the chest X-ray images in children infected with enterovirus 71.A total of 120 children with enterovirus 71 infection between April, 2010 and July, 2011 were classified into three groups according to the disease condition: mild (31 cases), severe (43 cases) and life-threatening (46 cases). The period from the onset of clinical symptoms to the first chest X-ray imaging examination and the results of the first chest X-ray findings were compared among the three groups.The period from the onset of clinical symptoms to the first chest X-ray imaging examination in the mild, severe and life-threatening groups was 26-48 hrs (median 37 hrs), 10-36 h (median 23 hrs) and 2-36 hrs (median 19 hrs) respectively. Chest X-ray abnormalities were initially observed at 30 hrs after the onset of clinical symptoms in the mild group, at 23 hrs in the severe group and at 2 hrs in the life-threatening group (P0.01). The mild group presented an initial imaging abnormality rate of 5.8%, the severe group 81.3% and the life-threatening group 100%. The life-threatening group showed a significantly higher initial X-ray abnormality rate than the other two groups (P0.01). In terms of chest X-ray performance, the mild group usually presented lung marking thickening or vagueness. Most children in the severe group presented lung effusion and consolidation. Signs of pulmonary edema were found in the life-threatening group, and lesions in the life-threatening group were characterized by wide distribution and many lung lobe involvements.The interval between the onset of clinical symptoms and the initial chest X-ray examination, the period of time of, and the onset of clinical symptoms, at which chest X-ray abnormalities, the abnormality rate and the severity of chest X-ray findings may be paralleled to the clinical situation in children with enterovirus 71 infection.