Selenium-sensitive histone deacetylase 2 is required for forkhead box O3A and regulates extracellular matrix metabolism in cartilage.

INTRODUCTION: Selenium (Se) as well as selenoproteins are vital for osteochondral system development. Se deficiency (SeD) has a definite impact on the expression and activity of histone deacetylases (HDACs). Abnormal expression of some HDACs affects cartilage development. This current study aims to explore the relationship between differentially expressed HDACs and cartilage development, especially extracellular matrix (ECM) homeostasis maintenance, under SeD conditions. MATERIALS AND METHODS: Dark Agouti rats and C28/I2 cell line under SeD states were used to detect the differently expressed HDAC by RT-qPCR, western blotting and IHC staining. Meanwhile, the biological roles of the above HDAC in cartilage development and homeostasis maintenance were confirmed by siRNA transfection, western blotting, RNA sequence and inhibitor treatment experiments. RESULTS: HDAC2 exhibited lower expression at protein level in both animals and chondrocytes during SeD condition. The results of cell-level experiments indicated that forkhead box O3A (FOXO3A), which was required to maintain metabolic homeostasis of cartilage matrix, was reduced by HDAC2 knockdown. Meanwhile, induced HDAC2 was positively associated with FOXO3A in rat SeD model. Meanwhile, knockdown of HDAC2 and FOXO3A led to an increase of intracellular ROS level, which activated NF-κB pathway. Se supplementary significantly inhibited the activation of NF-κB pathway with IL-1ß treatment. CONCLUSION: Our results suggested that low expression of HDAC2 under SeD condition increased ROS content by decreasing FOXO3A in chondrocytes, which led to the activation of NF-κB pathway and ECM homeostasis imbalance.

Upregulated PKM2 in Macrophages Exacerbates Experimental Arthritis via STAT1 Signaling.

Recent studies indicate that glucose metabolism is altered in rheumatoid arthritis. We hypothesize that Pkm2, as a key regulatory enzyme of glycolysis pathway, triggers the activation of macrophages (Mφ), which results in proinflammatory cytokine production during the arthritis progress. In this study, Pkm2 was found to be overexpressed in ED1-positive Mφ in spleens and synovial tissues from arthritic rats via immunofluorescence, Western blotting, and quantitative RT-PCR. To reveal the role of Pkm2, Dark Agouti rats were treated with either Pkm2 enzyme inhibitor shikonin or the RNA interference plasmids of Pkm2 and negative control plasmids, respectively, via i.p. injection. Pkm2 intervention could alleviate the severity of pristane-induced arthritis in aspects of the macroscopic arthritis score, perimeter changes of midpaw, and the synovitis and destruction of the bone and cartilage as well as reduce the ED1 and p-Stat1-positive cell population in rat synovial tissues. Silencing Pkm2 by RNA interference in classical activated rat and mouse Mφ resulted in less Tnf-α, Il-1ß production via Stat1 signaling. Collectively, Pkm2 is highly expressed in ED1-positive Mφ of spleens and synovial tissues from arthritic rats and promotes Mφ activation via Stat1 signaling. Pkm2 might be a promising selective metabolic target molecule for rheumatoid arthritis treatment.

Aberrant expression of long noncoding RNAs in the serum and myocardium of spontaneous hypertensive rats.

Circulating long noncoding RNAs as biomarkers of diseases have attracted increasing attention recently. However, circulating lncRNAs in hypertension is still unexplored niche. The levels of lncRNAs GAS5, NR024118, MRAK134679, AX765700 and MRNR026574 were measured in the serum and myocardium of hypertensive rats and normal controls with real time PCR. The levels of GAS5 were significantly higher both in the myocardium (P = 0.0067) and serum (P < 0.0001) of hypertensive rats compared with controls. The levels of NR024118 were remarkably higher in the myocardium of hypertensive rats (P = 0.0202) while the levels of serum NR024118 were not statistically significant in two groups (P = 0.6926). The levels of serum AX765700 (P = 0.0644) and cardiac AX765700 (P = 0.1938) were not statistically significant in hypertensive rats and controls. The levels of MRAK134679 were not different in the myocardium of two groups (P = 0.1692) and were too low in the serum to be detected. The levels of MRNR026574 were significantly higher in the myocardium of hypertensive rats compared with controls (P < 0.0001) and were too low in the serum to be detected. In conclusions, the levels of GAS5, NR024118 and MRNR026574 were increased in the myocardium of hypertensive rats, suggesting that they participate in the pathogenesis of hypertensive cardiac remodeling. Although, the levels of GAS5 in the serum and heart tissue were both significantly increased in SH rats, the potential biomarker capacity of GAS5 for HT needs to be further explored on larger human cohorts.

Abnormal Expression of DICER1 Leads to Dysregulation of Inflammatory Effectors in Human Synoviocytes.

Dysregulation of multiple microRNAs widely takes place during rheumatoid arthritis (RA) and experimental arthritides. This study is performed to explore the possible mechanism underlying DICER1 deficiency-mediated inflammation in human synoviocytes SW982. Firstly, RNAi of DICER1 led to increased COX2, MMP3, and MMP13 protein production, while DICER1 overexpression could reduce MMP13 expression. Secondly, the increase of IL-8 and decrease of TGF-ß1 and TIMP1 were determined in the supernatant derived from DICER1 siRNA-treated cells, while DICER1 overexpression was found capable to reverse this effect. Ingenuity pathway analysis (IPA) software predicted that the Dicer1 deficiency-induced dysregulated cytokines in synoviocytes could possibly lead to the inflammatory disorders in the synovial tissue. Moreover, DICER1 deficiency could also reduce apoptosis, while DICER1 overexpression was found to decrease the proliferation and enhance apoptosis. In addition, DICER1 deficiency could lower the expression of multiple RA-related miRNAs such as miR-155. Meanwhile, DICER1 overexpression could rescue their low expression levels. And then, gain or loss of miR-155 function could regulate the protein levels of MMP3 and MMP13. These results indicated that DICER1 might play its role through regulating its downstream RA-related miRNAs. Our data demonstrated that DICER1 deficiency could cause multiple proinflammatory events in human synoviocytes SW982. This mechanism study might provide the possible target molecule to modify the inflammatory destruction and overproliferation in synoviocytes.

Selenium-sensitive miRNA-181a-5p targeting SBP2 regulates selenoproteins expression in cartilage.

Selenium (Se) deficiency brings about defects in the biosynthesis of several selenoproteins and has been associated with aberrant chondrogenesis. Selenocysteine (Sec) Insertion Sequence (SECIS) and SECIS binding protein 2 (SBP2) interaction is a very critical node for the metabolic balance between Se and selenoproteins. The Gpx1, Gpx4 and SelS have different binding affinities with SBP2 in cells. According to our results, both miR-181a-5p and SBP2 appeared to be selenium-sensitive and regulated the expression of selenoproteins in C28/I2 cells under Se sufficient environment. However, they showed significantly opposite expression trend in Se deficiency rats cartilage and SeD C28/I2 cells. The SBP2 is a direct target gene of miR-181a-5p in C28/I2 cells as determined by reporter gene and off-target experiments. And the miR-181a-5p could regulate SBP2 and the selenoproteins in C28/I2 cells. Depending upon the Se supply levels, C28/I2 cells were divided into three groups, that is normal Se, SeD and SeS, which underwent through a 7-day Se deprivation process, then SBP2 was knocked-down and overexpressed in all the groups. Moreover, the selected selenoproteins were down-regulated in second-generation low Se diet rat cartilage. The selenoproteins expression was decreased by Se deficiency which depended on the Selenium-sensitive miR-181a-5p to participate and regulate SBP2 at post-transcriptional level. It involves a series of antioxidant and ECM (extracellular matrix) genes, to overcome the ROS-related stress for the protection of essential physiological functions and to maintain the balance between anabolism and catabolism of the cartilage.

Pristane induces autophagy in macrophages, promoting a STAT1-IRF1-TLR3 pathway and arthritis.

Autophagy is involved in both innate and adaptive immune regulation. We propose that autophagy regulates activation of TLR3 in macrophages and is thereby essential for development of pristane-induced arthritis. We found that pristane treatment induced autophagy in macrophages in vitro and in vivo, in spleen cells from pristane injected rats. The induced autophagy was associated with STAT1 phosphorylation and expression of IRF1 and TLR3. Blocking the pristane activated autophagy by Wortmannin and Bafilomycin A1 or by RNAi of Becn1 led to a downregulation of the associated STAT1-IRF1-TLR3 pathway. Most importantly, the development of arthritis was alleviated by suppressing either autophagy or TLR3. We conclude that pristane enhanced autophagy, leading to a STAT1-IRF1 controlled upregulation of TLR3 expression in macrophages, is a pathogenic mechanism in the development of arthritis.

Selenium effect on selenoprotein transcriptome in chondrocytes.

Selenium is an essential micronutrient and exerts its biological functions predominantly through selenoproteins. Selenium deficiency is associated with cartilage function. This study demonstrated that all 24 selenoprotein transcripts in mouse genome were detectable in ATDC5 chondrocytes except deiodinase 1 (DIO1), DIO2, and selenoprotein V (Sel V), while all 25 selenoprotein transcripts in human genome were detectable in C28/I2 chondrocytes except glutathione peroxidase 6 (GPx6) and DIO1. In addition, gene expression of five selenoproteins (GPx1, Sel H, Sel N, Sel P, and Sel W) was up-regulated and two selenoproteins (SPS2 and Sel O) was down-regulated by sodium selenite (Se) in both ATDC5 and C28/I2 cells. Gene expression of six selenoproteins (TrxR1, Sel I, Sel M, Sel R, Sel S, Sel T) and one selenoprotein (GPx3) was up-regulated by Se in ATDC5 and C28/I2 cells, respectively. Gene expression of one selenoprotein (TrxR2) was down-regulated by Se only in ATDC5 cells. Further transcription inhibition assay showed that both transcriptional and posttranscriptional mechanisms involved in Se-regulated gene expression of GPx1, TrxR1, TrxR2, SPS2, Sel O, and Sel S. However, Se-regulated gene expression of Sel H, Sel I, Sel M, Sel N, Sel P, Sel R, Sel T, and Sel W mainly at posttranscriptional level. Moreover, new protein synthesis inhibition assay indicated that Se-mediated new protein synthesis also played roles in Se-regulated gene expression of GPx1, TrxR1, TrxR2, Sel H, Sel O, Sel P, Sel R, and Sel W. In summary, this study described the selenoprotein transcriptome, Se-regulated selenoproteins and possible mechanisms involved in chondrocytes.

[A family-based association study of the EGR3 gene polymorphisms and schizophrenia].

Previous studies showed that EGR3 gene located in chromosome 8p21.3 was involved in the etiology of schizophrenia. However, the finding failed to be replicated in several case-control studies. To investigate the genetic role of the EGR3 gene in Chinese psychiatric patients, we genotyped five single nucleotide polymorphisms (SNPs) in EGR3 gene locus using 93 nuclear families in Han Chinese, and performed transmission disequilibrium test (TDT). In this study, two SNPs (rs1996147 and rs3750192) showed significant association with schizophrenia (c2>4.40, P<0.05). In the linkage disequilibrium analysis, the significant association was also found in two- (rs3750192-rs35201266), three- (rs1877670- rs3750192-rs7009708) and four-SNP (rs1996147-rs1877670-rs3750192-rs7009708) tests of haplotype analyses (c2>7.10, global P<0.05). Overall, the results suggested that EGR3 gene may play an important role in schizophrenia susceptibility in the Han Chinese population, and further functional exploration of the EGR3 gene will contribute to the underlying molecular mechanism for schizophrenia pathogenesis.

Evaluation and perception of online teaching of molecular biology using DingTalk for international medical students during the COVID-19 pandemic.

The COVID-19 pandemic has greatly impacted the education of international students. The authors taught a molecular biology course using the DingTalk platform for international medical students (IMS) in the autumn semester of 2020. We assessed the effect of this online teaching based on an online questionnaire and by analysis of the final examination scores. Our findings demonstrate that the DingTalk platform is a free, effective and convenient online teaching tool for international students. The students' feedback showed that most of them were satisfied with this live teaching with DingTalk. They considered who viewed that the questions used in the live classroom setting were helpful for their learning. There is nonetheless still scope to improve this online teaching mode for international students, such as providing more pre-recorded teaching videos for offline application and use of a virtual simulation experimental molecular biology course. We hope that our findings regarding the experience of IMS with this teaching mode will be of value to other academic faculty.

Analysis of correlation between blood biochemical indicators and bone mineral density of post-menopausal women.

Osteoporosis is a degenerative disease of the skeletal system, and its major complication is fracture that severely influences the living quality of the middle-aged and the aged. The purpose of this study was to investigate the significance of sex hormones and some biochemical indicators related to bone metabolism in the genesis and development of osteoporosis. The plasma samples were collected from 244 post-menopausal women of Xi'an urban area, and their plasma contents of testosterone, estradiol, calcitonin, osteocalcin and N-terminal propeptide of type I procollagen were detected by ELISA. The activity of tartrate-resistant acid phosphatase was determined by spectrophotometric method, and the content of nitric oxide was measured by Griess method. Bone mineral density (BMD) in lumbar vertebrae (L1-L4) and hips was measured by QDR-2000 dual energy X-ray absorptiometry. The concentrations of the biochemical indicators were compared among the three groups (normal bone mass group, osteopenia group and osteoporosis group), and Pearson correlation analysis was used to verify the correlations between the indicators and BMD. The comparison results of blood biochemical indicators of BMD-based groups showed that the plasma contents of estradiol (P = 0.006), testosterone (P = 0.038) and calcitonin (P = 0.042) decreased more significantly in the osteoporosis group, but the content of osteocalcin (P = 0.008) increased significantly in osteoporosis group than those in the other groups. The correlation analysis between BMD of different parts and the blood biochemical indicators showed that there was a significant positive correlation between estradiol and the BMD of lumber vertebra (r = 0.200, P = 0.002), femoral neck (r = 0.160, P = 0.013), and great trochanter (r = 0.204, P = 0.001). Significant positive correlations between calcitonin and BMD of lumber vertebra (r = 0.166, P = 0.018) and femoral great trochanter (r = 0.152, P = 0.041), and between testosterone and BMD of femoral great trochanter (r = 0.158, P = 0.014) were also observed. In addition, there existed significant negative correlations between osteocalcin and BMD of lumber vertebra (r = -0.220, P = 0.001), femoral neck (r = -0.259, P < 0.000), and great trochanter (r = -0.221, P = 0.001), and between the activity of tartrate-resistant acid phosphatase and BMD of femoral great trochanter (r = -0.135, P = 0.037). The partial correlation analysis also showed that there were significant correlations between estradiol (r = 0.160, P = 0.014), calcitonin (r = 0.240, P = 0.013), osteocalcin (r = -0.226, P = 0.023) and BMD when the influence of age was excluded. The Pearson correlation analysis of biochemical indicators showed there were positive correlations between the contents of testosterone and calcitonin, testosterone and osteocalcin, calcitonin and osteocalcin, calcitonin and PINP, calcitonin and NO, osteocalcin and NO, and PINP and NO, but negative correlations between the contents of testosterone and PINP, estradiol and calcitonin, estradiol and osteocalcin, and estradiol and NO. The blood contents of sex hormones and calcitonin significantly influence BMD and osteoporosis development, and the increase of osteocalcin contents could be used as a biomarker to indicate the degree of osteoporosis in post-menopausal women.

[Construction and expression of recombinant adenovirus containing human catalase gene in vitro].

OBJECTIVE: To construct the adenovirus vector containing recombinant human catalase (CAT) and to express the recombinant gene in vitro. METHODS: Total RNA was extracted from human leukocytes and full-length human CAT cDNA was obtained with RT-PCR method. The CAT gene was cloned into pcDNA3.1(+) vector and pcDNA3.1(+)CAT was constructed. The positive clones were confirmed by the restriction enzyme digestion and gene sequencing. The CAT gene was cloned into the entry vector pENTR1A, and pENTR1A-CAT vector was constructed. By LR reaction pENTR1A-CAT and pAd/CMV/V5-DEST was recombined in vitro, and the recombinant adenovirus pAd/CMV/V5-DEST-CAT was obtained. The positive pAd/CMV/V5-DEST-CAT was confirmed by sequencing and transfected into 293A cells with Pac I linearization and Lipofectamine 2 000, and the recombinant virus particles were packaged and amplified in the cells. The expression of CAT protein and CAT enzyme activities of the recombinant virus were determined by Western blot and 240 nm UV absorption methods. RESULT: High expression of recombinant adenovirus was obtained and the expressed human catalase had high enzyme activity. CONCLUSION: Ad/CMV/V5-DEST-CAT vector containing human catalase gene has been constructed successfully; and the expressed enzyme in 293A cells has high activity.

The impact and evaluation of COVID-19 pandemic on the teaching model of medical molecular biology course for undergraduates major in pharmacy.

Molecular biology is a very important basic course for undergraduates major in pharmacy. During the novel coronavirus epidemic, we first adopted an online teaching of molecular biology course with rain class and tencent meeting for undergraduates major in pharmacy, following a blended teaching mode. Finally, we evaluated the effect of this special-time teaching by analyzing the anonymous questionnaire and final examination scores. Student feedback showed that most of students were satisfied with this online teaching, classroom teaching, and experimental teaching, and considered that postlecture quizzes were very helpful for their study. The majority of students supported that classroom teaching should be integrated with online teaching. Analysis of final examination scores showed that the effect of 2020-year teaching was not worse than that of 2019-year teaching, but even better in the excellence rate and rate of poor and failure. Here, we share the experience and thinking of blended teaching of medical molecular biology course during the novel coronavirus epidemic, and hope it helpful for other teachers' teaching.

17ß-Oestradiol Attenuates the Photoreceptor Apoptosis in Mice with Retinitis Pigmentosa by Regulating N-myc Downstream Regulated Gene 2 Expression.

Retinitis pigmentosa (RP) is a heterogeneous group of retinal degenerative diseases in which the final pathological feature is photoreceptor cell apoptosis. Currently, the pathogenesis of RP remains poorly understood and therapeutics are ineffective. 17ß-Oestradiol (ßE2) is universally acknowledged as a neuroprotective factor in neurodegenerative diseases and has manifested neuroprotective effects in a light-induced retinal degeneration model. Recently, we identified N-myc downstream regulated gene 2 (NDRG2) suppression as a molecular marker of mouse retinal photoreceptor-specific cell death. ßE2 has also been reported to regulate NDRG2 in salivary acinar cells. Therefore, in this study, we investigated whether ßE2 plays a protective role in RP and regulates NDRG2 in photoreceptor cells. To this end, we generated RP models and observed that ßE2 not only reduced the apoptosis of photoreceptor cells, but also restored the level of NDRG2 expression in RP models. Then, we showed that siNDRG2 inhibits the anti-apoptotic effect of ßE2 on photoreceptor cells in a cellular RP model. Subsequently, we used a classic oestrogen receptor (ER) antagonist to attenuate the effects of ßE2, suggesting that ßE2 exerted its effects on RP models via the classic ERs. In addition, we performed a bioinformatics analysis, and the results indicated that the reported oestrogen response element (ERE) sequence is present in the promoter region of the mouse NDRG2 gene. Overall, our results suggest that ßE2 attenuated the apoptosis of photoreceptor cells in RP models by maintaining NDRG2 expression via a classic ER-mediated mechanism.

Identification of a cartilage specific novel miRNA which directly targets PRMT3 in rats.

Through experiments to testify a candidate novel miRNA previously discovered by us is a real miRNA and involved in cartilage development. DESIGN: The miR-novel and the newly hairpin miRNA transcribed sequence (pre-miR-novel) was verified as a genuinely existing miRNA by northern blotting. The predicted secondary structure, sequence alignment and targets of pre-miR-novel were performed by "RNAstructure 5.3" program, LASTN2.8.0+/miRbase22 program and RNA hybird program, respective. GO/KEGG pathway analysis also were performed. The miR-novel expression in cartilage tissue during development was detected by RT-qPCR and dot blotting. The chondrocyte differentiation model was established to examine whether miR-novel is involved in cartilage development. The regulation of PRMT3 expression by novel miRNA was determined with the luciferase reporter gene assay and Western blotting after novel miRNA mimic or inhibitor transfection. RESULTS: It's potential role in specifically regulating rodent cartilage development and associated cellular processes. Furthermore, the expression of protein arginine N-methyltransferase 3 (PRMT3), as a predicted target of the novel miRNA, was found consistently downregulated at rat cartilage during developmental stages and RCJ3.1C5.18 (C5.18) cells during the proliferating and hypertrophic phases of the cartilage development, where the miR-novel expression was significantly up-regulated. Both the dual-luciferase reporter gene assay and the up- or down-regulation of miR-novel suggest that the later can specifically bind with the Prmt3 3'-UTR. CONCLUSION: Overall, this study provides the first comprehensive evidence that a genuine cartilage-specific novel miRNA directly targets PRMT3 and may regulate multitudinous cellular processes and signal transduction during cartilage development.

The mechanisms of lncRNA GAS5 in cardiovascular cells and its potential as novel therapeutic target.

Long noncoding RNAs (lncRNAs) are a large class of non (protein)-coding RNAs, which are longer beyond 200 nucleotides. LncRNA GAS5 is widely considered as a tumour suppressor in cell proliferation, apoptosis, cell migration and invasion of tumour cells. Recently, a growing body of evidences indicated that GAS5 was also widely involved in the pathologic process of cardiovascular cells, including regulation of apoptosis and inflammatory injury of cardiomyocytes; proliferation, apoptosis, autophagy and angiogenesis of endothelial cells; and proliferation, migration, apoptosis and differentiation of VSMCs. In this regard, we summarised current studies of GAS5 in cardiovascular cells, which shed light on not only our understanding of the mechanisms of GAS5 in cardiovascular cells but also understanding of the potential of GAS5 as novel therapeutic target.

The mechanism of lncRNA H19 in fibrosis and its potential as novel therapeutic target.

Fibrosis is widely observed in multiple organs, which is generally associated with aging-related diseases, including liver fibrosis, lung fibrosis, cardiac fibrosis and renal fibrosis. The excess deposition of extracellular matrix ultimately leads to the disruption of organ architecture and loss of function. H19 is paternally imprinted maternally expressed lncRNA, which is highly expressed during the development of embryo but quickly downregulated after birth. Recently, a growing body of studies indicates that H19 is widely involved in the pathologic mechanism of fibrosis in various organs. In this review, we summarized current studies of H19 in fibrosis and hopefully aid in a better understanding of the molecular mechanism of fibrosis and the potential of H19 as novel therapeutic target for fibrosis.

Long noncoding RNAs as novel players in the pathogenesis of hypertension.

Long noncoding RNAs (lncRNAs) are non-(protein)-coding RNAs longer than ~200 nucleotides and have been reported to be involved in multiple human diseases by regulating gene expression. A growing body of evidence has demonstrated that lncRNAs are also widely implicated in mechanisms of hypertension, including regulation of the proliferation, migration, and apoptosis of VSMCs; the production of iNOS and NO; and the angiogenic function of endothelial cells. Several lncRNAs were also differentially expressed in the renal and cardiac tissues of hypertensive rats and even in placental samples from preeclampsia patients. In particular, several circulating lncRNAs have been identified as novel biomarkers of hypertension. In this review, we summarize the current studies of lncRNAs in the pathogenesis of hypertension in order to aid in better understanding the molecular mechanism of hypertension and provide a basis to explore new therapeutic targets.

The Human Novel Gene LNC-HC Inhibits Hepatocellular Carcinoma Cell Proliferation by Sequestering hsa-miR-183-5p.

Hepatocellular carcinoma (HCC) is the most commonly diagnosed cancer and the leading cause of cancer mortality. Several lines of evidence have demonstrated the aberrant expression of long noncoding RNAs (lncRNAs) in carcinogenesis and their universal regulatory properties. A thorough understanding of lncRNA regulatory roles in HCC pathology would contribute to HCC prevention and treatment. In this study, we identified a novel human lncRNA, LNC-HC, with significantly reduced levels in hepatic tumors from patients with HCC. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-dimethyltetrazolium bromide) assays as well as colony formation and wound healing experiments showed that LNC-HC significantly inhibited the proliferation of the HCC cell line Huh7. Xenograft transplantation of LNC-HC-overexpressing Huh7 cells in nude mice resulted in the production of smaller tumors. Mechanistically, LNC-HC inhibited the proliferation of HCC cells by directly interacting with hsa-miR-183-5p. LNC-HC rescued the expression of five tumor suppressors, including AKAP12, DYRK2, FOXN3, FOXO1, and LATS2, that were verified as target genes of hsa-miR-183-5p. Overall, human LNC-HC was identified as a novel tumor suppressor that could inhibit HCC cell proliferation in vitro and suppress tumor growth in vivo by competitively binding hsa-miR-183-5p as a competing endogenous RNA (ceRNA). These findings suggest that LNC-HC could be a biomarker of HCC and provide a novel therapeutic target for HCC treatment.

Intervening upregulated SLC7A5 could mitigate inflammatory mediator by mTOR-P70S6K signal in rheumatoid arthritis synoviocytes.

OBJECTIVE: The disruption of metabolic events and changes to nutrient and oxygen availability due to sustained inflammation in RA increases the demand of bioenergetic and biosynthetic processes within the damaged tissue. The current study aimed to understand the molecular mechanisms of SLC7A5 (amino acid transporter) in synoviocytes of RA patients. METHODS: Synovial tissues were obtained from OA and RA patients. Fibroblast-like synoviocytes (FLS) were isolated, and SLC7A5 expression was examined by using RT-qPCR, immunofluorescence, and Western blotting. RNAi and antibody blocking treatments were used to knockdown SLC7A5 expression or to block its transporter activities. mTOR activity assay and MMP expression levels were monitored in RA FLS under amino acid deprivation or nutrient-rich conditions. RESULTS: RA FLS displayed significantly upregulated expression of SLC7A5 compared to OA FLS. Cytokine IL-1ß was found to play a crucial role in upregulating SLC7A5 expression via the NF-κB pathway. Intervening SLC7A5 expression with RNAi or blocking its function by monoclonal antibody ameliorated MMP3 and MMP13 protein expression. Conversely, upregulation of SLC7A5 or tryptophan supplementation enhanced mTOR-P70S6K signals which promoted the protein translation of MMP3 and MMP13 in RA FLS. CONCLUSION: Activated NF-κB pathway upregulates SLC7A5, which enhances the mTOR-P70S6K activity and MMP3 and MMP13 expression in RA FLS.