Thyroid hormone postconditioning protects hearts from ischemia/reperfusion through reinforcing mitophagy.

Triiodothyronine (T3), the biologically active form of thyroid hormone, was reported to protect myocardium from ischemia/reperfusion (I/R) injury when given before sustained ischemia, but its cardioprotective effects when given at the onset of reperfusion (postconditioning), a protocol with more clinical impact is unknown. Therefore, the present study was designed to determine whether T3 postconditioning (THPostC) is able to protect the heart from reperfusion injury and its underlying mechanisms. Isolated Sprague-Dawley rat hearts were subjected to 30 min ischemia/45 min reperfusion, triiodothyronine was delivered at the first 5 min of reperfusion. Our data shown that T3 from 1 to 10 µM during the first 5-min of reperfusion concentration-dependently improved post-ischemic myocardial function. A similar protection was observed in isolated rat cardiomyocytes characterized by the alleviation of I/R-induced loss of mitochondrial membrane potential and exacerbated cell death. Moreover, mitophagy (selectively recognize and remove damaged mitochondria) was significantly stimulated by myocardial I/R, which was enhanced with THPostC. Meanwhile, we found that THPostC stimulated PINK1/Parkin pathway, a critical regulator for mitophagy. Then, adenoviral knockdown of PINK1 and Parkin conformed its roles in the THPostC-mediated cardioprotection. Our results suggest that THPostC confers cardioprotection against I/R injury at least in part by reinforcing PINK1-dependent mitophagy. These findings reveal new roles and mechanisms of triiodothyronine in the cardioprotection against I/R injury.

MiR-125b Inhibits LPS-Induced Inflammatory Injury via Targeting MIP-1α in Chondrogenic Cell ATDC5.

BACKGROUND/AIMS: Chondrocyte apoptosis is largely responsible for cartilage degeneration in osteoarthritis (OA). MicroRNAs (miRNAs) play an important role in chondrogenesis and cartilage remodeling. This study explored the effect of miR-125b on inflammatory injury in chondrogenic cells. METHODS: LPS was used to simulate inflammatory injury in murine chondrogenic ATDC5 cell lines. Targeting effect of miR-125b on MIP-1α 3'UTR was assessed by dual luciferase activity assay. Regulatory effect of miR-125b on MIP-1α expression and the potential regulatory mechanism on inflammatory injury were assessed by Western blot. RESULTS: miR-125b expression was decreased in LPS-induced ATDC5 cells and overexpression of miR-125b inhibited LPS-induced cell viability decline, the rise of apoptosis and inflammatory factors' productions. MIP-1α expression was negatively related to miR-125b, and miR-125b directly targeted with 3'UTR of MIP-1α. Knockdown of miR-125b promoted LPS-induced inflammatory response via upregulation of MIP-1α. miR-125b expression in LPS-induced ATDC5 cells was negatively related with activations of NF-κB and JNK signaling pathways. Overexpression of miR-125b inhibited LPS-induced inflammation injury via suppressing MIP-1α expression and inhibiting activations of NF-κB and JNK signaling pathways. CONCLUSION: miR-125b could play an important role in inflammatory injury of chondrogenic cells and miR-125b affected inflammatory injury of ATDC5 cells via regulating expression of MIP-1α and regulating NF-κB and JNK signaling pathways.

MiR-1246 Promotes LPS-Induced Inflammatory Injury in Chondrogenic Cells ATDC5 by Targeting HNF4γ.

BACKGROUND/AIMS: Osteoarthritis (OA) is a common inflammatory joint disease. miRNAs are associated with OA and functionally implicated in the pathogenesis of the disease. In the present study, we investigated the role of miR-1246 in the lipopolysaccharide (LPS)-induced inflammatory injury of ATDC5 cells. METHODS: ATDC5 cells were cultured and treated with LPS in a series of concentration (0, 1, 5, and 10 µg/ml) for 5 h. The cells were transfected with miR-1246-mimic, inhibitor, si-HNF4γ or negative control, then were assessed for cell viability using CCK8 assay, apoptosis by flow-cytometry and expressions of miR-1246 and pro-inflammatory cytokines by qRT-PCR and western blot analysis. RESULTS: Cell viability was significantly reduced and cell apoptosis was added in ATDC5 cells injured with LPS at the dosage of 5 and 10 µg/ml. Relative mRNA expressions of pro-inflammatory cytokines (IL-1ß, IL-6, IL-8 and TNF-α) were significantly increased. miR-1246 was up-regulated in ATDC5 cells treated with LPS. Moreover, miR-1246 overexpression aggravated LPS-induced decrease in cell viability, increase in apoptosis and overproduction of pro-inflammatory factors. mRNA and protein expressions of HNF4γ were significantly suppressed in cells transfected with miR-124-mimic. Further, miR-1246 knockdown alleviated LPS-induced inflammatory injury by up-regulating the expression of HNF4γ and activation of PI3K/AKT and JAK/STAT pathways. CONCLUSIONS: Suppression of miR-1246 alleviated LPS-induced inflammatory injury in chondrogenic ADTC5 cells by up-regulation of HNF4γ and activation of PI3K/AKT and JAK/STAT pathways. The findings of this study will provide a novel viewpoint regarding miR-1246 target for clinical.

Long non-coding RNA HOXA11-AS functions as a competing endogenous RNA to regulate ROCK1 expression by sponging miR-124-3p in osteosarcoma.

Long non-coding RNAs (lncRNAs) have been strongly associated with various types of cancer. this study was to explore the critical role of lncRNA HOXA11-AS in osteosarcoma (OS) progression. Briefly, we should that the expression of HOXA11-AS was upregulated in OS tissues and cell lines. The high expression of HOXA11-AS was associated with advanced clinical stage, distant metastasis and poor overall survival of OS. In addition, We found that HOXA11-AS silencing suppressed OS cells proliferation, invasion and induced cell arrest in G0/G1 phase. Furthermore, our data showed that HOXA11-AS acts as an endogenous sponge by directly binding miR-124-3p, and decreasing the expression of miR-124-3p. Moreover, we found that HOXA11-AS may regulate tumor progression by affecting miR-124-3p targets, and ROCK1 expression. To conclude, our study helps to elucidate the effectiveness of HOXA11-AS promotion on OS cell proliferation and metastasis. A better understanding of interaction mechanism between HOXA11-AS-miR-124-3p-ROCK1 signaling axis may be a step forward in the development of new therapeutic strategies for the treatment of OS.

MiR-409-3p regulates cell proliferation and tumor growth by targeting E74-like factor 2 in osteosarcoma.

Recent evidence has shown that miR-409-3p was down-regulated in several types of cancer, including osteosarcoma. However, the potential role of miR-409-3p in osteosarcoma remains largely unknown. In the present study, we showed that overexpression of miR-409-3p in osteosarcoma cells inhibited cell proliferation in vitro and suppressed tumor growth in vivo, and the restoration of miR-409-3p promoted G1/S cell cycle arrest and induced cell apoptosis. Additionally, E74-like factor 2 (ELF2) was recognized as a new target of miR-409-3p by dual-luciferase reporter assay. Restoration of ELF2 rescued the inhibitory effect of miR-409-3p on cell proliferation in osteosarcoma cells. Moreover, ELF2 was up-regulated in osteosarcoma tissues and negatively associated with miR-409-3p levels. Taken together, our findings collectively indicate that miR-409-3p may be a tumor suppressor in osteosarcoma and may serve as a promising therapeutic target for osteosarcoma.

Critical role of regulator of calcineurin 1 in spinal cord injury

Spinal cord injury (SCI) is a severe clinical problem worldwide. The pathogenesis of SCI is complicated and much is unknown. The current study was designed to investigate the possible role of regulator of calcineurin 1 (RCAN1) in SCI and to explore the possible molecular mechanisms. Rats were injected with LVshRNAi-RCAN1 and then contusion-induced SCI was established. We found that RCAN1 was significantly increased in spinal cord of rats with SCI. Knockdown of RCAN1 markedly facilitated the structural and functional recovery in the spinal cord, as illustrated by decrease of lesion volume and increase of Basso, Beattie, and Bresnahan (BBB) and combined behavioral score (CBS) scores. Downregulation of RCAN1 suppressed the increase of pro-inflammatory cytokines, including IL-1β and TNF-α, and inhibited the increase of TUNEL-positive cell numbers and caspases 3 and 9 activities. The decrease of oxygen consumption rate and increase of expression of glucose-regulated protein 78 (GRP78) and phosphorylation of protein kinase RNA-like endoplasmic reticulum (ER) kinase (PERK) in rats with SCI were inhibited by LVshRNAi-RCAN1. Moreover, knockdown of RCAN1 ameliorated oxidative stress in rats with SCI, as evidenced by decrease of TBA reactive substances (TBARS) and GSSG content and increase of glutathione (GSH) level. These results suggested that RCAN1 played an important role in SCI through regulation of various pathological processes. Overall, the data provide novel insights into the role of RCAN1 in SCI and novel therapeutic targets of the treatment of injury in the spinal cord (AU)

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Critical role of regulator of calcineurin 1 in spinal cord injury.

Spinal cord injury (SCI) is a severe clinical problem worldwide. The pathogenesis of SCI is complicated and much is unknown. The current study was designed to investigate the possible role of regulator of calcineurin 1 (RCAN1) in SCI and to explore the possible molecular mechanisms. Rats were injected with LVshRNAi-RCAN1 and then contusion-induced SCI was established. We found that RCAN1 was significantly increased in spinal cord of rats with SCI. Knockdown of RCAN1 markedly facilitated the structural and functional recovery in the spinal cord, as illustrated by decrease of lesion volume and increase of Basso, Beattie, and Bresnahan (BBB) and combined behavioral score (CBS) scores. Downregulation of RCAN1 suppressed the increase of pro-inflammatory cytokines, including IL-1ß and TNF-α, and inhibited the increase of TUNEL-positive cell numbers and caspases 3 and 9 activities. The decrease of oxygen consumption rate and increase of expression of glucose-regulated protein 78 (GRP78) and phosphorylation of protein kinase RNA-like endoplasmic reticulum (ER) kinase (PERK) in rats with SCI were inhibited by LVshRNAi-RCAN1. Moreover, knockdown of RCAN1 ameliorated oxidative stress in rats with SCI, as evidenced by decrease of TBA reactive substances (TBARS) and GSSG content and increase of glutathione (GSH) level. These results suggested that RCAN1 played an important role in SCI through regulation of various pathological processes. Overall, the data provide novel insights into the role of RCAN1 in SCI and novel therapeutic targets of the treatment of injury in the spinal cord.

MicroRNA-127-3p inhibits proliferation and invasion by targeting SETD8 in human osteosarcoma cells.

MicroRNAs (miRNAs) play an essential role in cancer development. Several studies have indicated that miRNAs mediate tumorigenesis processes, such as, inflammation, proliferation, apoptosis and invasion. In the present study, we focused on the influence of the miR-127-3p on the proliferation, migration and invasion of osteosarcoma (OS). MiR-127-3p was found at reduced levels in OS tissues and cell lines. Overexpression of miR-127-3p in the OS cell lines significantly inhibited the cell proliferation, migration and invasion; however, inhibition of miR-127-3p increased the proliferation, migration and invasion of OS in vitro. SETD8 was identified as a direct target of miR-127-3p, and SETD8 expression decreased post miR-127-3p overexpression, while SETD8 overexpression could reverse the potential influence of miR-127-3p on the migration and invasion of OS cells. MiR-127-3p is suggested to act mainly via the suppression of SETD8 expression. Overall, the results revealed that miR-127-3p acts as a tumor suppressor and that its down-regulation in cancer may contribute to OS progression and metastasis, suggesting that miR-127-3p could be a potential therapeutic target in the treatment of OS.

MiR-374a promotes the proliferation of osteosarcoma cell proliferation by targeting Axin2.

BACKGROUND: MicroRNA-374a (miR-374a) has been implicated in several cancers. However, its role in osteosarcoma (OS) remains unclear. Thus the aim of this study was to investigate its expression and role in progression of OS. METHODS: Quantitative real-time PCR (qRT-PCR) was performed to detect the expression of miR-374a in OS cell lines and tissues. To further understand its role, we restored expression of miR-374a in MG63 cell line by transfection with miR-374a mimics or inhibitors. Effects of miR-374a on cell proliferation on targets were also determined. RESULTS: In the present study, our results showed that miR-374a was significantly up-regulated in both OS cell lines and OS tissues. Over expression of miR-374a markedly accelerated proliferation of OS cells, while its inhibition significantly suppressed cell proliferation. Moreover, Axin2 was identified to be a functional downstream target of miR-374a, and decreased expression of Axin2 could promote OS cell proliferation. CONCLUSION: Our study suggested that miR-374a functions as an oncogene in OS, and the miR-374a/Axin2 axis might represent a potential therapeutic target for OS intervention.

[Impact of PTTG1 downregulation on cell proliferation, cell cycle and cell invasion of osteosarcoma and related molecular mechanisms].

OBJECTIVE: To downregulate the expression of pituitary tumor transforming gene 1 (PTTG1) in osteosarcoma (OS) cells by siRNA technology and to investigate related biological impact on cell proliferation, cell cycle and cell invasion of OS. METHODS: Three OS cell lines and osteoblast hFOB1.19 cell line were used in this study. Control siRNA and PTTG1 siRNA were employed to transfect OS U2OS cells, and PTTG1 protein level was detected by Western blot after the transfection. Effects of PTTG1 siRNA on cell proliferation, cell cycle and cell invasion were investigated by CCK-8, flow cytometry and Boyden chamber, respectively. Finally, activity of Akt and its downstream target gene expression were analyzed by Western blot in U2OS cells upon various treatments. RESULTS: Expression of PTTG1 protein in 3 OS cells (MG-63, SaOS-2 and U2OS) was significantly higher than that in osteoblast hFOB1.19, among which U2OS cells displayed the highest level. PTTG1 siRNA markedly downregulated the expression of PTTG1 protein in U2OS cells, leading to obvious inhibition of cell proliferation, altered cell cycle distribution and reduced ability of invasion of U2OS cells. Moreover, downregulation of PTTG1 reduced the expression of p-Akt (S473 and T308), MMP-2 and MMP-9 proteins, along with enhanced expression of p21 and E-cadherin proteins. CONCLUSIONS: PTTG1 may be tightly linked to the development of OS and therefore may serve as a novel target for precision therapy of OS.

Studies on correlation between single-nucleotide polymorphisms of tumor necrosis factor gene and different stages of ankylosing spondylitis.

To examine if there is any correlation between ankylosing spondylitis (AS) and TNF-α gene promoter single-nucleotide polymorphisms (SNP) and their associated haplotypes. Using restriction fragment length polymorphism-polymerase chain reaction method, the polymorphism of TNF-α-238, -308, -850, -857, -863 locus, and TNF-ß +252 were analyzed in patients with progressive AS, stable AS and control. (1) Neither the genotypes nor the allele frequencies of TNF-α (-308), (-238), (-863), and TNF-ß +252 showed differences in each group. TNF-α (-850) CC genotype and C allele frequency distribution was significantly higher in healthy controls group than in the stable and progressive groups. TNF-α (-857) CT, CC genotype, and C, T allele frequency showed differences in all groups. (2) Polymorphism linkage equilibrium test revealed that association of six TNF-α, ß gene SNPs with haplotype GACTCG in progressive group is significantly higher than in the stable group and healthy control group (P < 0.05). TNF-α (-857), (-850) gene polymorphism may increase the susceptibility to AS, but do not reflect the disease active state. The CC genotype and C allele may play a protective role in the pathogenesis of AS. TNF-α (-308) may be a weak indicator reflecting the active state of AS. Haplotype GACTCG may indicate both the susceptibility and the activity of AS.

DLC1 as a regulator of proliferation, invasion, cell cycle, and apoptosis in cutaneous squamous cell carcinoma.

Increasing evidence has demonstrated that the tumor suppressor gene deleted in liver cancer-1 (DLC1) is tightly implicated in the development and progression of tumors and is verified to be downregulated in a variety of tumors. However, the roles and precise molecular mechanisms of DLC1 in cutaneous squamous cell carcinoma (cutaneous SCC) remain to be elucidated. In the present study, we confirmed the reduced level in cutaneous SCC tissues and cells, and DLC1 mRNA relative level in cutaneous SCC tissues with lymph node metastasis (0.801 ± 0.079) was markedly lower than those without lymph node metastasis (1.245 ± 0.071) (P < 0.0001). Importantly, the survival rates of patients with low DLC1 level were lower than those with high DLC1 level (P = 0.0051). Further investigation revealed that DLC1 overexpression inhibited proliferation and arrested cell cycle at G0/G1 phase in A431 cells, which may be tightly associated with upregulation of p21 protein and downregulation of cyclin D1 and cdk2 proteins. Moreover, the decreases of FAK and p-FAK as well as the increase of E-cadherin level mediated by elevated DLC1 level suppressed invasion in A431 cells. Additionally, DLC1 overexpression induced apoptosis coupled with elevations of Bax level and caspase-3 activity and decrease of Bcl-2 level in A431 cells. Taken altogether, our data presented herein suggest that DLC1 plays a pivotal role in the development and progression of cutaneous SCC, which may be in part achieved by regulating the signaling pathway related to proliferation, invasion, cell cycle, and apoptosis in cutaneous SCC cells.