Rational design of multifunctional hydrogels targeting the microenvironment of diabetic periodontitis.

Periodontitis is a chronic inflammatory disease and is the primary contributor to adult tooth loss. Diabetes exacerbates periodontitis, accelerates periodontal bone resorption. Thus, effectively managing periodontitis in individuals with diabetes is a long-standing challenge. This review introduces the etiology and pathogenesis of periodontitis, and analyzes the bidirectional relationship between diabetes and periodontitis. In this review, we comprehensively summarize the four pathological microenvironments influenced by diabetic periodontitis: high glucose microenvironment, bacterial infection microenvironment, inflammatory microenvironment, and bone loss microenvironment. The hydrogel design strategies and latest research development tailored to the four microenvironments of diabetic periodontitis are mainly focused on. Finally, the challenges and potential solutions in the treatment of diabetic periodontitis are discussed. We believe this review will be helpful for researchers seeking novel avenues in the treatment of diabetic periodontitis.

GDF11 mitigates high glucose-induced cardiomyocytes apoptosis by inhibiting the ALKBH5-FOXO3-CDR1as/Hippo signaling pathway.

Diabetic cardiomyopathy remains a formidable health challenge with a high mortality rate and no targeted treatments. Growth differentiation factor 11 (GDF11) has shown promising effects on cardiovascular diseases; however, its role and the underlying mechanism in regulating diabetic cardiomyopathy remain unclear. In this study, we developed mouse models of diabetic cardiomyopathy using leptin receptor-deficient (db/db) mice and streptozocin-induced C57BL/6 mice. The diabetic cardiomyopathy model mice exhibited apparent structural damage in cardiac tissues and a significant increase in the expression of apoptosis-related proteins. Notably, we observed a significant decreased expression of GDF11 in the myocardium of mice with diabetic cardiomyopathy. Moreover, GDF11 cardiac-specific knock-in mice (transgenic mice) exhibited improved cardiac function and reduced apoptosis. Moreover, exogenous administration of GDF11 mitigated high glucose-induced cardiomyocyte apoptosis. Mechanistically, we demonstrated that GDF11 alleviated high glucose-induced cardiomyocytes apoptosis by inhibiting the activation of the alkylation repair homolog 5 (ALKBH5)-forkhead box group O3a (FOXO3)-cerebellar degeneration-related protein 1 transcript (CDR1as)/Hippo signaling pathway. Consequently, this novel mechanism effectively counteracted myocardial cell apoptosis, providing valuable insights into potential therapeutic strategies for clinical diabetic cardiomyopathy.

The role of TNC in atherosclerosis and drug development opportunities.

Tenascin C (TNC), a rich glycoprotein of the extracellular matrix, exhibits a pro-atherosclerosis or anti-atherosclerosis effect depending on its location. TNC, especially its C domain/isoform (TNC-C), is strongly overexpressed in atherosclerotic plaque active areas but virtually undetectable in most normal adult tissues, suggesting that TNC is a promising delivery vector target for atherosclerosis-targeted drugs. Many delivery vectors were investigated by recognizing TNC-C, including G11, G11-iRGD, TN11, PL1, and PL3. F16 and FNLM were also investigated by recognizing TNC-A1 and TNC, respectively. Notably, iRGD was undergoing clinical trials. PL1 not only recognizes TNC-C but also the extra domain-B (EDB) of fibronectin (FN), which is also a promising delivery vector for atherosclerosis-targeted drugs, and several conjugate agents are undergoing clinical trials. The F16-conjugate agent F16IL2 is undergoing clinical trials. Therefore, G11-iRGD, PL1, and F16 have great development value. Furthermore, ATN-RNA and IMA950 were investigated in clinical trials as therapeutic drugs and vaccines by targeting TNC, respectively. Therefore, targeting TNC could greatly improve the success rate of atherosclerosis-targeted drugs and/or specific drug development. This review discussed the role of TNC in atherosclerosis, atherosclerosis-targeted drug delivery vectors, and agent development to provide knowledge for drug development targeting TNC.

The translational potential of miR-26 in atherosclerosis and development of agents for its target genes ACC1/2, COL1A1, CPT1A, FBP1, DGAT2, and SMAD7.

Atherosclerosis is one of the leading causes of death worldwide. miR-26 is a potential biomarker of atherosclerosis. Standardized diagnostic tests for miR-26 (MIR26-DX) have been developed, but the fastest progress has been in predicting the efficacy of IFN-α therapy for hepatocellular carcinoma (HCC, phase 3). MiR-26 slows atherosclerosis development by suppressing ACC1/2, ACLY, ACSL3/4, ALDH3A2, ALPL, BMP2, CD36, COL1A1, CPT1A, CTGF, DGAT2, EHHADH, FAS, FBP1, GATA4, GSK3ß, G6PC, Gys2, HMGA1, HMGB1, LDLR, LIPC, IL-1ß, IL-6, JAG2, KCNJ2, MALT1, ß-MHC, NF-κB, PCK1, PLCß1, PYGL, RUNX2, SCD1, SMAD1/4/5/7, SREBF1, TAB3, TAK1, TCF7L2, and TNF-α expression. Many agents targeting these genes, such as the ACC1/2 inhibitors GS-0976, PF-05221304, and MK-4074; the DGAT2 inhibitors IONIS-DGAT2Rx, PF-06427878, PF-0685571, and PF-07202954; the COL1A1 inhibitor HT-100; the stimulants 68Ga-CBP8 and RCT-01; the CPT1A inhibitors etomoxir, perhexiline, and teglicar; the FBP1 inhibitors CS-917 and MB07803; and the SMAD7 inhibitor mongersen, have been investigated in clinical trials. Interestingly, miR-26 better reduced intima-media thickness (IMT) than PCSK9 or CT-1 knockout. Many PCSK9 inhibitors, including alirocumab, evolocumab, inclisiran, AZD8233, Civi-007, MK-0616, and LIB003, have been investigated in clinical trials. Recombinant CT-1 was also investigated in clinical trials. Therefore, miR-26 is a promising target for agent development. miR-26 promotes foam cell formation by reducing ABCA1 and ARL4C expression. Multiple materials can be used to deliver miR-26, but it is unclear which material is most suitable for mass production and clinical applications. This review focuses on the potential use of miR-26 in treating atherosclerosis to support the development of agents targeting it.

The regulatory effect of growth differentiation factor 11 on different cells.

Growth differentiation factor 11 (GDF11) is one of the important factors in the pathophysiological process of animals. It is widely expressed in many tissues and organs of animals, showing its wide biological activity and potential application value. Previous research has demonstrated that GDF11 has a therapeutic effect on various diseases, such as anti-myocardial aging and anti-tumor. This has not only sparked intense interest and enthusiasm among academics but also spurred some for-profit businesses to attempt to develop GDF11 as a medication for regenerative medicine or anti-aging application. Currently, Sotatercept, a GDF11 antibody drug, is in the marketing application stage, and HS-235 and rGDF11 are in the preclinical research stage. Therefore, we believe that figuring out which cells GDF11 acts on and its current problems should be an important issue in the scientific and commercial communities. Only through extensive, comprehensive research and discussion can we better understand the role and potential of GDF11, while avoiding unnecessary risks and misinformation. In this review, we aimed to summarize the role of GDF11 in different cells and its current controversies and challenges, providing an important reference for us to deeply understand the function of GDF11 and formulate more effective treatment strategies in the future.

Unlocking the potential of targeting histone-modifying enzymes for treating IBD and CRC.

Dysregulation of histone modifications has been implicated in the pathogenesis of both inflammatory bowel disease (IBD) and colorectal cancer (CRC). These diseases are characterized by chronic inflammation, and alterations in histone modifications have been linked to their development and progression. Furthermore, the gut microbiota plays a crucial role in regulating immune responses and maintaining gut homeostasis, and it has been shown to exert effects on histone modifications and gene expression in host cells. Recent advances in our understanding of the roles of histone-modifying enzymes and their associated chromatin modifications in IBD and CRC have provided new insights into potential therapeutic interventions. In particular, inhibitors of histone-modifying enzymes have been explored in clinical trials as a possible therapeutic approach for these diseases. This review aims to explore these potential therapeutic interventions and analyze previous and ongoing clinical trials that examined the use of histone-modifying enzyme inhibitors for the treatment of IBD and CRC. This paper will contribute to the current body of knowledge by exploring the latest advances in the field and discussing the limitations of existing approaches. By providing a comprehensive analysis of the potential benefits of targeting histone-modifying enzymes for the treatment of IBD and CRC, this review will help to inform future research in this area and highlight the significance of understanding the functions of histone-modifying enzymes and their associated chromatin modifications in gastrointestinal disorders for the development of potential therapeutic interventions.

The role of CDR1as/ciRS-7 in cardio-cerebrovascular diseases.

Cerebellar degeneration-related protein 1 antisense RNA (CDR1as), also known as ciRS-7, is a circular natural antisense transcript of CDR1. It is a widely studied and powerful representative of circular RNAs. Based on its widely reported role in cancer, CDR1as is considered one of the most promising biomarkers for diagnosing and treating tumours. However, some recent studies have extensively focused on its regulatory role in cardio-cerebrovascular diseases instead of in tumours. Studies have shown that CDR1as plays a unique role in the occurrence of cardio-cerebrovascular diseases; thus, it may be a potential target for preventing and treating cardio-cerebrovascular diseases. Furthermore, CDR1as has also been found to be related to signal transduction pathways related to inflammatory response, oxidative stress, etc., which may reveal its potential mechanism in cardio-cerebrovascular diseases. However, there is no literature to summarize the role and possible mechanism of CDR1as in cardio-cerebrovascular diseases. Therefore, in the present review, we have comprehensively summarised the latest progress in the biological characteristics, development processes, regulatory mechanisms, and roles of CDR1as in cardio-cerebrovascular diseases, aiming to provide a reference and guidance for future studies.

Growth differentiation factor 11: A new hope for the treatment of cardiovascular diseases.

Growth differentiation factor 11 (GDF11) is a member of the transforming growth factor-ß superfamily that has garnered significant attention due to its anti-cardiac aging properties. Many studies have revealed that GDF11 plays an indispensable role in the onset of cardiovascular diseases (CVDs). Consequently, it has emerged as a potential target and novel therapeutic agent for CVD treatment. However, currently, no literature reviews comprehensively summarize the research on GDF11 in the context of CVDs. Therefore, herein, we comprehensively described GDF11's structure, function, and signaling in various tissues. Furthermore, we focused on the latest findings concerning its involvement in CVD development and its potential for clinical translation as a CVD treatment. We aim to provide a theoretical basis for the prospects and future research directions of the GDF11 application regarding CVDs.

The potential role and mechanism of circRNA/miRNA axis in cholesterol synthesis.

Cholesterol levels are an initiating risk factor for atherosclerosis. Many genes play a central role in cholesterol synthesis, including HMGCR, SQLE, HMGCS1, FDFT1, LSS, MVK, PMK, MVD, FDPS, CYP51, TM7SF2, LBR, MSMO1, NSDHL, HSD17B7, DHCR24, EBP, SC5D, DHCR7, IDI1/2. Especially, HMGCR, SQLE, FDFT1, LSS, FDPS, CYP51, and EBP are promising therapeutic targets for drug development due to many drugs have been approved and entered into clinical research by targeting these genes. However, new targets and drugs still need to be discovered. Interestingly, many small nucleic acid drugs and vaccines were approved for the market, including Inclisiran, Patisiran, Inotersen, Givosiran, Lumasiran, Nusinersen, Volanesorsen, Eteplirsen, Golodirsen, Viltolarsen, Casimersen, Elasomeran, Tozinameran. However, these agents are all linear RNA agents. Circular RNAs (circRNAs) may have longer half-lives, higher stability, lower immunogenicity, lower production costs, and higher delivery efficiency than these agents due to their covalently closed structures. CircRNA agents are developed by several companies, including Orna Therapeutics, Laronde, and CirCode, Therorna. Many studies have shown that circRNAs regulate cholesterol synthesis by regulating HMGCR, SQLE, HMGCS1, ACS, YWHAG, PTEN, DHCR24, SREBP-2, and PMK expression. MiRNAs are essential for circRNA-mediated cholesterol biosynthesis. Notable, the phase II trial for inhibiting miR-122 with nucleic acid drugs has been completed. Suppressing HMGCR, SQLE, and miR-122 with circRNA_ABCA1, circ-PRKCH, circEZH2, circRNA-SCAP, and circFOXO3 are the promising therapeutic target for drug development, specifically the circFOXO3. This review focuses on the role and mechanism of the circRNA/miRNA axis in cholesterol synthesis in the hope of providing knowledge to identify new targets.

Marine Sulfated Polysaccharide PMGS Synergizes with Paclitaxel in Inhibiting Cervical Cancer In Vitro.

The incidence and mortality of cervical cancer in female malignancies are second only to breast cancer, which brings a heavy health and economic toll worldwide. Paclitaxel (PTX)-based regimens are the first-class choice; however, severe side effects, poor therapeutic effects, and difficulty in effectively preventing tumor recurrence or metastasis are unavoidable. Therefore, it is necessary to explore effective therapeutic interventions for cervical cancer. Our previous studies have shown that PMGS, a marine sulfated polysaccharide, exhibits promising anti-human papillomavirus (anti-HPV) effects through multiple molecular mechanisms. In this article, a continuous study identified that PMGS, as a novel sensitizer, combined with PTX exerted synergistic anti-tumor effects on cervical cancer associated with HPV in vitro. Both PMGS and PTX inhibited the proliferation of cervical cancer cells, and the combination of PMGS with PTX displayed significant synergistic effects on Hela cells. Mechanistically, PMGS synergizes with PTX by enhancing cytotoxicity, inducing cell apoptosis and inhibiting cell migration in Hela cells. Collectively, the combination of PTX and PMGS potentially provides a novel therapeutic strategy for cervical cancer.

MST1: A future novel target for cardiac diseases.

Major heart diseases pose a serious threat to human health. Finding early diagnostic markers and key therapeutic targets is an urgent scientific problem in this field. Mammalian sterile 20-like kinase 1 (MST1) is a protein kinase, and the occurrence of many heart diseases is related to the continuous activation of the MST1 gene. With the deepening of the research, the potential role of MST1 in promoting the development of heart disease has become more apparent. Therefore, to better understand the role of MST1 in the pathogenesis of heart disease, this work systematically summarizes the role of MST1 in the pathogenesis of heart disease, gives a comprehensive overview of its possible strategies in the diagnosis and treatment of heart disease, and analyzes its potential significance as a marker for the diagnosis and treatment of heart disease.

GDF11 promotes wound healing in diabetic mice via stimulating HIF-1ɑ-VEGF/SDF-1ɑ-mediated endothelial progenitor cell mobilization and neovascularization.

Non-healing diabetic wounds (DW) are a serious clinical problem that remained poorly understood. We recently found that topical application of growth differentiation factor 11 (GDF11) accelerated skin wound healing in both Type 1 DM (T1DM) and genetically engineered Type 2 diabetic db/db (T2DM) mice. In the present study, we elucidated the cellular and molecular mechanisms underlying the action of GDF11 on healing of small skin wound. Single round-shape full-thickness wound of 5-mm diameter with muscle and bone exposed was made on mouse dorsum using a sterile punch biopsy 7 days following the onset of DM. Recombinant human GDF11 (rGDF11, 50 ng/mL, 10 µL) was topically applied onto the wound area twice a day until epidermal closure (maximum 14 days). Digital images of wound were obtained once a day from D0 to D14 post-wounding. We showed that topical application of GDF11 accelerated the healing of full-thickness skin wounds in both type 1 and type 2 diabetic mice, even after GDF8 (a muscle growth factor) had been silenced. At the cellular level, GDF11 significantly facilitated neovascularization to enhance regeneration of skin tissues by stimulating mobilization, migration and homing of endothelial progenitor cells (EPCs) to the wounded area. At the molecular level, GDF11 greatly increased HIF-1ɑ expression to enhance the activities of VEGF and SDF-1ɑ, thereby neovascularization. We found that endogenous GDF11 level was robustly decreased in skin tissue of diabetic wounds. The specific antibody against GDF11 or silence of GDF11 by siRNA in healthy mice mimicked the non-healing property of diabetic wound. Thus, we demonstrate that GDF11 promotes diabetic wound healing via stimulating endothelial progenitor cells mobilization and neovascularization mediated by HIF-1ɑ-VEGF/SDF-1ɑ pathway. Our results support the potential of GDF11 as a therapeutic agent for non-healing DW.

NAD+ attenuates cardiac injury after myocardial infarction in diabetic mice through regulating alternative splicing of VEGF in macrophages.

Diabetic mellitus (DM) complicated with myocardial infarction (MI) is a serious clinical issue that remained poorly comprehended. The aim of the present study was to investigate the role of NAD+ in attenuating cardiac damage following MI in diabetic mice. The cardiac dysfunction in DM mice with MI was more severe compared with the non-diabetic mice and NAD+ administration could significantly improve the cardiac function in both non-diabetic and diabetic mice after MI for both 7 days and 28 days. Moreover, application of NAD+ could markedly reduce the cardiac injury area of DM complicated MI mice. Notably, the level of NAD+ was robustly decreased in the cardiac tissue of MI mice, which was further reduced in the DM complicated mice and NAD+ administration could significantly restore the NAD+ level. Furthermore, NAD+ was verified to facilitate the angiogenesis in the MI area of both diabetic mice and non-diabetic mice by microfil perfusion assay and immunofluorescence. Additionally, we demonstrated that NAD+ promoted cardiac angiogenesis after myocardial infarction in diabetic mice by promoting the M2 polarization of macrophages. At the molecular level, NAD+ promoted the secretion of VEGF in macrophages and therefore facilitating migration and tube formation of endothelial cells. Mechanistically, NAD+ was found to promote the generation of pro-angionesis VEGF165 and inhibit the generation of anti-angionesis VEGF165b via regulating the alternative splicing factors of VEGF (SRSF1 and SRSF6) in macrophages. The effects of NAD+ were readily reversible on deficiency of it. Collectively, our data showed that NAD+ could attenuate myocardial injury via regulating the alternative splicing of VEGF and promoting angiogenesis in diabetic mice after myocardial infarction. NAD+ administration may therefore be considered a potential new approach for the treatment of diabetic patients with myocardial infarction.

Review of preclinical data of PF-07304814 and its active metabolite derivatives against SARS-CoV-2 infection.

Main protease (Mpro) is a superior target for anti-SARS-COV-2 drugs. PF-07304814 is a phosphate ester prodrug of PF-00835231 that is rapidly metabolized into the active metabolite PF-00835231 by alkaline phosphatase (ALP) and then suppresses SARS-CoV-2 replication by inhibiting Mpro. PF-07304814 increased the bioavailability of PF-00835231 by enhancing plasma protein binding (PPB). P-glycoprotein (P-gp) inhibitors and cytochrome P450 3A (CYP3A) inhibitors increased the efficacy of PF-00835231 by suppressing its efflux from target cells and metabolism, respectively. The life cycle of SARS-CoV-2 is approximately 4 h. The mechanisms and efficacy outcomes of PF-00835231 occur simultaneously. PF-00835231 can inhibit not only cell infection (such as Vero E6, 293T, Huh-7.5, HeLa+angiotensin-converting enzyme 2 (ACE2), A549+ACE2, and MRC-5) but also the human respiratory epithelial organ model and animal model infection. PF-07304814 exhibits a short terminal elimination half-life and is cleared primarily through renal elimination. There were no significant adverse effects of PF-07304814 administration in rats. Therefore, PF-07304814 exhibits good tolerability, pharmacology, pharmacodynamics, pharmacokinetics, and safety in preclinical trials. However, the Phase 1 data of PF-07304814 were not released. The Phase 2/3 trial of PF-07304814 was also suspended. Interestingly, the antiviral activities of PF-00835231 derivatives (compounds 5-22) are higher than, similar to, or slightly weaker than those of PF-00835231. In particular, compound 22 exhibited the highest potency and had good safety and stability. However, the low solubility of compound 22 limits its clinical application. Prodrugs, nanotechnology and salt form drugs may solve this problem. In this review, we focus on the preclinical data of PF-07304814 and its active metabolite derivatives to hopefully provide knowledge for researchers to study SARS-CoV-2 infection.

LncRNA-ZFAS1 Promotes Myocardial Ischemia-Reperfusion Injury Through DNA Methylation-Mediated Notch1 Down-Regulation in Mice.

The most devastating and catastrophic deterioration of myocardial ischemia-reperfusion injury (MIRI) is cardiomyocyte death. Here we aimed to evaluate the role of lncRNA-ZFAS1 in MIRI and delineate its mechanism of action. The level of lncRNA-ZFAS1 was elevated in MIRI hearts, and artificial knockdown of lncRNA-ZFAS1 in mice improved cardiac function. Notch1 is a potential target of lncRNA-ZFAS1, and lncRNA-ZFAS1 could bind to the promoter region of Notch1 and recruit DNMT3b to induce Notch1 methylation. Nicotinamide mononucleotide could promote the expression of Notch1 by competitively inhibiting the expression of DNMT3b and improving the apoptosis of cardiomyocytes and cardiac function.

Design, synthesis and biological evaluation of novel diarylpyridine derivatives as tubulin polymerisation inhibitors.

A set of novel diarylpyridines as anti-tubulin agents were designed, synthesised using a rigid pyridine as a linker to fix the cis-orientation of ring-A and ring-B. All of the target compounds were evaluated for their in vitro antiproliferative activities. Among them, 10t showed remarkable antiproliferative activities against three cancer cell lines (HeLa, MCF-7 and SGC-7901) in sub-micromolar concentrations. Consistent with its potent antiproliferative activity, 10t also displayed potent anti-tubulin activity. Cellular mechanism investigation elucidated 10t disrupted the cellular microtubule structure, arrested cell cycle at G2/M phase and induces apoptosis. Molecular modelling studies showed that 10t could bind to the colchicine binding site on microtubules. These results provide motivation and further guidance for the development of new CA-4 analogues.

Recent advances in bacteria-mediated cancer therapy.

Cancer is among the leading cause of deaths worldwide. Although conventional therapies have been applied in the fight against the cancer, the poor oxygen, low extracellular pH, and high interstitial fluid pressure of the tumor microenvironment mean that these treatments fail to completely eradicate cancer cells. Recently, bacteria have increasingly been considered to be a promising platform for cancer therapy thanks to their many unique properties, such as specific tumor-targeting ability, high motility, immunogenicity, and their use as gene or drug carriers. Several types of bacteria have already been used for solid and metastatic tumor therapies, with promising results. With the development of synthetic biology, engineered bacteria have been endowed with the controllable expression of therapeutic proteins. Meanwhile, nanomaterials have been widely used to modify bacteria for targeted drug delivery, photothermal therapy, magnetothermal therapy, and photodynamic therapy, while promoting the antitumor efficiency of synergistic cancer therapies. This review will provide a brief introduction to the foundation of bacterial biotherapy. We begin by summarizing the recent advances in the use of many different types of bacteria in multiple targeted tumor therapies. We will then discuss the future prospects of bacteria-mediated cancer therapies.

Comprehensive analysis of karyopherin alpha family expression in lung adenocarcinoma: Association with prognostic value and immune homeostasis.

Background: Karyopherin alpha (KPNA), a nuclear transporter, has been implicated in the development as well as the progression of many types of malignancies. Immune homeostasis is a multilevel system which regulated by multiple factors. However, the functional significance of the KPNA family in the pathogenesis of lung adenocarcinoma (LUAD) and the impact of immune homeostasis are not well characterized. Methods: In this study, by integrating the TCGA-LUAD database and Masked Somatic Mutation, we first conducted an investigation on the expression levels and mutation status of the KPNA family in patients with LUAD. Then, we constructed a prognostic model based on clinical features and the expression of the KPNA family. We performed functional enrichment analysis and constructed a regulatory network utilizing the differential genes in high-and low-risk groups. Lastly, we performed immune infiltration analysis using CIBERSORT. Results: Analysis of TCGA datasets revealed differential expression of the KPNA family in LUAD. Kaplan-Meier survival analyses indicated that the high expression of KPNA2 and KPNA4 were predictive of inferior overall survival (OS). In addition, we constructed a prognostic model incorporating clinical factors and the expression level of KPNA4 and KPNA5, which accurately predicted 1-year, 3-years, and 5-years survival outcomes. Patients in the high-risk group showed a poor prognosis. Functional enrichment analysis exhibited remarkable enrichment of transcriptional dysregulation in the high-risk group. On the other hand, gene set enrichment analysis (GSEA) displayed enrichment of cell cycle checkpoints as well as cell cycle mitotic in the high-risk group. Finally, analysis of immune infiltration revealed significant differences between the high-and low-risk groups. Further, the high-risk group was more prone to immune evasion while the inflammatory response was strongly associated with the low-risk group. Conclusions: the KPNA family-based prognostic model reflects many biological aspects of LUAD and provides potential targets for precision therapy in LUAD.

CircRNA CDR1as promotes cardiomyocyte apoptosis through activating hippo signaling pathway in diabetic cardiomyopathy.

Diabetic cardiomyopathy (DCM), as a major complication of diabetic patients, can cause myocardial metabolic remodeling and lead to severe and irreversible cardiac dysfunction. Previously, we found that the circular RNA cerebellar degeneration-related protein 1 antisense (Circ-CDR1as) independently predicted acute myocardial infarction (AMI) and might be a new indicator marker for this. However, CDR1as was not clearly described in diabetic cardiomyopathy. Therefore, our purpose was to deeply explore the function of CDR1as in DCM. In this study, we found that CDR1as was upregulated in DCM, and knockdown of CDR1as could improve the apoptosis caused by DCM. Mechanistically, CDR1as activates the Hippo signaling pathway by significantly inhibiting Mammalian sterile 20-like kinase 1 (MST1) ubiquitination level. Furthermore, as a transcriptional factor of CDR1as, Forkhead box group O3a (FOXO3) was identified to activate the Hippo signaling pathway. Notably, the total m6A level was downregulated in the cardiac tissue of DCM. Alk B homolog 5 (ALKBH5), a m6A demethylation enzyme, was upregulated in the cardiomyocytes of DCM mice and posttranscriptionally activated FOXO3 by m6A demethylation in an m6A-YTHDF2-dependent manner. Hence, our work reveals the key function of the ALKBH5-FOXO3-CDR1as/Hippo signaling pathway in DCM and provides insight into the critical roles of m6A methylation in DCM.

GDF11 replenishment protects against hypoxia-mediated apoptosis in cardiomyocytes by regulating autophagy.

GDF11 has been reported to play a critical role in rejuvenating hypertrophy heart, skeletal muscle, and blood vessel regeneration in aged mice. Whether GDF11 can regulate autophagy in cardiomyocytes remains largely unknown. Thus, the purpose of the present study was to investigate the effects of GDF11 on cardiomyocyte autophagy induced by hypoxia, in addition to the underlying mechanisms. By using the MTT assay, Flow cytometry assay, LIVE/DEAD® Viability/Cytotoxicity Kit Stains and TUNEL assay, we found that exogenous GDF11 decreased apoptosis caused by prolonged hypoxia in cardiomyocytes. The expression of GDF11 was decreased obviously both in the cardiac tissue of myocardial infarction mice and the hypoxia treated cardiomyocytes. Protein levels of cleaved caspase-3, p-AMPK, SQSTM1, LC3B-I/II and GDF11 were detected by western blot. Autophagosomes and autolysosomes were identified by confocal laser microscopy after transfecting with the mRFP-eGFP-LC3 plasmids. Antibody against GDF11 (anti-GDF11) was used to inhibit the function of GDF11. At the molecular level, exogenous GDF11 increased AMPK function and enhanced autophagy activity. Anti-GDF11 inhibited autophagy and aggravated hypoxia-induced apoptosis in cardiomyocytes. Thus, GDF11 might be a potential target for myocardial infarction therapy.