Knockdown MTMR14 promotes cell apoptosis and inhibits migration in liver cancer cells

HDAC1 Promotes Mitochondrial Pathway Apoptosis and Inhibits the Endoplasmic Reticulum Stress Response in High Glucose-Treated Schwann Cells via Decreased U4 Spliceosomal RNA

Dysfunction of Schwann cells, including cell apoptosis, autophagy inhibition, dedifferentiation, and pyroptosis, is a pivotal pathogenic factor in induced diabetic peripheral neuropathy (DPN). Histone deacetylases (HDACs) are an important family of proteins that epigenetically regulate gene transcription by affecting chromatin dynamics. Here, we explored the effect of HDAC1 on high glucose-cultured Schwann cells. HDAC1 expression was increased in diabetic mice and high glucose-cultured RSC96 cells, accompanied by cell apoptosis. High glucose also increased the mitochondrial pathway apoptosis-related Bax/Bcl-2 and cleaved caspase-9/caspase-9 ratios and decreased endoplasmic reticulum response-related GRP78, CHOP, and ATF4 expression in RSC96 cells (P < 0.05). Furthermore, overexpression of HDAC1 increased the ratios of Bax/Bcl-2, cleaved caspase-9/caspase-9, and cleaved caspase-3 and reduced the levels of GRP78, CHOP, and ATF4 in RSC96 cells (P < 0.05). In contrast, knockdown of HDAC1 inhibited high glucose-promoted mitochondrial pathway apoptosis and suppressed the endoplasmic reticulum response. Moreover, RNA sequencing revealed that U4 spliceosomal RNA was significantly reduced in HDAC1-overexpressing RSC96 cells. Silencing of U4 spliceosomal RNA led to an increase in Bax/Bcl-2 and cleaved caspase-9 and a decrease in CHOP and ATF4. Conversely, overexpression of U4 spliceosomal RNA blocked HDAC1-promoted mitochondrial pathway apoptosis and inhibited the endoplasmic reticulum response. In addition, alternative splicing analysis of HDAC1-overexpressing RSC96 cells showed that significantly differential intron retention (IR) of Rpl21, Cdc34, and Mtmr11 might be dominant downstream targets that mediate U4 deficiency-induced Schwann cell dysfunction. Taken together, these findings indicate that HDAC1 promotes mitochondrial pathway-mediated apoptosis and inhibits the endoplasmic reticulum stress response in high glucose-cultured Schwann cells by decreasing the U4 spliceosomal RNA/IR of Rpl21, Cdc34, and Mtmr11.

MTMR14 Alleviates Chronic Obstructive Pulmonary Disease as a Regulator in Inflammation and Emphysema

Extensive inflammation and apoptosis in structural cells of the lung are responsible for the progression and pathogenesis of chronic obstructive pulmonary disease (COPD). Myotubularin-related protein 14 (MTMR14) has been shown to participate in various biological processes, including apoptosis, inflammation, and autophagy. Nonetheless, the role of MTMR14 in COPD remains elusive. In the present study, we explored the expression of MTMR14 in human lung tissues and investigated the effects of overexpressed MTMR14 on in vitro and in vivo COPD models. Moreover, one of the possible mechanisms of MTMR14 alleviating COPD was explored based on mitochondrial function and mitophagy homeostasis. The results showed that MTMR14 expression was reduced in COPD patients' lungs in comparison to control subjects. MTMR14 overexpression inhibited cigarette smoke extract-induced inflammation and apoptosis and improved mitochondrial function and mitophagy in vitro. Further verification was carried out in COPD model mice. MTMR14 overexpression inhibited lung inflammation and reduced levels of IL-6 and KC in bronchoalveolar lavage fluid, as well as prevented emphysema and a decline in lung function. Furthermore, MTMR14 overexpression improved mitochondrial function and mitophagy to a certain extent. Collectively, our data support the hypothesis that MTMR14 participates in the pathogenesis of COPD. Improving mitochondrial function and mitophagy homeostasis may be one of the mechanisms by which MTMR14 alleviates COPD and may potentially be a novel therapeutic target for COPD.

Structural characterization of a low molecular weight Bletilla striata polysaccharide and antitumor activity on H22 tumor-bearing mice

In this study, a novel low molecular weight polysaccharide (named LMW-BSP) was extracted from Bletilla striata at 4 °C. The results of structural characteristics analysis showed that LMW-BSP was a 23 kDa neutral polysaccharide contained glucose and mannose at a molar ratio of 1.00:1.26. Structural investigations of the periodate oxidation studies, Smith-degradation as well as methylation were performed, and combined with 1D and 2D NMR spectroscopy, the main chain residues sequence of LMW-BSP was concluded to be: α-D-Manp-(1 → 3)-β-D-Manp-(1 → [4)-β-D-Glcp-(1]₂ → 4)-β-D-Manp-(1 → 3)-β-D-Manp-(1→. Moreover, the antitumor activity of LMW-BSP was evaluated in H22 tumor-bearing mice. And the results suggested that LMW-BSP could effectively improve immune cells activities and lymphocytes subsets proportions dose-dependently in tumor-bearing mice, leading to the apoptosis of H22 cells via G1 phase arrested. LMW-BSP inhibited tumor growth and exhibited antitumor effects in vivo. And it supported considering the novel polysaccharide as a potential drug component in hepatocellular carcinoma treatment.

Calcitonin gene-related peptide induces the histone H3 lysine 9 acetylation in astrocytes associated with neuroinflammation in rats with neuropathic pain

Aims

Calcitonin gene‐related peptide (CGRP) as a regulator of astrocyte activation may facilitate spinal nociceptive processing. Histone H3 lysine 9 acetylation (H3K9ac) is considered an important regulator of cytokine and chemokine gene expression after peripheral nerve injury. In this study, we explored the relationship between CGRP and H3K9ac in the activation of astrocytes, and elucidated the underlying mechanisms in the pathogenesis of chronic neuropathic pain.

Methods

Astroglial cells (C6) were treated with CGRP and differentially enrichments of H3K9ac on gene promoters were examined using ChIP‐seq. A chronic constriction injury (CCI) rat model was used to evaluate the role of CGRP on astrocyte activation and H3K9ac signaling in CCI‐induced neuropathic pain. Specific inhibitors were employed to delineate the involved signaling.

Results

Intrathecal injection of CGRP and CCI increased the number of astrocytes displaying H3K9ac in the spinal dorsal horn of rats. Treatment of CGRP was able to up‐regulate H3K9ac and glial fibrillary acidic protein (GFAP) expression in astroglial cells. ChIP‐seq data indicated that CGRP significantly altered H3K9ac enrichments on gene promoters in astroglial cells following CGRP treatment, including 151 gaining H3K9ac and 111 losing this mark, which mostly enriched in proliferation, autophagy, and macrophage chemotaxis processes. qRT‐PCR verified expressions of representative candidate genes (ATG12, ATG4C, CX3CR1, MMP28, MTMR14, HMOX1, RET) and RTCA verified astrocyte proliferation. Additionally, CGRP treatment increased the expression of H3K9ac, CX3CR1, and IL‐1β in the spinal dorsal horn. CGRP antagonist and HAT inhibitor attenuated mechanical and thermal hyperalgesia in CCI rats. Such analgesic effects were concurrently associated with the reduced levels of H3K9ac, CX3CR1, and IL‐1β in the spinal dorsal horn of CCI rats.

Conclusion

Our findings highly indicate that CGRP is associated with the development of neuropathic pain through astrocytes‐mediated neuroinflammatory responses via H3K9ac in spinal dorsa horn following nerve injury.

This study found that CGRP act on their astrocytic receptors and lead to H3K9 acetylation (H3K9ac), which are mainly associated with proliferation‐, autophagy‐, and inflammation‐related gene expression. The number of astrocytes with H3K9ac expression is increased after nerve injury. Inhibition of CGRP attenuates the development of neuropathic pain, which was accompanied by the suppression of H3K9ac, CX3CR1, and IL‐1β expression in CCI rats.

Identification of autophagy-related risk signatures for the prognosis, diagnosis, and targeted therapy in cervical cancer

Background

To rummage autophagy-related prognostic, diagnostic, and therapeutic biomarkers in cervical cancer (CC).

Methods

The RNA-sequence and clinical information were from the TCGA and GTEx databases. We operated Cox regression to determine signatures related to overall survival (OS) and recurrence-free survival (RFS) respectively. The diagnostic and therapeutic effectiveness of prognostic biomarkers were further explored.

Results

We identified nine (VAMP7, MTMR14, ATG4D, KLHL24, TP73, NAMPT, CD46, HGS, ATG4C) and three risk signatures (SERPINA1, HSPB8, SUPT20H) with prognostic values for OS and RFS respectively. Six risk signatures (ATG4C, ATG4D, CD46, TP73, SERPINA1, HSPB8) were selected for qPCR. We screened five prognostic signatures(ATG4C, CD46, HSPB8, MTMR14, NAMPT) with diagnostic function through the GEO database. Correlation between our models and treatment targets certificated the prognostic score provided a reference for precision medicine.

Conclusions

We constructed OS and RFS prognostic models in CC. Autophagy-related risk signatures might serve as diagnostic and therapeutic biomarkers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02073-w.

The Effects of Autophagy-Related Genes and lncRNAs in Therapy and Prognosis of Colorectal Cancer

Cellular autophagy plays an important role in the occurrence and development of colorectal cancer (CRC). Whether autophagy-related genes and lncRNAs can be used as ideal markers in CRC is still controversial. The purpose of this study is to identify novel treatment and prognosis markers of CRC. We downloaded transcription and clinical data of CRC from the GEO (GSE40967, GSE12954, GSE17536) and TCGA database, screened for differentially autophagy-related genes (DEAGs) and lncRNAs, constructed prognostic model, and analyzed its relationship with immune infiltration. TCGA and GEO datasets (GSE12954 and GSE17536) were used to validate the effect of the model. Oncomine database and Human Protein Atlas verified the expression of DEAGs. We obtained a total of 151 DEAGs in three verification sets collaboratively. Then we constructed a risk prognostic model through Lasso regression to obtain 15 prognostic DEAGs from the training set and verified the risk prognostic model in three verification sets. The low-risk group survived longer than the high-risk group. Age, gender, pathological stage, and TNM stage were related to the prognostic risk of CRC. On the other hand, BRAF status, RFS event, and tumor location are considered as most significant risk factors of CRC in the training set. Furthermore, we found that the immune score of the low-risk group was higher. The content of CD8 + T cells, active NK cells, macrophages M0, macrophages M1, and active dendritic cells was noted more in the high-risk group. The content of plasma cells, resting memory CD4 + T cells, resting NK cells, resting mast cells, and neutrophil cells was higher in the low-risk group. After all, the Oncomine database and immunohistochemistry verified that the expression level of most key autophagy-related genes was consistent with the results that we found. In addition, we obtained six lncRNAs co-expressed with DEAGs from the training set and found that the survival time was longer in the low-risk group. This finding was verified in the verification set and showed same trend to the results mentioned above. In the final analysis, these results indicate that autophagy-related genes and lncRNAs can be used as prognostic and therapeutic markers for CRC.

Combination treatment strategies with a focus on rosiglitazone and adriamycin for insulin resistant liver cancer

Insulin resistance promotes the occurrence of liver cancer and decreases its chemosensitivity. Rosiglitazone (ROSI), a thiazolidinedione insulin sensitiser, could be used for diabetes with insulin resistance and has been reported to show anticancer effects on human malignant cells. In this paper, we investigated the combination of ROSI and chemotherapeutics on the growth and metastasis of insulin-resistant hepatoma. In vitro assay, ROSI significantly enhanced the inhibitory effects of adriamycin (ADR) on the proliferation, autophagy and migration of insulin-resistant hepatoma HepG2/IR cells via downregulation of EGFR/ERK and AKT/mTOR signalling pathway. In addition, ROSI promoted the apoptosis of HepG2/IR cells induced by ADR. In vivo assay, high fat and glucose diet and streptozotocin (STZ) induced insulin resistance in mice by increasing the body weight, fasting blood glucose (FBG) level, oral glucose tolerance, fasting insulin level and insulin resistance index. Both the growth of mouse liver cancer hepatoma H22 cells and serum FBG level in insulin resistant mice were significantly inhibited by combination of ROSI and ADR. Thus, ROSI and ADR in combination showed a stronger anti-tumour effect in insulin resistant hepatoma cells accompanying with glucose reduction and might represent an effective therapeutic strategy for liver cancer accompanied with insulin resistant diabetes.

MTMR14 protects against hepatic ischemia-reperfusion injury through interacting with AKT signaling in vivo and in vitro

Hepatic ischemia-reperfusion (IR) injury is characterized by severe inflammation and cell death. However, very few effective therapies are presently available for hepatic IR injury treatment. Here, we reported a protective function and the underlying mechanism of myotubularin-related protein 14 (MTMR14) during hepatic IR injury. Hepatocyte-specific MTMR14 knockout (HKO) and transgenic (TG) mice were subjected to hepatic IR operation to explore MTMR14 function in vivo. Primary hepatocytes isolated from MTMR14-HKO and MTMR14-TG mice were subjected to hypoxia/reoxygenation (HR) insult in vitro. We found that MTMR14 expression in liver tissues from individuals with hepatic IR was markedly decreased, and similar results were detected in mice with hepatic IR surgery. MTMR14-TG mice following hepatic IR operation had obviously ameliorated liver pathological changes, along with improved hepatic dysfunction, which was proved by the decreased serum alanine amino transferase (ALT) and aspartate amino transferase (AST) levels. MTMR14-HKO and MTMR14-TG animal models indicated that MTMR14 alleviated cell death and inflammatory response. In addition, MTMR14 inhibited nuclear transcription factor κB (NF-κB) signaling. Of note, promoting MTMR14 expression improved phosphatidylinositol 3-kinase/protein kinase-B (PI3K/AKT) pathway through a physical interaction with AKT, subsequently reducing cell death and inflammation. Therefore, MTMR14 is a protective factor during hepatic IR injury, and the MTMR14/AKT signaling is involved the pathogenesis hepatic IR injury. Improvement of this axis might be a novel therapeutic strategy for the prevention of this pathological process.

Myotubularin-related protein 14 suppresses cardiac hypertrophy by inhibiting Akt

Cardiac hypertrophy (CH) is an independent risk factor for many cardiovascular diseases, and is one of the primary causes of morbidity and mortality in elderly people. Pathological CH involves excessive protein synthesis, increased cardiomyocyte size, and ultimately the development of heart failure. Myotubularin-related protein 14 (MTMR14) is a member of the myotubularin (MTM)-related protein family, which is involved in apoptosis, aging, inflammation, and autophagy. However, its exact function in CH is still unclear. Herein, we investigated the roles of MTMR14 in CH. We show that MTMR14 expression was increased in hypertrophic mouse hearts. Mice deficient in heart MTMR14 exhibited an aggravated aortic-banding (AB)-induced CH phenotype. In contrast, MTMR14 overexpression prevented pressure overload-induced hypertrophy. At the molecular level, prevention of CH in the absence of MTMR14 involved elevations in Akt pathway components, which are key elements that regulate apoptosis and cell proliferation. These results demonstrate that MTMR14 is a new molecular target for the treatment of CH.

Phosphatidylinositol 3 monophosphate metabolizing enzymes in blood platelet production and in thrombosis

Blood platelets, produced by the fragmentation of megakaryocytes, play a key role in hemostasis and thrombosis. Being implicated in atherothrombosis and other thromboembolic disorders, they represent a major therapeutic target for antithrombotic drug development. Several recent studies have highlighted an important role for the lipid phosphatidylinositol 3 monophosphate (PtdIns3P) in megakaryocytes and platelets. PtdIns3P, present in small amounts in mammalian cells, is involved in the control of endocytic trafficking and autophagy. Its metabolism is finely regulated by specific kinases and phosphatases. Class II (α, β and γ) and III (Vps34) phosphoinositide-3-kinases (PI3Ks), INPP4 and Fig4 are involved in the production of PtdIns3P whereas PIKFyve, myotubularins (MTMs) and type II PIPK metabolize PtdIns3P. By regulating the turnover of different pools of PtdIns3P, class II (PI3KC2α) and class III (Vps34) PI3Ks have been recently involved in the regulation of platelet production and functions. These pools of PtdIns3P appear to modulate membrane organization and intracellular trafficking. Moreover, PIKFyve and INPP4 have been recently implicated in arterial thrombosis. In this review, we will discuss the role of PtdIns3P metabolizing enzymes in platelet production and function. Potential new anti-thrombotic therapeutic perspectives based on inhibitors targeting specifically PtdIns3P metabolizing enzymes will also be commented.

Role of CircRNAs_100395 in Proliferation and Metastases of Liver Cancer

BACKGROUND Circular RNAs (circRNAs) are a kind of noncoding RNA with high cancer-specific expression, and great potential in regulating tumorigenesis. Among these, circRNA_100395 (circ_100395) has been reported to be downregulated in lung cancer, and participates in the process of tumor cell proliferation and metastasis. However, its expression and function in liver cancer remain unknown. MATERIAL AND METHODS Quantitative real-time polymerase chain reaction (RT-qPCR) was used to evaluate the expression level of circ_100395 and microRNAs-1228 (miR-1228) in liver cancer samples and the adjacent non-tumor tissues. Cell proliferation, apoptosis, invasion, migration, and epithelial-mesenchymal transition (EMT) pathway of circ_100395 upregulated cells were analyzed using a Cell Counting Kit-8 (CCK-8), flow cytometry, Transwell assay, and Western blot analysis. RESULTS We found that circ_100395 was downregulated in cancerous liver tissues relative to the adjacent normal tissues. The overexpression of circ_100395 was negatively associated with tumor differentiation, microvascular invasion, and portal vein tumor thrombosis. However, patients with higher circ_10039 expression tended to have better postoperative disease-free survival time. Moreover, upregulation of circ_100395 in liver cancer cells inhibited cell proliferation, induced apoptosis, then silenced the EMT pathway and reduced migration and invasion abilities, while this anti-tumor effect was significantly reversed by the downstream target, miR-1228. CONCLUSIONS circ_100395 appears to be a promising therapeutic target for liver cancer.