Bone marrow mesenchymal stem cells differentiate into intestinal epithelioid cells through the ERK1/2 pathway.

BACKGROUND/AIMS: Previous studies have found that the injection of rat bone marrow mesenchymal stem cells (rBMSCs) in a mouse model of acute hepatic failure significantly relieves intestinal damage and endotoxemia. However, the mechanism of this process remains unknown. This study demonstrated the differentiation of rBMSCs into enterocyte-like cells and possible molecular mechanisms for this with the aim of finding a new treatment for intestinal epithelial injury and endotoxemia during liver failure. MATERIALS AND METHODS: rBMSCs were isolated from rat femurs and tibias. Differentiation was induced by co-culturing rBMSCs with rat intestinal epithelial cells (mIEC-6) using Transwell plates; after three, seven, and ten days of induction, expression of specific differentiation molecules were quantified. To inhibit the activity of the Mitogen-activated protein kinase 1/2 (ERK1/2) signaling pathway, an inhibitor of Mitogen-activated protein kinase kinase 1/2 (MEK1/2) was added to the co-culture medium, and western blot analysis was performed after 36 or 72 h to evaluate the expression of ERK1/2 signaling pathway markers (p-MEK1/2 and p-ERK1/2). RESULTS: The rBMSCs differentiated into enterocyte-like cells when co-cultured with mIEC-6 cells. Inhibition of ERK1/2 signaling abrogated the activity of MEK1/2, but MEK increased after 72 h, and the epithelioid differentiation of rBMSCs was consistent with the change in MEK expression. CONCLUSION: rBMSCs differentiate into intestinal epithelium after co-culture with mIEC-6 by regulation of the ERK1/2 signaling pathway. Further research is needed to elucidate the network of mechanisms.

Kupffer Cells Regulate Natural Killer Cells Via the NK group 2, Member D (NKG2D)/Retinoic Acid Early Inducible-1 (RAE-1) Interaction and Cytokines in a Primary Biliary Cholangitis Mouse Model.

BACKGROUND Kupffer cells and natural killer (NK) cells has been identified as contributing factors in the pathogenesis of hepatitis, but the detailed mechanism of these cell types in the pathogenesis of primary biliary cholangitis (PBC) is poorly understood. MATERIAL AND METHODS In this study, polyinosinic: polycytidylic acid (poly I: C), 2-octynoic acid-bovine serum albumin (2OA-BSA) and Freund's adjuvant (FA) were injected to establish a murine PBC model, from which NK cells and Kupffer cells were extracted and isolated. The cells were then co-cultivated in a designed culture system, and then NK group 2, member D (NKG2D), retinoic acid early inducible-1 (RAE-1), F4/80, and cytokine expression levels were detected. RESULTS The results showed close crosstalk between Kupffer cells and NK cells. PBC mice showed increased surface RAE-1 protein expression and Kupffer cell cytokine secretion, which subsequently activated NK cell-mediated target cell killing via NKG2D/RAE-1 recognition, and increased inflammation. NK cell-derived interferon-γ (IFN-γ) and Kupffer cell-derived tumor necrosis factor alpha (TNF-alpha) were found to synergistically regulate inflammation. Moreover, interleukin (IL)-12 and IL-10 improved the crosstalk between NK cells and Kupffer cells. CONCLUSIONS Our findings in mice are the first to suggest the involvement of the NKG2D/RAE-1 interaction and cytokines in the synergistic effects of NK and Kupffer cells in PBC.

Rise in Low-Density Lipoprotein Cholesterol during Hospitalization is Related with Poor Outcome at Discharge in Patients with Acute Ischemic Stroke.

BACKGROUND: The statistical association between a short-term rise in low-density lipoprotein cholesterol (LDL-C) levels and the short-term outcome of acute ischemic stroke remains unknown. We aimed to evaluate the association in acute ischemic stroke patients during hospitalization. METHODS: Patients with acute ischemic stroke who received statin at discharge were enrolled in this multicenter registry study. LDL-C values were measured on the first day after admission and on the day before discharge to determine the rise in LDL-C levels. Poor outcome was defined as a modified Ranking Scale score ≥2 at discharge. The National Institutes of Health Stroke Scale increase from admission to discharge by 2 points was defined as clinical deterioration. Logistic regression analyses were used to analyze the relationship between LDL-C rise during hospitalization and poor outcome at discharge. Variables that were significantly different between the LDL-C rise and LDL-C fall groups were considered in adjustment for confounding variables in model 1. Age, sex, and those variables in model 1 were considered in adjustment for confounding variables in model 2. RESULTS: Among the 676 patients, 110 (16.3%) showed a rise in LDL-C levels during hospitalization. Multivariate analyses showed that LDL-C at admission <1.6 mmol/L was significantly correlated with LDL-C rise during hospitalization (p < 0.001). There were significantly more patients with a poor outcome in the "LDL-C rise" group than in the "LDL-fall" group (p = 0.002). Multiple models consistently showed that LDL-C rise increased the risk of a poor outcome at discharge in model 1 (OR [95% CI] 1.351 [1.059-1.723], p = 0.016) and model 2 (OR [95% CI] 1.370 [1.071-1.751], p = 0.012). LDL-C rise also increased the risk of clinical deterioration, although its p value only was 0.043 in model 1 and 0.048 in model 2. CONCLUSIONS: Rise in LDL-C during hospitalization from acute ischemic stroke is an independent predictor of poor outcome at discharge. In particular, patients with lower LDL-C values at admission are a higher at risk, and LDL-C in these patients should thus be monitored while in hospital.