Circular RNA circANKRD36 regulates Casz1 by targeting miR-599 to prevent osteoarthritis chondrocyte apoptosis and inflammation.

Osteoarthritis (OA) is an ageing-related disease characterized by articular cartilage degradation and joint inflammation. circRNA has been known to involve in the regulation of multiple inflammatory diseases including OA. However, the mechanism underlying how circRNA regulates OA remains to be elucidated. Here, we report circANKRD36 prevents OA chondrocyte apoptosis and inflammation by targeting miR-599, which specifically degrades Casz1. We performed circRNA sequencing in normal and OA tissues and found the expression of circANKRD36 is decreased in OA tissues. circANKRD36 is also reduced in IL-1ß-treated human chondrocytes. FACS analysis and Western blot showed that the knockdown of circANKRD36 promotes the apoptosis and inflammation of chondrocytes in IL-1ß stress. We then found miR-599 to be the target of circANKRD36 and correlate well with circANKRD36 both in vitro and in vivo. By database analysis and luciferase assay, Casz1 was found to be the direct target of miR-599. Casz1 helps to prevent apoptosis and inflammation of chondrocytes in response to IL-1ß. In conclusion, our results proved circANKRD36 sponge miR-599 to up-regulate the expression of Casz1 and thus prevent apoptosis and inflammation in OA.

NEAT1 promotes myocardial ischemia-reperfusion injury via activating the MAPK signaling pathway.

Myocardial ischemia-reperfusion (IR) injury is a common cardiovascular problem, which remains a major cause of death in the world. Emerging evidence has suggested that long noncoding RNAs are crucial players in myocardial injury. However, the functional involvement of nuclear enriched abundant transcript 1 (NEAT1) in myocardial IR injury remains poorly investigated. Our study focused on the mechanism of NEAT1 in myocardial IR injury. Here, we reported a crucial role for NEAT1 in exacerbating cardiac IR injury. NEAT1 was greatly increased in myocardial IR injury mice models. As exhibited knockdown of NEAT1 resulted in attenuated myocardial IR injury in vivo. In addition, we found that NEAT1 was dramatically induced by hypoxia/reoxygenation in H9c2 cells. Lactate dehydrogenase (LDH), malondialdehyde, reactive oxygen species levels, and endoplasmic reticulum stress-regulated cardiomyocyte apoptosis were inhibited by the downregulation of NEAT1. Here, it was shown that knockdown of NEAT1 was able to repress tumor necrosis factor-α, interleukin-1ß, and IL-6 expression. The silence of NEAT1 protected against IR injury via decreasing troponin levels, cardiocytes apoptosis, creatine kinase, and lactate LDH release in vivo. Meanwhile, the mitogen-activated protein kinase (MAPK) signaling was involved in NEAT1-mediated myocardial IR injury. In summary, our data indicated that NEAT1 contributed to myocardial IR injury via activating the MAPK pathway.

MiR-181a inhibits vascular inflammation induced by ox-LDL via targeting TLR4 in human macrophages.

Atherosclerosis is a kind of chronic inflammation disease with lipid accumulation in in blood vessel linings. Increasing evidence has reported that microRNAs can exert crucial roles in atherosclerosis. In previous study, miR-181a has been implicated to be abnormally expressed in atherosclerosis mice, however its detailed function in atherosclerosis remains uninvestigated. Hence, in our current study, we focused on the biological role of miR-181a in atherosclerosis progression. Ox-LDL has been commonly identified as an important atherosclerosis regulator. We observed that ox-LDL induced THP-1 cell apoptosis dose-dependently and time- dependently. Meanwhile, 25 µg/ml ox-LDL can promote foam cell formation and increased miR-181a expression significantly. CD36 has been involved in atherosclerosis progression and it was found that overexpression of miR-181a inhibited its protein levels. Moreover, miR-181a mimics repressed foam cell formation, TC and TG levels induced by ox-LDL dramatically. In addition, miR-181a mimics were able to reverse THP-1 cell apoptosis, increased IL-6, IL-1ß, and TNF-α protein expression triggered by 25 µg/ml ox-LDL. TLR4 has been linked to various inflammation-associated diseases. In our present study, TLR4 was indicated as miR-181a target and the binding correlation between them was validated by dual-luciferase reporter assay. In conclusion, these results improves the understanding of atherosclerosis modulated by miR-181a/TLR4 and can contribute to development of new approaches for atherosclerosis.

MiR-370 inhibits vascular inflammation and oxidative stress triggered by oxidized low-density lipoprotein through targeting TLR4.

Atherosclerosis, as a chronic cardiovascular disease, still remains a serious threat to human health. Inflammation and oxidative stress are commonly involved in various stages of atherosclerosis development. MicroRNAs are reported to play important roles in macrophages, which can respond to inflammation and oxidative stress. In our current study, we focused on the biological roles of miR-370 in atherosclerosis. According to the previously research, miR-370 was downregulated in AS mice models. Oxidized low-density lipoprotein (Ox-LDL) is regarded as a crucial regulator of atherosclerosis and we observed that miR-370 was decreased by ox-LDL dose-dependently and time-dependently in THP-1 cells. Then, it was found that miR-370 overexpression was able to inhibit inflammation molecules including IL-6 and IL-1ß. Meanwhile, ROS levels, and malondialdehyde (MDA) were also restrained by miR-370 mimics in vitro. Toll-like receptor 4 (TLR4) has been implicated in many inflammation diseases. It can serve as a target of miR-370 and TLR4 expression was greatly increased in ox-LDL-incubated THP-1 cells in a time and dose dependent manner. The negative correlation was validated using a dual-luciferase reporter assay in our study. In conclusion, our present study revealed that miR-370 can reduce inflammatory reaction and inhibit the ROS production by targeting TLR4 in THP-1 cells.

MiR-135a represses oxidative stress and vascular inflammatory events via targeting toll-like receptor 4 in atherogenesis.

Plenty of microRNAs have been identified as critical mediators in atherosclerosis progression, which is still a great threat to human health. Oxidative stress and inflammation have been implicated to contribute a lot to atherosclerosis development. MiR-135a is abnormally expressed in various cancer types, however its function in atherosclerosis is largely unexplored. Ox-LDL is commonly recognized as a crucial atherosclerosis regulator. In our current study, we observed ox-LDL was able to induce RAW264.7 cell apoptosis and meanwhile miR-135a was restrained by ox-LDL both dose-dependently and time- dependently. CD36 has been reported to participate in atherosclerosis process and miR-135a mimics can inhibit its expression while miR-135a inhibitors exhibited a reverse phenomenon. Meanwhile, miR-135a overexpression can suppress foam cell formation, TC, TG levels, and cell apoptosis induced by 20 µg/mL ox-LDL. Subsequently, it was found that miR-135a overexpression can inhibit oxidative stress by decreasing ROS, MDA levels, and increasing SOD levels. Reversely, miR-135a inhibition demonstrated an inhibitory effect in vitro. Apart from these, miR-135a can also modulate inflammation molecules including IL-6, IL-1ß, and TNF-α. TLR4 was predicted as a target of miR-135a and the negative correlation between them was confirmed by dual-luciferase reporter assay in our study. This work improves our understanding of atherosclerosis events mediated by miR-135a/TLR4 and helps to develop new approaches for atherosclerosis.

XIST/miR-544 axis induces neuropathic pain by activating STAT3 in a rat model.

An increasing number of studies have reported that lncRNAs are responsible for the development of neuropathic pain. In our current study, chronic constriction injury (CCI) rat models were established and we observed that lncRNA XIST was greatly increased. Knockdown of XIST can relieve pain characteristics including both mechanical and thermal hyperalgesia in CCI rats. Meanwhile, XIST down-regulation could inhibit neuro-inflammation by reducing expression of inflammatory cytokines including tumor necrosis factor (TNF)-α, IL-1ß, and IL-6 and in CCI rats. By performing bioinformatics technology, miR-544 was predicted to have interactions with XIST and dual-luciferase reporter assays validated the correlation between them. A negative correlation between miR-544 and XIST was observed by carrying out XIST loss or gain of function tests. miR-544 markedly alleviated neuropathic pain development in CCI rats via targeting inflammatory cytokines, which was reversed by XIST over-expression. Moreover, STAT3 was manifested to be a target gene of miR-544 by bioinformatics predictions and it was activated in CCI rats. Over-expression of STAT3 was able to induce neuropathic pain and miR-544 inhibited this process in vivo. Furthermore, XIST increased STAT3 expression by sponging miR-544 in neuropathic pain development. To conclude, our present study indicated that XIST can contribute to neuropathic pain progression in rats through down-regulating miR-544 and up-regulating STAT3. Our results suggested that XIST/miR-544/STAT3 axis can serve as a novel therapeutic target in neuropathic pain development.

L-arginine-glycine amidinotransferase, betaine-homocysteine S-methyltransferase, and neuropolypeptide H3 are diminished in renal clear cell carcinoma of humans.

OBJECTIVE: To identify renal clear cell carcinoma-associated marker proteins. METHODS: Twelve patients with renal cell carcinoma (RCC) were collected and processed in the Department of Urology, Renmin Hospital, Wuhan University, China, between January 2008 and September 2009. Two-dimensional polyacrylamide gel electrophoresis and matrix assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) were employed to investigate differentially expressed protein spots between RCC tissues and adjacent normal tissues, then reverse transcription polymerase chain reaction and western blot were employed to confirm the proteomic results. RESULTS: One protein spot was upregulated, 13 were downregulated, and 22 were absent in RCC tissues. Four of the absent proteins were L-arginine-glycine amidinotransferase (AGAT), Betaine-homocysteine S-methyltransferase (BHMT), Ketohexokinase (KHK), and Neuropolypeptide h3 (NPh3). The reverse transcriptase-polymerase chain reaction analysis demonstrated mRNA expression of AGAT, BHMT, and Nph3 was significantly decreased in 12 RCC tissues. In addition, Western blot analysis showed AGAT protein was absent in 11/12, BHMT in 9/12, and Nph3 in 5/12 RCC tissues. CONCLUSION: Absence of AGAT, BHMT, and Nph3 is common events in clear cell RCC; hence, it may be involved in the development of RCC; therefore, they have the potential to be tumor markers for diagnosis, treatment, and prognosis of RCC patients.

[Long-term culture and identification of spermatogonial stem cells from BALB/c mice in vitro].

OBJECTIVE: To establish a long-term culture system for mouse spermatogonial stem cells (SSCs) and to discuss the key factor that supports mouse SSC self-renewal and proliferation. METHODS: Testis cells from 4-6 days postpartum male transgenic BALB/c mce were collected by a modified two-step enzymatic digestion method and plated on 0. 2% elatin-coated tissue culture plates. The germ cells were enriched by differential adherence selections after respectively incubated for 1, 5 and 24 h and then plated on the mitomycin C-inactivated mouse embryonic fibroblast (MEF) feeder layer. The basal culture medium was StemPro-34 SFM supplemented with other 15 nutrient factors. The 20 ng/ml Glial cell line-derived neurotrophic factor (GDNF), 10 ng/ml basic fibroblast growth factor (bFGF) and 200 ng/ml GDNF-family receptor alpha 1 (GFRalpha1) were added to the serum-free medium to promote SSC proliferation. Several important surface markers and special genes were examined by immunocytochemical staining and RT-PCR analysis. RESULTS: After 3-4 days culture on the MEF feeder, SSCs proliferated continuously and formed typical colonies. SSCs from the BALB/c mice could be cultured in a steady state for 3 months. Immunocytochemical staining showed that Oct4 was specifically expressed in the cultured SSC nucleus and GFRalpha1 strongly expressed on the surface of the membrane. RT-PCR confirmed that the cultured SSCs expressed Oct-4, GFRalpha1, Sox2 and several other special genes resembling undifferentiated spermatogonia. CONCLUSION: SSCs from BALB/c mice could be cultured in the improved culture system for 3 months. This culture system could help further understand the regulating mechanism of SSCs and might provide an opportunity for the treatment of male infertility by SSC transplantation.