LncRNA PMS2L2 protects ATDC5 chondrocytes against lipopolysaccharide-induced inflammatory injury by sponging miR-203

Long non-coding RNA PMS2L2 is down-regulated in osteoarthritis and inhibits chondrocyte proliferation by up-regulating miR-34a

Long non-coding RNA (lncRNA) PMS2L2 has been reported to participate in endotoxin-induced inflammatory responses. As these types of responses can promote osteoarthritis (OA), it was of interest to ascertain if PMS2L2 may be involved in OA. To explore any potential participation of PMS2L2 in OA, synovial fluid was extracted from both OA patients and healthy controls (n = 62 each) and PMS2L2 expression of each sample determined by RT-qPCR. In addition, as miR-34a has a potential binding site on PMS2L2, hypothetical interactions between PMS2L2 and miR-34a in chondrocytes were analyzed by performing over-expression experiments. Furthermore, the role of PMS2L2 and miR-34a in the regulation of chondrocyte proliferation was analyzed using CCK-8 and BrdU assays. The results showed that PMS2L2 expression in OA patient synovial fluid was lower compared to that in control group fluid, and the extent of this reduction was related to disease stage. In in vitro studies, it was seen that endotoxin treatment of chondrocytes led to decreased PMS2L2 expression. It was found that PMS2L2 over-expression caused increased miR-34a expression in OA patient chondrocytes but not in cells from healthy controls. In contrast, miR-34a over-expression in either cell population did not affect PMS2L2 expression. Lastly, over-expression of both PMS2L2 and miR-34a led to inhibited chondrocyte proliferation. Of note, a combined over-expression of PMS2L2 and miR-34a resulted in stronger effects on proliferation compared to that from either single over-expression. Based on the findings that PMS2L2 is down-regulated during ongoing states of OA, and that changes in PMS2L2 expression can lead to increases in chondrocyte expression of miR-34a - resulting in inhibition of chondrocyte proliferation in OA. From these findings, one may conclude that finding means to regulate PMS2L2 could be a promising new target in the development of regimens for the treatment of OA.

Understanding MCL1: from cellular function and regulation to pharmacological inhibition

Myeloid cell leukemia-1 (MCL1), an antiapoptotic member of the BCL2 family characterized by a short half-life, functions as a rapid sensor that regulates cell death and other relevant processes that include cell cycle progression and mitochondrial homeostasis. In cancer, MCL1 overexpression contributes to cell survival and resistance to diverse chemotherapeutic agents; for this reason, several MCL1 inhibitors are currently under preclinical and clinical development for cancer treatment. However, the nonapoptotic functions of MCL1 may influence their therapeutic potential. Overall, the complexity of MCL1 regulation and function represent challenges to the clinical application of MCL1 inhibitors. We now summarize the current knowledge regarding MCL1 structure, regulation, and function that could impact the clinical success of MCL1 inhibitors.

Epigenetic underpinnings of inflammation: Connecting the dots between pulmonary diseases, lung cancer and COVID-19

Inflammation is an essential component of several respiratory diseases, such as chronic obstructive pulmonary disease (COPD), asthma and acute respiratory distress syndrome (ARDS). It is central to lung cancer, the leading cancer in terms of associated mortality that has affected millions of individuals worldwide. Inflammation and pulmonary manifestations are also the major causes of COVID-19 related deaths. Acute hyperinflammation plays an important role in the COVID-19 disease progression and severity, and development of protective immunity against the virus is greatly sought. Further, the severity of COVID-19 is greatly enhanced in lung cancer patients, probably due to the genes such as ACE2, TMPRSS2, PAI-1 and furin that are commonly involved in cancer progression as well as SAR-CoV-2 infection. The importance of inflammation in pulmonary manifestations, cancer and COVID-19 calls for a closer look at the underlying processes, particularly the associated increase in IL-6 and other cytokines, the dysregulation of immune cells and the coagulation pathway. Towards this end, several reports have identified epigenetic regulation of inflammation at different levels. Expression of several key inflammation-related cytokines, chemokines and other genes is affected by methylation and acetylation while non-coding RNAs, including microRNAs as well as long non-coding RNAs, also affect the overall inflammatory responses. Select miRNAs can regulate inflammation in COVID-19 infection, lung cancer as well as other inflammatory lung diseases, and can serve as epigenetic links that can be therapeutically targeted. Furthermore, epigenetic changes also mediate the environmental factors-induced inflammation. Therefore, a better understanding of epigenetic regulation of inflammation can potentially help develop novel strategies to prevent, diagnose and treat chronic pulmonary diseases, lung cancer and COVID-19.

LncRNAs in Osteoarthritis

Osteoarthritis (OA) is a progressive joint disease that affects millions of older adults around the world. With increasing rates of incidence and prevalence worldwide, OA has become an enormous global socioeconomic burden on healthcare systems. Long non-coding ribonucleic acids (lncRNAs), essential functional molecules in many biological processes, are a group of non-coding RNAs that are greater than approximately 200 nucleotides in length. Fast-growing and recent developments in lncRNA research are captivating and represent a novel and promising field in understanding the complexity of OA pathogenesis. The involvement of lncRNAs in OA's pathological processes and their altered expressions in joint tissues, blood and synovial fluid make them attractive candidates for the diagnosis and treatment of OA. We focus on the recent advances in major regulator mechanisms of lncRNAs in the pathophysiology of OA and discuss potential diagnostic and therapeutic uses of lncRNAs for OA. We investigate how upregulation or downregulation of lncRNAs influences the pathogenesis of OA and how we can use lncRNAs to elucidate the molecular mechanism of OA. Furthermore, we evaluate how we can use lncRNAs as a diagnostic marker or therapeutic target for OA. Our study not only provides a comprehensive review of lncRNAs regarding OA's pathogenesis but also contributes to the elucidation of its molecular mechanisms and to the development of diagnostic and therapeutic approaches for OA.

Crosstalk Among circRNA/lncRNA, miRNA, and mRNA in Osteoarthritis

Osteoarthritis (OA) is a joint disease that is pervasive in life, and the incidence and mortality of OA are increasing, causing many adverse effects on people's life. Therefore, it is very vital to identify new biomarkers and therapeutic targets in the clinical diagnosis and treatment of OA. ncRNA is a nonprotein-coding RNA that does not translate into proteins but participates in protein translation. At the RNA level, it can perform biological functions. Many studies have found that miRNA, lncRNA, and circRNA are closely related to the course of OA and play important regulatory roles in transcription, post-transcription, and post-translation, which can be used as biological targets for the prevention, diagnosis, and treatment of OA. In this review, we summarized and described the various roles of different types of miRNA, lncRNA, and circRNA in OA, the roles of different lncRNA/circRNA-miRNA-mRNA axis in OA, and the possible prospects of these ncRNAs in clinical application.

Recent Advances in Pharmacological Intervention of Osteoarthritis: A Biological Aspect

Osteoarthritis (OA) is a degenerative joint disease in the musculoskeletal system with a relatively high incidence and disability rate in the elderly. It is characterized by the degradation of articular cartilage, inflammation of the synovial membrane, and abnormal structure in the periarticular and subchondral bones. Although progress has been made in uncovering the molecular mechanism, the etiology of OA is still complicated and unclear. Nevertheless, there is no treatment method that can effectively prevent or reverse the deterioration of cartilage and bone structure. In recent years, in the field of pharmacology, research focus has shifted to disease prevention and early treatment rather than disease modification in OA. Biologic agents become more and more attractive as their direct or indirect intervention effects on the initiation or development of OA. In this review, we will discuss a wide spectrum of biologic agents ranging from DNA, noncoding RNA, exosome, platelet-rich plasma (PRP), to protein. We searched for key words such as OA, DNA, gene, RNA, exosome, PRP, protein, and so on. From the pharmacological aspect, stem cell therapy is a very special technique, which is not included in this review. The literatures ranging from January 2016 to August 2021 were included and summarized. In this review, we aim to help readers have a complete and precise understanding of the current pharmacological research progress in the intervention of OA from the biological aspect and provide an indication for the future translational studies.

Interactions Among lncRNA/circRNA, miRNA, and mRNA in Musculoskeletal Degenerative Diseases

Musculoskeletal degenerative diseases (MSDDs) are pathological conditions that affect muscle, bone, cartilage, joint and connective tissue, leading to physical and functional impairments in patients, mainly consist of osteoarthritis (OA), intervertebral disc degeneration (IDD), rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) are novel regulators of gene expression that play an important role in biological regulation, involving in chondrocyte proliferation and apoptosis, extracellular matrix degradation and peripheral blood mononuclear cell inflammation. Research on MSDD pathogenesis, especially on RA and AS, is still in its infancy and major knowledge gaps remain to be filled. The effects of lncRNA/circRNA-miRNA-mRNA axis on MSDD progression help us to fully understand their contribution to the dynamic cellular processes, provide the potential OA, IDD, RA and AS therapeutic strategies. Further studies are needed to explore the mutual regulatory mechanisms between lncRNA/circRNA regulation and effective therapeutic interventions in the pathology of MSDD.

lncRNA myocardial infarction-associated transcript (MIAT) knockdown alleviates LPS-induced chondrocytes inflammatory injury via regulating miR-488-3p/sex determining region Y-related HMG-box 11 (SOX11) axis

Long noncoding RNA (lncRNA) has been shown to be involved in the development of osteoarthritis (OA), an age-related bone and joint disease. However, the function and possible molecular mechanism of lncRNA myocardial infarction-associated transcript (MIAT) in lipopolysaccharide (LPS)-induced chondrocytes injury model remain unexplored. Cell viability and apoptosis were detected by methyl thiazolyl tetrazolium (MTT) and flow cytometry, respectively. Western blot was used to detect protein expression. The concentrations of inflammatory factors were estimated by enzyme-linked immunosorbent assay (ELISA). Abundances of MIAT, microRNA-488-3p (miR-488-3p), and sex determining region Y-related HMG-box 11 (SOX11) were examined by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were performed to analyze the interaction between miR-488-3p and MIAT or SOX11. LPS caused chondrocytes injury by reducing cell activity and increasing apoptosis rate and inflammatory factor secretions. Higher levels of MIAT and SOX11 and lower miR-488-3p were observed in LPS-treated C28/I2 cells. Importantly, knockdown of MIAT attenuated the LPS-induced cell injury by targeting miR-488-3p, and miR-488-3p overexpression weakened the LPS-induced cell injury by targeting SOX11. Additionally, repression of MIAT inactivated the LPS-induced NF-κB signaling pathway by decreasing SOX11 and increasing miR-488-3p. Knockdown of MIAT alleviated the LPS-induced chondrocytes injury by inhibiting the NF-κB signaling pathway mediated by the miR-488-3p/SOX11 axis.

Roles of long non‑coding RNA in osteoarthritis (Review)

Osteoarthritis (OA) is a chronic bone and joint disease characterized by articular cartilage degeneration and joint inflammation and is the most common form of arthritis. The clinical manifestations of OA are chronic pain and joint activity disorder, which severely affect the patient quality of life. Long non-coding RNA (lncRNA) is a class of RNA molecules >200 nucleotides long that are expressed in animals, plants, yeast, prokaryotes and viruses. lncRNA molecules lack an open reading frame and are not translated into protein. The present review collated the results of recent studies on the role of lncRNA in the pathogenesis of OA to provide information for the prevention, diagnosis and treatment of OA.

Noncoding RNAs: modulators and modulatable players during infection-induced stress response

The human genome has an almost equal distribution of unique and transposable genetic elements. Although at the transcriptome level, a relatively higher contribution from transposable elements derived RNA has been reported. This is further highlighted with evidence from pervasive transcription. Of the total RNA, noncoding RNAs (ncRNAs) are significant contributors to the transcriptome pool with sizeable fraction from repetitive elements of the human genome, inclusive of Long Interspersed Nuclear Elements (LINEs) and Short Interspersed Nuclear Elements (SINEs). ncRNAs are increasingly being implicated in diverse functional roles especially during conditions of stress. These stress responses are driven through diverse mediators, inclusive of long and short ncRNAs. ncRNAs such as MALAT1, GAS5, miR-204 and miR-199a-5p have been functionally involved during oxidative stress, endoplasmic reticulum (ER) stress and unfolded protein response (UPR). Also, within SINEs, Alu RNAs derived from primate-specific Alu repeats with ~11% human genome contribution, playing a significant role. Pathogenic diseases, including the recent COVID-19, leads to differential regulation of ncRNAs. Although, limited evidence suggests the need for an inquest into the role of ncRNAs in determining the host response towards pathogen challenge.

Long Noncoding RNA PMS2L2 Downregulates miR-24 through Methylation to Suppress Cell Apoptosis in Ulcerative Colitis

BACKGROUND

Ulcerative colitis (UC) is an inflammatory bowel disease characterized by chronic inflammation of the colon. It has been reported that PMS2L2 plays protective roles in inflammatory injury. This study aimed to investigate the role of the long noncoding RNA PMS2L2 in UC.

METHODS

Sixty-two patients with UC as well as 62 age- and gender-matched healthy controls were enrolled. Expressions of PMS2L2 and miR-24 in plasma from UC patients and healthy controls were determined by RT-qPCR. The interaction between PMS2L2 and miR-24 was predicted by bioinformatics and confirmed by RNA immunoprecipitation and RNA pull-down. The role of PMS2L2 in the regulation of miR-24 gene methylation was analyzed by methylation-specific PCR. The effects of PMS2L2 and miR-24 on the expressions of apoptosis-related proteins were detected by Western blots.

RESULTS

PMS2L2 was downregulated in the plasma of UC patients compared to that in age- and gender-matched healthy control. In human colonic epithelial cells (HCnEpCs), PMS2L2 overexpression inhibited miR-24 expression via promoting the methylation of miR-24 gene. In contrast, miR-24 overexpression failed to affect PMS2L2. In the detection of cell apoptosis, PMS2L2 overexpression could promote the expression of Bcl-2 and inhibit Bax, cleaved-caspase-3, and cleaved-caspase-9 expressions stimulated by LPS. Flow cytometer revealed that PMS2L2 elevation suppressed the apoptosis of HCnEpCs induced by LPS, but miR-24 aggravated the apoptosis. PMS2L2 overexpression rescued the detrimental effect of miR-24 on cell apoptosis.

CONCLUSION

PMS2L2 may downregulate miR-24 via methylation to suppress cell apoptosis in UC.

LncRNA MIAT regulated by selenium and T-2 toxin increases NF-κB-p65 activation, promoting the progress of Kashin-Beck Disease

LncRNA myocardial infarction associated transcript (MIAT) has been shown to be involved in osteoarthritis (OA), but its role in Kashin-Beck Disease (KBD) has rarely been reported. In this study, rats were administered with low selenium and/or T-2 toxin for 4 weeks to establish a KBD animal model. The serum selenium level, TNF-α and IL-1β contents, phosphorylated p65 (p-p65) and MIAT expression were increased in each intervention group. Next, we isolated the primary epiphyseal chondrocytes, and found that selenium treatment reversed the effects of T-2 toxin on chondrocyte injury, p-p65 and MIAT expression. In addition, MIAT overexpression or T-2 toxin treatment led to increased cell death, apoptosis, inflammation, NF-κB-p65 pathway activation and MIAT expression, which was rescued by selenium treatment or MIAT siRNA transfection. Our results suggested that lncRNA MIAT regulated by selenium and T-2 toxin increased the activation of NF-κB-p65, thus being involved in the progress of KBD.

The emerging role of lncRNAs in chondrocytes from osteoarthritis patients

Long non-coding RNAs (lncRNAs) play important roles in many physiological and pathological processes, including osteoarthritis (OA). Recent studies have demonstrated that lncRNAs are involved in the pathogenesis of OA by affecting various essential cellular features of chondrocytes, such as proliferation, apoptosis, inflammation, and degradation of the extracellular matrix (ECM). However, there are only a limited number of studies in this area, indicating that the role of lncRNAs in OA may have been overlooked. The aim of this literature review is to summarize the versatile roles and molecular mechanisms of lncRNAs in chondrocytes involved in OA. At the end of this article, the function of the lncRNA HOX transcript antisense RNA (HOTAIR) in chondrocytes in OA is highlighted. Because lncRNAs affect proliferation, apoptosis, inflammatory responses, and ECM degradation by chondrocytes in OA, they may serve as potential biomarkers or therapeutic targets for the diagnosis or treatment of OA. The specific role and related mechanisms of lncRNAs in OA warrants further investigation.

Therapeutic potential of extracellular vesicle-associated long noncoding RNA

Both extracellular vesicles (EVs) and long noncoding RNAs (lncRNAs) have been increasingly investigated as biomarkers, pathophysiological mediators, and potential therapeutics. While these two entities have often been studied separately, there are increasing reports of EV-associated lncRNA activity in processes such as oncogenesis as well as tissue repair and regeneration. Given the powerful nature and emerging translational impact of other noncoding RNAs such as microRNA (miRNA) and small interfering RNA, lncRNA therapeutics may represent a new frontier. While EVs are natural vehicles that transport and protect lncRNAs physiologically, they can also be engineered for enhanced cargo loading and therapeutic properties. In this review, we will summarize the activity of lncRNAs relevant to both tissue repair and cancer treatment and discuss the role of EVs in enabling the potential of lncRNA therapeutics.

The Therapeutic Potential and Role of miRNA, lncRNA, and circRNA in Osteoarthritis

BACKGROUND

Osteoarthritis (OA) is a disease characterized by progressive degeneration, joint hyperplasia, narrowing of joint spaces, and extracellular matrix metabolism. Recent studies have shown that the pathogenesis of OA may be related to non-coding RNA, and its pathological mechanism may be an effective way to reduce OA.

OBJECTIVE

The purpose of this review was to investigate the recent progress of miRNA, long noncoding RNA (lncRNA) and circular RNA (circRNA) in gene therapy of OA, discussing the effects of this RNA on gene expression, inflammatory reaction, apoptosis and extracellular matrix in OA.

METHODS

The following electronic databases were searched, including PubMed, EMBASE, Web of Science, and the Cochrane Library, for published studies involving the miRNA, lncRNA, and circRNA in OA. The outcomes included the gene expression, inflammatory reaction, apoptosis, and extracellular matrix.

RESULTS AND DISCUSSION

With the development of technology, miRNA, lncRNA, and circRNA have been found in many diseases. More importantly, recent studies have found that RNA interacts with RNA-binding proteins to regulate gene transcription and protein translation, and is involved in various pathological processes of OA, thus becoming a potential therapy for OA.

CONCLUSION

In this paper, we briefly introduced the role of miRNA, lncRNA, and circRNA in the occurrence and development of OA and as a new target for gene therapy.

Downregulation of lncRNA PMS2L2 in patients with gastric adenocarcinoma predicts poor prognosis

Long non-coding RNA PMS1 homolog 2 mismatch repair system component pseudogene 2 (PMS2L2) is a key player in lipopolysaccharide-induced inflammatory responses. Preliminary deep sequencing data revealed that PMS2L2 was downregulated in gastric adenocarcinoma (GA) tissues compared with healthy adjacent tissues and the aim of the present study was to investigate the role of PMS2L2 in GA. In the present study, reverse transcription-quantitative PCR assays were performed to analyze gene expression. Cell transfections were performed to analyze gene interactions and Transwell assays were performed to analyze cell invasion and migration. The results revealed that PMS2L2 expression was downregulated in cancer tissues obtained from patients with GA compared with healthy adjacent tissues and was not significantly affected by clinical stage. Furthermore, low levels of PMS2L2 in cancer tissues were closely associated with a low overall 5-year survival rate in patients. MicroRNA (miR)-25 was upregulated in GA tissues compared with healthy adjacent tissues and inversely associated with PMS2L2 levels. In GA cells in vitro, overexpression of PMS2L2 downregulated the expression of miR-25, while miR-25 overexpression did not significantly affect PMS2L2 expression. Furthermore, PMS2L2 overexpression inhibited the migration and invasion of GA cells. miR-25 overexpression partially rescued the decreased migration and invasion of GA cells caused by PMS2L2 overexpression. Therefore, PMS2L2 may downregulate miR-25 expression to inhibit GA.

Role of MicroRNA, LncRNA, and Exosomes in the Progression of Osteoarthritis: A Review of Recent Literature

Osteoarthritis (OA) is a common clinical degenerative disease characterized by the destruction of articular cartilage, which has an increasing impact on people's lives and social economy. The pathogenesis of OA is complex and unclear, and there is no effective way to block its progress. The study of the pathogenesis of OA is the prerequisite for the early diagnosis and effective treatment of OA. To define the pathogenesis of OA, this review considers the pathological mechanism of OA that involves microRNA, lncRNA, and exosomes. More and more evidence shows that microRNA, lncRNA, and exosomes are closely related to OA. MicroRNA inhibits the target gene by binding to the 3'- untranslated region of the targets. LncRNA usually competes with microRNA to regulate the expression level of downstream genes, while exosomes, as a carrier of intercellular information transfer, transmit the biological information of mother cells to target cells, and the effect of exosomes secreted by different cells on OA are different. In this review, we emphasized that different microRNA, lncRNA, and exosomes have different regulatory effects on chondrocyte proliferation and apoptosis, extracellular matrix degradation and inflammation. Besides, we classified and analyzed these molecules according to their effects on the progress of OA. Based on the analysis of the reported literature, this review reveals some pathogenesis of OA, and emphasizes that microRNA, lncRNA, and exosomes have great potential to assist early diagnosis and effective treatment of OA.

Macrophage-derived exosomes accelerate wound healing through their anti-inflammation effects in a diabetic rat model

Chronic, subclinical inflammation was often observed in the diabetic wound area, causing inadequate and delayed wound-healing effects by failing to initiate cell migration, proliferation, and extracellular matrix deposition. Therefore, we presented macrophage-derived exosomes (Exos) and explored their potential for inhibiting inflammation and accelerating diabetic wound healing in a skin defect, diabetic rat model. A thorough investigation demonstrated that Exos exerted anti-inflammatory effects by inhibiting the secretion of pro-inflammatory enzymes and cytokines. Furthermore, they accelerated the wound-healing process by inducing endothelial cell proliferation and migration to improve angiogenesis and re-epithelialization in diabetic wounds.

Unveiling ncRNA regulatory axes in atherosclerosis progression

Completion of the human genome sequencing project highlighted the richness of the cellular RNA world, and opened the door to the discovery of a plethora of short and long non-coding RNAs (the dark transcriptome) with regulatory or structural potential, which shifted the balance of pathological gene alterations from coding to non-coding RNAs. Thus, disease risk assessment currently has to also evaluate the expression of new RNAs such as small micro RNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), competing endogenous RNAs (ceRNAs), retrogressed elements, 3'UTRs of mRNAs, etc. We are interested in the pathogenic mechanisms of atherosclerosis (ATH) progression in patients suffering Chronic Kidney Disease, and in this review, we will focus in the role of the dark transcriptome (non-coding RNAs) in ATH progression. We will focus in miRNAs and in the formation of regulatory axes or networks with their mRNA targets and with the lncRNAs that function as miRNA sponges or competitive inhibitors of miRNA activity. In this sense, we will pay special attention to retrogressed genomic elements, such as processed pseudogenes and Alu repeated elements, that have been recently seen to also function as miRNA sponges, as well as to the use or miRNA derivatives in gene silencing, anti-ATH therapies. Along the review, we will discuss technical developments associated to research in lncRNAs, from sequencing technologies to databases, repositories and algorithms to predict miRNA targets, as well as new approaches to miRNA function, such as integrative or enrichment analysis and their potential to unveil RNA regulatory networks.

Noncoding RNAs: New regulatory code in chondrocyte apoptosis and autophagy

Osteoarthritis (OA) is a bone and joint disease characterized by progressive cartilage degradation. In the face of global trends of population aging, OA is expected to become the fourth most common disabling disease by 2020. Nevertheless, the detailed pathogenesis of OA has not yet been elucidated. Noncoding RNAs (ncRNAs), including long noncoding RNAs, microRNAs, and circular RNAs, do not encode proteins but have recently emerged as important regulators of apoptosis and autophagy of chondrocytes, thereby highlighting a potential role in chondrocyte injury leading to OA onset and progression. We here review recent findings on these regulatory roles of ncRNAs to provide new directions for research on the pathogenesis of OA and offer new therapeutic targets for prevention and treatment. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.

Saga of Mcl-1: regulation from transcription to degradation

The members of the Bcl-2 family are the central regulators of various cell death modalities. Some of these proteins contribute to apoptosis, while others counteract this type of programmed cell death, thus balancing cell demise and survival. A disruption of this balance leads to the development of various diseases, including cancer. Therefore, understanding the mechanisms that underlie the regulation of proteins of the Bcl-2 family is of great importance for biomedical research. Among the members of the Bcl-2 family, antiapoptotic protein Mcl-1 is characterized by a short half-life, which renders this protein highly sensitive to changes in its synthesis or degradation. Hence, the regulation of Mcl-1 is of particular scientific interest, and the study of Mcl-1 modulators could aid in the understanding of the mechanisms of disease development and the ways of their treatment. Here, we summarize the present knowledge regarding the regulation of Mcl-1, from transcription to degradation, focusing on aspects that have not yet been described in detail.

Re-recognition of pseudogenes: From molecular to clinical applications

Pseudogenes were initially regarded as "nonfunctional" genomic elements that did not have protein-coding abilities due to several endogenous inactivating mutations. Although pseudogenes are widely expressed in prokaryotes and eukaryotes, for decades, they have been largely ignored and classified as gene "junk" or "relics". With the widespread availability of high-throughput sequencing analysis, especially omics technologies, knowledge concerning pseudogenes has substantially increased. Pseudogenes are evolutionarily conserved and derive primarily from a mutation or retrotransposon, conferring the pseudogene with a "gene repository" role to store and expand genetic information. In contrast to previous notions, pseudogenes have a variety of functions at the DNA, RNA and protein levels for broadly participating in gene regulation to influence the development and progression of certain diseases, especially cancer. Indeed, some pseudogenes have been proven to encode proteins, strongly contradicting their "trash" identification, and have been confirmed to have tissue-specific and disease subtype-specific expression, indicating their own value in disease diagnosis. Moreover, pseudogenes have been correlated with the life expectancy of patients and exhibit great potential for future use in disease treatment, suggesting that they are promising biomarkers and therapeutic targets for clinical applications. In this review, we summarize the natural properties, functions, disease involvement and clinical value of pseudogenes. Although our knowledge of pseudogenes remains nascent, this field deserves more attention and deeper exploration.

Silence of lncRNA MIAT protects ATDC5 cells against lipopolysaccharides challenge via up-regulating miR-132

The over-expanding role of lncRNA myocardial infarction associated transcript (MIAT) in various human diseases has been recently revealed. This study attempted to see the role of MIAT in a cell model of osteoarthritis (OA). ATDC5 cells were subjected to lipopolysaccharides (LPS) to mimic a cell model of OA. The effects of MIAT on the model were tested by performing CCK-8 assay, flow cytometry, qRT-PCR, western blot and ELISA. The downstream miRNA and signalling pathways were studied by utilizing qRT-PCR and western blot. Transfection of ATDC5 cells with the shRNA specific against MIAT significantly attenuated LPS-evoked apoptosis and cytokines release. At the meantime, the viability loss and the cleavage of caspases were ameliorated as well. MIAT overexpressed lead to the opposite result. Further, miR-132 was found to be negatively regulated by MIAT. The protective effects of MIAT silence were flattened when miR-132 expression was suppressed. Besides that the inhibitory effects of MIAT silence on LPS-evoked NF-κB and JNK activation were eliminated by miR-132 silence. This study illustrated that silence of MIAT protected ATDC5 cells against LPS challenge. The chondroprotective effects of MIAT silence may be via up-regulation of miR-132 and inhibition of NF-κB and JNK pathways.

The pivotal role and mechanism of long non-coding RNA B3GALT5-AS1 in the diagnosis of acute pancreatitis

The present study planned to dig the potential impacts of long non-coding RNA B3GALT5-AS1 in acute pancreatitis (AP). A total of 66 patients who were diagnosed with AP using ultrasonic imaging were enrolled in the study. Expression levels of B3GALT5-AS1 in the serum of AP patients were determined. Afterwards, rat pancreatic AR42J acinar cells were disposed with caerulein to produce AP-like injury. The role and molecular mechanisms of B3GALT5-AS1 in AP were explored through in vitro cell experiments. The levels of lncRNA B3GALT5-AS1 were observed to be lessened in patients with AP relative to healthy controls. In addition, caerulein was observed to induce injuries in the AR42J cells (depressed cell viability, enhanced cell apoptosis, cytokines production, and levels of amylase). Overexpression of B3GALT5-AS1 alleviated the caerulein-produced injury in the AR42J cells. Moreover, it was determined that miR-203 showed a downside expression by B3GALT5-AS1 regulation, and the overexpression of B3GALT5-AS1 retrained caerulein-produced injury through the suppression of miR-203. In addition, it was observed that miR-203 lessened the level of nuclear factor interleukin-3 (NFIL3) and that NFIL3 was targeted by miR-203. Lastly, the impacts of B3GALT5-AS1 on caerulein-induced cell injury were manifested through the NF-κB signalling pathway. The data from the present study revealed that in patients with AP, B3GALT5-AS1 is expressed in reduced amounts. Overexpression of B3GALT5-AS1 may alleviate caerulein-induced cell injury in AR42J cells through the regulation of miR-203/NFIL3 axis and by inhibiting the activation of the NF-κB signals.

Downregulation Of LncRNA PMS2L2 In Endometrial Adenocarcinoma Upon Carboplatin Treatment

Background

LncRNA PMS2L2 plays critical protective roles in chondrocytes during lipopolysaccharide-induced inflammation. Our preliminary deep sequencing revealed the altered expression of PMS2L2 in endometrial adenocarcinoma (EA) during chemotherapy. This observation triggered our interest to explore the functions of PMS2L2 in EA.

Methods

Levels of PMS2L2 in plasma were measured by qPCR. ROC curve analysis was used for diagnostic analysis. Cell viability was analyzed by cell viability assay.

Results

We showed that plasma PMS2L2 was downregulated in EA patients compared with healthy controls, and downregulation of PMS2L2 distinguished early-stage EA patients from healthy controls. During carboplatin-based chemotherapy, plasma levels of PMS2L2 were significantly downregulated in endometrial cancer patients. Overexpression of PMS2L2 led to decreased viability of EA cells, while PMS2L2 siRNA silencing led to increased viability of EA cells.

Conclusion

LncRNA PMS2L2 in endometrial cancer was downregulated during carboplatin treatment and regulates chemosensitivity.

Inhibition of Long Non-coding RNA CTD-2574D22.4 Alleviates LPS-induced Apoptosis and Inflammatory Injury of Chondrocytes

Background:

Osteoarthritis (OA) is a common joint disease characterized by cartilage degeneration. Long non-coding RNAs (lncRNAs) have been associated with inflammatory diseases, including OA. Here, we investigated the potential molecular role of lncRNAs in OA pathogenesis.

Methods:

ATDC5 cells were treated with lipopolysaccharides (LPS), and qPCR was used to identify and determine expression of potential lncRNAs involved in LPS-induced chondrocyte injury. Cell viability, apoptosis, and expression of cartilage-related genes and inflammatory cytokines were assessed after CTD-2574D22.4 knockdown.

Results:

After LPS stimulation, CTD-2574D22.4 was found to be the second highest up-regulated gene, and the enhanced expression was validated in OA chondrocytes. Moreover, CTD-2574D22.4 inhibition significantly rescued cell viability, suppressed by LPS stress, and markedly attenuated LPS-induced apoptosis. The expression of cartilage-degrading enzymes MMP-13 and ADAMTS-5 were increased, while type II collagen was reduced after LPS treatment. This trend was largely reversed by CTD-2574D22.4 knockdown. Additionally, mRNA and protein levels of key inflammatory cytokines (TNF-a, IL-6, and IL-1β) were significantly elevated in the LPS group and partially relieved upon CTD-2574D22.4 knockdown.

Conclusion:

CTD2574D22.4 knockdown ameliorates LPS-induced cartilage injury by protecting chondrocytes from apoptosis via anti-inflammation and anti- cartilage-degrading pathways. Thus, CTD2574D22.4 might be a potential diagnostic and therapeutic target for OA.

PRR34-AS1 overexpression promotes protection of propofol pretreatment against ischemia/reperfusion injury in a mouse model after total knee arthroplasty via blockade of the JAK1-dependent JAK-STAT signaling pathway

Long noncoding RNAs have been documented to be protective against ischemia/reperfusion (I/R) injury. However, few research works have focused on the protective effects of PRR34-AS1 on I/R injury after total knee arthroplasty (TKA). The objective of the present study was to investigate the possible effect of PRR34-AS1 on I/R injury after TKA. A mouse model with I/R injury after TKA was established. The interaction between PRR34-AS1 and Janus kinase 1 (JAK1) was examined and thoroughly investigated. Next, the effects of PRR34-AS1 on the expression of apoptosis-related proteins, JAS-signal transducer and activator of transcription (STAT) signaling pathways, and inflammation-related genes, chondrocyte proliferation, and apoptosis were analyzed after gain- and loss-of-function experiments. Attenuated symptoms were observed in mice pretreated with propofol, which was evidenced by decreased positive expression rate of JAK1 protein and superoxide dismutase content along with increased malondialdehyde content and IL-10 levels. PRR34-AS1 was poorly expressed in mice with I/R injury after TKA. JAK1 was a target of PRR34-AS1. Upregulated PRR34-AS1 diminished expression of JAK1, STAT1, JAK2, and STAT3 as well as cell apoptosis, while enhancing cell proliferation in vitro. Furthermore, JAK1 silencing could reverse the suppressed cell proliferation and enhanced cell apoptosis of chondrocytes imposed by silencing PRR34-AS1. Upregulation of PRR34-AS1 can potentially relieve I/R injury after TKA in mice pretreated with propofol through inhibition of the JAS-STAT signaling pathway by targeting JAK1.

Non-Coding RNAs in Cartilage Development: An Updated Review

In the development of the skeleton, the long bones are arising from the process of endochondral ossification (EO) in which cartilage is replaced by bone. This complex process is regulated by various factors including genetic, epigenetic, and environmental elements. It is recognized that DNA methylation, higher-order chromatin structure, and post-translational modifications of histones regulate the EO. With emerging understanding, non-coding RNAs (ncRNAs) have been identified as another mode of EO regulation, which is consist of microRNAs (miRNAs or miRs) and long non-coding RNAs (lncRNAs). There is expanding experimental evidence to unlock the role of ncRNAs in the differentiation of cartilage cells, as well as the pathogenesis of several skeletal disorders including osteoarthritis. Cutting-edge technologies such as epigenome-wide association studies have been employed to reveal disease-specific patterns regarding ncRNAs. This opens a new avenue of our understanding of skeletal cell biology, and may also identify potential epigenetic-based biomarkers. In this review, we provide an updated overview of recent advances in the role of ncRNAs especially focus on miRNA and lncRNA in the development of bone from cartilage, as well as their roles in skeletal pathophysiology.

CXCL16 protects against oxygen and glucose deprivation-induced injury in human microvascular endothelial cells-1: Potential role in ischemic stroke

AIM

To explore the protective effect of chemokine ligand 16 (CXCL16) against cell damage induced by oxygen-glucose deprivation (OGD) in human microvascular endothelial cells-1 (HMEC-1) and its possible mechanism.

METHODS

Cell Counting Kit-8 (CCK-8) assay and flow cytometry were performed to determine cell viability and apoptosis of HMEC-1, respectively. qRT-PCR analysis was applied to display the expression of CXCL16 and miR-424. Western blot analysis was used to detect the expression of apoptosis-related proteins, CXCL16, cAMP/PKA/CREB, and PI3K-AKT-GSK3β pathway-related proteins.

RESULTS

OGD significantly inhibited cell viability and promoted apoptosis. CXCL16 overexpression decreased the proliferation inhibition and apoptosis of HMEC-1 induced by OGD. Furthermore, we found that CXCL16 was a target of miR-424 and was downregulated by miR-424. The further study showed that overexpression of miR-424 significantly increased proliferation inhibition and apoptosis of HMEC-1 induced by OGD. In addition, we also found that miR-424 was downregulated by PMS2L2. In the subsequence experiment, overexpression of PMS2L2 significantly decreased the proliferation inhibition and apoptosis of HMEC-1 induced by OGD, which suggested that PMS2L2 decreased cell damage of HMEC-1 induced by OGD. Simultaneously, CXCL16 treatment markedly increased the phosphorylation of PKA/CREB and PI3K-AKT-GSK3β and these signal pathways were blocked by signal inhibitors.

CONCLUSION

Our study first demonstrates that oxygen-glucose deprivation (OGD)-induced human microvascular endothelial cells-1 (HMEC-1) cell injury was alleviated by CXCL16 targeted by miR-424 which further targeted by PMS2L2. This process might also be regulated by activating PKA/CREB and PI3K-AKT-GSK3β pathways.