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Microplastics have emerged as environmental hazards in recent years. This study was intended to prove the toxic effects of microplastics on the male reproductive system and further elucidate its mechanism. C57bl/6 mice were exposed to ultrapure water or different doses (0.25, 0.5 and 1 mg/d) of 5 μm polystyrene microplastics (PS-MPs) for 4 weeks, and the GC-1 mouse spermatogonium was treated with different concentrations of PS-MPs. The results showed that sperm count and motility were decreased, and sperm deformity rate was increased after exposure to PS-MPs. The morphology of testes in PS-MPs groups exhibited pathological changes, such as abnormal development of spermatogenic tubules, and inhibited spermatogonium function. Furthermore, the fluorescence intensity of TUNEL staining and the BAX/BCL2 ratio were increased. Exposure to PS-MPs resulted in impaired mitochondrial morphology of spermatogonium, decreased activity of GSH-px and SOD, and increased the MDA level. In vitro, after treatment with PS-MPs, the cell apoptosis rate of spermatogonium was significantly increased, mitochondrial membrane potential was decreased, mitochondrial morphology was damaged, and exposure to PS-MPs increased mitochondrial reactive oxygen species, inducing an oxidative stress state in spermatogonia. In summary, PS-MPs induced a decrease in sperm quality by activating spermatogonium mitochondrial oxidative stress and apoptosis, offering novel insights into mitigating the reproductive toxicity of microplastics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Inhibition of histone deacetylase (HDAC) is a promising therapeutic strategy for various hematologic cancers. Panobinostat has been approved for treating patients with multiple myeloma (MM) by the FDA. Since the mechanism for the resistance of panobinostat to MM remains elusive, we aimed to clarify this mechanism and the synergism of panobinostat with lenalidomide. The mRNA and protein of transcription factor IRF4 were overexpressed in CD138 + mononuclear cells from MM patients compared with in those from healthy donors. Given that direct IRF4 inhibitors are clinically unavailable, we intended to explore the mechanism by which IRF4 expression was regulated in MM. Heme oxygenase-1 (HO-1) promotes the growth and drug resistance of various malignant tumors, and its expression is positively correlated with IRF4 mRNA and protein expression levels. Herein, panobinostat induced acetylation of histone H3K9 and activation of caspase-3 in MM cells, being inversely correlated with the reduction of HO-1/IRF4/MYC protein levels. Adding Z-DEVD-FMK, a caspase-3 inhibitor, abolished the HO-1/IRF4 reduction by panobinostat alone or in combination with lenalidomide, suggesting that caspase-3-mediated HO-1/IRF4/MYC degradation occurred. Given that lenalidomide stabilized cereblon and facilitated IRF4 degradation in MM cells, we combined it with LBH589, an HDAC inhibitor. LBH589 and lenalidomide exerted synergistic effects, and LBH589 reversed the efficacy of lenalidomide on the resistance of CD138 + primary MM cells, in part due to simultaneous suppression of HO-1, IRF4 and MYC. The results provide an eligible therapeutic strategy for targeting MM depending on the IRF4 network and clinical testing of this drug combination in MM patients., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Advanced glycation end products (AGEs), which accumulate in the body during the development of diabetes, may be one of the factors leading to pancreatic β-cell failure and reduced β-cell mass. However, the mechanisms responsible for AGE‑induced apoptosis remain unclear. This study identified the role and mechanisms of action of tribbles homolog 3 (TRB3) in AGE-induced β-cell oxidative damage and apoptosis. Rat insulinoma cells (INS-1) were treated with 200 µg/ml AGEs for 48 h, and cell apoptosis was then detected by TUNEL staining and flow cytometry. The level of intracellular reactive oxygen species (ROS) was measured by a fluorescence assay. The expression levels of receptor of AGEs (RAGE), TRB3, protein kinase C β2 (PKCβ2) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) were evaluated by RT-qPCR and western blot analysis. siRNA was used to knockdown TRB3 expression through lipofection, followed by an analysis of the effects of TRB3 on PKCβ2 and NOX4. Furthermore, the PKCβ2-specific inhibitor, LY333531, was used to analyze the effects of PKCβ2 on ROS levels and apoptosis. We found that AGEs induced the apoptosis of INS-1 cells and upregulated RAGE and TRB3 expression. AGEs also increased ROS levels in β-cells. Following the knockdown of TRB3, the AGE-induced apoptosis and intracellular ROS levels were significantly decreased, suggesting that TRB3 mediated AGE-induced apoptosis. Further experiments demonstrated that the knockdown of TRB3 decreased the PKCβ2 and NOX4 expression levels. When TRB3 was knocked down, the cells expressed decreased levels of PKCβ2 and NOX4. The PKCβ2‑specific inhibitor, LY333531, also reduced AGE-induced apoptosis and intracellular ROS levels. Taken together, our data suggest that TRB3 mediates AGE-induced oxidative injury in β-cells through the PKCβ2 pathway.

Objective: To investigate the protective effect of ginsenoside Rg1 on oxygen-glucose deprivation (OGD) in PC-12 cells, and preliminarily discuss the potential molecular mechanism of mTOR/Akt/FoxO3 signaling pathway., Method: The OGD PC-12 cell model was established. The cell viability was measured by MTT assay. After the pretreatment with Rg1 with the concentration of 10, 20, 40 micromol x L(-1) for 24 h, the cell viability was observed. Lactate dehydrogenase (LDH) release, superoxide dismutase (SOD) ac- tivity and malondialdehyde (MDA) level were detected by colorimetry assay. mTOR, p-Akt(ser473), p-Akt(tjr308), Akt, p-FoxO3, FoxO3 in cytoplasm and nucleus, and total FoxO3 protein expression were detected by Western blot assay., Result: OGD could significantly in- hibit cell proliferation in 4-24 h in a time-dependent manner. After pretreatment for 24 h, Rg1 (20, 40 micromol x L(-1)) could notably elevate the cell viability and SOD viability and reduce the LDH release and MDA content. Besides, Rg1 also inhibited OGD-induced mTOR and p-Akt(ser473) decreases. After treatment for 6 h, OGD could reduce FoxO3 phosphorylation and promote FoxO3 in cytoplasm. This data suggested that Rg1 could protect PC-12 cell injury through mTOR/p-Akt/FoxO3 signaling pathway., Conclusion: Ginsenoside Rg1 could attenuate OGD-induced PC-12 cell injury. Its action mechanism may be closely related to activation of mTOR/p-Akt/FoxO3 signaling pathway.

Objective: To examine the effect of TRIB3 on endoplasmic reticulum stress induced β-cell apoptosis and to investigate the mechanism with a specific emphasis on the role of NF-κB pathway., Materials/methods: We investigated the effect of TRIB3 on ER stress-induced β-cell apoptosis in INS-1 cells and primary rodent islets. The potential role of TRIB3 in ER stress inducer thapsigargin (Tg)-induced β-cell apoptosis was assessed using overexpression and siRNA knockdown approaches. Inducible TRIB3 β-cells, regulated by the tet-on system, were used for sub-renal capsule transplantation in streptozotocin (STZ)-diabetic mice, to study the effect of TRIB3 on ER stress-induced β-cell apoptosis in vivo. Apoptosis was determined by TUNEL staining both in vivo and in vitro, while the molecular mechanisms of NF-κB activation were investigated., Results: TRIB3 was induced in ER-stressed INS-1 cells and rodent islets, and its overexpression was accompanied by increased β-cell apoptosis. Specifically, TRIB3 overexpression enhanced Tg-induced INS-1 derived β-cell apoptosis both in vitro and in sub-renal capsular transplantation animal model. Additionally, knockdown of Trib3 blocked Tg-induced apoptosis. Mechanistically, the induction of TRIB3 during ER stress resulted in the activation of NF-κB and aggravated INS-1 derived β-cell apoptosis, while inhibiting the NF-κB pathway significantly abrogated this response and prevented β-cell apoptosis, both in vitro and in sub-renal capsular transplantation animal model., Conclusion: TRIB3 mediated ER stress-induced β-cell apoptosis via the NF-κB pathway., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Chronic exposure to free fatty acids (FFAs) may induce β cell apoptosis in type 2 diabetes. However, the precise mechanism by which FFAs trigger β cell apoptosis is still unclear. Tribbles homolog 3 (TRB3) is a pseudokinase inhibiting Akt, a key mediator of insulin signaling, and contributes to insulin resistance in insulin target tissues. This paper outlined the role of TRB3 in FFAs-induced INS-1 β cell apoptosis. TRB3 was promptly induced in INS-1 cells after stimulation by FFAs, and this was accompanied by enhanced INS-1 cell apoptosis. The overexpression of TRB3 led to exacerbated apoptosis triggered by FFAs in INS-1-derived cell line and the subrenal capsular transplantation animal model. In contrast, cell apoptosis induced by FFAs was attenuated when TRB3 was knocked down. Moreover, we observed that activation and nuclear accumulation of protein kinase C (PKC) δ was enhanced by upregulation of TRB3. Preventing PKCδ nuclear translocation and PKCδ selective antagonist both significantly lessened the pro-apoptotic effect. These findings suggest that TRB3 was involved in lipoapoptosis of INS-1 β cell, and thus could be an attractive pharmacological target in the prevention and treatment of T2DM.

The calcium-regulated transcription coactivator, Ca(2)(+)-responsive transactivator (CREST) was expressed in pancreatic β-cells. Moreover, CREST expression became significantly increased in pancreatic islets isolated from hyperglycemic Goto-Kakizaki rats compared with normoglycemic Wistar controls. In addition, culture of β-cells in the presence of high glucose concentrations also increased CREST expression in vitro. To further investigate the role of this transactivator in the regulation of β-cell function, we established a stable β-cell line with inducible CREST expression. Hence, CREST overexpression mimicked the glucotoxic effects on insulin secretion and cell growth in β-cells. Moreover, high glucose-induced apoptosis was aggravated by upregulation of the transactivator but inhibited when CREST expression was partially silenced by siRNA technology. Further investigation found that upregulation of Bax and downregulation of Bcl2 was indeed induced by its expression, especially under high glucose conditions. In addition, as two causing factors leading to β-cell apoptosis under diabetic conditions, endoplasmic reticulum stress and high free fatty acid, mimicked the high glucose effects on CREST upregulation and generation of apoptosis in β-cells, and these effects were specifically offset by the siRNA knockdown of CREST. These results indicated that CREST is implicated in β-cell apoptosis induced by culture in high glucose and hence that CREST may become a potential pharmacological target for the prevention and treatment of type 2 diabetes mellitus.

Elevated extracellular free fatty acids (FFAs) can induce pancreatic beta cell apoptosis, thereby contributing to the pathogenesis of type 2 diabetes mellitus (T2D). Mitochondrial dysfunction has been implicated in FFA-induced beta cell apoptosis. However, molecular mechanisms linking mitochondrial dysfunction and FFA-induced beta cell apoptosis are not clear. Dynamin-related protein 1 (DRP-1) is a mitochondrial fission modulator. In this study, we investigated its role in FFA-induced INS-1 beta cell apoptosis. DRP-1 protein was promptly induced in INS-1 cells and rat islets after stimulation by FFAs, and this DRP-1 upregulation was accompanied by increased INS-1 cell apoptosis. Induction of DRP-1 expression significantly promoted FFA-induced apoptosis in DRP-1 WT (DRP-1 wild type) inducible INS-1-derived cell line, but not in DRP-1K38A (a dominant negative mutant of DRP-1) inducible INS-1-derived cell line. To validate these in vitro results, we transplanted DRP-1 WT or DRP-1 K38A cells into renal capsules of streptozotocin (STZ)-treated diabetic mice to study the apoptosis in xenografts. Consistent with the in vitro results, the over-expression of DRP-1 led to aggravated INS-1-derived cell apoptosis triggered by FFAs. In contrast, dominant-negative suppression of DRP-1 function as represented by DRP-1 K38A significantly prevented FFA-induced apoptosis in xenografts. It was further demonstrated that mitochondrial membrane potential decreased, while cytochrome c release, caspase-3 activation, and generation of reactive oxygen species (ROS) were enhanced by the induction of DRP-1WT, but prevented by DRP-1 K38A in INS-1-derived cells under FFA stimulation. These results indicated that DRP-1 mediates FFA-induced INS-1-derived cell apoptosis, suggesting that suppression of DRP-1 is a potentially useful therapeutic strategy for protecting against beta cell loss that leads to type 2 diabetes.

Purpose: The histone deacetylase inhibitor (HDACi) suberoylanilide hydroxamic acid (SAHA) enhances taxol-induced antitumor effects against some human cancer cells. The aim of this study is to investigate whether SAHA can enhance taxol-induced cell death against human breast cancer cells and to illustrate the mechanism in detail., Methods: A panel of eight human breast cancer cell lines and an immortalized human breast epithelial cell line were used to determine the inhibitory effects of SAHA, taxol, or their combination by MTT assay. The effects of SAHA with or without taxol on cell cycle distributions, apoptosis, and protein expressions were also examined. The inhibitory effects on tumor growth were characterized in vivo in BALB/c nude mice bearing a breast cancer xenograft model., Results: Taxol-resistant and multi-resistant breast cancer cells were as sensitive to SAHA as taxol-sensitive breast cancer cells. A dose-dependent synergistic growth inhibition was found in all the tested breast cancer cell lines treated with the SAHA/taxol combinations. The synergetic effect was also observed in the in vivo xenograft tumor model. The cell cycle analysis and apoptosis assay showed that the synergistic effects resulted from enhanced G2/M arrest and apoptosis., Conclusions: SAHA increased the anti-tumor effects of taxol in breast cancer in vitro and in vivo. The combination of SAHA and taxol may have therapeutic potential in the treatment of breast cancer.

Objective: Human selenoprotein P (HSelP) is unique protein that contains 10 selenocysteines encoded by 10 inframe UGA, which typically function as stop codon. The function of HSelP remains unclear, in part due to the inability to express it by gene recombinant technique. This study is to investigate expression and purification of recombinant HSelP in prokaryotic expression system, and its activity to induce apoptosis in vitro., Methods: The shorter HSelP isoform was cloned. After the selenocysteine (SeCys) at 40th position from N terminus of the HSelP shorter isoform was mutated into cysteine by PCR, it was expressed in E. coli. The expressed product was purified with DEAE column and identified by Western blot. Subsequently, its function on induction of mitochondrial apoptotic activity was studied., Results: The mutant HSelP shorter isoform expressed in prokaryotic system was purified by DEAE column to 90% homogeneity. The purified product, HSelP280m, induced the opening of mitochondrial permeability transition pore (PTP) and decreased the transmembrane potential in a dose-dependent manner. These events could be abolished by PTP specific inhibitors., Conclusion: HSelP280m can induce the opening of mitochondrial PTP, which provides a basis for investigating the structure and function of recombinant HSelP.

Liver cancer is the most lethal form of cancer and carries a high risk of death around the world. Goniothalamin (GTN) is a styryl-lactone that possesses antiproliferative and apoptotic activity. The molecular action of GTN is not yet fully evaluated. Thus, our research has been intended to assess the chemopreventive and apoptotic activities of diethylnitrosamine (DEN)-induced hepatocellular carcinoma (HCC) in rats. Rats were separated into 4 groups: control, DEN only, DEN + GTN (30 mg/kg bw), and GTN (30 mg/kg bw) alone. We evaluated body weight, liver weight, tumor incidence, hepatic toxic markers, antioxidants, inflammatory cytokines, histopathology, immunohistochemistry, and Western blot studies. DEN lessened body weight, antioxidants, and apoptosis, whereas it elevated tumor incidence, toxic markers, cytokines, and Bcl-2 expression. GTN treatment maintains body weight, liver weight, and antioxidant levels, and it also prevents tumor incidence, oxidative stress, toxic markers, pro-inflammatory cytokines, and histological changes. It triggers apoptosis by constraining Bcl-2 and elevating caspase-3 levels. GTN also attenuated the P13K/AKT signaling which enhanced apoptosis. These findings revealed that GTN subdues the P13K/AKT pathway and has auspicious chemopreventive and apoptotic actions in DEN-induced HCC. Therefore, GTN would be suggested as a new medicine in natural remedies for liver cancer. [ABSTRACT FROM AUTHOR]

Phellinus igniarius (PI) has various kinds of biological activities, such as antitumour activities, and polysaccharides are one of its main components. In this study, polysaccharides from PI (PIP) were prepared, purified, analysed for their structure and investigated for their antitumour activity and mechanism in vitro. PIP consists of 12138 kDa of carbohydrates containing 90.5 ± 1.6% neutral carbohydrates. PIP consists of glucose, galactose, mannose, xylose, D-fructose, L-guluronic acid, glucosamine hydrochloride, rhamnose, arabinose and D-mannoturonic acid. PIP can significantly inhibit HepG2 cell proliferation, induce cell apoptosis and also inhibited migration and invasion in a concentration-dependent manner. PIP increased reactive oxygen species (ROS), increased the expression of p53, and induced cytochrome c release into the cytoplasm to activate caspase-3. PIP is a promising potential candidate for the therapeutic treatment of hepatic carcinoma via the ROS-mediated mitochondrial apoptosis pathway. [ABSTRACT FROM AUTHOR]

Introduction: Evodiamine (Evo) is one of the main bioactive components derived from the drying mature fruit of the genus Evodia rutaecarpa (Juss.) Benth. Although Evo has shown its anti-cancer activity in several cancers, the effects on multiple myeloma (MM) remain unknown. In this study, we aim to investigate the cytotoxic role of Evo on MM cells. Methods: CCK-8 assay, apoptotic cell analysis, xenografted mice model, caspase activity assay and mitochondrial membrane potential assay were performed. Results: We found that Evo selectively inhibits cell proliferation and increases apoptosis rate in MM cells, but not in healthy B lymphocytes, in a time and dose-dependent manner. Evo treatment significantly activated caspase-3 and −9 in MM cells. Evo also increased cytochrome C expression and ROS production in cytosol in a dose-dependent manner, which was abolished by MitoTEMPO cotreatment. In addition, co-treatment with bortezomib and Evo showed a more potent reduction of cell viability and a higher apoptosis than that of bortezomib single treatment in U266 and RPMI8226 cells. Conclusion: We provided evidence to demonstrate that Evo selectively suppresses cell growth and increases apoptosis rate in MM cells through the intrinsic apoptosis pathway. Application of Evo and bortezomib might enhance the anti-cancer effect on MM cells. [ABSTRACT FROM AUTHOR]

Advanced glycation end products (AGEs) are believed to be involved in diverse complications of diabetes mellitus. Overexposure to AGEs of pancreatic β-cells leads to decreased insulin secretion and cell apoptosis. Here, to understand the cytotoxicity of AGEs to pancreatic β-cells, we used INS-1-3 cells as a β-cell model to address this question, which was a subclone of INS-1 cells and exhibited high level of insulin expression and high sensitivity to glucose stimulation. Exposed to large dose of AGEs, even though more insulin was synthesized, its secretion was significantly reduced from INS-1-3 cells. Further, AGEs treatment led to a time-dependent increase of depolymerized microtubules, which was accompanied by an increase of activated p38/MAPK in INS-1-3 cells. Pharmacological inhibition of p38/MAPK by SB202190 reversed microtubule depolymerization to a stabilized polymerization status but could not rescue the reduction of insulin release caused by AGEs. Taken together, these results suggest a novel role of AGEs-induced impairment of insulin secretion, which is partially due to a disturbance of microtubule dynamics that resulted from an activation of the p38/MAPK pathway. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to investigate the possible role of TIPE2 on acute lung injury (ALI) induced by myocardial ischemia/reperfusion (MIR) in diabetic rats. Sprague-Dawley (SD) rats were randomly separated into four groups: control+sham (C + sham); control+MIR (C + MIR); diabetes+sham (D + sham); diabetes+MIR (D + MIR). Diabetes was induced using streptozotocin. Eight weeks after diabetes induction, MIR was conducted. At 2 h after MIR, myocardial injury indices were assessed; arterial blood, bronchoalveolar lavage fluid (BALF) and lung tissues were collected for corresponding detection. Rats subjected to MIR showed serious ALI (estimated via pathological changes, lung injury score and Wet/Dry weight ratio), lung inflammation and pulmonary cell apoptosis compared with sham groups, especially in D + MIR group. Evaluation of protein expression in lung tissues showed that p-JNK and nuclear NF-κB p65 protein levels were higher in D + MIR group as compared with C + MIR group. Besides, either hyperglycemia or MIR can significantly upregulate TIPE2 protein levels. In conclusion, diabetic lungs are more susceptible to MIR. TIPE2 may involve in this pathological process, possibly through regulation of inflammation, oxidative stress and apoptosis. • Diabetic rats subjected to MIR showed aggravated ALI • TIPE2 were upregulated either after STZ injection or MIR • TIPE2 may have protective effect on MIR-induced ALI in Diabetic rats • TIPE2 negatively regulates inflammation, oxidative stress, apoptosis, NF-κB and JNK pathways that involved in MIR-induced ALI [ABSTRACT FROM AUTHOR]