Bcl-2 family proteins: the sentinels of the mitochondrial apoptosis pathway

CCCP inhibits DPV infection in DEF cells by attenuating DPV manipulated ROS, apoptosis, and mitochondrial stability

Duck plague virus (DPV) is extremely infectious and lethal, so antiviral drugs are urgently needed. Our previous study shows that DPV infection with duck embryo fibroblast (DEF) induces reactive oxygen species (ROS) changes and promotes apoptosis. In this study, we tested the antiviral effect of the carbonyl cyanide m-chlorophenyl hydrazone (CCCP), a common mitochondrial autophagy inducer. Our results demonstrated a dose-dependent anti-DPV effect of CCCP, CCCP-treatment blocked the intercellular transmission of DPV after infection, and we also proved that CCCP could have an antiviral effect up to 48 hpi. The addition of CCCP reversed the DPV-induced ROS changes, CCCP can inhibit virus-induced apoptosis; meanwhile, CCCP can affect mitochondrial fusion and activate mitophagy to inhibit DPV. In conclusion, CCCP can be an effective antiviral candidate against DPV.

A novel protein extracted from Hemerocallis citrina Borani inhibits hepatocellular carcinoma cell proliferation by regulating mitochondria-dependent apoptosis and aerobic glycolysis

Hemerocallis citrina Borani is a commonly consumed food in Asia and possesses many biologically active ingredients. In this study, a protein named Hemerocallis citrina Borani protein (HcBP) was purified using ammonium sulfate fractionation and anion exchange chromatography. Protease assays revealed that HcBP has peroxidase activity. Meanwhile, the UV absorption spectrum showed that HcBP contains heme. Notably, HcBP showed significant inhibitory effects on human hepatoma cancer cell proliferation. Mechanism investigations indicated that HcBP treatment resulted in overproduction of reactive oxygen species (ROS) and induced mitochondria-dependent apoptosis in human hepatoma cancer cells. Furthermore, we found HcBP not only downregulated pyruvate kinase M2 (PKM2) activity but also decreased the expression and nuclear levels of PKM2. The inhibition of PKM2 led to the downregulation of GLUT1, LDHA and PDK, and thus caused the suppression of glycolysis. In summary, our results suggested that HcBP has potential anti-hepatocellular carcinoma activity.

In-vivo and in vitro assessments of the radioprotective potential natural and chemical compounds: a review

PURPOSE

The study of the radioactive role of natural and chemical substances on human and animal studies has been the subject of research by some researchers. Therefore, the review of some of the past and current studies conducted in this field, can provide helpful information to elucidate of the importance of radioprotective components in reducing radiation exposure side effects.

METHODS

The authors search for keywords including In vitro, In vivo, Radioprotective, Ionizing radiation, and Vitamin in ScienceDirect, Scopus, Pubmed, and Google Scholar databases to access previously published articles and search for more reference articles on the role of radioprotective materials from natural and chemical compounds.

RESULTS

Radiation exposure can produce reactive oxygen species (ROS) in the body, however most of which are eliminated by the body's natural mechanisms, but when the body's antioxidant systems do not have enough ability to neutralize free radicals, oxidative stress occurs, which causes damage to DNA and body tissues. Therefore, it is necessary use of alternative substances that reduce and inhibit free radicals.

CONCLUSION

In general, recommended that antioxidant component(s) can be protect tissue damages in humans or animals, due to the their ability to scavenge free radicals generated by ionizing radiation.

Swietenine and swietenolide from Swietenia macrophylla king improve insulin secretion and attenuate apoptosis in H2 O2 induced INS-1 cells

Oxidative stress is an important factor that causes pancreatic β-cell dysfunction leading to the development and aggravation of diabetes. Swietenine (Stn) and swietenolide (Std) were isolated from the fruits of Swietenia macrophylla King and had the potential effects on treatment and prevention of diabetes. The aim of this study is to investigate the effects of Stn and Std on insulin secretion and apoptosis in H2 O2 induced insulinoma cell line (INS-1) cells. In the present study, INS-1 cells were treated with 300 μM H2 O2 for 4 h to establish the oxidative damage model. Cell apoptosis, insulin secretion, reactive oxygen species (ROS), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) levels, and Caspase-3 enzyme activity were measured via corresponding methods. Finally, pancreatic duodenal home box factor-1 (PDX-1), B cell lymphoma-2 (Bcl-2), and Bax protein expression were detected by western blot. Experimental results showed that Stn and Std could significantly improve the INS-1 cell viability, increase the secretion of insulin and reduce the ROS level in H2 O2 induced INS-1 cells. Furthermore, the SOD and GSH levels increased, and the MDA levels decreased compared with the model group after Stn and Std treatment. In addition, after treated with Stn and Std, cell apoptosis was improved, and the activity of Caspase 3 was also significantly inhibited. Meanwhile, Western blot results showed that Stn and Std could up-regulate the expression of PDX-1 protein, and affect the cell apoptosis pathway by up-regulating the expression of Bcl-2 protein and down-regulating the expression of Bax protein. In conclusion, Stn and Std can signifcantly improve the insulin secretion function, protect oxidative stress injury, and reduce apoptosis in H2 O2 induced INS-1 cells, which provides a research basis for Stn and Std to be new drug candidates for the treatment and prevention of diabetes.

Anti-Aging Effects of R-Phycocyanin from Porphyra haitanensis on HUVEC Cells and Drosophila melanogaster

Aging has become a global public health challenge. Many studies have revealed that the excessive generation of ROS and oxidative stress could be the major causative factors contributing to aging. In this study, R-phycocyanin (R-PC) was isolated from Porphyra haitanensis, and its anti-aging ability was explored by natural aging Drosophila melanogaster and H₂O₂-induced HUVEC cells as the aging model. Results showed that R-PC α and β subunits expressed have antioxidant activity and can inhibit the generation of radicals, exhibiting a protective effect against H₂O₂-induced apoptotic HUVEC cells death. R-PC prevented the H₂O₂-induced HUVEC cell cycle phase arrest by regulating cell cycle-related protein. Furthermore, R-PC prevented the H₂O₂-induced HUVEC cell cycle phase arrest by regulating cell-cycle-related protein expression. In vivo study also indicated that R-PC significantly increased the survival time and alleviated the oxidative stress of Drosophila melanogaster. Moreover, R-PC notably decreased levels of ROS in natural aging flies and inhibited lipid peroxidation by enhancing the expressions of the endogenous stress marker genes (SOD1, SOD2, CAT of Drosophila melanogaster). Taken together, a study on the antioxidation extract from Porphyra haitanensis, such as R-PC, may open a new window for the prevention of anti-aging.

Duck Tembusu virus infection induces mitochondrial-mediated and death receptor-mediated apoptosis in duck embryo fibroblasts

Duck Tembusu virus (DTMUV) is a pathogenic flavivirus that has caused enormous economic losses in Southeast Asia. Our previous study showed that DTMUV could induce duck embryo fibroblast (DEF) apoptosis, but the specific mechanism was not clear. In this study, we confirmed that DTMUV could induce the apoptosis of DEFs by DAPI staining and TUNEL staining. Furthermore, we found that the expression levels of cleaved-caspase-3/7/8/9 were significantly upregulated after DTMUV infection. After treatment of cells with an inhibitor of caspase-8 or caspase-9, DTMUV-induced apoptosis rates were significantly decreased, indicating that the caspase-8-mediated death receptor apoptotic pathway and caspase-9-mediated mitochondrial apoptotic pathway were involved in DTMUV-induced apoptosis. Moreover, we found that DTMUV infection not only caused the release of mitochondrial cytochrome C (Cyt C) and the downregulation of the apoptosis-inhibiting protein Bcl-2 but also reduced the mitochondrial membrane potential (MMP) and the accumulation of intracellular reactive oxygen species (ROS). Key genes in the mitochondrial apoptotic pathway and death receptor apoptotic pathway were upregulated to varying degrees, indicating the activation of the mitochondrial apoptosis pathway and death receptor apoptosis pathway. In conclusion, this study clarifies the molecular mechanism of DTMUV-induced apoptosis and provides a theoretical basis for revealing the pathogenic mechanism of DTMUV infection.

Functional characterization of BAG3 in orange-spotted grouper (Epinephelus coioides) during viral infection

Bcl-2-associated athanogene 3 (BAG3) is a cochaperone protein that interacts with Bcl-2 and mediate cell death. However, little is known about the roles of fish BAG3 during viral infection. In this study, we characterized a BAG3 homolog from orange-spotted grouper (Epinephelus coioides) (EcBAG3) and investigated its roles during viral infection. The EcBAG3 protein encoded 579 amino acids with typical WW, PXXP and BAG domains, which shared high identities with reported fish BAG3. Quantitative real-time PCR (qRT-PCR) analysis revealed that EcBAG3 was highly expressed in brain and heart. And the expression of EcBAG3 was significantly up-regulated after red-spotted grouper nervous necrosis virus (RGNNV) stimulation in vitro. EcBAG3 overexpression could promoted the expression of viral genes (coat protein (CP) and RNA-dependent RNA polymerase (RdRp)), which was enhanced by co-transfection with Hsp70 and Hsp22. Also, EcBAG3 overexpression up-regulated the expression of LC3-Ⅱ and down-regulated the expression of Bax and BNIP3, the IFN- (IRF1, IRF3, IRF7, IFP35, Mx1) or inflammation-related (IL-1β and TNFα) factors, as well as decreased the activities of NF-κB, ISRE and IFN-3. While knockdown of EcBAG3 decreased the transcripts of RGNNV CP gene and RdRp gene. Further studies showed that EcBAG3 knockdown impaired the expression level of autophagy factor LC3-Ⅱ, and promoted the expression level of Bax and BNIP3, inflammatory factors and interferon factors. These data indicate that EcBAG3 can affect viral infection through modulating virus-induced cell death, regulating the expression of IFN- and inflammation-related factors, which will be helpful to further explore the immune response of fish during viral infection.

HiPSC-Derived Hepatocyte-like Cells Can Be Used as a Model for Transcriptomics-Based Study of Chemical Toxicity

Traditional toxicity risk assessment approaches have until recently focussed mainly on histochemical readouts for cell death. Modern toxicology methods attempt to deduce a mechanistic understanding of pathways involved in the development of toxicity, by using transcriptomics and other big data-driven methods such as high-content screening. Here, we used a recently described optimised method to differentiate human induced pluripotent stem cells (hiPSCs) to hepatocyte-like cells (HLCs), to assess their potential to classify hepatotoxic and non-hepatotoxic chemicals and their use in mechanistic toxicity studies. The iPSC-HLCs could accurately classify chemicals causing acute hepatocellular injury, and the transcriptomics data on treated HLCs obtained by TempO-Seq technology linked the cytotoxicity to cellular stress pathways, including oxidative stress and unfolded protein response (UPR). Induction of these stress pathways in response to amiodarone, diclofenac, and ibuprofen, was demonstrated to be concentration and time dependent. The transcriptomics data on diclofenac-treated HLCs were found to be more sensitive in detecting differentially expressed genes in response to treatment, as compared to existing datasets of other diclofenac-treated in vitro hepatocyte models. Hence iPSC-HLCs generated by transcription factor overexpression and in metabolically optimised medium appear suitable for chemical toxicity detection as well as mechanistic toxicity studies.

The Protective Mechanism of Dexmedetomidine in Regulating Atg14L-Beclin1-Vps34 Complex Against Myocardial Ischemia-Reperfusion Injury

The blood flow restoration of ischemic tissues causes myocardial injury. Dexmedetomidine (Dex) protects multi-organs against ischemia/reperfusion (I/R) injury. This study investigated the protective mechanism of Dex post-treatment in myocardial I/R injury. The rat model of myocardial I/R was established. The effects of Dex post-treatment on cardiac function and autophagy flow were observed. Dex attenuated myocardial I/R injury and reduced I/R-induced autophagy in rats. Dex weakened the interactions between Beclin1 and Vps34 and Beclin1 and Atg14L, thus downregulating Vps34 kinase activity. In vitro, the cardiomyocytes subjected to oxygen glucose deprivation/reoxygenation were treated with Dex and PI3K inhibitor LY294002. LY294002 attenuated the myocardial protective effect of DEX, indicating that Dex protected against cardiac I/R by activating the PI3K/Akt pathway. In conclusion, Dex upregulated the phosphorylation of Beclin1 at S295 site by activating the PI3K/Akt pathway and reduced the interactions of Atg14L-Beclin1-Vps34 complex, thus inhibiting autophagy and protecting against myocardial I/R injury.

Chlorogenic acid inhibits apoptosis in thiram-induced tibial dyschondroplasia via intrinsic pathway

Tibial dyschondroplasia (TD) is a common skeletal disease occurred in growth plate of fast-growing broilers. Thiram is a sort of chemical used for pesticide and fungicide. The excessive use of thiram increased the threat to animal and human health. In this study, we aimed to investigate the therapeutic mechanism of chlorogenic acid (CGA) on thiram-induced tibial dyschondroplasia. Broiler chickens were divided into three different groups, e.g., control, TD, and CGA. CGA was administrated after the induction of TD from 4^th day to 7^th day. Biochemical analysis was performed to detect the content of calcium (Ca) and phosphorus (P). Histological changes and degradation of extracellular matrix were observed through hematoxylin-eosin (H & E) and Masson staining. To further determine the mechanism, TUNEL staining and western blot were also performed to detect the apoptosis changes in growth plate of all groups. The results showed the disproportionation of Ca and P content and upregulation of apoptosis during the development of TD. But, after the administration of CGA, the ratio of Ca:P was upregulated, and the apoptosis was also downregulated. The current study shows the toxic effect of thiram on chickens and suggests that CGA is associated with a mechanism that plays a significant role in apoptosis induced by thiram in poultry industry.

Glycyrrhizic acid exhibits strong anticancer activity in colorectal cancer cells via SIRT3 inhibition

Sirtuin-3 (SIRT3) has been described as a colorectal cancer oncogene and to be regulated by glycyrrhizic acid (GA). However, few studies have explored the interaction between GA and SIRT3. Therefore, in the present study, we showed that GA could significantly decrease SIRT3 protein levels in SW620 and HT29 cells in a dose-dependent manner. Then, we overexpressed SIRT3 by lentivirus infection on SW620 and HT29 cells. We found that, in vitro, GA treatment significantly decreased cell viability, cell clone number, and invasion and migration number, besides significantly increasing apoptosis. Also, GA treatment significantly decreased the Bax/Bcl2 protein ratio and the expression of Cyclin D1, CDK2, CDK4, MMP-9, N-cadherin, and vimentin in SW620 and HT29 cells. Meanwhile, the SIRT3 overexpression could significantly reverse these changes. Moreover, the GA treatment could significantly decrease the weight of xenograft tumor tissues and its SIRT3 protein levels in vivo, while SIRT3 overexpression reversed these effects. Overall, GA inhibited the proliferation, invasion, and migration of colorectal cancer cells, and induced their apoptosis by SIRT3 inhibition.

Inhibit inflammation and apoptosis of pyrroloquinoline on spinal cord injury in rat

Background

Pyrroloquinoline quinone (PQQ) is a redox cofactor that can participate in a variety of physiological and biochemical processes, such as anti-inflammatory, cytoprotection, anti-aging, and anti-apoptosis. PQQ plays an important protective role in the central nervous system (CNS). However, the effects of PQQ on astrocytes of the CNS and spinal cord injury (SCI) of rats is still unclear. The present study investigates the role of PQQ in inflammation, apoptosis, and autophagy after SCI in rats. And the effect of PQQ on lipopolysaccharide (LPS)-induced apoptosis and inflammation of astrocytes in vitro, to explore the neuroprotective mechanism of PQQ.

Methods

Sixty specific pathogen free (SPF) SD male rats (200–250 g) were randomly divided into Normal group, Sham group, SCI group, and SCI + PQQ group, with 15 rats in each group. BBB score, HE staining, Nissl staining, Western blot, immunofluorescence, and other methods were used for detection.

Results

Our results showed that PQQ could upregulate BBB score in SCI rats. In the second place, PQQ can increase the number and improve the morphology of neurons after SCI. The expression of IL-1β, TNF-α, IL-6 was significantly decreased after PQQ treatment. And then, the ratio of B-cell lymphoma-2 (Bcl-2)/Bcl-2 associated X protein (Bax) increased significantly, and the positive signal of NeuN increased obviously after PQQ treatment. There are a large number of co-localizations between Bcl-2 and NeuN. Meanwhile, PQQ could down-regulate the expression of Active-Caspase3, and PQQ treatment could reverse the transfer of Active-Caspase3/Caspase3 from the cytoplasm to the nucleus in neurons and astrocytes after SCI. At the same time, PQQ had no significant effect on the LC3b/a ratio. PQQ could decrease the LAMP2 expression in spinal cord after injury. The expression level of phospho-Akt (p-AKT) increased after SCI and decreased after PQQ treatment. In primary astrocytes, LPS could induce the expression levels of IL-1β, TNF-α, and IL-6, and which were inhibited by PQQ treatment at 12 hours. After treatment with LPS, the expression level of Active-Caspase3 increased, which could be reversed by PQQ treatment for 24 h.

Conclusions

These results suggest that PQQ can ameliorate the motor function of hind limbs and the pathological changes of neurons and injured spinal cord after SCI, down-regulate the expressions of IL-1β, TNF-α, and IL-6, inhibit apoptosis after SCI, and inhibit LPS-induced apoptosis and inflammation of astrocytes.

Lysionotin induces apoptosis of hepatocellular carcinoma cells via caspase-3 mediated mitochondrial pathway

As the sixth most prevalent cancer, liver cancer has been reported as the second cause of cancer-induced deaths globally. Lysionotin, a flavonoid compound widely distributed in Lysionotus pauciflorus Maxim, has attracted considerable attention due to its multiple biological activities. The present study analyzes the anti-liver cancer effects of lysionotin in cells and mouse models. In HepG2 and SMMC-7721 cells, lysionotin significantly reduced the viability of cells, inhibited cell proliferation and migration, enhanced cell apoptosis, promoted the increase of intracellular reactive oxygen species (ROS) levels, decreased mitochondrial membrane potential (MMP), and alternated the content of apoptosis-related proteins. In HepG2-and SMMC-7721-xenograft tumor mouse models, lysionotin inhibited tumor growth, reduced the expression levels of anti-apoptotic proteins and enhanced the expression levels of pro-apoptotic proteins in tumor tissues. Additionally, the pre-treatment of Ac-DEVD-CHO, an inhibitor of caspase-3, strongly restored the low cell viability, the enhanced apoptosis rate, the dissipation of MMP caused by lysionotin exposure, as well as prevented the lysionotin-caused enhancement on expressions of apoptosis related proteins, especially cleaved poly (ADP-ribose) polymerase (PARP), Fas Ligand (FasL), cleaved caspase-3 and Bax in both HepG2 and SMMC-7721 cells. Altogether, lysionotin showed significant anti-liver cancer effects related to caspase-3 mediated mitochondrial apoptosis.

Radiation exposure and mitochondrial insufficiency in chronic fatigue and immune dysfunction syndrome

Chronic fatigue and Immune Dysfunction Syndrome (CFIDS) is a heterogeneous disease that may be promoted by various environmental stressors, including viral infection, toxin uptake, and ionizing radiation exposure. Previous studies have identified mitochondrial dysfunction in CFIDS patients, including modulation of mitochondrial respiratory chain activity, deletions in the mitochondrial genome, and upregulation of reactive oxygen species (ROS). This paper focuses on radiation effects and hypothesizes that CFIDS is primarily caused by stressor-induced mitochondrial metabolic insufficiency, which results in decreased energy production and anabolic metabolites required for normal cellular metabolism. Furthermore, tissues neighbouring or distant from directly perturbed tissues compensate for this dysfunction, which causes symptoms associated with CFIDS. This hypothesis is justified by reviewing the links between radiation exposure and CFIDS, cancer, immune dysfunction, and induction of oxidative stress. Moreover, the relevance of mitochondria in cellular responses to radiation and metabolism are discussed and putative mitochondrial biomarkers for CFIDS are introduced. Implications for diagnosis are then described, including a potential urine assay and PCR test for mitochondrial genome mutations. Finally, future research needs are offered with an emphasis on where rapid progress may be made to assist the afflicted.

Discovery of novel dihydroartemisinin-cinnamic hybrids inducing lung cancer cells apoptosis via inhibition of Akt/Bad signal pathway

A series of dihydroartemisinin-cinnamic acid hybrids were designed, synthesized and evaluated. Most of the tested compounds showed enhanced anti-proliferative activities than artemisinin and dihydroartemisinin, among which 16 g had the superior potency with IC₅₀ values ranging from 5.07 μM to 7.88 μM against four tested cancer cell lines. The cell cycle arrest revealed that 16 g induced A549 cell cycle arrest at G0/G1 phase via regulation of G1-related protein expression (Cdk4). Further mechanism studies reveal that 16 g induced A549 cells apoptosis via inhibiting Akt/Bad pathway. Moreover, 16 g depolarized the mitochondria membrane potentials and induced ROS generation in A549. Additionally, 16 g blocked migration of A549 cells in a concentration-dependent manner. What's more, 16 g is barely nontoxic to zebrafish embryos. Overall, the cell cycle arrest, inhibition of Akt/Bad signal pathway, ROS generation and migration blocked might explain the potent anti-proliferative activities of these compounds.

The Dual Regulation of Apoptosis by Flavivirus

Apoptosis is a form of programmed cell death, which maintains cellular homeostasis by eliminating pathogen-infected cells. It contains three signaling pathways: death receptor pathway, mitochondria-mediated pathway, and endoplasmic reticulum pathway. Its importance in host defenses is highlighted by the observation that many viruses evade, hinder or destroy apoptosis, thereby weakening the host’s immune response. Flaviviruses such as Dengue virus, Japanese encephalitis virus, and West Nile virus utilize various strategies to activate or inhibit cell apoptosis. This article reviews the research progress of apoptosis mechanism during flaviviruses infection, including flaviviruses proteins and subgenomic flaviviral RNA to regulate apoptosis by interacting with host proteins, as well as various signaling pathways involved in flaviviruses-induced apoptosis, which provides a scientific basis for understanding the pathogenesis of flaviviruses and helps in developing an effective antiviral therapy.

Kaempferol Alleviates Oxidative Stress and Apoptosis Through Mitochondria-dependent Pathway During Lung Ischemia-Reperfusion Injury

In previous study, we reported that kaempferol ameliorates significantly lung ischemia-reperfusion injury (LIRI), and may be achieved by targeting the SIRT 1 pathway. This study further explored the anti-LIRI mechanism of kaempferol. In vitro, the rat alveolar epithelial cells L2 was cultured and subjected to anoxia/reoxygenation (A/R) insult. In vivo, SD rats were operated to establish LIRI model. The related indicators of oxidative stress and apoptosis in L2 cells and rats lung tissues were detected. Results showed that kaempferol pre-treatment significantly increased the cell viability, improved mitochondrial membrane potential, inhibited the opening of mitochondrial permeability transition pores, reduced the levels of oxidative stress and apoptosis, increased the expressions of Bcl-2 and mitochondrial cytochrome c, and decreased the expressions of Bax and cytoplasmic cytochrome c in L2 cells after A/R insult. In vivo, kaempferol improved the pathological injury, inhibited the levels of oxidative stress and apoptosis, increased the expressions of Bcl-2 and mitochondrial cytochrome c, and decreased the expressions of Bax and cytoplasmic cytochrome c in rats lung tissues after I/R. However, the aforementioned effects of kaempferol were significantly attenuated by the SIRT 1 inhibitor EX527 or the PGC-1α inhibitor SR-18292. What's more, SR-18292 has not reversed the effect of kaempferol on increasing the protein activity of SIRT 1. Above results suggest that kaempferol ameliorates LIRI by improving mitochondrial function, reducing oxidative stress and inhibiting cell apoptosis. Its molecular mechanism of action includes the SIRT 1/PGC-1α/mitochondria signaling pathway.

Knockdown of sorcin increases HEI-OC1 cell damage induced by cisplatin in vitro

Hearing loss caused by ototoxic drugs is a kind of acquired hearing loss. Cisplatin is one of the most commonly used drugs and its main action sites are hair cells (HCs). Sorcin is a drug-resistant calcium-binding protein belonging to the small penta-EF-hand protein family. Sorcin is highly expressed in many tissues, including bone, heart, brain, lung, and skin tissues. Single-cell RNA sequencing showed that sorcin was expressed in the outer HCs of mice, but its role remained unknown. We also found that sorcin was highly expressed in the cytoplasm of cochlear HCs and HEI-OC1 cells. After cisplatin injury, the expression of sorcin in HCs and HEI-OC1 cells decreased significantly. SiRNA transfection technology was used to knock down the expression of sorcin. The results showed that the number of apoptotic cells, the expression of cleaved caspased-3, and the expression of Bax increased while the anti-apoptotic factor Bcl-2 decreased in the siRNA-Sorcin + CIS group. The observed increase in apoptosis was related to the increase of reactive oxygen species (ROS) and the destruction of the mitochondrial membrane potential (MMP). Finally, we found that the downregulated sorcin worked by activating the P-ERK1/2 signaling pathway. Overall, this study showed that sorcin can be used as a new target to prevent the ototoxicity of platinum drugs.

Allomyrina dichotoma larva extract attenuates free fatty acid-induced lipotoxicity in pancreatic beta cells

BACKGROUD/OBJECTIVES

Allomyrina dichotoma larva (ADL), one of the many edible insects recognized as future food resources, has a range of pharmacological activities. In a previous study, an ADL extract (ADLE) reduced the hepatic insulin resistance of high-fat diet (HFD)-induced diabetic mice. On the other hand, the associated molecular mechanisms underlying pancreatic beta-cell dysfunction remain unclear. This study examined the effects of ADLE on palmitate-induced lipotoxicity in a beta cell line of a rat origin, INS-1 cells.

MATERIALS/METHODS

ADLE was administered to high-fat diet treated mice. The expression of apoptosis-related molecules was measured by Western blotting, and reactive oxidative stress generation and nitric oxide production were measured by DCH-DA fluorescence and a Griess assay, respectively.

RESULTS

The administration of ADLE to HFD-induced diabetic mice reduced the hyperplasia, 4-hydroxynonenal levels, and the number of apoptotic cells while improving the insulin levels compared to the HFD group. Treatment of INS-1 cells with palmitate reduced insulin secretion, which was attenuated by the ADLE treatment. Furthermore, the ADLE treatment prevented palmitate-induced cell death in INS-1 cells and isolated islets by reducing the apoptotic signaling molecules, including cleaved caspase-3 and PARP, and the Bax/Bcl2 ratio. ADLE also reduced the levels of reactive oxygen species generation, lipid accumulation, and nitrite production in palmitate-treated INS-1 cells while increasing the ATP levels. This effect corresponded to the decreased expression of inducible nitric oxide synthase (iNOS) mRNA and protein.

CONCLUSIONS

ADLE helps prevent lipotoxic beta-cell death in INS-1 cells and HFD-diabetic mice, suggesting that ADLE can be used to prevent or treat beta-cell damage in glucose intolerance during the development of diabetes.

ATP5A1 Participates in Transcriptional and Posttranscriptional Regulation of Cancer-Associated Genes by Modulating Their Expression and Alternative Splicing Profiles in HeLa Cells

Background: Aberrant expression and alternative splicing of oncogenes are the driving events in tumor initiation and development. But how these events are regulated in cancer cells is largely unknown. Functions of ATP5A1, an important mitochondrial ATP synthase gene, in transcriptional and posttranscriptional regulation were explored in this study. Methods: ATP5A1 was overexpressed using plasmid-transformed HeLa cells, and its influence on cell apoptosis and proliferation is evaluated. Transcriptome sequencing was then performed using RNA-seq to study the changes in gene expression and regulation of alternative splicing events. Validation of the implicated genes was achieved using RT-qPCR analysis. Results: It was found that ATP5A1 could significantly promote cellular apoptosis, but it had no influence on cell proliferation. ATP5A1 overexpression significantly increased the expression levels of genes associated with the innate immune response, angiogenesis, and collagen catabolic processes. This included enrichment of MMP2 and MMP19. It was also found that ATP5A1 could interfere with the alternative splicing of hundreds of genes associated with glucose homeostasis, HIF-1 signaling activation, and several pathways associated with cancers. Eight ATP5A1-regulated differentially expressed genes and 3 genes altered by splicing were selected and validated using RT-qPCR analysis. Conclusions: In summary, we illustrate the regulatory functions of ATP5A1 on the transcriptome of HeLa cells by exploring its influence on gene expression and alternative splicing. The results suggest that ATP5A1 may play an important regulatory role in cervical cancer cells by regulating expression and alternative splicing of cancer-associated genes. This study provides novel insights into the current understanding of the mechanisms of ATP5A1 on carcinogenesis and cancer progression.

Cellular Prion Protein (PrPc): Putative Interacting Partners and Consequences of the Interaction

Cellular prion protein (PrPc) is a small glycosylphosphatidylinositol (GPI) anchored protein most abundantly found in the outer leaflet of the plasma membrane (PM) in the central nervous system (CNS). PrPc misfolding causes neurodegenerative prion diseases in the CNS. PrPc interacts with a wide range of protein partners because of the intrinsically disordered nature of the protein’s N-terminus. Numerous studies have attempted to decipher the physiological role of the prion protein by searching for proteins which interact with PrPc. Biochemical characteristics and biological functions both appear to be affected by interacting protein partners. The key challenge in identifying a potential interacting partner is to demonstrate that binding to a specific ligand is necessary for cellular physiological function or malfunction. In this review, we have summarized the intracellular and extracellular interacting partners of PrPc and potential consequences of their binding. We also briefly describe prion disease-related mutations at the end of this review.

Atractylenolide I Induces Apoptosis and Suppresses Glycolysis by Blocking the JAK2/STAT3 Signaling Pathway in Colorectal Cancer Cells

Colorectal cancer (CRC) is the third most common cancer worldwide and is associated with a poor clinical outcome and survival. Therefore, the development of novel therapeutic agents for CRC is imperative. Atractylenolide I (AT-I) is a sesquiterpenoid lactone derivative of Rhizoma Atractylodis macrocephalae that exhibits diverse biological activities, including anti-cancer activities. However, the effects and potential mechanism of AT-I in CRC have yet to be fully elucidated. In this study, we aimed to examine the anti-cancer properties of AT-I and the associated functional mechanisms in vitro and in vivo. We found that AT-I treatment significantly suppressed the viability of CRC cell lines and inhibited colony formation, but to a lesser extent in NCM460 cells. Annexin V/PI staining showed that AT-I induced apoptosis in CRC cells, accompanied by increased caspase-3 and PARP-1 cleavage, enhanced expression of Bax, and reduced expression of Bcl-2. Furthermore, AT-I blocked cell glycolysis by inhibiting both glucose uptake and lactate production in CRC cells, and specifically downregulated the expression of the rate-limiting glycolytic enzyme HK2. In contrast, it had no discernable effects on the glycolytic enzymes PFK and PKM2. A mechanistic study revealed that AT-1 negatively regulates STAT3 phosphorylation through direct interaction with JAK2, thereby inhibiting its activation. Moreover, restoring the expression of STAT3 reversed the effect of AT-I on apoptosis and glycolysis in CRC cells. In vivo results revealed that AT-I significantly suppressed tumor growth in HCT116-xenografted mice. Collectively, our findings indicate that the anti-cancer activity of AT-I in CRC is associated with the induction of apoptosis and suppression of glycolysis in CRC cells, via the disruption of JAK2/STAT3 signaling. Our preliminary experimental data indicate that AT-I may have applications as a promising candidate for the treatment of CRC.

Isoquercitrin Attenuates Renal Ischemia/Reperfusion Injury Through Antioxidation, Anti-inflammation, and Antiapoptosis in Mice

Renal ischemia-reperfusion injury (RIRI) occurs after several surgical procedures such as kidney transplantation and partial nephrectomy. Isoquercitrin (IQ) exhibited protective effects in cerebral ischemia-reperfusion injury. In the present study, we aimed to evaluate the effects of IQ on the prevention of RIRI. The mouse model of RIRI was induced by 30-minute clamping of the left renal pedicle after excising of the right kidney, followed by 24-hour reperfusion. Thirty mice were randomly divided into the following 3 groups: sham operation, RIRI model group, and IQ pretreatment + RIRI. Serum creatinine and blood urea nitrogen (BUN) were used for evaluating renal function. Kidney cell apoptosis was measured by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining. Moreover, the pro-inflammatory cytokines (TNF-α, IL-6), the oxidative stress associated factors (malondialdehyde, superoxide dismutase), and the apoptotic factors (Bcl-2, Bax) were assessed. After RIRI, BUN, creatinine, TNF-α, IL-6, malondialdehyde, and Bax were significantly increased, and levels of superoxide dismutase and Bcl-2/Bax ratio and Bcl-2 expression were decreased markedly. As expect, IQ reversed these changes. These data indicate that IQ plays a protective role during RIRI, which may be partially mediated through the actions of antioxidation, anti-inflammation, and antiapoptosis.

Combination of metformin and berberine represses the apoptosis of sebocytes in high-fat diet-induced diabetic hamsters and an insulin-treated human cell line

Obesity and insulin resistance affect metabolic reactions, but their ensuing contributions to macrophage metabolism remain insufficiently understood. We investigated the contributions of berberine and metformin combination to the inhibition of sebocyte apoptosis in high-fat diet-induced diabetic hamsters and an insulin-treated human cell line. Golden hamsters were fed a high-glucose high-fat diet and administered a 6-week treatment with a combination of metformin and two concentrations of berberine (100 or 50 mg·kg^-1 ). Body weights of treated hamsters were remarkably reduced compared with those of controls. Histological examination indicated that berberine repressed liver fat accumulation. Moreover, insulin and glucose concentrations were noticeably decreased by the combination treatments. In glucose tolerance tests, hamsters receiving berberine displayed higher tolerance to glucose, compared with the control group. Sebocytes isolated from high-fat diet-induced diabetic hamsters and insulin-treated human sebocytes displayed elevated cell death rates, which were attenuated by berberine and metformin treatments. Further studies showed that the effects of metformin and berberine on cellular apoptosis were mediated via the Bik pathway. Thus, berberine may effectively decrease circulating glucose levels, ameliorate insulin resistance, reduce body weight, and attenuate sebocyte apoptosis in diabetic hamsters, potentially decreasing vulnerability to the cardiovascular complications of diabetes. SIGNIFICANCE OF THE STUDY: The present data indicate that insulin stimulates changes in the expression levels of cell death-associated proteins, which participate in sebaceous gland diseases during obesity or diabetes. The anti-apoptotic effects of BBR and MET in sebaceous gland cells are regulated partially by Bik expression. To the best of our knowledge, this study is the first to suggest cell death counteracting effects of BBR in hamster and human sebocytes as well as to propose BBR as an innovative therapeutic agent for insulin-related sebaceous gland diseases, including acne.

T-2 Toxin Induces Oxidative Stress, Apoptosis and Cytoprotective Autophagy in Chicken Hepatocytes

T-2 toxin is type A trichothecenes mycotoxin, which produced by fusarium species in cereal grains. T-2 toxin has been shown to induce a series of toxic effects on the health of human and animal, such as immunosuppression and carcinogenesis. Previous study has proven that T-2 toxin caused hepatotoxicity in chicken, but the regulatory mechanism is unclear. In the present study, we assessed the toxicological effect of T-2 toxin on apoptosis and autophagy in hepatocytes. The total of 120 1-day-old healthy broilers were allocated randomly into four groups and reared for 21 day with complete feed containing 0 mg/kg, 0.5 mg/kg, 1 mg/kg or 2 mg/kg T-2 toxin, respectively. The results showed that the apoptosis rate and pathological changes degree hepatocytes were aggravated with the increase of T-2 toxin. At the molecular mechanism level, T-2 toxin induced mitochondria-mediated apoptosis by producing reactive oxygen species, promoting cytochrome c translocation between the mitochondria and cytoplasm, and thus promoting apoptosomes formation. Meanwhile, the expression of the autophagy-related protein, ATG5, ATG7 and Beclin-1, and the LC3-II/LC3-I ratio were increased, while p62 was downregulated, suggesting T-2 toxin caused autophagy in hepatocytes. Further experiments demonstrated that the PI3K/AKT/mTOR signal may be participated in autophagy induced by T-2 toxin in chicken hepatocytes. These data suggest a possible underlying molecular mechanism for T-2 toxin that induces apoptosis and autophagy in chicken hepatocytes.

Matrine Exerts Hepatotoxic Effects via the ROS-Dependent Mitochondrial Apoptosis Pathway and Inhibition of Nrf2-Mediated Antioxidant Response

Matrine, an alkaloid isolated from Sophora flavescens, possesses a wide range of pharmacological properties. However, the use of matrine in clinical practice is limited due to its toxic effects. The present study investigated the roles of mitochondria and reactive oxygen species (ROS) in matrine-induced liver injury. Our results showed that treatment of HL-7702 cells with matrine led to significant and concentration- and time-dependent reductions in their viability, as well as significant and concentration-dependent increases in the number of apoptotic cells and supernatant lactate dehydrogenase (LDH) activity. The treatment led to significant increases in the population of cells in S phase and significant reduction of cell proportion in G0/G1 and G2/M phases. It also significantly and concentration-dependently increased the levels of ROS and malondialdehyde (MDA) but significantly and concentration-dependently reduced superoxide dismutase (SOD) activity, level of reduced glutathione (GSH), and mitochondrial membrane potential (MMP). Matrine treatment significantly and concentration-dependently upregulated the expressions of Bax, p53, p-p53, p21, cyclin E, Fas, cleaved caspase-3, caspase-8, and caspase-9 proteins and downregulated the expressions of Bcl-2, cyclin-dependent kinase 2 (CDK2), and cyclin A. It also significantly promoted the cleavage of poly(ADP-ribose)polymerase (PARP), upregulated Kelch-like ECH-associated protein 1 (Keap1) expression, and downregulated the expressions of cellular total and nuclear Nrf2. Matrine significantly inhibited the expressions of downstream oxidoreductases (Heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductases 1 (NQO-1)) and enhanced the formation of Keap1/Nrf2 protein complex. These results show that the hepatotoxic effect of matrine is exerted via inhibition of Nrf2 pathway, activation of ROS-mediated mitochondrial apoptosis pathway, and cell cycle arrest at S phase. Pretreatment with N-acetyl cysteine (NAC) partially reversed matrine-induced hepatotoxicity.

Detoxification, Apoptosis, and Immune Transcriptomic Responses of the Gill Tissue of Bay Scallop Following Exposure to the Algicide Thiazolidinedione 49

Thiazolidinedione 49 (TD₄₉), a newly synthesized algicide, shows strong toxicity at low concentrations of 0.1-2.0 μM. However, its potential effects on non-target species at the transcript level were not investigated. Differentially expressed genes (DEGs) in the gills of the bay scallop, Argopecten irradians, were accessed after treatment with 0.68 μM TD₄₉ for up to 48 h. Following exposure, it was observed that 5214 genes were upregulated and 3497 were downregulated. Functional enrichment analysis revealed that the apoptosis pathway was activated. The extrinsic apoptosis pathway was activated and the survival factors related pathway was suppressed. Furthermore, gene expressions related to ATP-binding cassette, nuclear factor erythroid 2-related factor, B cell lymphoma-2 family protein, glutathione reductase, glutathione peroxidase, catalase, NADPH2:quinone reductase, and superoxide dismutase were decreased. Conversely, gene expressions related to FAS-associated death domain protein, glutathione S-transferase, caspase 6, 8, cytochrome P450 1A1, and 2C8 were increased. These results comprehensively demonstrated the toxicity of the novel algicide TD₄₉, and should draw the attention of researchers to the importance of analyzing the potential impact of chemical compounds as algicides to control the proliferation of harmful algae, due to the secondary pollution caused by their application.

Anticancer Function and ROS-Mediated Multi-Targeting Anticancer Mechanisms of Copper (II) 2-hydroxy-1-naphthaldehyde Complexes

Multi-targeting of oncoproteins by a single molecule represents an effectual, rational, and an alternative approach to target therapy. We carried out a systematic study to reveal the mechanisms of action of newly synthesized Cu²⁺ compounds of 2-naphthalenol and 1-(((2-pyridinylmethyl)imino)methyl)- (C1 and C2). The antiproliferative activity of the as-synthesized complexes in three human cancer cell lines indicates their potential as multi-targeted antitumor agents. Relatively, C1 and C2 showed better efficacy in vitro relative to Cisplatin and presented promising levels of toxicity against A-549 cells. On the whole, the Cu²⁺ complexes exhibited chemotherapeutic effects by generating reactive oxygen species (ROS) and arresting the cell cycle in the G₀/G₁ phase by competent regulation of cyclin and cyclin-dependent kinases. Fascinatingly, the Cu²⁺ complexes were shown to activate the apoptotic and autophagic pathways in A-549 cells. These complexes effectively induced endoplasmic reticulum stress-mediated apoptosis, inhibited topoisomerase-1, and damaged cancer DNA through a ROS-mediated mechanism. The synthesized Cu²⁺ complexes established ROS-mediated targeting of multiple cell signaling pathways as a fabulous route for the inhibition of cancer cell growth.

Inhibition of miR-337-3p involved in the protection of CoCl2 -induced injury in PC12 cells via activating JAK2/STAT3 signaling pathway

OBJECTIVE

To investigate the possibility of microRNA (miR)-337-3p in the protection of hypoxia-induced injury in PC12 cells via modulating the JAK2/STAT3 signaling pathway.

METHODS

Dual-luciferase reporter assay analyzed the relationship between the miR-337-3p and JAK2. PC12 cells were divided into normal, CoCl₂ , CoCl2 + NC, CoCl2 + inhibitors, CoCl2 + JAK2, and CoCl2 + mimics + JAK2 groups. Then, PC12 cell viability and apoptosis were measured by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and Annexin-V-fluorescein isothiocyanate/propidium iodide methods. Quantitative real-time polymerase chain reaction and Western blot analysis were used to determine expressions. Besides, the intracellular reactive oxygen species (ROS) was examined by dichloro-dihydro-fluorescein diacetate (DCFH-DA) while the mitochondrial membrane potential (MMP) by using JC-1.

RESULTS

The negative targeting relationship between miR-337-3p and JAK2 was confirmed. When compared with the normal group, miR-337-3p was increased while JAK2 and STAT3 were decreased in CoCl₂ -induced PC12 cells, with decreased cell viability. Moreover, either miR-337-3p inhibitor or JAK2 overexpression could partially reverse CoCl₂ -induced decrease in PC12 cell viability. Besides, CoCl₂ could also trigger PC12 cell apoptosis by increasing cleaved caspase 3 and Bax but decreasing Bcl-2 and Bcl-XL, which, however, were abolished with the transfection of miR-337-3p inhibitors or lentivirus transfection to activate JAK2. Compared with the CoCl₂ group, the average of fluorescent signals of ROS in the CoCl2 + inhibitors group and the CoCl2 + JAK2 group was lower, while the activities of superoxide dismutase, catalase, glutathione peroxidase, and total anti-oxidative capacity were higher, together with an increase in MMP.

CONCLUSION

Inhibiting miR-337-3p could activate the JAK2/STAT3 signaling pathway to suppress CoCl ₂ -induced cytotoxicity and apoptosis and ameliorate oxidative stress and MMP in PC12 cells.

Mitochondria as playmakers of apoptosis, autophagy and senescence

Mitochondria are the key energy-producing organelles and cellular source of reactive species. They are responsible for managing cell life and death by a balanced homeostasis passing through a network of structures, regulated principally via fission and fusion. Herein we discuss about the most advanced findings considering mitochondria as dynamic biophysical systems playing compelling roles in the regulation of energy metabolism in both physiologic and pathologic processes controlling cell death and survival. Precisely, we focus on the mitochondrial commitment to the onset, maintenance and counteraction of apoptosis, autophagy and senescence in the bioenergetic reprogramming of cancer cells. In this context, looking for a pharmacological manipulation of cell death processes as a successful route for future targeted therapies, there is major biotechnological challenge in underlining the location, function and molecular mechanism of mitochondrial proteins. Based on the critical role of mitochondrial functions for cellular health, a better knowledge of the main molecular players in mitochondria disfunction could be decisive for the therapeutical control of degenerative diseases, including cancer.

Down-regulation of CCNE1 expression suppresses cell proliferation and sensitizes gastric carcinoma cells to Cisplatin

A novel oncogene CCNE1 (cyclin E) is considered to be associated with the development of various tumor types, its role in gastric carcinoma (GC) is little studied and the effect of CCNE1 on chemotherapy also remains unclear. We recruited 55 cases of GC tissues and corresponding normal tissues. Immunohistochemistry (IHC), quantitative real-time PCR (qRT-PCR) and Western blot analysis were performed to detect the expression of CCNE1. We also examined the expression of CCNE1 in gastric mucosal GES-1 cells and five GC cell lines. Silencing CCNE1 was used to assess its effect on proliferation and cell cycle in MGC-803 and NCI-N87 cells, as performed by Cell counting kit-8 (CCK-8) and flow cytometry assay. Meanwhile, cell cycle related genes were also detected through qRT-PCR and Western blot. The results showed CCNE1 up-regulation mainly expressed in GC tissues and GC cell lines, also was associated with tumor node metastasis (TNM) stage and lymphatic invasion. Three-year survival curve analysis showed CCNE1 with high expression had a poor prognosis. Silencing CCNE1 significantly reduced cell viability in 48 h, cultured and arrested cell cycle in G₁ phase, moreover, Cyclin A, D1 and C-myc all revealed down-regulation in both MGC-803 and NCI-N87 cells. CCNE1 expression was significantly increased at low and moderate concentrations of Cisplatin. Down-regulation of CCNE1 expression would remarkably promote cell apoptosis induced by Cisplatin, and regulate the rate of Bax/Bcl-2. Down-regulation of CCNE1 expression could inhibit cell proliferation and enhance GC cells sensibility to Cisplatin, possibly involving the regulation of Bcl-2 family.

Regulation of apoptosis in health and disease: the balancing act of BCL-2 family proteins

The loss of vital cells within healthy tissues contributes to the development, progression and treatment outcomes of many human disorders, including neurological and infectious diseases as well as environmental and medical toxicities. Conversely, the abnormal survival and accumulation of damaged or superfluous cells drive prominent human pathologies such as cancers and autoimmune diseases. Apoptosis is an evolutionarily conserved cell death pathway that is responsible for the programmed culling of cells during normal eukaryotic development and maintenance of organismal homeostasis. This pathway is controlled by the BCL-2 family of proteins, which contains both pro-apoptotic and pro-survival members that balance the decision between cellular life and death. Recent insights into the dynamic interactions between BCL-2 family proteins and how they control apoptotic cell death in healthy and diseased cells have uncovered novel opportunities for therapeutic intervention. Importantly, the development of both positive and negative small-molecule modulators of apoptosis is now enabling researchers to translate the discoveries that have been made in the laboratory into clinical practice to positively impact human health.

Lens differentiation is controlled by the balance between PDGF and FGF signaling

How multiple receptor tyrosine kinases coordinate cell fate determination is yet to be elucidated. We show here that the receptor for platelet-derived growth factor (PDGF) signaling recruits the p85 subunit of Phosphoinositide 3-kinase (PI3K) to regulate mammalian lens development. Activation of PI3K signaling not only prevents B-cell lymphoma 2 (BCL2)-Associated X (Bax)- and BCL2 Antagonist/Killer (Bak)-mediated apoptosis but also promotes Notch signaling to prevent premature cell differentiation. Reducing PI3K activity destabilizes the Notch intracellular domain, while the constitutive activation of Notch reverses the PI3K deficiency phenotype. In contrast, fibroblast growth factor receptors (FGFRs) recruit Fibroblast Growth Factor Receptor Substrate 2 (Frs2) and Rous sarcoma oncogene (Src) Homology Phosphatase 2 (Shp2) to activate Mitogen-Activated Protein Kinase (MAPK) signaling, which induces the Notch ligand Jagged 1 (Jag1) and promotes cell differentiation. Inactivation of Shp2 restored the proper timing of differentiation in the p85 mutant lens, demonstrating the antagonistic interaction between FGF-induced MAPK and PDGF-induced PI3K signaling. By selective activation of PI3K and MAPK, PDGF and FGF cooperate with and oppose each other to balance progenitor cell maintenance and differentiation.

A central aim in understanding cell signaling is to decode the cellular logic that underlies the functional specificity of growth factors. Although these factors are known to activate a common set of intracellular pathways, they nevertheless play specific roles in development and physiology. Using lens development in mice as a model, we show that fibroblast growth factor (FGF) and platelet-derived growth factor (PDGF) antagonize each other through their intrinsic biases toward distinct downstream targets. While FGF primarily induces the Ras–Mitogen-Activated Protein Kinase (MAPK) axis to promote lens cell differentiation, PDGF preferentially stimulates Phosphoinositide 3-kinase (PI3K) to enhance Notch signaling, which is necessary for maintaining the lens progenitor cell pool. By revealing the intricate interactions between PDGF, FGF, and Notch, we present a paradigm for how signaling crosstalk enables balanced growth and differentiation in multicellular organisms.

Traditional Chinese medicine-based neurorestorative therapy for Alzheimer’s and Parkinson’s disease

The prevalence of multiple neurodegenerative diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD), has been dramatically increasing, particularly in the aging population. However, the currently available therapies merely alleviate the symptoms of these diseases and are unable to retard disease progression significantly. Traditional Chinese medicine (TCM) has been used in clinical practice for thousands of years for ameliorating symptoms or interfering with the pathogenesis of aging- associated diseases. Modern pharmacological studies have proved that TCM imparts disease-modifying therapeutic effects against these diseases, such as protection of neurons, clearance of protein aggregates, and regulation of neuroinflammation. This review summarizes the evidence from recent studies on AD and PD therapies regarding the neuroprotective activities and molecular mechanisms of a series of TCM formulations comprising herbs and their active ingredients. The findings of this review support the use of TCM as an alternative source of therapy for the treatment of neurodegenerative diseases.

Sodium tanshinone IIA sulfonate protects ARPE-19 cells against oxidative stress by inhibiting autophagy and apoptosis

Oxidative stress in retinal pigment epithelium (RPE) is considered to be a major contributor to the development and progression of age-related macular degeneration (AMD). Previous investigations have shown that sodium tanshinone IIA sulfonate (STS) can alleviate oxidative stress in haemorrhagic shock-induced organ damage and cigarette smoke-induced chronic obstructive pulmonary disease in mice. However, whether STS has a protective effect in ARPE-19 cells under oxidative stress and its exact mechanisms have not yet been fully elucidated. In the present study, we utilized H₂O₂ to establish an oxidative stress environment. Our findings show that STS activated the PI3K/AKT/mTOR pathway to inhibit autophagy and diminished the expression of the autophagic proteins Beclin 1, ATG3, ATG7 and ATG9 in ARPE-19 cells under oxidative stress. Detection of the intrinsic apoptosis-related factors BAX, mitochondrial membrane potential (MMP), caspase-9, caspase-3 and BCL-2, as well as the extrinsic apoptosis-related factors c-FLIP, v-FLIP and caspase-8, confirmed that STS inhibited the intrinsic and extrinsic apoptotic pathways, and attenuated apoptosis in ARPE-19 cells under oxidative stress conditions. These findings shed new light on the protective effects of STS in ARPE-19 cells and its mechanisms under oxidative stress to provide novel and promising therapeutic strategies for AMD.

Effects of insulin-like growth factor binding protein 3 on apoptosis of cutaneous squamous cell carcinoma cells

Background

Cutaneous squamous cell carcinoma (CSCC) is the second most common carcinoma worldwide. Clinical treatment for patients with CSCC remains non-ideal. Insulin-like growth factor binding protein 3 (IGFBP3), a member of the insulin-like growth (IGF) system, participates in several biological processes, including cellular proliferation and apoptosis. Here, we explored the functional role of IGFBP3 in apoptosis and proliferation of A431 cells, a human CSCC cell line.

Materials and methods

Differential expression analysis, immunohistochemistry, immunoblotting, TUNEL assay, and CCK8 assay techniques were used to investigate the IGFBP3 expression levels in both A431 cells and CSCC tissue surgically obtained from humans as well as to explore the functional role of IGFBP3 in the apoptosis and proliferation of A431 cells.

Results

By using normal epidermal keratinocytes for comparison, we identified the top 10 ranked differentially upregulated genes expressed in human cutaneous squamous cell carcinoma cell lines. Among these 10 genes, IGFBP3 was ranked number 1. By using immunohistochemistry, we found that the expression level of IGFBP3 was significantly elevated in CSCC tissue compared with that in normal human skin tissue. Knockdown of IGFBP3 in A431 cells by transfection with IGFBP3-specific siRNA markedly altered the expression of proteins that contribute to apoptosis via mitochondrial pathways, significantly suppressing the expression of Bax and active caspase-3, while significantly increasing B-cell lymphoma-2 expression. TUNEL assay confirmed the effect of knockdown of IGFBP3 on the apoptosis as well. In addition, knockdown of IGFBP3 inhibited the proliferation of A431 cells.

Conclusion

IGFBP3 is overexpressed in both CSCC cell lines and tissue. Knockdown of IGFBP3 enhanced the apoptosis via a mitochondrial pathway and inhibited the proliferation of A431 cells. These findings indicate that IGFBP3 may be a biomarker and a potential therapeutic target for CSCC.

MG-132 treatment promotes TRAIL-mediated apoptosis in SEB-1 sebocytes

AIMS

This study aimed to identify the mechanism of how MG-132 stimulates cell death in SEB-1 sebocytes.

MATERIALS AND METHODS

TUNEL staining and annexin-FITC/PI flow cytometry were utilized to examine the apoptotic cell number of SEB-1 sebocytes and HaCaT keratinocytes upon MG-132 and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) treatment. MTT assay and CCK-8 assay monitored the proliferative rate and viability of both cell lines with different treatment. Western blotting (WB) and qPCR were performed to detect the expression of TRAIL and members of Bcl-2 family at protein and gene level. Additionally, RNA interfering was used to knockdown the mRNA transcription of TRAIL and BIK gene.

KEY FINDINGS

MG-132 treatment enhanced cell death in SEB-1 sebocytes but not in HaCaT keratinocytes. Meanwhile, TRAIL concentrations in SEB-1 sebocytes treated with MG-132 were markedly elevated. Furthermore, treatment with TRAIL or the TRAIL receptor-specific monoclonal antibody AY4 at various doses stimulated cell death in SEB-1 sebocytes in a time- and dose-dependent manner. Silencing of TRAIL restored the cell viability of SEB-1 cells to a normal level after MG-132 treatment. Combined treatment of SEB-1 sebocytes with TRAIL and MG-132 synergistically triggered cell death, suppressed cell proliferation and survival, and promoted BIK expression. Furthermore, BCL2 Interacting Killer (BIK) knockdown via RNA interference participated in the recovery of cell survival reduced by treatment with TRAIL and MG-132.

SIGNIFICANCE

These findings suggest that treatment with the selective proteasome suppressor MG-132 and TRAIL induces cell death in sebocytes through upregulation of BIK, a member of the Bcl-2 family.

Designing anticancer copper(II) complexes by optimizing 2-pyridine-thiosemicarbazone ligands

To develop potential next-generation metal anticancer agents, we designed and synthesised five Cu(II) 2-pyridine-thiosemicarbazone complexes by modifying the hydrogen atom at the N-4 position of ligands, and then investigated their structure-activity relationships and anticancer mechanisms. Modification of the N-4 position with different groups caused significant differences in cellular uptake and produced superior antitumor activity. Cu complexes arrested the cell cycle at S phase, leading to down-regulation of levels of cyclin and cyclin-dependent kinases and up-regulation of expression of cyclin-dependent kinase inhibitors. Cu complexes exerted chemotherapeutic effects via activating p53 and inducing production of reactive oxygen species to regulate expression of the B-cell lymphoma-2 family of proteins, causing a change in the mitochondrial membrane potential and release of cytochrome c to form a dimer with apoptosis protease activating factor-1, resulting in activation of caspase-9/3 to induce apoptosis. In addition, Cu complexes inhibited telomerase by down-regulating the c-myc regulator gene and expression of the human telomerase reverse transcriptase.

T Cells and Regulated Cell Death: Kill or Be Killed

Cell death plays two major complementary roles in T cell biology: mediating the removal of cells that are targeted by T cells and the removal of T cells themselves. T cells serve as major actors in the adaptive immune response and function by selectively killing cells which are infected or dysfunctional. This feature is highly involved during homeostatic maintenance, and is relied upon and modulated in the context of cancer immunotherapy. The vital recognition and elimination of both autoreactive T cells and cells which are unable to recognize threats is a highly selective and regulated process. Moreover, detection of potential threats will result in the activation and expansion of T cells, which on resolution of the immune response will need to be eliminated. The culling of these T cells can be executed via a multitude of cell death pathways which are used in context-specific manners. Failure of these processes may result in an accumulation of misdirected or dysfunctional T cells, leading to complications such as autoimmunity or cancer. This review will focus on the role of cell death regulation in the maintenance of T cell homeostasis, as well as T cell-mediated elimination of infected or dysfunctional cells, and will summarize and discuss the current knowledge of the cellular mechanisms which are implicated in these processes.

Anti-Proliferative Activities of Vasicinone on Lung Carcinoma Cells Mediated via Activation of Both Mitochondria-Dependent and Independent Pathways

Vasicinone, a quinazoline alkaloid from Adhatoda vasica Nees. is well known for its bronchodilator activity. However its antiproliferative activities is yet to be elucidated. Here-in we investigated the anti-proliferative effect of vasicinone and its underlying mechanism against A549 lung carcinoma cells. The A549 cells upon treatment with various doses of vasicinone (10, 30, 50, 70 µM) for 72 h showed significant decrease in cell viability. Vasicinone treatment also showed DNA fragmentation, LDH leakage, and disruption of mitochondrial potential, and lower wound healing ability in A549 cells. The Annexin V/PI staining showed disrupted plasma membrane integrity and permeability of PI in treated cells. Moreover vasicinone treatment also lead to down regulation of Bcl-2, Fas death receptor and up regulation of PARP, BAD and cytochrome c, suggesting the anti-proliferative nature of vasicinone which mediated apoptosis through both Fas death receptors as well as Bcl-2 regulated signaling. Furthermore, our preliminary studies with vasicinone treatment also showed to lower the ROS levels in A549 cells and have potential free radical scavenging (DPPH, Hydroxyl) activity and ferric reducing power in cell free systems. Thus combining all, vasicinone may be used to develop a new therapeutic agent against oxidative stress induced lung cancer.

Differential ability of formononetin to stimulate proliferation of endothelial cells and breast cancer cells via a feedback loop involving MicroRNA-375, RASD1, and ERα

For postmenopausal cardiovascular disease, long-term estrogen therapy may increase the risk of breast cancer. To reduce this risk, estrogen may be replaced with the phytoestrogen formononetin, but how formononetin acts on vascular endothelial cells (ECs) and breast cancer cells is unclear. Here, we show that low concentrations of formononetin induced proliferation and inhibited apoptosis more strongly in cultured human umbilical vein endothelial cells (HUVECs) than in breast cancer cells expressing estrogen receptor α (ERα) (MCF-7, BT474) or not (MDA-MB-231), and that this differential stimulation was associated with miR-375 up-regulation in HUVECs. For the first time, we demonstrate the presence of a feedback loop involving miR-375, ras dexamethasone-induced 1 (RASD1), and ERα in normal HUVECs, and we show that formononetin stimulated this feedback loop in HUVECs but not in MCF-7 or BT474 cells. In all three cell lines, formononetin increased Akt phosphorylation and Bcl-2 expression. Inhibiting miR-375 blocked these changes and increased proliferation in HUVECs, but not in MCF-7 or BT474 cells. In ovariectomized rats, formononetin increased uterine weight and caused similar changes in levels of miR-375, RASD1, ERα, and Bcl-2 in aortic ECs as in cultured HUVECs. In mice bearing MCF-7 xenografts, tumor growth was stimulated by 17β-estradiol but not by formononetin. These results suggest selective action of formononetin in ECs (proliferation stimulation and apoptosis inhibition) relative to breast cancer cells, possibly via a feedback loop involving miR-375, RASD1, and ERα. This differential effect may explain why formononetin may not increase the risk of postmenopausal breast cancer.

Structure and biological properties of five Pt(II) complexes as potential anticancer agents

We synthesized and validated five Schiff base Pt(II) complexes derived from 2-hydroxy-1-naphthaldehyde benzoyl hydrazone and its derivatives, which are modified at the benzohydrazide structures (L1-L5). The complexes were [Pt(L1)(DMSO)Cl] (C1), [Pt(L2)(DMSO)Cl] (C2), [Pt(L3)(DMSO)Cl] (C3), [Pt(L4)(DMSO)Cl] (C4), and [Pt(L5)(DMSO)Cl] (C5). Crystal structures showed that the Pt centers of all complexes were tetra-coordinated with other atoms. The structure-activity relationships and anticancer mechanisms of the complexes were explored. These five Pt(II) complexes were toxic at micromolar doses and exhibited cytotoxicity similar to or somewhat higher than that of cisplatin, with IC₅₀ values ranging from 4.38 μM to 25.16 μM. The complexes exerted chemotherapeutic effects via inhibition of telomerase by targeting the c-myc promoter and down-regulating the expression of human telomerase reverse transcriptase, consequently triggering cell apoptosis. In addition, Pt(II) complexes also caused cell cycle arrest at S-phase, leading to the down-regulation of cdc25 A, cyclin A2, and CDK2 and up-regulation of p53, p27, and p21 proteins. Other complex-associated events were reactive oxygen species production, transformation of the mitochondrial membrane potential (Δψ_m), release of cytochrome c, regulation of Bcl-2 family protein expression, facilitated release of apoptotic active substances, and activation of caspases to induce apoptosis.

The combination of TRAIL and MG-132 induces apoptosis in both TRAIL-sensitive and TRAIL-resistant human follicular lymphoma cells

We have previously shown that the human follicular lymphoma cell line, HF28GFP, is sensitive to TRAIL-mediated apoptosis. Nevertheless, when the same cells overexpress anti-apoptotic Bcl-2 family protein, Bcl-xL (HF28Bcl-xL), they become resistant to TRAIL. Thus, these cell lines help us to investigate the action of novel apoptosis inducing candidate drugs. In the present study, we examined the effects of MG-132 (a proteasome inhibitor), LiCl (a glycogen synthase kinase-3 inhibitor) and/or TRAIL on pro-apoptotic Bcl-2 family proteins such as Bim and Bid. Here we demonstrate that the combination of MG-132 and TRAIL induced significant apoptotic cell death in both cell lines, HF28GFP and HF28BclxL. Apoptosis correlated with a decrease of phospho-ERK1/2, the accumulation of Bim and translocation of truncated Bid (tBid) and jBid. In addition, the combination of MG-132 and TRAIL seemed to target other apoptotic factors, which led to the accumulation of active capsase-3. Furthermore, co-stimulation of LiCl and TRAIL induced apoptosis in HF28GFP cells. However, HF28Bcl-xL cells were far less sensitive to the combinatorial effects of LiCl and TRAIL. Interestingly, we observed that LiCl did not target Bim and Bid proteins. In conclusion, these data show that targeting of pro-apoptotic Bcl-2 family proteins simultaneously through a selective proteasome inhibition might help to overcome TRAIL resistance caused by overexpression of anti-apoptotic Bcl-2 family proteins. Moreover, the data may provide new strategies to develop targeted therapies against lymphomas.

Clearance of Apoptotic Cells by Tissue Epithelia: A Putative Role for Hepatocytes in Liver Efferocytosis

Toxic substances and microbial or food-derived antigens continuously challenge the liver, which is tasked with their safe neutralization. This vital organ is also important for the removal of apoptotic immune cells during inflammation and has been previously described as a “graveyard” for dying lymphocytes. The clearance of apoptotic and necrotic cells is known as efferocytosis and is a critical liver function to maintain tissue homeostasis. Much of the research into this form of immunological control has focused on Kupffer cells, the liver-resident macrophages. However, hepatocytes (and other liver resident cells) are competent efferocytes and comprise 80% of the liver mass. Little is known regarding the mechanisms of apoptotic and necrotic cell capture by epithelia, which lack key receptors that mediate phagocytosis in macrophages. Herein, we discuss recent developments that increased our understanding of efferocytosis in tissues, with a special focus on the liver parenchyma. We discuss the impact of efferocytosis in health and in inflammation, highlighting the role of phagocytic epithelia.

HDAC inhibitor PAC-320 induces G2/M cell cycle arrest and apoptosis in human prostate cancer

HDAC inhibitors (HDACis) have been demonstrated with profound antiproliferative activities in various tumor types. Previously, we screened several polyoxometalate HDACis based on our p21 luciferase promoter system and demonstrated that such HDACis have antitumor activity. Here, we further investigate the antitumor mechanism of PAC-320, a compound among the polyoxometalates, in human prostate cancer. We demonstrate that PAC-320 is a broad-spectrum HDACi and could inhibit growth of prostate cancer cells in vitro and in vivo. Furthermore, we find that PAC-320 induces cell cycle arrest at G2/M phase and apoptosis. Mechanically, PAC-320 induced cell cycle arrest is associated with an increase of p21 and decrease of cyclin A and cyclin B1, while PAC-320 induced apoptosis is mediated through mitochondria apoptotic pathway and is closely associated with increase of BH3-only proteins Noxa and Hrk. Meanwhile, we demonstrate that p38 MAPK pathway is involved in PAC-320 induced antiproliferative activities in prostate cancer. Taken together, our data indicates that PAC-320 has potent prostate cancer inhibitory activity in vitro and in vivo, which is mediated by G2/M cell cycle arrest and apoptosis.

Leukemia Inhibitory Factor Increases Survival of Pluripotent Stem Cell-Derived Cardiomyocytes

Leukemia inhibitory factor (LIF) is a growth factor with pleiotropic biological functions. It has been reported that LIF acts at different stages during mesoderm development. Also, it has been shown that LIF has a cytoprotective effect on neonatal murine cardiomyocytes (CMs) in culture, but little is known about the role of LIF during human cardiogenesis. Thus, we analyzed the effects of LIF on human pluripotent stem cells (PSC) undergoing cardiac differentiation. We first showed that LIF is expressed in the human heart during early development. We found that the addition of LIF within a precise time window during the in vitro differentiation process significantly increased CMs viability. This finding was associated to a decrease in the expression of pro-apoptotic protein Bax, which coincides with a reduction of the apoptotic rate. Therefore, the addition of LIF may represent a promising strategy for increasing CMs survival derived from PSCs.

Oral administration of Ginsenoside Rg1 prevents cardiac toxicity induced by doxorubicin in mice through anti-apoptosis

Although Ginsenoside Rg1 has been reported to have protective cardiac effects, its effects on cardiac toxicity induced by doxorubicin needs to be studied. The present study investigated the effects of oral administration of Rg1 on the heart in mice treated with doxorubicin and found improved fractional shortening and ejection fraction of the heart and decreased cardiac apoptosis in mice treated with doxorubicin. The underlying mechanisms include increased phosphorylation of Akt and Erk by Rg1, increased ratio of Bcl-2 and Bax, and decreased release of cytochrome c from mitochondria, thereby protecting the heart from doxorubicin-induced apoptosis. This phenotype suggested that the oral administration of Rg1 may be a potential method preventing the cardiac toxicity caused by doxorubicin in clinical practice.