👤 SaeYun Baik

Bacteroides-centric gut dysbiosis reported to exacerbates liver cirrhosis via inflammation and fibrosis, therefore utilizing Bacteroides species as microbiome-based therapeutic logical to mitigate disease progression. Feces were collected from 52 Healthy and 144 Liver cirrhosis individuals for V3-V4 dependent 16rRNA-bsed comparative metagenomics analysis, followed a by microbiome depleted and non-depleted DDC mice model to explain the role of Bacteroidetes phylum classified microbial species P. plebeius in liver fibrosis pathophysiological pathways. Bacteroides presented cirrhosis-dependent decrease in human and animal microbiome, and negatively correlated to key molecular pattern associated with cirrhosis. P. plebeius significantly reduced in abundance and identified as a microbial biomarker for cirrhosis (AUC = 0.73) and treatment with P. plebeius significantly improved the levels of cirrhosis-related phenotypical and biochemical markers in the microbiome-depleted cirrhosis group. P. plebeius decrease the expression of S100a9, CCR1, ADAM8, TREM2, ITGAM, and MYO5A which are primarily responsible for inducing inflammation in liver cirrhosis. P. plebeius downregulated the fibrosis related genes expression including CD51, PLAT, ITGA3, CXCR4, and TGFBR1 and gene related to extracellular matrix formation including COL1A1, LTBP2, S100A6, and SMCO2. Additionally, P. plebeius treatment decreased the expression of hepatotoxicity-related genes including LPL, KRT18, ALDOA, and MCM10, and increased the expression of FABP1 and RDX. Additionally, P. plebeius normalized the expression of genes connected to two pathophysiological process including TIMP4, TGFB3, S100A8, PLSCR1, MMP8, CXCL4, and BMP. Our study revealed P. plebeius as a multifaceted bio-therapeutic candidate that normalized dysregulated gene expression and reversed hepatic inflammation, fibrogenesis, and hepatotoxicity. Show less

Metabolic syndrome (MetS) is a cluster of conditions associated with glucose intolerance, hypertension, abdominal obesity, dyslipidemia, and insulin resistance that increase the risk of cardiovascular diseases (CVD) and type 2 diabetes (T2D). Since MetS is known as a complex symptom with a high incidence of genetic factors, it is important to identify genetic variants for each clinical characteristic of MetS. We performed targeted next-generation sequencing (NGS) to identify genetic variants related to obesity, blood glucose, triacylglycerol (TG), and high-density lipoprotein (HDL)-cholesterol level, and hypertension in 48 subjects with MetS and in 48 healthy subjects. NGS analysis revealed that 26 of 48 subjects (54.2%) with MetS had putative non-synonymous variants related to the clinical features of MetS. Of the subjects with MetS, 8 (16.7%) had variants in 4 genes (COL6A2, FTO, SPARC, and MTHFR) related to central obesity, 17 (35.4%) had variants in 6 genes (APOB, SLC2A2, LPA, ABCG5, ABCG8, and GCKR) related to hyperglycemia, 3 (6.3%) had variants in 4 genes (APOA1, APOC2, APOA4, and LMF1) related to hypertriglyceridemia, 8 (16.7%) had variants in 4 genes (ABCA1, CETP, SCARB1, and LDLR) related to low HDL-cholesterolemia, and 5 (10.4%) had variants in ADD1 related to hypertension. Our findings may contribute to broadening the genetic spectrum of risk variants related to the development of MetS. Show less

Immune checkpoint inhibitor (ICI) treatment has recently become a first-line therapy for many non-small cell lung cancer (NSCLC) patients. Unfortunately, most NSCLC patients are refractory to ICI monotherapy, and initial attempts to address this issue with secondary therapeutics have proven unsuccessful. To identify entities precluding CD8+ T cell accumulation in this process, we performed unbiased analyses on flow cytometry, gene expression, and multiplexed immunohistochemical data from a NSCLC patient cohort. The results revealed the presence of a myeloid-rich subgroup, which was devoid of CD4+ and CD8+ T cells. Of all myeloid cell types assessed, neutrophils were the most highly associated with the myeloid phenotype. Additionally, the ratio of CD8+ T cells to neutrophils (CD8/PMN) within the tumor mass optimally distinguished between active and myeloid cases. This ratio was also capable of showing the separation of patients responsive to ICI therapy from those with stable or progressive disease in 2 independent cohorts. Tumor-bearing mice treated with a combination of anti-PD1 and SX-682 (CXCR1/2 inhibitor) displayed relocation of lymphocytes from the tumor periphery into a malignant tumor, which was associated with induction of IFN-γ-responsive genes. These results suggest that neutrophil antagonism may represent a viable secondary therapeutic strategy to enhance ICI treatment outcomes. Show less

The melanocortin-4 receptor (MC4R) belongs to the G protein-coupled receptor (GPCR) family and plays an essential role in the control of energy homeostasis. Here, we identified a novel MC4R-interacting protein, glucose-regulated protein 78 (GRP78), from a pulldown assay using hypothalamic protein extracts and the third intracellular loop of MC4R. We found that MC4R interacted with GRP78 in both the cytosol and at the cell surface and that this interaction increased when MC4R was internalized in the presence of the agonist melanotan-II (MTII). Downregulation of GRP78 using a short interfering RNA approach attenuated MTII-mediated receptor internalization. Reduction in GRP78 expression during tunicamycin-induced endoplasmic reticulum stress also suppressed MTII-mediated internalization of MC4R and cAMP-mediated transcriptional activity. Furthermore, lentiviral-mediated short hairpin RNA knockdown of endogenous GRP78 in the paraventricular nucleus (PVN) of the hypothalamus resulted in an increase in body weight in mice fed a high-fat diet. These results suggest that GRP78 in the PVN binds to MC4R and may have a chaperone-like role in the regulation of MC4R trafficking and signaling. Show less