LIM homeobox transcription factor 1B expression affects renal interstitial fibrosis and apoptosis in unilateral ureteral obstructed rats

Knockdown of LMX1B Suppressed Cell Apoptosis and Inflammatory Response in IL-1β-Induced Human Osteoarthritis Chondrocytes through NF-κB and NLRP3 Signal Pathway

Osteoarthritis (OA), a chronic degenerative joint disease, always occurred in the aging population. There is evidence suggests that chondrocytes' survival, inflammation, and apoptosis play critical roles in OA pathogenesis. LMX1B has been shown to be involved in antiosteogenic function in early patterning of the calvaria. However, the role and mechanism of LMX1B in OA is not unknown. The present study observed that LMX1B was highly expressed in OA patients compared with normal patients. Besides, we found that IL-1β increased LMX1B mRNA and protein expression in SW1353 and C28/I2 chondrocytes. LMX1B knockdown increased IL-1β-induced cell viability and proliferation and suppressed cell apoptosis and inflammation response, including IFN-γ, TNF-α, IL-6, prostaglandin E2 (PGE2), and NO both in SW1353 and C28/I2. Furthermore, LMX1B silence inhibited MMP-3 and MMP-13 expression both in SW1353 and C28/I2 cells. Also, the activation of the NF-κB and NLRP3 signaling pathway was suppressed in LMX1B silence cells by decreasing the p-p65 and NLRP3 protein expressions. Additionally, inhibition of NF-κB by PDTC suppressed NLRP3 expression. Moreover, NLRP3 overexpression reversed the effects of LMX1B silence on chondrocytes' survival, proliferation, apoptosis, and inflammation. Finally, we confirmed that LMX1B depletion had protective effects in OA rats in vivo.

Transcriptome analysis reveals differentially expressed genes between human primary bone marrow mesenchymal stem cells and human primary dermal fibroblasts

Stromal cells have been widely used in biomedical research and disease modeling studies in vitro. The most commonly used types of stromal cells are mesenchymal stem cells and fibroblasts. Their cellular phenotypes and differentiation capabilities are quite similar and there are no specific distinction criteria. In order to identify transcriptomic differences between these 2 cell types, we performed next-generation RNA sequencing. Using the global gene expression profile and pathway analysis, we showed that human primary bone marrow mesenchymal stem cells and human primary dermal fibroblasts have different molecular signatures. We also identified critical transcription factors that are differentially expressed between these cells. We then proposed that homeobox genes and some other sequence-specific transcription factors are not only responsible for transcriptional differences, but also discriminate bone marrow mesenchymal stem cells and dermal fibroblasts at the transcriptional level.

Identification of key microRNAs, transcription factors and genes associated with congenital obstructive nephropathy in a mouse model of megabladder

OBJECTIVE

The present study aimed to investigate the molecular mechanism underlying congenital obstructive nephropathy (CON).

METHODS

The microarray dataset GSE70879 was downloaded from the Gene Expression Omnibus, including 3 kidney samples of megabladder mice and 4 control kidneys. Using this dataset, differentially expressed miRNAs (DEMs) were identified between the kidney samples from megabladder mice and controls, followed by identification of the target genes for these DEMs and construction of a DEM and target gene interaction network. Additionally, the target genes were subjected to Gene Ontology and pathway enrichment analyses, and were used for construction of a protein-protein interaction (PPI) network. Finally, regulatory networks were constructed to analyze transcription factors for the key miRNAs.

RESULTS

From 17 DEMs identified between kidney samples of megabladder mice and controls, 3 key miRNAs were screened, including mmu-miR-150-5p, mmu-miR-374b-5p and mmu-miR-126a-5p. The regulatory networks identified vascular endothelial growth factor A (Vegfa) as the common target gene of mmu-miR-150-5p and five transcription factors, including nuclear receptor subfamily 4, group A, member 2 (Nr4a2), Jun dimerisation protein 2 (Jdp2), Kruppel-like factor 6 (Klf6), Neurexophilin-3 (Nxph3) and RNA binding motif protein 17 (Rbm17). The gene encoding phosphatase and tensin homolog (Pten) was found to be co-regulated by mmu-miR-374b-5p and high mobility group protein A1 (Hmga1), whereas the kirsten rat sarcoma viral oncogene (Kras) was identified as a common target gene of mmu-miR-126a-5p and paired box 6 (Pax6).

CONCLUSIONS

In summary, the above-listed key miRNAs, transcription factors and key genes may be involved in the development of CON.

Hydrogen Sulfide Mitigates Kidney Injury in High Fat Diet-Induced Obese Mice

Obesity is prevalent worldwide and is a major risk factor for the development and progression of kidney disease. Hydrogen sulfide (H2S) plays an important role in renal physiological and pathophysiological processes. However, whether H2S is able to mitigate kidney injury induced by obesity in mice remains unclear. In this study, we demonstrated that H2S significantly reduced the accumulation of lipids in the kidneys of high fat diet- (HFD-) induced obese mice. The results of hematoxylin and eosin, periodic acid-Schiff, and Masson's trichrome staining showed that H2S ameliorated the kidney structure, decreased the extent of interstitial injury, and reduced the degree of kidney fibrosis in HFD-induced obese mice. We found that H2S decreased the expression levels of tumor necrosis factor-α, interleukin- (IL-) 6, and monocyte chemoattractant protein-1 but increased the expression level of IL-10. Furthermore, H2S treatment decreased the protein expression of p50, p65, and p-p65 in the kidney of HFD-induced obese mice. In conclusion, H2S is able to mitigate renal injury in HFD-induced obese mice through the reduction of kidney inflammation by downregulating the expression of nuclear factor-kappa B. H2S or its releasing compounds may serve as a potential therapeutic molecule for obesity-induced kidney injury.

Potential signal pathway between all-trans retinoic acid and LMX1B in hypoxia-induced renal tubular epithelial cell injury

All-trans retinoic acid (ATRA), an active metabolite of vitamin A, exerts various effects on physiological processes such as cell growth, differentiation, apoptosis and inflammation. LMX1B, a developmental LIM-homeodomain transcription factor, is widely expressed in vertebrate embryos, and it takes part in the development of diverse structures such as limbs, kidneys, eyes, brains, etc. Renal tubular epithelial cell culture was performed, and mRNA and protein expression of some factors were detected. We recently demonstrated that ATRA up-regulated the LMX1B, and down-regulated the transforming growth factor-β1, collagen IV and fibronectin in a hypoxia/reoxygenation (H-R) injury system in renal tubular epithelial cells (RTEC). In conclusion, ATRA acts as a positive regulator of LMX1B in H-R RTEC.