Acta biochimica et biophysica Sinica最新文献

Glucocorticoids (GCs) are commonly used to treat sudden sensorineural hearing loss (SSNHL), although some patients are resistant to this therapeutic approach. Clinical studies have demonstrated the efficacy of tanshinone IIA (TA) in combination with GC for managing various human ailments. However, it remains unclear whether TA can mitigate GC resistance in SSNHL. Our aim is to elucidate the role of NRF2-induced transcriptional regulation of HDAC2 in influencing GC resistance and investigate the involvement of TA-related molecular pathways in GC resistance. Here, HEI-OC1 cells are treated with lipopolysaccharide (LPS) to establish an in vitro model for SSNHL. The cells are subsequently treated with dexamethasone (DXE) or DXE+TA. RT-qPCR and western blot analysis are used to measure the mRNA and protein levels of Forkhead box P3 (FOXP3), nuclear factor erythroid 2-related factor 2 (NRF2), and histone deacetylase 2 (HDAC2). Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) assays are carried out to assess cell proliferation. Flow cytometry analysis is performed to evaluate apoptosis. Mechanistic studies involve chromatin immunoprecipitation (ChIP), luciferase reporter, and DNA pull-down assays. Our results show that treatment with TA+DEX significantly increases proliferation and suppresses apoptosis in LPS-treated HEI-treated OC1 cells. TA upregulates HDAC2 expression by activating NRF2-mediated transcription of HDAC2, with the NRF2-HDAC2 binding site located at bases 419-429 (ATGACACTCCA) in the promoter sequence of HDAC2. Furthermore, TA upregulates FOXP3 expression to activate NRF2 transcription, with the predicted FOXP3-binding site located at bases 864-870 (GCAAACA) in the promoter sequence of NRF2. In summary, these findings suggest that TA enhances the therapeutic effects of GC on the proliferation and apoptosis of HEI OC1 cells by increasing FOXP3/Nrf2 expression. These results indicate that TA may be promising for ameliorating GC resistance in patients with SSNHL.

Clitoria ternatea L. flowers are used as traditional herbal medicines and are known for their advanced pharmacological activities. Flavonoids and anthocyanins reportedly contribute to the therapeutic properties of C. ternatea flowers; however, their potential anti-bladder cancer effects and molecular mechanisms remain unknown. In this study, flavonoid- and anthocyanin-rich samples from C. ternatea flowers (DDH) are prepared via macroporous resin-based extraction coupled with an efficient and reliable two-dimensional UPLC-DAD-MS/MS method. In vitro and in vivo studies reveal that DDH can inhibit bladder cancer cell growth and enhance the anti-bladder cancer activity of cisplatin. RNA-seq combined with KEGG analysis reveals that fatty acid synthesis is closely related to the anti-bladder cancer effect of DDH. Furthermore, DDH dose-dependently reduces cellular fatty acid levels in bladder cancer cells, and the addition of fatty acids significantly mitigates DDH-induced cell growth inhibition. Subsequent findings reveal that DDH downregulates sterol regulatory element-binding protein 1 (SREBP1), a key transcriptional regulator of de novo fatty acid synthesis in cancer cells, and its downstream targets (FASN, SCD1, and ACC). Additionally, this study demonstrates that gallic acid not only enhances the stability of DDH but also synergistically potentiates its anti-bladder cancer activity. Our study suggests that targeting the SREBP1 pathway is an effective strategy in bladder cancer therapy, and the ability of DDH to induce cell death by inhibiting the SREBP1 pathway and its good tolerance in mice make it a promising strategy for preventing and treating bladder cancer.

Osteoarthritis (OA) is a significant contributor to pain and disability worldwide. Pain is the main complaint of OA patients attending the clinic and has a large impact on their quality of life and economic standards. However, existing treatments for OA-related pain have not been shown to achieve good relief. The main focus is on preventing and slowing the progression of OA so that the problem of OA pain can be resolved. Pain caused by OA is complex, with the nature, location, duration, and intensity of pain changing as the disease progresses. Previous research has highlighted the role of various forms of cell death, such as apoptosis and necrosis, in the progression of pain in OA. Emerging studies have identified additional forms of novel cell death, such as pyroptosis, ferroptosis, and necroptosis that are linked to pain in OA. Different types of cell death contribute to tissue damage in OA by impacting inflammatory responses, reactive oxygen species (ROS) production, and calcium ion levels, ultimately leading to the development of pain. Evidence suggests that targeting novel types of cell death could help alleviate pain in OA patients. This review delves into the complex mechanisms of OA pain, explores the relationship between different modes of novel cell death and pain, and proposes novel cell death as a viable strategy for the treatment of these conditions, with the goal of providing scientific references for the development of future OA pain treatments and drugs.

Circular RNAs play a pivotal role in the progression of various cancers. In our previous study, we observed high expression of the circRNA MALAT1 (cMALAT1) in intrahepatic cholangiocarcinoma (ICC) cells co-incubated with activated hepatic stellate cells. This study is designed to explore the roles of cMALAT1 and the underlying mechanisms in ICC. We find that cMALAT1 significantly facilitates the progression of ICC both in vitro and in vivo. The binding between cMALAT1 and miR-512-5p is subsequently confirmed through RNA pull-down experiments. As anticipated, the application of miR-512-5p mimics noticeably reverses the cMALAT1 overexpression-induced malignant phenotypes of ICC cells. Furthermore, VCAM1 is identified as a downstream gene of the cMALAT1/miR-512-5p axis. Importantly, silencing of VCAM1 not only effectively suppresses the malignant phenotypes of ICC cells but also significantly impairs the functions of cMALAT1. Our study reveals that cMALAT1 promotes the progression of ICC by competitively binding to VCAM1 mRNA with miR-512-5p, leading to the upregulation of VCAM1 expression and the activation of the PI3K/AKT signaling pathway.

In this study, we aim to investigate diacylglycerol kinase (DGK) γ expression in developing neural tubes (NTs) and its effects on neural stem cell (NSC) proliferation and migration. Whole-mount in situ hybridization (WMISH) and immunohistochemistry are performed to explore DGKγ localization in developing NTs in vivo. NSCs are treated with sh-DGKγ, R59949, or PMA in vitro. Cell counting kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay and neurosphere formation assay are utilized to evaluate NSC proliferation. Neurosphere migration assay and a transwell chamber assay are used to assess NSC migration. The diacylglycerol (DAG) content is detected via enzyme-linked immunosorbent assay (ELISA). The mRNA expression of DGKγ is detected via quantitative real-time polymerase chain reaction (qRT-PCR). The protein expression levels of DGKγ, protein kinase C (PKC) and phosphorylated PKC (p-PKC) are detected via western blot analysis. The results show that DGKγ mRNA is expressed predominantly in developing NTs. The neuroepithelium in developing NTs is positive for NSC markers, including Nestin, glial fibrillary acidic protein (GFAP), and DGKγ. DGKγ is expressed in the cytoplasm and nucleus of the neuroepithelium and is coexpressed with p-PKCγ and p-PKCδ. The proliferation of NSCs, the number of EdU-positive NSCs, and the number of neurospheres are decreased by sh-DGKγ and R59949 but increased by PMA. There is a shorter migration distance of NSCs and fewer migrated NSCs in the sh-DGKγ, R59949 and PMA groups. DAG content and the p-PKCδ/PKCδ ratio are increased by sh-DGKγ, R59949 and PMA, whereas the p-PKCγ/PKCγ ratio is decreased by PMA. Taken together, our findings indicate that DGKγ facilitates NSC proliferation and migration, which is responsible for the participation of DGK in NT development. DGKγ facilitates NSC migration via the DAG/PKCδ pathway.

Tim-1 (T-cell immunoglobulin and mucin domain 1), also known as Kim-1 (kidney injury molecule 1) or hepatitis A virus cellular receptor 1 (HAVCR1), is a transmembrane protein expressed on various immune and epithelial cells. It plays a role in modulating inflammatory and immune responses. In this study, we find that Tim-1 is overexpressed in hepatocellular carcinoma (HCC) samples and that its expression is significantly correlated with postoperative survival. Bulk RNA sequencing reveals a general upregulation of extracellular matrix-related genes in HCC tissues with Tim-1 overexpression. The results of the cell and in vivo experiments reveal that Tim-1 in HCC not only affects biological processes such as the proliferation, migration, and invasion of HCC cells but also broadly promotes extracellular matrix processes by influencing cytokine secretion. Further studies demonstrate that Tim-1 mediates the activation of hepatic stellate cells and upregulates Th1 and Th2 cytokines, thereby promoting HCC progression. Thus, Tim-1 may represent a novel target for future interventions in HCC and liver fibrosis.

Intestinal ischemia-reperfusion (I/R) injury severely affects the lungs. Germacrone (Ger) possesses anti-inflammatory and antioxidant properties. However, it is unclear whether it protects the lungs from I/R injury. In this study, we elucidate the mechanisms by which Ger protects lungs from I/R injury. C57BLKS/J male mice are subjected to I/R injury via complete clamping of the superior mesenteric artery. Ger is administered before intestinal I/R. Mitochondrial morphology is observed via electron microscopy. The histopathology of the lung tissues is monitored via hematoxylin-eosin and immunofluorescence staining. The mitochondrial oxygen consumption rate is measured via an XF96 extracellular flux analyzer. In the I/R mouse model, lung specimens present significant lung damage accompanied by increases in the levels of collagen III, vimentin, and α-SMA in lung tissues. After treatment with Ger, lung impairment and fibrosis in I/R-induced acute lung injury (ALI) model mice are restored, suggesting that Ger improves I/R-ALI. In addition, Ger administration decreases the release of inflammatory factors such as IL-1β, IL-6, and COX2, as well as the expressions of M1 macrophage markers, facilitating cell survival in the I/R-ALI model. Additionally, Ger (EC50: 47.16 μM) ameliorates mitochondrial dysfunction by increasing I/R-ALI-induced apoptosis, increasing the expression of SIRT1, and reducing the levels of HIF1-α, Nrf2, and OGG1 in MLE-12 cells. Ger may affect macrophage polarization and improve subsequent mitochondrial defects through the SIRT1-HIF1α-Nrf2 signaling pathway in MLE-12 cells, which ultimately improves lung function and lung inflammation in the I/R-ALI model.

Studies have shown that stress is associated with ovarian dysfunction. Norepinephrine (NE), a classic stress hormone involved in the stress response, is less recognized for its role in ovarian function. In this study, an NE-treated mouse model is induced by intraperitoneal injection of NE for 4 weeks. Compared with normal control mice, NE-treated mice show disturbances in the estrous cycle, decreased levels of anti-Mullerian hormone (AMH) and estradiol (E2), and increased level of follicle-stimulating hormone (FSH). Additionally, the numbers of primordial follicles, primary follicles, secondary follicles, and antral follicles are decreased, whereas the number of atretic follicles is increased in NE-treated mice, indicating NE-induced ovarian dysfunction. RNA sequencing further reveals that genes associated with ferroptosis are significantly enriched in NE-treated ovarian tissues. Concurrently, the levels of reactive oxygen species (ROS), ferrous ions, and malondialdehyde (MDA) are increased, whereas the expression level of glutathione peroxidase 4 (GPX4) is decreased. To elucidate the mechanism of NE-induced ferroptosis in ovaries and the potential reversal by Coenzyme Q10 (CoQ10), an antioxidant, we conduct both in vitro and in vivo experiments. In vitro, the granulosa cell line KGN, when treated with NE, shows decreased cell viability, reduced expression of GPX4, elevated levels of ferrous ion and ROS, and increased MDA level. However, these NE-induced changes are reversed by the addition of CoQ10. Compared with the NE group, the NE-treated mice supplemented with CoQ10 present increased GPX4 level and decreased iron, ROS, and MDA levels. Moreover, the differential expression of genes associated with ferroptosis induced by NE is ameliorated by CoQ10 in NE-treated mice. Additionally, CoQ10 improves ovarian function, as evidenced by increased ovarian weight, more regular estrous cycles, and an increase in follicles at various stages of growth in NE-treated mice. In conclusion, NE induces ovarian dysfunction by triggering ferroptosis in ovarian tissues, and CoQ10 represents a promising approach for protecting reproductive function by inhibiting ferroptosis.

Pyroptosis, a newly discovered form of programmed cell death, is involved in the occurrence, development and drug resistance of a variety of tumors and has attracted increasing attention in recent years. LINC00365 is a novel lncRNA that has rarely been reported before. We previously reported that LINC00365 expression in colorectal cancer is closely associated with poor patient outcomes. Additionally, LINC00365 was confirmed to be positively correlated with miR-221-5p, and miR-221-5p is negatively correlated with gasdermin-D (GSDMD) in colorectal cancer tissues. Bioinformatics analysis and luciferase reporter gene experiments revealed that GSDMD is the target gene of miR-221-5p. Cell function experiments and nude mouse tumor transplantation assays confirmed that LINC00365 could regulate the expressions of pyroptosis-related proteins such as Caspase-1, Caspase-11, NLRP3 and GSDMD. RNA pulldown and RNA immunoprecipitation experiments further elucidated the mechanism by which LINC00365 regulates miR-221-5p. In the present study, we observe that LINC00365 promotes the expression of miR-221-5p by binding to the Dicer enzyme to inhibit GSDMD and plays an antipyroptotic role. Our findings suggest that LINC00365 may serve as a molecular biomarker for estimating the prognosis of patients with colorectal cancer and as a potential therapeutic target for colorectal cancer.