Pretreatment with Rho-kinase inhibitor ameliorates lethal endotoxemia-induced liver injury by improving mitochondrial function

Allicin treats myocardial infarction in I/R through the promotion of the SHP2 axis to inhibit p-PERK-mediated oxidative stress

OBJECTIVE

The study attempted to explore how allicin reduces oxidative stress levels by promoting SHP2 expression to inhibit p-PERK in I/R mice.

METHODS

The GEO database and RNA sequencing were used to predict downstream gene. TTC staining was used to visualize the myocardial infarction area. Masson staining was used to assess the level of fibrosis. IF was used to examine the expression of SHP2, CTGF, ROS. RT-PCR analysis was used to quantify the expression of SHP2 mRNA. Western blot was used to detect the protein expression levels of SHP2, p-PERK, MFN1, NLRP3, NOX2, and NOX3.

RESULTS

GEO and transcriptomic data revealed low expression of SHP2 in the heart tissues I/R mice. In the I/R mouse model, TTC staining result showed that allicin can reduce the area of myocardial infarction; Masson staining results indicated that allicin can reduce fibrosis; Macrophage transcriptome sequencing found SHP2 is a target gene of allicin; Immunofluorescence showed allicin can increase SHP2; qPCR results showed allicin can raise SHP2 mRNA level; Immunofluorescence indicated that allicin can inhibit ROS in myocardial infarction tissue, but the specific SHP2-KD eliminates changes in ROS. Western blot analysis demonstrated allicin can increase SHP2 protein and reduce the expression of p-PERK, MFN1, NLRP3, NOX2, and NOX3; SHP2-KD eliminates the expression differences in p-PERK, MFN1, NLRP3, NOX2, and NOX3.

CONCLUSIONS

Allicin can modulate p-PERK activation by enhancing the expression of SHP2, thereby inhibiting myocardial ischemia-reperfusion-induced oxidative stress in mice.

DNA methyltransferase 1 (DNMT1) suppresses mitophagy and aggravates heart failure via the microRNA-152-3p/ETS1/RhoH axis

DNA methyltransferase 1 (DNMT1) shows close link with heart disease. This study aimed to define the role DNMT1 plays in heart failure and determine the underlying mechanism. Expression of microRNA (miR)-152-3p, DNMT1, E26 transformation specific-1 (ETS1) and ras homolog gene family member H (RhoH) was determined by RT-qPCR and/or western blot analysis. The interaction between miR-152-3p and ETS1 was predicted and verified. Methylation of the miR-152-3p promoter region was assessed using methylation-specific PCR. H9c2 cells were chosen for in vitro assays to examine the regulatory role of DNMT1 in autophagy and mitophagy with respect to miR-152-3p/ETS1/RhoH. Doxorubicin (DOX)-induced rat models of heart failure were employed for in vivo validation. DNMT1 expression was upregulated in the heart tissues of DOX-induced rats, where it showed an inverse correlation with miR-152-3p expression. Moreover, DNMT1 was shown to enhance methylation of the miR-152-3p promoter region and suppress its expression, leading to inhibition of mitophagy in H9c2 cells. In addition, DNMT1 enhanced expression of ETS1, which further elevated RhoH expression. Moreover, ETS1-elevated RhoH reduced cell viability and promoted autophagy and mitophagy in H9c2 cells upon treatment with DOX. Next, in vivo results demonstrated that depletion of DNMT1 protected rats from heart failure in a miR-152-3p/ETS1/RhoH-dependent manner. Overall, these findings indicate that DNMT1 may inhibit expression of miR-152-3p by promoting the methylation of miR-152-3p and enhancing the expression of ETS1, thereby inducing RHOH transcriptional activation and inhibiting mitochondrial autophagy, ultimately promoting the development of heart failure.

Rho-Kinase as a Therapeutic Target for Nonalcoholic Fatty Liver Diseases

Nonalcoholic fatty liver disease (NAFLD) is a major public health problem and the most common form of chronic liver disease, affecting 25% of the global population. Although NAFLD is closely linked with obesity, insulin resistance, and type 2 diabetes mellitus, knowledge on its pathogenesis remains incomplete. Emerging data have underscored the importance of Rho-kinase (Rho-associated coiled-coil-containing kinase [ROCK]) action in the maintenance of normal hepatic lipid homeostasis. In particular, pharmacological blockade of ROCK in hepatocytes or hepatic stellate cells prevents the progression of liver diseases such as NAFLD and fibrosis. Moreover, mice lacking hepatic ROCK1 are protected against obesity-induced fatty liver diseases by suppressing hepatic de novo lipogenesis. Here we review the roles of ROCK as an indispensable regulator of obesity-induced fatty liver disease and highlight the key cellular pathway governing hepatic lipid accumulation, with focus on de novo lipogenesis and its impact on therapeutic potential. Consequently, a comprehensive understanding of the metabolic milieu linking to liver dysfunction triggered by ROCK activation may help identify new targets for treating fatty liver diseases such as NAFLD.

Rho-Proteins and Downstream Pathways as Potential Targets in Sepsis and Septic Shock: What Have We Learned from Basic Research

Sepsis and septic shock are associated with acute and sustained impairment in the function of the cardiovascular system, kidneys, lungs, liver, and brain, among others. Despite the significant advances in prevention and treatment, sepsis and septic shock sepsis remain global health problems with elevated mortality rates. Rho proteins can interact with a considerable number of targets, directly affecting cellular contractility, actin filament assembly and growing, cell motility and migration, cytoskeleton rearrangement, and actin polymerization, physiological functions that are intensively impaired during inflammatory conditions, such as the one that occurs in sepsis. In the last few decades, Rho proteins and their downstream pathways have been investigated in sepsis-associated experimental models. The most frequently used experimental design included the exposure to bacterial lipopolysaccharide (LPS), in both in vitro and in vivo approaches, but experiments using the cecal ligation and puncture (CLP) model of sepsis have also been performed. The findings described in this review indicate that Rho proteins, mainly RhoA and Rac1, are associated with the development of crucial sepsis-associated dysfunction in different systems and cells, including the endothelium, vessels, and heart. Notably, the data found in the literature suggest that either the inhibition or activation of Rho proteins and associated pathways might be desirable in sepsis and septic shock, accordingly with the cellular system evaluated. This review included the main findings, relevance, and limitations of the current knowledge connecting Rho proteins and sepsis-associated experimental models.

Increased TLR4 Expression Aggravates Sepsis by Promoting IFN-γ Expression in CD38-/- Mice

Gram-negative bacterial sepsis accounts for up to 50% worldwide sepsis that causes hospital mortality. Acute kidney injury (AKI), a common complication of Gram-negative bacterial sepsis, is caused by Toll-like receptor 4 (TLR4) activation. Lipopolysaccharide (LPS) is an endotoxin in Gram-negative bacteria and is recognized specifically by TLR4, which initiates innate immune response. Also, TLR4 signaling pathway activation is essential in response to LPS infection. CD38 is one of the well-known regulators of innate immunity, whose dysregulation contributes to sepsis. Many studies have proven that an attenuated Gram-positive bacterium induces sepsis in a CD38-blocking model. However, the pathogenesis of Gram-negative bacteria-induced sepsis in a CD38^−/− mouse model remains unclear. The aim of this study is to investigate whether kidney injury is still attenuated in a LPS-induced CD38^−/− sepsis model and identify the potential mechanism. We assess the severity of kidney injury related to proinflammatory cytokine expressions (IFN-γ, TNF-α, IL-1β, and IL-6) in WT and CD38^−/− mice. Our results showed more aggravated kidney damage in CD38^−/− mice than in WT mice, accompanied with an increase of proinflammatory cytokine expression. In addition, compared with CD38^−/−TLR4^mut mice, we found an increase of TLR4 expression and mRNA expression of these cytokines in the kidney of CD38^−/− mice, although only increased IFN-γ level was detected in the serum. Taken together, these results demonstrated that an increased TLR4 expression in CD38^−/− mice could contribute to the aggravation of AKI through boosting of the production of IFN-γ.

Hepatoprotective activity of iridoids, seco-iridoids and analog glycosides from Gentianaceae on HepG2 cells via CYP3A4 induction and mitochondrial pathway

Gentianaceae herb extracts have been widely used as food additives, teas or medicinal remedies for various diseases and disorders of the human body.

Rho-kinase inhibitor Y-27632 facilitates the proliferation, migration and pluripotency of human periodontal ligament stem cells

The selective in vitro expansion and differentiation of multipotent stem cells are critical steps in cell-based regenerative therapies, while technical challenges have limited cell yield and thus affected the success of these potential treatments. The Rho GTPases and downstream Rho kinases are central regulators of cytoskeletal dynamics during cell cycle and determine the balance between stem cells self-renewal, lineage commitment and apoptosis. Trans-4-[(1R)-aminoethyl]-N-(4-pyridinyl)cylohexanecarboxamidedihydrochloride (Y-27632), Rho-associated kinase (ROCK) inhibitor, involves various cellular functions that include actin cytoskeleton organization, cell adhesion, cell motility and anti-apoptosis. Here, human periodontal ligament stem cells (PDLSCs) were isolated by limiting dilution method. Cell counting kit-8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU) labelling assay, cell apoptosis assay, cell migration assay, wound-healing assay, alkaline phosphatase (ALP) activity assay, Alizarin Red S staining, Oil Red O staining, quantitative real-time polymerase chain reaction (qRT-PCR) were used to determine the effects of Y-27632 on the proliferation, apoptosis, migration, stemness, osteogenic and adipogenic differentiation of PDLSCs. Afterwards, Western blot analysis was performed to elucidate the mechanism of cell proliferation. The results indicated that Y-27632 significantly promoted cell proliferation, chemotaxis, wound healing, fat droplets formation and pluripotency, while inhibited ALP activity and mineral deposition. Furthermore, Y-27632 induced PDLSCs proliferation through extracellular-signal-regulated kinase (ERK) signalling cascade. Therefore, control of Rho-kinase activity may enhance the efficiency of stem cell-based treatments for periodontal diseases and the strategy may have the potential to promote periodontal tissue regeneration by facilitating the chemotaxis of PDLSCs to the injured site, and then enhancing the proliferation of these cells and maintaining their pluripotency.

Effects of sepsis on the metabolism of sphingomyelin and cholesterol in mice with liver dysfunction

Sepsis is characterized by a severe inflammatory response to infection. With the spread of sepsis, various tissues, including the lungs, liver and kidney, may be damaged. This may finally develop into multiple organ dysfunction syndrome. Sphingomyelin and cholesterol are two main lipids involved in sepsis. The metabolism of sphingomyelin and cholesterol in the livers of mice with sepsis needs to be clarified. To achieve this, the present study intraperitoneally injected mice with PBS, lipopolysaccharide (LPS; 10 mg/kg) and LPS + pyrrolidine dithiocarbamate (PDTC; 30 mg/kg). Subsequently, sphingomyelin and cholesterol content were measured using kits, the sphingomyelin synthase (SMS) activity was measured using thin layer chromatography, and the expression levels of SMS1 and 2, hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), ATP binding cassette subfamily A member 1 (ABCA1), scavenger receptor class B member 1 (SR-B1) and apolipoprotein A1 (Apo A1) were determined by western blotting in the livers of mice. Results demonstrated that, in the LPS group, sphingomyelin and cholesterol content was significantly increased (P<0.001; n=6), the SMS activity significantly enhanced (P<0.001; n=6), the expression levels of SMS2, HMGCR, ABCA1 and SR-B1 were augmented (P<0.05; n=6), and the expression of Apo A1 was decreased (P<0.05; n=6), whereas SMS1 level only slightly increased with no statistical significance (P>0.05; n=6), compared to the levels in the control group. However, PDTC was able to attenuate these alterations. These results indicated that sphingomyelin and cholesterol content may increase in the liver dysfunction of sepsis by increasing the expression of SMS2, HMGCR, SR-B1 and ABCA1, and downregulating Apo A1.