Genetically engineered long-acting Esculentin-2CHa(1-30) fusion protein with potential applicability for the treatment of NAFLD.

Esculentin-2CHa(1-30) (?ESC") has been reported as a potent anti-diabetic peptide with little toxicity. However, its very short plasma residence time severely limits the therapeutic efficacy. To address this issue, we genetically engineered a fusion protein of tandem trimeric ESC with an albumin binding domain (ABD) and a fusion partner, SUMO (named ?SUMO-3×ESC-ABD"). The SUMO-3×ESC-ABD, successfully produced from E. coli, showed low cellular and hemolytic toxicity while displaying potent activities for the amelioration of hyperglycemia as well as non-alcoholic fatty liver disease (NAFLD) in vitro. In animal studies, the estimated plasma half-life of SUMO-3×ESC-ABD was markedly longer (427-fold) than that of the ESC peptide. In virtue of the extended plasma residence, the SUMO-3×ESC-ABD could produce significant anti-hyperglycemic effects that lasted for >2 days, while both the ESC or ESC-ABD peptides elicited little effects. Further, twice-weekly treatment for 10 weeks, the SUMO-3×ESC-ABD displayed significant improvement in blood glucose control with a reduction in body weight. Most importantly, a significant improvement in the conditions of NAFLD was observed in the SUMO-3×ESC-ABD-treated mice. Along the systemic effects (by improved glucose tolerance and body weight reduction), direct inhibition of the hepatocyte lipid uptake was suggested as the major mechanism of the anti-NAFLD effects. Overall, this study demonstrated the utility of the long-acting SUMO-3×ESC-ABD as a potent drug candidate for the treatment of NAFLD.

Loss of SREBP-1c ameliorates iron-induced liver fibrosis by decreasing lipocalin-2.

Sterol regulatory element-binding protein (SREBP)-1c is involved in cellular lipid homeostasis and cholesterol biosynthesis and is highly increased in nonalcoholic steatohepatitis (NASH). However, the molecular mechanism by which SREBP-1c regulates hepatic stellate cells (HSCs) activation in NASH animal models and patients have not been fully elucidated. In this study, we examined the role of SREBP-1c in NASH and the regulation of LCN2 gene expression. Wild-type and SREBP-1c knockout (1cKO) mice were fed a high-fat/high-sucrose diet, treated with carbon tetrachloride (CCl4), and subjected to lipocalin-2 (LCN2) overexpression. The role of LCN2 in NASH progression was assessed using mouse primary hepatocytes, Kupffer cells, and HSCs. LCN2 expression was examined in samples from normal patients and those with NASH. LCN2 gene expression and secretion increased in CCl4-induced liver fibrosis mice model, and SREBP-1c regulated LCN2 gene transcription. Moreover, treatment with holo-LCN2 stimulated intracellular iron accumulation and fibrosis-related gene expression in mouse primary HSCs, but these effects were not observed in 1cKO HSCs, indicating that SREBP-1c-induced LCN2 expression and secretion could stimulate HSCs activation through iron accumulation. Furthermore, LCN2 expression was strongly correlated with inflammation and fibrosis in patients with NASH. Our findings indicate that SREBP-1c regulates Lcn2 gene expression, contributing to diet-induced NASH. Reduced Lcn2 expression in 1cKO mice protects against NASH development. Therefore, the activation of Lcn2 by SREBP-1c establishes a new connection between iron and lipid metabolism, affecting inflammation and HSCs activation. These findings may lead to new therapeutic strategies for NASH.

Prediction model for mild cognitive impairment in patients with type 2 diabetes using the autonomic function test.

OBJECTIVE: Type 2 diabetes mellitus (T2DM) is a risk factor for cognitive impairment, and reduced heart rate variability (HRV) has been correlated with cognitive impairment in elderly individuals. This study investigated risk factors and validated a predictive model for mild cognitive impairment (MCI) in patients with T2DM using an autonomic function test. METHODS: Patients with T2DM, 50-85 years of age, who attended the diabetes clinic at Gyeongsang National University Hospital between March 2018 and December 2019, were included. A total of 201 patients had been screened; we enrolled 124 patients according to the inclusion and exclusion criteria in this study. Cognitive function was assessed using the Montreal Cognitive Assessment-Korean version (MOCA-K); MCI was defined as a total MOCA-K score ≤ 23. Risk factors for MCI in patients with T2DM, including demographic- and diabetes-related factors, and autonomic function test results, were analyzed. Based on multivariate logistic regression, a nomogram was developed as a prediction model for MCI. RESULTS: Thirty-nine of 124 patients were diagnosed with MCI. Age, education, and decreased cardiovagal function were associated with a high risk for MCI, with cardiovagal function exerting the greatest influence. However, diabetes-related factors, such as glycemic control, duration of diabetes, or medications, were not associated with the risk for MCI. The nomogram demonstrated excellent discrimination (area under the curve, 0.832) and was well calibrated. CONCLUSION: Approximately one-third of patients had MCI; as such, carefully evaluating cognitive function in elderly T2DM patients with reduced HRV is important to prevent progression to dementia.

Intermittent Fasting Reduces Neuroinflammation and Cognitive Impairment in High-Fat Diet-Fed Mice by Downregulating Lipocalin-2 and Galectin-3.

Intermittent fasting (IF), an alternating pattern of dietary restriction, reduces obesity-induced insulin resistance and inflammation. However, the crosstalk between adipose tissue and the hippocampus in diabetic encephalopathy is not fully understood. Here, we investigated the protective effects of IF against neuroinflammation and cognitive impairment in high-fat diet(HFD)-fed mice. Histological analysis revealed that IF reduced crown-like structures and adipocyte apoptosis in the adipose tissue of HFD mice. In addition to circulating lipocalin-2 (LCN2) and galectin-3 (GAL3) levels, IF reduced HFD-induced increases in LCN2- and GAL3-positive macrophages in adipose tissue. IF also improved HFD-induced memory deficits by inhibiting blood-brain barrier breakdown and neuroinflammation. Furthermore, immunofluorescence showed that IF reduced HFD-induced astrocytic LCN2 and microglial GAL3 protein expression in the hippocampus of HFD mice. These findings indicate that HFD-induced adipocyte apoptosis and macrophage infiltration may play a critical role in glial activation and that IF reduces neuroinflammation and cognitive impairment by protecting against blood-brain barrier leakage.