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Background: Submucosal fibrosis (OSF) of the oral cavity is a chronic scarring disease. Arecoline (Are) is the driving factor for the occurrence and deterioration of OSF. Curcumin plays a vital anti-inflammatory role in Are-induced OSF development. However, its potential pharmacological mechanism needs to be elucidated., Methods: The relative molecular level was measured via qRT-PCR or Western blot. MTT assay, transwell assay and flow cytometry detected cell proliferation, migration, and apoptosis. The correlation between hypoxia-inducible factor-1α (HIF-1α) and LTBP2 promoter was confirmed through dual-luciferase reporter assay. ELISA was performed to detect inflammatory cytokines levels., Results: Curcumin alleviated Are-induced oral mucosal fibroblast cells fibrosis by reducing oral mucosa fibroblasts viability, promoting cell apoptosis, suppressing cell migration, and down-regulating the levels of fibrosis markers and inflammatory factors. Curcumin relieved Are-induced OSF via inhibiting HIF-1α. Mechanically, HIF-1α bound to the promoter of LTBP2 to transcriptionally activated LTBP2. LTBP2 knockdown relieved Are-induced OSF, and curcumin down-regulated LTBP2 via inhibiting HIF-1α to relieve Are-induced OSF. Moreover, curcumin decreased NF-κB signal associated proteins via inhibiting LTBP2 to relieve Are-induced OSF., Conclusion: Curcumin reduced the transcription level of LTBP2 by inhibiting HIF-1α, thereby inactivating NF-κB pathway to alleviate Are-induced OSF., (© 2023 Wiley Periodicals LLC.)

Hypoxia, as one of the severe cellular stresses, can cause cellular injury and even cell death. Apoptosis is the main mechanism of regulating cell death and is closely related to the cell death caused by hypoxia. However, hypoxia-induced apoptosis is not entirely the result of direct hypoxic stimulus of cells. In recent years, it has been found that cells injured by hypoxia can shed a kind of membranous vesicles, which are called microvesicles (MVs). MVs can carry bioactive molecules from injured mother cells and appear in blood, cerebrospinal fluid, and other body fluids. MVs can induce normal cell apoptosis by transferring bioactive molecules into adjacent cells and amplifying the hypoxic injury in an organism. This review summarizes the characteristic changes of MVs derived from hypoxic cells and the mechanism of normal cell apoptosis mediated by hypoxic cell-derived MVs. Finally, we introduce the significance of this apoptosis-apoptosis cascade reaction in hypoxic diseases.

Hypoxia is a kind of common pathological condition existing in various diseases such as sleep apnea syndrome, myocardial infarction and stroke, which can precipitate the onset of diseases through inducing cell apoptosis. Ca²⁺ is the ubiquitous message in cell. Given the crucial role of Ca2²⁺ in physiology, intracellular Ca²⁺ overload is a significant regulator of apoptosis. Numerous experiments show that hypoxia may cause changes of multiple cellular Ca²⁺ channels, for instance, Na⁺/ Ca²⁺ Exchanger (NCX), L-type voltage dependent Ca²⁺ channel (L-VDCC), inositol triphosphate receptors (IP3R) and so on, which contribute to intracellular Ca²⁺ overload, thus eventually triggering cell apoptosis. However, the mechanisms underlying different Ca²⁺ channels involved in hypoxic apoptosis are complex. For example, chronic hypoxia or acute hypoxia may select different Ca²⁺ channels to influence cell apoptosis. In addition, intracellular Ca²⁺ overload may initiate different apoptotic pathways due to hypoxic duration. Furthermore, different locations in the cell of specific Ca²⁺ channels activated by hypoxia will determine different apoptosis signaling pathways. Moreover, activation of different Ca²⁺ channel isoforms will result in different outcomes of the cell under hypoxia. Hence, we aim to highlight the potential mechanisms of the main Ca²⁺ channels in regulation of apoptosis under hypoxic stress.

Endoplasmic reticulum (ER) stress is a common cellular stress response that is triggered by a variety of conditions that disturb cellular homeostasis, and induces cell apoptosis. Autophagy, an important and evolutionarily conserved mechanism for maintaining cellular homeostasis, is closely related to the apoptosis induced by ER stress. There are common upstream signaling pathways between autophagy and apoptosis induced by ER stress, including PERK/ATF4, IRE1α, ATF6, and Ca 2+ . Autophagy can not only block the induction of apoptosis by inhibiting the activation of apoptosis-associated caspase which could reduce cellular injury, but also help to induce apoptosis. In addition, the activation of apoptosis-related proteins can also inhibit autophagy by degrading autophagy-related proteins, such as Beclin-1, Atg4D, Atg3, and Atg5. Although the interactions of different autophagy- and apoptosis-related proteins, and also common upstream signaling pathways have been found, the potential regulatory mechanisms have not been clearly understood. In this review, we summarize the dual role of autophagy, and the interplay and potential regulatory mechanisms between autophagy and apoptosis under ER stress condition., (© 2017 Wiley Periodicals, Inc.)

Objective: To investigate the effects of artesunate (ART) on proliferation, cell cycle and apoptosis of SKM-1 cells in vitro and to explore the underlying mechanisms., Methods: After SKM-1 cells were treated with different concentrations of ART, the cell proliferation was determined by CCK-8 method. Apoptosis and distribution of cell cycle were detected by flow cytometry. Both DCFH-DA fluorescent probe and Fluo-3-Am fluorescent probe were used to detect the changes of intracellular reactive oxygen species (ROS) and calcium ion concentration. Western blot was used to measure the protein levels of BCL-2, BAX, BAD, P-BAD, survivin and XIAP., Results: ART obviously inhibited the growth of SKM-1 cells in time and dose-dependent manners (r = -0.841; r = 0.-786). The antioxidant trolox-pretreatment significantly decreased the growth inhibition effect of ART on SKM-1 cells. Caspase inhibitor Ac-DEVD-CHO partially reduced the growth inhibition effect of ART on SKM-1 cells. After treatment with ART for 24 hours, the apoptosis of SKM-1 cells was found, the cell cycle of SKM-1 was arrested in G0/G1 phase, ART could elevate the levels of calciumion and reactive orygen. ART could significantly down-regulate the protein expression levels of P-BAD and survivin in SKM-1 cells, and showed a highly negative correlation with ART dose (r = -0.909; r = -0.849). On the contrary, ART had no significant effect on expression levels of BAD and XIAP in SKM-1 cells, and after ART treatment, although BCL-2 protein expression was not significantly different when compared with control group, but the BCL-2/BAX ratio significantly decreased and highly negatively correlated with ART dose (r = -0.866)., Conclusion: The ART significantly suppresses the cell proliferation, induces the apoptosis and promoted cell cycle arrest at G0/G1 phase in SKM-1 cells. The mechanisms of ART anti-MDS is associated with the increase of intracellular calciumion concentration and ROS levels. In addition, the pro-apoptotic activity of ART may be involved in the regulation of BCL-2 /BAX ratio and the expressions of P-bad and survivin.

Hypoxia is one of severe cellular stress and it is well known to be associated with a worse outcome since a lack of oxygen accelerates the induction of apoptosis. Autophagy, an important and evolutionarily conserved mechanism for maintaining cellular homeostasis, is closely related to the apoptosis caused by hypoxia. Generally autophagy blocks the induction of apoptosis and inhibits the activation of apoptosis-associated caspase which could reduce cellular injury. However, in special cases, autophagy or autophagy-relevant proteins may help to induce apoptosis, which could aggravate cell damage under hypoxia condition. In addition, the activation of apoptosis-related proteins-caspase can also degrade autophagy-related proteins, such as Atg3, Atg4, Beclin1 protein, inhibiting autophagy. Although the relationship between autophagy and apoptosis has been known for rather complex for more than a decade, the underlying regulatory mechanisms have not been clearly understood. This short review discusses and summarizes the dual role of autophagy and the interaction and molecular regulatory mechanisms between autophagy and apoptosis under hypoxia.

Traumatic brain injury (TBI) is a major cause of chronic disability and death in young adults worldwide. Multiple cellular, molecular and biochemical changes impact the development and outcome of TBI. Neuronal cell apoptosis, which is an important pathological change in secondary brain damage, is crucial to determine the functional recovery after TBI. miR-21, a widely-reported oncogene, which can reduce cell apoptosis in cancer, has been confirmed to be a pronounced up-regulated miRNA after TBI in animal model. Our study is designed to investigate whether miR-21 has the function of antiapoptosis in experimental TBI model in vitro and to explore the possible regulatory mechanism of miR-21 on neuronal apoptosis. The scratch cell injury was performed to mimic TBI-induced apoptosis in neurons, and miR-21 agomir/antagomir was transfected to up-/down-regulate the miR-21 level. Our data suggests that miR-21 can reduce the number of TUNEL-positive neurons. Meanwhile, miR-21 decreased the expression level of PTEN, and increased the phosphorylation of Akt significantly. In neurons transfected with miR-21 agomir, the expression of Bcl-2 was promoted while the caspase-3, caspase-9 and Bax level were down-regulated, which are crucially the downstream apoptosis-related proteins of PTEN-Akt signaling pathway. In conclusion, miR-21 can exert the function of reducing neuronal apoptosis through activating the PTEN-Akt signaling pathway. Our research provides new insights into the molecular mechanisms of neuronal apoptosis following TBI, which reminds that miR-21may be a potential therapeutic target for TBI treatment., (Copyright © 2014. Published by Elsevier B.V.)

Autophagy is shown to be beneficial for renal tubular injury caused by nephrotoxic drugs. To investigate whether autophagy could protect renal tubular epithelial cells (TECs) from injury induced by urinary proteins, we studied the activity and action of autophagy in TECs after urinary protein overload in vivo and in vitro. We found that autophagic vacuoles increased in TECs from patients with minimal change nephrotic syndrome (MCNS) and rat models with severe proteinuria induced by cationic BSA. In HK-2 cells, exposure to urinary proteins extracted from patients with MCNS led to a significant increase in autophagosome and autolysosome formation and decrease in SQSTM1/p62 protein level. Urinary protein addition also induced lysosomal turnover of LC3-II and perinuclear clustering of lysosomes. These changes were mediated by a reactive oxygen species (ROS)-dependent mechanism. Furthermore, pretreatment of HK-2 cells with rapamycin reduced the production of LCN2/NGAL and HAVCR1/KIM-1 and the level of apoptosis induced by urinary proteins. In contrast, blocking autophagy with chloroquine or BECN1 siRNAs exerted an opposite effect. Similar results were also observed in animal models with proteinuria after treatments with rapamycin and chloroquine. Taken together, our results indicated an increase in autophagic flux, which mounts an adaptive response in TECs after urinary protein overload.

Background: CC chemokine receptor 3 (CCR3), expressed on some inflammatory cells, is a member of the chemokine receptor family. Its ligand is eotaxin/CCL11. In this research, we studied the expression and function of CCR3 induced by interleukin-2 (IL-2) and interleukin-4 (IL-4) on human germinal centre (GC) B cells., Methods: Cells isolated from human tonsils were stimulated with IL-2 or/and IL-4 followed by bonding with eotaxin/CCL11. Flow cytometry was used to detect expression of CCR3 on GC B cells and apoptosis of GC B cells. Real time quantitative reverse transcription polymerase chain reaction and Northern blot assays were used to analyse the CCR3 mRNA expressed in the GC B cells. Chemotaxis and adhesion assays were used to determine the effect of eotaxin/CCL11 ligand bonded to CCR3 on GC B cells., Results: There was no CCR3 expression on human freshly isolated GC B cells. The combination IL-2 and IL-4 could upregulate CCR3 mRNA and protein expression on GC B cells. Eotaxin could not induce GC B cell chemotaxis and adhesion but triggered apoptosis of GC B cells., Conclusion: IL-2 and IL-4 together induced expression of CCR3 on GC B cells, and the receptor acted as a death receptor.

This study aimed to clarify the intervention effect of salidroside (SAL) on lung injury caused by PM 2.5 in mice and illuminate the function of SIRT1-PGC-1ɑ axis. Specific pathogen-free (SPF) grade male C57BL/6 mice were randomly assigned to the following groups: control group, SAL group, PM 2.5 group, SAL+PM 2.5 group. On the first day, SAL was given by gavage, and on the second day, PM 2.5 suspension was given by intratracheal instillation. The whole experiment consist of a total of 10 cycles, lasting 20 days. At the end of treatment, blood samples and lung tissues were collected and analyzed. Observation of pathological changes in lung tissue using inverted microscopy and transmission electron microscopy. The expression of inflammatory, antioxidants, apoptosis, and SIRT1-PGC-1ɑ proteins were detected by Western blotting. Exposure to PM 2.5 leads to obvious morphological and pathologica changes in the lung of mice. PM 2.5 caused a decline in levels of antioxidant-related enzymes and protein expressions of HO-1, Nrf2, SOD2, SIRT1 and PGC-1ɑ, and an increase in the protein expressions of IL-6, IL-1β, Bax, caspase-9 and cleaved caspase-3. However, SAL reversed the aforementioned changes caused by PM 2.5 by activating the SIRT1-PGC-1α pathway. SAL can activate SIRT1-PGC-1ɑ to ameliorate PM 2.5 -induced lung injury. [ABSTRACT FROM AUTHOR]

Bladder cancer is a common tumour of the urinary system, and more than 90% is urothelial carcinoma. Therefore, it is important for discovering the key target genes and molecules of bladder tumour cell metastasis and invasion. Our research initially explored the regulation of deltaN p63 on the progression and metastasis of bladder cancer and found that deltaN p63 can influence the occurrence of EMT through PTEN and ultimately regulate the growth and metastasis of bladder cancer. In summary, this study identified a new EMT regulator, deltaN p63, further revealed the mechanism of the invasion and metastasis of bladder cancer cells, and provided a theoretical basis for finding new target molecules and drugs to treat bladder cancer. In conclusion, this study will further reveal the mechanism of tumour cell invasion and metastasis and provide a theoretical basis for cancer treatment to find new target molecules and drugs. [ABSTRACT FROM AUTHOR]

Cell‐derived microvesicles are membrane vesicles produced by the outward budding of the plasma membrane and released by almost all types of cells. These have been considered as another mechanism of intercellular communication, because they carry active molecules, such as proteins, lipids and nucleic acids. Furthermore, these are present in circulating fluids, such as blood and urine, and are closely correlated to the progression of pathophysiological conditions in many diseases. Recent studies have revealed that microvesicles have a dual effect of damage and protection of receptor cells. However, the nature of the active molecules involved in this effect remains unclear. The present study mainly emphasized the mechanism of microvesicles and the active molecules mediating the different biological effects of receptor cells by affecting autophagy, apoptosis and inflammation pathways. The effective ways of blocking microvesicles and its active molecules in mediating cell damage when microvesicles exert harmful effects were also discussed. [ABSTRACT FROM AUTHOR]

Background/Aims: Intermittent hypoxia (IH) causes apoptosis in pancreatic β-cells, but the potential mechanisms remain unclear. Endoplasmic reticulum (ER) stress, autophagy, and apoptosis are interlocked in an extensive crosstalk. Thus, this study aimed to investigate the contributions of ER stress and autophagy to IH-induced pancreatic β-cell apoptosis. Methods: We established animal and cell models of IH, and then inhibited autophagy and ER stress by pharmacology and small interfering RNA (siRNA) in INS-1 cells and rats. The levels of biomarkers for autophagy, ER stress, and apoptosis were evaluated by immunoblotting and immunofluorescence. The number of autophagic vacuoles was observed by transmission electron microscopy. Results: IH induced autophagy activation both in vivo and in vitro, as evidenced by increased autophagic vacuole formation and LC3 turnover, and decreased SQSTM1 level. The levels of ER-stress-related proteins, including GRP78, CHOP, caspase 12, phosphorylated (p)-protein kinase RNA-like ER kinase (PERK), p-eIF2α, and activating transcription factor 4 (ATF4) were increased under IH conditions. Inhibition of ER stress with tauroursodeoxycholic acid or 4-phenylbutyrate partially blocked IH-induced autophagy in INS-1 cells. Furthermore, inhibition of PERK with GSK2606414 or siRNA blocked the ERstress-related PERK/eIF2α/ATF4 signaling pathway and inhibited autophagy induced by IH, which indicates that IH-induced autophagy activation is dependent on this signaling pathway. Promoting autophagy with rapamycin alleviated IH-induced apoptosis, whereas inhibition of autophagy with chloroquine or autophagy-related gene (Atg5 and Atg7) siRNA aggravated pancreatic β-cell apoptosis caused by IH. Conclusion: IH induces autophagy activation through the ER-stress-related PERK/eIF2α/ATF4 signaling pathway, which is a protective response to pancreatic β-cell apoptosis caused by IH. [ABSTRACT FROM AUTHOR]

Miracle fruit (Synsepalum dulcificum) is an edible berry, and is known for its ability to turn sour to sweet. The leaf of S. dulcificum has been used as additives in food, medicine and cosmetic industries. In this study, two new pairs of enantiomeric coumarinolignans, synsepalumins A and B (1 and 2), three new pentacyclic triterpenoids, 3- O - cis - p -coumaroyl-2 α ,3 β ,29-trihydroxy-olean-12-en-28-oic acid (3), 3- O - trans - p -coumaroyl-2 α ,3 β ,29-trihydroxy-olean-12-en-28-oic acid (4), and 3- O - cis - p -coumaroyl-3 β ,19 α -hydroxy-urs-12-en-28-oic acid (6), along with twenty-five known compounds (5 , 7 − 30) were isolated from the leaves of S. dulcificum. Compounds 1 and 2 are two rare tricyclic 7-hydroxycoumarins featuring a classic bicyclic 7-hydroxycoumarin fused with a (1,4)-dioxane ring. Their structures were elucidated by the spectroscopic data analyses and quantum chemical electronic circular dichroism calculations. Meanwhile, compound 4 (SMG-1) significantly inhibited proliferation of HepG2 (IC 50 = 13.9 ± 0.3 μM) and HCCLM3 (IC 50 = 11.8 ± 0.2 μM) cells. We further explored the underlying mechanism of SMG-1 for hepatocellular carcinoma (HCC) cells death, and found that SMG-1 induced reactive oxygen to increase the level of BNIP3 through JNK/p53 pathway and decreased mitochondrial membrane potential, resulting in activating mitophagy. Moreover, SMG-1 up-regulated the Bax and cytoplasm level of Cyt-c to promote Caspase-9/Caspase-3-mediated apoptosis in HCC cells. Therefore, the leaves of S. dulcificum possess the ability to treat HCC. [Display omitted] • Synsepalum dulcificum has high medicinal and economic values. • Two pairs of undescribed enantiomeric coumarinolignans, three undescribed triterpenoids, along with twenty-five known compounds were isolated from Synsepalum dulcificum leaves. • Some compounds showed significantly antitumor activity against hepatocellular carcinoma cells. • Compound 4 induced reactive oxygen to activate mitophagy and promote Caspase-9/Caspase-3-mediated apoptosis in hepatocellular carcinoma cells. [ABSTRACT FROM AUTHOR]

• Silencing VCAM-1 and BMSCs synergistically improve cardiac function of MI rats. • Injection with BMSCs and sh-VCAM-1 increases CPR and survival rate of MI rats. • Injection with BMSCs and sh-VCAM-1 reduce the IS and myocardial apoptosis. • sh-VCAM-1 could inhibit the NF-κB signaling pathway. • sh-VCAM-1 enhances the therapeutic effects of BMSCs by NF-κB pathway. Bone mesenchymal stem cells (BMSCs) has been well known to exert therapeutic potential for patients with myocardial infarction (MI). VCAM-1 can promote the migration of lymphocytes to the inflammatory zone. In the present study, we tried to explore whether VCAM-1 silenced-BMSCs have better therapeutic effects on MI. BMSCs were isolated and cultured followed by treatment of a lentivirus silencing VCAM-1 and NF-κB activator (PMA). Besides, MI rat models were also established and injected with treated BMSCs to detect the effect of VCAM-1 silenced-BMSCs in MI, as evidenced by detection of cardiac function, survival of rats within 72 h, infarct size and myocardial cell apoptosis. Moreover, the expression of NF-κB-regulated gene products was also determined. The implantation of sh-VCAM-1 BMSCs into MI rats resulted in more reductions in myocardial infarct size as well as myocardial cell apoptosis, improved cardiac function, the number of survived rats within 72 h, and survival time within 72 h compared with the individual treatments of either BMSCs or control. In addition, transplanted BMSCs down-regulated the expression of NF-κB-p65, MMP-9, TNF-α, and Bax, and up-regulated VEGF and Bcl-2 in myocardial tissue, which could be further enhanced by sh-VCAM-1 and rescued by PMA. Our study demonstrated that silencing VCAM-1 in BMSCs could inhibit inflammation and apoptosis, thus improving cardiac function in MI. [ABSTRACT FROM AUTHOR]