Regulating Chondrogenesis of Human Mesenchymal Stromal Cells with a Retinoic Acid Receptor-Beta Inhibitor: Differential Sensitivity of Chondral Versus Osteochondral Development

Background/Aims: Hypoxia has recently been proposed as one of the most important factors in progressive renal injury. Hypoxia-induced vascular endothelial growth factor (VEGF) expression may play a critical role in maintaining peritubular capillary endothelium in renal disease. This study was designed to investigate the effect and underlying mechanism of all-trans retinoic acid (ATRA) on hypoxia-induced injury in NRK52E cells. Methods: For mimicking hypoxia, cells were treated with 100 µM of cobalt chloride (CoCl2). The cell viability, expression of VEGF, p65, transforming growth factor-β2 (TGF-β2) and serine carboxypeptidase 1 (Scpep1), and nuclear factor of kappaB (NF-κB) activities after ATRA treatment were determined by MTT, western blot and electrophoretic mobility shift assay. Co-immunoprecipitation analysis was performed to demonstrate whether Scpep1 interacted with TGF-β2. Results: It was found that CoCl2 triggered hypoxia injury and significantly reduced cell viability. ATRA pretreatment increased the cell survival rate. Under hypoxic conditions, the expression of VEGF, p65 and TGF-β2 increased. Addition of ATRA significantly attenuated the expression of VEGF, p65 and TGF-β2. There was a corresponding variation of NF-κB/DNA binding activities. In addition, ATRA stimulated Scpep1 expression under normoxic and hypoxia condition. Furthermore, TGF-β2 interacted with Scpep1. Conclusions: This study indicated that ATRA may attenuate hypoxia-induced injury in NRK52E cells via inhibiting NF-κB/VEGF and TGF-β2/VEGF pathway.

Section: Introductionmentioning

confidence: 99%

All-Trans Retinoic Acid Attenuates Hypoxia-Induced Injury in NRK52E Cells via Inhibiting NF-κB/VEGF and TGF-β2/VEGF Pathway

Gao²,

Ji³

et al. 2016

“…While chondrogenic differentiation is regulated by many different factors, including retinoic acid receptor signaling, microRNAs (miRNAs), small non-coding RNAs that post-transcriptionally regulate gene expression, have been implicated in regulating all stages of ossification [10,11,12,13]. For example, miR-140 regulates cartilage and bone formation [14,15], and miR-365 increases chondrocyte proliferation and differentiation [16].…”

Section: Introductionmentioning

confidence: 99%

The Role of MicroRNA-381 in Chondrogenesis and Interleukin-1-β Induced Chondrocyte Responses

Hou

Meng

Zhang

et al. 2015

Aim: The molecular pathways regulating cartilage degradation are unclear. miR-381 was identified as a putative regulator of chondrogenesis related genes. Here, we examined its role in chondrogenesis and osteoarthritic cartilage degeneration. Methods: miR-381 expression was assessed in vitro in response to IL-1β stimulation in primary human (PHC) and mouse (PMC) chondrocytes, and ATDC5 derived chondrocytes; and in vivo in mouse embryos and human osteoarthritic cartilage. The effects of miR-381 on chondrogenesis and NF-kB signaling were assessed using a synthetic RNA mimic or inhibitor and luciferase assay, respectively. Upstream regulators of miR381 were probed using siRNA or overexpression plasmids for Sox9 and Runx2. Results: miR-381 expression was elevated in chondrogenic and hypertrophic ATDC5 cells. miR-381 was induced in vitro by IL-1β in ATDC5 cells, PMCs, and PHCs, and was expressed in areas of cartilage degradation or absorption in vivo. Overexpression of Runx2 or Sox9 increased miR-381 expression in ATDC5 cells. miR-381 suppressed expression of collagen, type II, alpha 1, and enhanced expression of metalloproteinase-13 (MMP-13), but did not regulate NFKBIA and NKRF activity. Conclusion: miR-381 was highly expressed during chondrogenesis and in arthritic cartilage. It may contribute to absorption of the cartilage matrix by repressing type II collagen and inducing MMP-13.

“…Disc damage caused by mechanical injury, inflammation, or aging may modulate the structure of the discs through regulating disc homeostasis [5]. Matrix metalloproteinase 13 (MMP13) is also called collagenase 3 [6][7][8][9], and has been found to strongly upregulate by proinflammatory cytokines related to LDD, in which MMP13 acts as a proteoglycans (PG)-degrading enzyme in addition to assisting in collagen degradation for promoting LDD [10]. PG is critical for disc cell maintenance and regeneration after injury [11,12].…”

Section: Introductionmentioning

confidence: 99%

Lumbar Disc Degeneration is Facilitated by MiR-100-Mediated FGFR3 Suppression

Yan¹,

Yu²,

Zhang³

et al. 2015

Background/Aims: The pathogenesis of lumbar disc degeneration (LDD) involved activation of matrix metalloproteinase 13 (MMP13) by differential expression of fibroblast growth factor receptor 1 (FGFR1) and FGFR3. Nevertheless, the molecular regulation of FGFR1 and FGFR3 in the lumber disc cells remains elusive. Methods: We examined the FGFR1 and FGFR3 levels and microRNAs (miRNAs) levels in the resected LDD discs, compared to the traumatized, non-LDD discs. We analyzed the binding of miR-100 to the 3′UTR of FGFR3 mRNA and its effects on FGFR3 translation by bioinformatics analysis and by luciferase-reporter assay, respectively. We modified miR-100 levels in a human nucleus pulposus SV40 cell line (HNPSV), and examined the effects on the expression of FGFR3 and MMP13, by RT-qPCR, Western blot and ELISA. Results: The levels of FGFR1 and miR-100 were significantly higher, while the levels of FGFR3 were significantly lower, in LDD discs, compared to the control non-LDD discs. The levels of FGFR3, but not the levels of FGFR1, inversely correlated with the levels of miR-100. Moreover, miR-100 was found to bind to the 3'UTR of FGFR3 mRNA to prevent its translation. In miR-100-modified HNPSV cells, we found that miR-100 decreased FGFR3 levels, and increased MMP13 levels. Conclusion: miR-100 may activate MMP13 through 3′UTR-suppressoin of FGFR3 mRNA to facilitate development of LDD.