No abstract

The upregulation of Wnt/β-catenin signaling occurs in virtually all types of kidney disease and is associated with podocyte injury. However, the precise mechanisms involved in the development of kidney disease remain to be elucidated. MicroRNAs (miRNAs or miRs) are a class of short non-coding RNAs and they have been shown to be regulators of gene expression, mainly by binding to the untranslated region (UTR) of mRNAs. The aim of the present study was to determine the role of the 2 members of the miR-135 family (miR-135a and miR-135b) in podocyte injury and to elucidate the mechanisms responsible for the damage to podocytes. The results revealed that miR-135a and miR-135b were upregulated in models of podocyte injury and in glomeruli isolated from patients with focal segmental glomerulosclerosis (FSGS). The ectopic expression of miR-135a and miR-135b led to severe podocyte injury and the disorder of the podocyte cytoskeleton. Our findings demonstrated that miR-135a and miR-135b activated Wnt/β-catenin signaling and induced the nuclear translocation of β-catenin. Using luciferase reporter assays, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis, glycogen synthase kinase 3β (GSK3β) was identified as a target gene of miR-135a and miR-135b. To the best of our knowledge, this is the first study to demonstrate that members of the miR-135 family (specifically miR-135a and miR-135b) regulate the expression of GSK3β, thus playing a role in the development of podocyte injury and the disorder of the podocyte cytoskeleton. This is an important finding as it may contribute to the development of novel therapeutics for podocyte injury-associated glomerulopathies.

Over the last few decades, the epithelial-to-mesenchymal transition (EMT) has been identified as being involved in a number of aspects of physiological processes and various pathological events, including embryonic development and renal fibrosis. Transforming growth factor-β receptor 2 (TGFβR2) is a widely studied gene, which fulfils a vital role in the TGFβ signaling pathway and exerts a crucial function in the progression of EMT. Previous studies demonstrated that the dysregulation of microRNAs (miRNAs) is considered to be associated with the EMT process. However, the precise functional involvement of miRNAs in EMT remains to be fully elucidated. In the present study, the level of miR-590 was decreased in an EMT model in vitro and in vivo. Furthermore, the overexpression of miR-590 inhibited EMT by upregulating the epithelial marker, E-cadherin, and downregulating the mesenchymal markers, laminin, α-smooth muscle actin (α-SMA) and collagen, in the human kidney 2 (HK2) cell line. Furthermore, TGFβR2 was negatively regulated by miR-590. In addition, performing a knockdown of TGFβR2 with small-interfering RNA had an effect similar to miR-590 on EMT in the HK2 cell line, whereas the transfection of pCMV-tag2B-TGFβR2 reversed the effect of miR-590 on EMT in HK2 cells. Taken together, the present study demonstrated that miR-590 is a novel EMT-suppressive microRNA, which targets TGFβR2.

Background Candida tropicalis (C. tropicalis) is an important opportunistic pathogenic Candida species that can cause nosocomial infection. In this study, we analyzed the distribution and drug susceptibility of C. tropicalis and the relationship between ERG11 and UPC2 expression and resistance to azole antifungal agents. Methods C. tropicalis was cultured and identified by Sabouraud Agar Medium, CHROM Agar Candida and ATB tests (Bio-Mérieux, France). Total RNA was extracted from the collected strains, and the ERG11 and UPC2 mRNA expression levels were analyzed by quantitative real-time PCR. Results In total, 2872 clinical isolates of Candida, including 319 strains of C. tropicalis, were analyzed herein; they were mainly obtained from the Departments of Respiratory Medicine and ICU. The strains were predominantly isolated from airway secretion samples, and the detection trend in four years was mainly related to the type of department and specimens. The resistance rates of C. tropicalis to fluconazole, itraconazole and voriconazole had been increasing year by year. The mRNA expression levels of ERG11 and UPC2 in the fluconazole-resistant group were significantly higher than they were in the susceptible group. In addition, there was a significant positive linear correlation between these two genes in the fluconazole-resistant group. Conclusions Overexpression of the ERG11 and UPC2 genes in C. tropicalis could increase resistance to azole antifungal drugs. The routine testing for ERG11 and UPC2 in high-risk patients in key departments would provide a theoretical basis for the rational application of azole antifungal drugs.

Abstract. Fibroblast growth factor 21 (FGF21) is a novel metabolic regulator. The present study aimed to investigate the effect of FGF21 on cholesterol efflux and the expression of ATP binding cassette (ABC) A1 and G1 in human THP-1 macrophage-derived foam cells. Furthermore, the present study aimed to investigate the role of the liver X receptor (LXR) α in this process. A model of oxidized low-density lipoprotein-induced foam cells from human THP-1 cells was established. The effect of FGF21 on cholesterol efflux was analyzed using a liquid scintillation counter. The expression of ABCA1 and ABCG1 was determined using quantitative polymerase chain reaction and western blot analyses. FGF21 was found to enhance apolipoprotein A1-and high-density lipoprotein-mediated cholesterol efflux. FGF21 was also observed to increase the mRNA and protein expression of ABCA1 and ABCG1. Furthermore, LXRα-short interfering RNA attenuated the stimulatory effects induced by FGF21. These findings suggest that FGF21 may have a protective effect against atherosclerosis by enhancing cholesterol efflux through the induction of LXRα-dependent ABCA1 and ABCG1 expression. IntroductionAtherosclerosis, one of the leading causes of morbidity and mortality worldwide, is a chronic inflammatory disease and a disorder of lipid metabolism (1). The accumulation of excess cholesterol has been recognized as a crucial event in the development of atherosclerosis (2); therefore, preventing or reversing cholesterol accumulation may be effective protective strategies against atherosclerosis. A growing body of evidence suggests that high density lipoprotein (HDL) has an important role in the removal of cholesterol from atherosclerotic plaques and the transport of the excess cholesterol back to the liver for its subsequent elimination as bile acids and neutral steroids. This process is termed reverse cholesterol transport (RCT) and is one of the major protective mechanisms against the development of atherosclerosis (3-5).Cholesterol efflux from macrophage-derived foam cells is an initial and key step in RCT (6), and serves as an integrated measure of HDL quantity and quality (7). This cholesterol efflux involves numerous genes, including ATP-binding cassette (ABC) A1 and G1 (8). ABCA1 is a member of the ABC superfamily and is the defective gene in Tangier disease. ABCA1 has been reported to have an important role in the prevention of atherosclerosis through facilitating cholesterol efflux from macrophages to lipid-poor apolipoproteinA-Ⅰ (apoA-Ⅰ), and decreasing cholesterol accumulation in macrophages (9). Similar to ABCA1, ABCG1 is capable of promoting cholesterol efflux from macrophages to mature HDL particles, but not to apoA-Ⅰ (10).Liver X receptor (LXR) α, a member of the nuclear hormone receptor superfamily, has a crucial role in cholesterol metabolism (11). Upon activation, LXRα induces numerous genes, which are involved in cholesterol efflux, absorption, transport and excretion. ABCA1 and ABCG1 have been identified as direct targets of LXRα (12).Fibro...

Increasing evidence revealed that miRNAs, the vital regulators of gene expression, are involved in various cellular processes, including cell growth, differentiation, apoptosis and progression. In addition, miRNAs act as oncogenes and/or tumor suppressors. The present study aimed to verify the potential roles of miR148b in human renal cancer cells. miR-148b was found to be downregulated in human renal cancel tissues and human renal cancer cell lines. Functional studies demonstrated that plasmid-mediated overexpression of miR-148b promoted cell proliferation, increased the S-phase population of the cell cycle and enhanced apoptosis in the 786-O and OS-RC-2 renal cancer cell lines, while it did not appear to affect the total number of viable cells according to a Cell Counting Kit-8 assay. Subsequently, a luciferase reporter assay verified that miR148b directly targeted mitogen-activated protein kinase (MAPK) kinase kinase 9 (MAP3K9), an upstream activator of MAPK kinase/c-Jun N-terminal kinase (JNK) signaling, suppressing the protein but not the mRNA levels. Furthermore, western blot analysis indicated that overexpression of miR148b in renal cancer cells inhibited MAPK/JNK signaling by decreasing the expression of phosphorylated (p)JNK. In addition, over-expression of MAP3K9 and pJNK was detected in clinical renal cell carcinoma specimens compared with that in their normal adjacent tissues. The present study therefore suggested that miR-148b exerts an oncogenic function by enhancing the proliferation and apoptosis of renal cancer cells by inhibiting the MAPK/JNK pathway.

Transient receptor potential (TRP) cation channels are essential for normal cellular physiology, and their abnormal expression may lead to a number of disorders, including podocytopathy. Therefore, it is crucial to understand the mechanisms underlying the regulation of TRP channels. In the present study, microRNA (miR)-135a was found to be upregulated in patients with focal segmental glomerulosclerosis and mice treated with adriamycin (ADR). In cultured podocytes, transforming growth factor (TGF)-β and ADR were found to promote miR-135a expression. Conversely, TRP channel 1 (TRPC1) protein levels were markedly downregulated in podocytes from mice treated with ADR, as well as in cultured podocytes treated with ADR and TGF-β. Ectopic expression of miR-135a led to severe podocyte injury and disarray of the podocyte cytoskeleton, whereas podocyte-specific expression of TRPC1 was able to reverse the pathological effects of miR-135a in cultured podocytes. Moreover, using Luciferase reporter assays and western blot analysis, TRPC1 was identified as a target gene of miR-135a. To the best of our knowledge, this is the first study to demonstrate the role of TRPC1 in the development of podocyte injury and disorders of the podocyte cytoskeleton, which may contribute to the development of novel therapeutics for podocyte injury-associated kidney diseases.

Hypervirulent Klebsiella pneumoniae (hvKp), one of the major community-acquired pathogens, can cause invasive infections such as liver abscess. In recent years, bacteriophages have been used in the treatment of K. pneumoniae, but the characteristics of the phage-resistant bacteria produced in the process of phage therapy need to be evaluated. In this study, two Podoviridae phages, hvKpP1 and hvKpP2, were isolated and characterized. In vitro and in vivo experiments demonstrated that the virulence of the resistant bacteria was significantly reduced compared with that of the wild type. Comparative genomic analysis of monoclonal sequencing showed that nucleotide deletion mutations of wzc and wcaJ genes led to phage resistance, and the electron microscopy and mucoviscosity results showed that mutations led to the loss of the capsule. Meanwhile, animal assay indicated that loss of capsule reduced the virulence of hvKp. These findings contribute to a better understanding of bacteriophage therapy, which not only can kill bacteria directly but also can reduce the virulence of bacteria by phage screening.