Starfish Apaf-1 activates effector caspase-3/9 upon apoptosis of aged eggs

Molecular mechanisms and potential interventions during aging-associated sarcopenia

Sarcopenia, a common condition observed in the elderly, presenting a significant public health challenge due to its high prevalence, insidious onset and diverse systemic effects. Despite ongoing research, the precise etiology of sarcopenia remains elusive. Aging-related processes, which included inflammation, oxidative stress, compromised mitochondrial function and apoptosis, have been implicated in its development. Notably, effective pharmacological treatments for sarcopenia are currently lacking, highlighting the necessity for a deeper understanding of its pathogenesis and causative factors to enable proactive interventions. This article is aimed to provide an extensive overview of the pathogenesis of sarcopenia, along with a summary of current treatment and prevention strategies.

Pathogen-induced apoptosis in echinoderms: A review

Echinoderms possess unique biological traits that make them valuable models in immunology, regeneration, and developmental biology studies. As a class rich in active substances with significant nutritional and medicinal value, echinoderms face threats from marine pathogens, including bacteria, viruses, fungi, protozoa, and parasites, which have caused substantial economic losses in echinoderm aquaculture. Echinoderms counteract pathogen invasion through innate immunity and programmed cell death, in particular, with apoptosis being essential for eliminating infected or damaged cells and maintaining homeostasis in many echinoderm cell types. Despite the importance of this process, there is a lack of comprehensive and updated reviews on this topic. This review underscores that echinoderm apoptotic pathways exhibit a complexity comparable to that of vertebrates, featuring proteins with unique domains that may indicate the presence of novel signaling mechanisms. We synthesize current knowledge on how echinoderms utilize diverse transcriptional and post-transcriptional mechanisms to regulate apoptosis in response to pathogen infections and explore how pathogens have evolved strategies to manipulate echinoderm apoptosis, either by inhibiting it to create survival niches or by inducing excessive apoptosis to weaken the host. By elucidating the primary apoptotic pathways in echinoderms and the host-pathogen interactions that modulate these pathways, this review aims to reveal new mechanisms of apoptosis in animal immune defense and provide insights into the evolutionary arms race between hosts and pathogens.

Synthesis and antitumor activity of copper(II) complexes of imidazole derivatives

Complexes [Cu(PI)2(H2O)](NO3)2 (1), [Cu(PBI)2(NO3)]NO3 (2), [Cu(TBI)2(NO3)]NO3 (3), [Cu(BBIP)2](ClO4)2 (4) and [Cu(BBIP)(CH3OH)(ClO4)2] (5) were synthesized from the reactions of Cu(II) salts with 2-(2'-pyridyl)imidazole (PI), (2-(2'-pyridyl)benzimidazole (PBI), 2-(4'-thiazolyl)-benzimidazole (TBI), 2,6-bis(benzimidazol-2-yl)-pyridine (BBIP), respectively. Their compositions and crystal structures were determined. Their in-vitro antitumor activities were screened on four cancer cell lines and one normal cell line (HL-7702) using cisplatin as the positive control. Complexes 2 and 4 show higher cytotoxicity than the other three complexes. The cytotoxicity of complex 2 are comparable to those for cisplatin, and the cytotoxicity for 4 are much higher than those for cisplatin. From a viewpoint of antitumor, 2 might be a nice choice on the tumor cell line of T24 because its IC50 values on T24 and HL-7702 are 15.03 ± 1.10 and 21.34 ± 0.35, respectively. Thus, a mechanistic study for complexes 2 and 4 on T24 cells was conducted. It revealed that they can reduce mitochondrial membrane potential and increase mitochondrial membrane permeability, resulting in increased intracellular ROS levels, Ca2+ inward flow, dysfunctional mitochondria and the eventual cell apoptosis. In conclusion, they can induce cell apoptosis through mitochondrial dysfunction. These findings could be useful in the development of new antitumor agents.

Fertility-enhancing effects of inositol & vitamin C on cisplatin induced ovarian and uterine toxicity in rats via suppressing oxidative stress and apoptosis

Cisplatin can lead to infertility due to its negative impact on the uterus and ovaries. This study aimed to explore the effects of Inositol and vitamin C on cisplatin-induced infertility. Forty-eight adult female Wistar rats were divided into eight groups (N = 6) and orally treated for 21 days. The treatments were as follows: negative control (saline), positive control (saline and cisplatin injected into the abdomen on day 15), T1-T3: rats given vitamin C (150 mg/kg), Inositol (420 mg/kg), and vitamin C + Inositol, respectively, along with cisplatin injected into the abdomen on day 15, T4-T6: rats given only vitamin C, Inositol, and vitamin C + Inositol, respectively. Vitamin C and Inositol enhanced cisplatin-induced histopathological improvements in the uterus and ovaries, raising progesterone and estradiol serum levels. Furthermore, the supplements enhanced ESR1 gene expression in the uterus and ovary, reducing uterine and ovarian apoptosis caused by cisplatin through modulation of caspase 3, 8, and Bcl-2 gene levels. These substances decreased ovarian and uterine malondialdehyde levels, boosted total antioxidant capacity and superoxide dismutase, and alleviated oxidative stress. The findings reveal that vitamin C and Inositol shield against cisplatin-related infertility by reducing oxidative stress and apoptosis in the uterus and ovaries.

Kaempferol as a therapeutic agent in Alzheimer's disease: Evidence from preclinical studies

BACKGROUND

Alzheimer's disease (AD) is the most common type of dementia and seriously affects human life and health. Kaempferol (KMP) is a common flavonoid, that is mainly derived from the rhizomes of Kaempferol galanga L. and is widely found in various fruits and vegetables. Previous studies have suggested that KMP has multiple pharmacological activities. However, the anti-AD mechanism of KMP has not been elucidated.

METHODS

This systematic review aims to summarize the existing preclinical experiments on KMP, further confirm the therapeutic effect of KMP in an AD model, and summarize the possible mechanism by which KMP exerts anti-AD effects. Electronic databases, including PubMed, China National Knowledge Infrastructure (CNKI), Baidu Academic, and Wanfang, were searched using the keywords of 'Kaempferol,' 'KMP,' 'pharmacology,' and 'Alzheimer's disease'.

RESULTS

We evaluated the reliability of the 12 included studies, and the results showed that the anti-AD mechanism of KMP was reliable and that the prospect of KMP in the treatment of cognitive impairment was promising. We comprehensively assessed the neuroprotective effects of KMP in in vivo and in vitro models of AD. These studies shown that KMP ameliorated AD through several mechanisms, including its antioxidant, anti-inflammatory, anti-apoptotic, and anti-acetylcholinesterase effects.

CONCLUSION

KMP may exert anti-AD effects through various mechanisms and is a potential drug with broad prospects for the treatment of AD.

Bioactive Peptides from Skipjack Tuna Cardiac Arterial Bulbs (II): Protective Function on UVB-Irradiated HaCaT Cells through Antioxidant and Anti-Apoptotic Mechanisms

The aim of this study was to investigate the protective function and mechanism of TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM) from skipjack tuna cardiac arterial bulbs on skin photoaging using UVB-irradiated HaCaT cell model. The present results indicated that TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM) had significant cytoprotective effect on UVB-irradiated HaCaT cells (p < 0.001). Hoechst 33342 staining showed that apoptosis of UV-irradiated HaCaT cells could be significantly reduced by the treatment of TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM); JC-1 staining showed that TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM) could protect HaCaT cells from apoptosis by restoring mitochondrial membrane potential (MMP); Furthermore, TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM) could significantly down-regulate the ratio of Bax/Bcl-2 and reduce the expression level of the apoptosis-executing protein Caspase-3 by decreasing the expression of protein Caspase-8 and Caspase-9 (p < 0.05). The action mechanism indicated that TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM) could up-regulate the expression levels of Nrf2, NQO1 and HO-1 (p < 0.05), which further increased the activity of downstream proteases (SOD, CAT and GSH-Px), and scavenged reactive oxygen species (ROS) and decreased the intracellular levels of malondialdehyde (MDA). In addition, molecular docking indicated that TCP3 (PKK) and TCP6 (YEGGD) could competitively inhibit the Nrf2 binding site because they can occupy the connection site of Nrf2 by binding to the Kelch domain of Keap1 protein. TCP9 (GPGLM) was inferred to be non-competitive inhibition because it could not bind to the active site of the Kelch domain of Keap1 protein. In summary, the antioxidant peptides TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM) from cardiac arterial bulbs of skipjack tuna can effectively protect HaCaT cells from UVB-irradiated damage and can be used in the development of healthy and cosmetic products to treat diseases caused by UV radiation.

Hydroxysafflor yellow B induces apoptosis via mitochondrial pathway in human gastric cancer cells

OBJECTIVES

Hydroxysafflor yellow B (HSYB) is extracted from the petals of the safflower, a Chinese medicine. Relevant research results have demonstrated that HSYA can suppress the abnormal tumour cell proliferation and induce cell apoptosis. However, the properties of HSYB have rarely been reported, especially its antitumour effects on gastric cancer (GC).

METHODS

SGC-7901 and BGC-823 cells were treated with different concentrations of HSYB. Cell proliferation inhibition rate was detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and colony formation detection. The changes in morphology of cells was observed by Hoechst 33258 staining. Cell apoptosis was evaluated by Annexin V-FITC/PI (fluoresceinisothiocyanate/propidium iodide) double staining. JC-1 was used to detect the level of mitochondrial membrane potential (MMP). The protein levels of cleaved-caspase-3, cleaved-caspase-9, APAF-1, cytoplasmic cytochrome C, BAX and BCL-2 were examined by western blot.

KEY FINDINGS

HSYB significantly suppressed the proliferation of SGC-7901 and BGC-823 cells. Hoechst 33258 staining assay showed that HSYB treatment triggered apoptotic morphology and the apoptotic rates were significantly increased after being treated with HSYB and the mitochondrial membrane potential was gradually decreased in human GC cells. In addition, Western blot analysis revealed that the levels of cleaved-caspase-3 and cleaved-caspase-9 were remarkably increased in HSYB-treated BGC-823 and SGC-7901 cells. And, the levels of apoptotic protease activating factor-1 (APAF-1) and cytoplasmic cytochrome C were remarkably up-regulated in HSYB-treated cells. At the same time, HSYB could up-regulate the level of BAX and down-regulate the level of BCL-2.

CONCLUSIONS

Our data suggest that HSYB could induce GC cell apoptosis via the mitochondrial pathway.

Evolutionarily Ancient Caspase-9 Sensitizes Immune Effector Coelomocytes to Cadmium-Induced Cell Death in the Sea Cucumber, Holothuria leucospilota

Heavy-metal pollution has increasingly jeopardized the habitats of marine organisms including the sea cucumber, a seafloor scavenger vital to seawater bio-decontamination, ocean de-acidification and coral-reef protection. Normal physiology including immune functions of sea cucumbers is toxicologically modulated by marine metal pollutants such as cadmium (Cd). The processes underpinning Cd's toxic effects on immune systems in the sea cucumber, Holothuria leucospilota, are still poorly understood. To this end, we cloned and characterized a full-length caspase-9 (Hl-CASP9) cDNA in the sea cucumber, Holothuria leucospilota. Hl-CASP9 mRNA levels evolved dynamically during embryonic development. Coelomocytes, a type of phagocytic immune effectors central to H. leucospilota immunity, were found to express Hl-CASP9 mRNA most abundantly. Hl-CASP9 protein structurally resembles caspases-2 and -9 in both invertebrate and vertebrate species, comprising a CARD domain and a CASc domain. Remarkably, Hl-CASP9 was transcriptionally sensitive to abiotic oxidative stress inducers including hydrogen peroxide (H₂O₂), nitric oxide (^•NO) and cadmium (Cd), but insensitive to immunostimulants including lipopolysaccharide (LPS), and poly(I:C). Overexpression of Hl-CASP9 augmented mitochondria-dependent apoptosis in HEK293T cells, while knock-down of Hl-CASP9 blunted Cd-induced coelomocyte apoptosis in vivo. Overall, we illustrate that an evolutionarily ancient caspase-9-dependent pathway exists to sensitize coelomocytes to premature cell death precipitated by heavy metal pollutants, with important implications for negative modulation of organismal immune response in marine invertebrates.

A triphenylphosphine coordinated cinnamaldehyde-derived copper(I) Fenton-like agent with mitochondrial aggregation damage for chemodynamic therapy

Chemodynamic therapy (CDT), which uses agents to induce cell death by decomposing endogenous hydrogen peroxide (H₂O₂) into highly toxic hydroxyl radicals (˙OH), has been recognized as a promising approach to treat cancer. However, improving the efficiency of ˙OH production is considered one of the biggest challenges that limits the therapeutic efficacy of CDT. Herein, to controllably and efficiently induce oxidative damage through the production of ˙OH, we developed a new metal complex CDT agent with atomically precise structural characteristics as a deviation from traditional nanomaterial-CDT agents. The obtained CDT agent, a cinnamaldehyde derived copper(I) complex (denoted Cin-OD-Cu), was found to be continuously enriched in the mitochondria of A2780 ovarian carcinoma cells, which was accompanied by the generation of large amounts of ˙OH via Cu(I)-mediated Fenton-like reactions of H₂O₂, thereby stimulating oxidative stress in the mitochondria and eventually leading to cell death. Moreover, in vivo experiments showed that Cin-OD-Cu was capable of effectively inhibiting tumor growth with excellent biocompatibility. We believe this research enriches the limited selection of atomically precise metal complex CDT agents in particular for reactive oxygen species-mediated treatments aimed at inducing mitochondria oxidative damage; we anticipate that it will provide new insights into the development of novel, atomically precise agents for CDT.

Metazoans and Intrinsic Apoptosis: An Evolutionary Analysis of the Bcl-2 Family

The B-cell lymphoma-2 (Bcl-2) family is a group of genes regulating intrinsic apoptosis, a process controlling events such as development, homeostasis and the innate and adaptive immune responses in metazoans. In higher organisms, Bcl-2 proteins coordinate intrinsic apoptosis through their regulation of the integrity of the mitochondrial outer membrane; this function appears to have originated in the basal metazoans. Bcl-2 genes predate the cnidarian-bilaterian split and have been identified in porifera, placozoans and cnidarians but not ctenophores and some nematodes. The Bcl-2 family is composed of two groups of proteins, one with an α-helical Bcl-2 fold that has been identified in porifera, placozoans, cnidarians, and almost all higher bilaterians. The second group of proteins, the BH3-only group, has little sequence conservation and less well-defined structures and is found in cnidarians and most bilaterians, but not porifera or placozoans. Here we examine the evolutionary relationships between Bcl-2 proteins. We show that the structures of the Bcl-2-fold proteins are highly conserved over evolutionary time. Some metazoans such as the urochordate Oikopleura dioica have lost all Bcl-2 family members. This gene loss indicates that Bcl-2 regulated apoptosis is not an absolute requirement in metazoans, a finding mirrored in recent gene deletion studies in mice. Sequence analysis suggests that at least some Bcl-2 proteins lack the ability to bind BH3-only antagonists and therefore potentially have other non-apoptotic functions. By examining the foundations of the Bcl-2 regulated apoptosis, functional relationships may be clarified that allow us to understand the role of specific Bcl-2 proteins in evolution and disease.

Assessment spermatogenic cell apoptosis and the transcript levels of metallothionein and p53 in Meretrix meretrix induced by cadmium

Cadmium (Cd) has been widely used in industry and can accumulate in the water, soil, and food. Meretrix meretrix is one of the marine shellfishes cultivated for economic purpose in China. The increasing Cd levels in coastal marine water could adversely affect the economic benefits of shellfish cultivation. In the present study, M. meretrix were exposed to different Cd²⁺ concentrations (0, 1.5, 3, 6, and 12 mg L^-1) for 5 d to evaluate the effects of Cd on spermatogenic cell. The Cd accumulation, survival rate and the indices of oxidative stress and apoptosis were determined in the spermatogenic cells of M. meretrix. The expression levels of p53 and metallothionein (MT) mRNA were also measured in the spermatogenic cells. Cd accumulation and the mortality rate of spermatogenic cells were found to increase in a dose-response manner with Cd²⁺ concentrations. Histopathology changes, especially the damage of membranous structure, were more severe as the Cd²⁺ levels in the testis became higher. The indexes of oxidative stress, including reactive oxygen species, malondialdehyde, protein carbonyl derivates and DNA-protein crosslinks all increased after exposure to Cd²⁺. However, the total antioxidant capacity gradually decreased with the increasing Cd²⁺ concentration. In addition, exposure to Cd²⁺ increased the apoptotic rate and caspase-3 and 9 activities but decreased the level of mitochondrial membrane potential and cytochrome C oxidase in the spermatogenic cells. MT mRNA expression increased in lower Cd²⁺ concentration treated groups whereas decreased in higher groups, while the p53 mRNA expression increased in a dose-response manner with Cd²⁺ and was positively correlated with the oxidative damage indices. These results indicated that Cd²⁺ caused oxidative stress and p53 induced apoptosis in the spermatogenic cells, and thus decreased the survival rate of sperm cells. This finding highlights that Cd can reduce the reproductive capacity of M. meretrix, thus threatening to wild shellfish populations and reducing the efficiency of shellfish farming.

Inhibition of MAGL activates the Keap1/Nrf2 pathway to attenuate glucocorticoid-induced osteonecrosis of the femoral head

Glucocorticoids (GCs) are used in treating viral infections, acute spinal cord injury, autoimmune diseases, and shock. Several patients develop GC-induced osteonecrosis of the femoral head (ONFH). However, the pathogenic mechanisms underlying GC-induced ONFH remain poorly understood. GC-directed bone marrow mesenchymal stem cells (BMSCs) fate is an important factor that determines GC-induced ONFH. At high concentrations, GCs induce BMSC apoptosis by promoting oxidative stress. In the present study, we aimed to elucidate the molecular mechanisms that relieve GC-induced oxidative stress in BMSCs, which would be vital for treating ONFH. The endocannabinoid system regulates oxidative stress in multiple organs. Here, we found that monoacylglycerol lipase (MAGL), a key molecule in the endocannabinoid system, was significantly upregulated during GC treatment in osteoblasts both in vitro and in vivo. MAGL expression was positively correlated with expression of the NADPH oxidase family and apoptosis-related proteins. Functional analysis showed that MAGL inhibition markedly reduced oxidative stress and partially rescued BMSC apoptosis. Additionally, in vivo studies indicated that MAGL inhibition effectively attenuated GC-induced ONFH. Pathway analysis showed that MAGL inhibition regulated oxidative stress in BMSCs via the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. The expression of Nrf2, a major regulator of intracellular antioxidants, was upregulated by inhibiting MAGL. Nrf2 activation can mimic the effect of MAGL inhibition and significantly reduce GC-induced oxidative damage in BMSCs. The beneficial effects of MAGL inhibition were attenuated after the blockade of the Keap1/Nrf2 antioxidant signaling pathway. Notably, pharmacological blockade of MAGL conferred femoral head protection in GC-induced ONFH, even after oxidative stress responses were initiated. Therefore, MAGL may represent a novel target for the prevention and treatment of GC-induced ONFH.

Protective Effect of Lemon Peel Polyphenols on Oxidative Stress-Induced Damage to Human Keratinocyte HaCaT Cells Through Activation of the Nrf2/HO-1 Signaling Pathway

Lemon peel can be used as traditional Chinese medicine. Flavonoids are the most important components in lemon peel, which can be developed as natural medicine without side effects. This study investigated the protective effect of lemon peel polyphenols (LPP) on human keratinocyte HaCaT cells under oxidative stress. The active components of LPP were determined by high performance liquid chromatography. The abilities of LPP to scavenge DPPH and ABTS+ free radicals were studied for detection of antioxidation in vitro. Cell survival rates were determined by MTT assay. The antioxidant enzyme activity and antioxidant index of cells were determined using kit. The mRNA and protein expression of cells were determined by qPCR and western blot. The ability of LPP to scavenge DPPH and ABTS+ free radicals were stronger than those of vitamin C (Vc) at the same concentration. As expected, compared with the normal group of cells, the model group had decreased cell survival, increased lactate dehydrogenase (LDH), decreased levels of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH), and increased malondialdehyde (MDA) content. qPCR and western blot results indicated that the expression of Bcl-2-related X protein (Bax), caspases-3, erythroid-derived nuclear factor 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) were decreased and the expression of B-cell lymphoma-2 (Bcl-2) was increased in the model group, compared with the normal group. LPP treatment improved cell survival rate, reduced intracellular LDH and MDA levels, increased intracellular SOD, CAT, GSH levels, down-regulated Bax, caspases-3, Nrf2, HO-1 expression, and up-regulated Bcl-2 expression. Component analyses found that LPP contains gallic acid, neochlorogenic acid, (+)-catechin, caffeic acid, (-)-Catechin gallate, isochlorogenic acid A, rosmarinic acid, and protocatechuic acid. LPP was found to regulate the Nrf2/HO-1 signaling pathway through 8 active substances to protect HaCaT cells against oxidative stress in vitro.

Primary and Secondary Markers of Doxorubicin-Induced Female Infertility and the Alleviative Properties of Quercetin and Vitamin E in a Rat Model

The incidence of cancer has recently risen among the women at the reproductive age. Therefore, exposure to doxorubicin (DOX) chemotherapy has become a cause of reproductive toxicity followed by secondary destructive effects. The present study aimed to evaluate the effects of quercetin (QCT) and vitamin.E (Vit.E) on doxorubicin-induced toxicity in the ovary and uterus, and the secondary bone-related effects in a rat model. Animals were divided into six groups including control normal saline/corn oil (CON), QCT at 20 mg/Kg, Vit.E at 200 mg/Kg, DOX at accumulative 15 mg/Kg, DOX/QCT, and DOX/Vit.E. After 21 days of treatment, the alterations were analyzed in histoarchitecture, apoptosis, hormones secretion, the gene expression of aromatase and estrogen α-receptor (ER-α) in the uterine and ovarian tissues, and serum levels of bone-related factors. The results demonstrated the ameliorative effects of QCT and Vit.E on doxorubicin caused altered ovarian histology, increased apoptosis, decreased ovarian aromatase and ER-α gene expression (p-value<0.05), decreased estrogen and progesterone levels, decreased ALP (p-value<0.001), and increased osteocalcin (p-value<0.05). The findings suggested that the studied antioxidants administration could be a promising fertility preservation strategy in DOX-treated females.

Probucol recovers pathological damage in viral Myocarditis through improvement of myocardium-related proteins

This study explored the effects of probucol on myocardial injury, oxidative stress, and Cav-3 and Smad3 expression in myocardial tissues by establishing VMC rat models, in order to provide a basis for exploring the mechanism of probucol in treatment of VMC. Sixty rats were randomly divided into control group, model group, probucollowdose group, andprobucol highdose group, with 15 in each group. Except for the control group, rats in each group were intraperitoneally injected coxsackievirus B3 diluent (0.2 ml) to replicate VMC models every 4 days. The results showed that Caspase-3 and Caspase-9, myocardial enzymes, cTn I, and MDA levels in the model group significantly increased (P < 0.05), while the SOD level significantly decreased (P < 0.05); and after probucol treatment, Caspase-3 and Caspase-9, myocardial enzymes, cTn I and MDA levels significantly decreased (P < 0.05), and the SOD level significantly increased (P < 0.05). Compared with the control group, there was an increase in myocardial fibers with significant lesions in the model group, and the pathological scores and the mRNA and protein expression levels of Cav-3 and Smad3 in myocardial cells significantly increased (P < 0.05). Compared with the control group, the myocardial tissue lesions were improved in the probucol low dose group and highdose group, and the pathological scores and the mRNA and protein expression levels of Cav-3 and Smad3 in myocardial cells were significantly reduced (P < 0.05). In conclusion, probucol can significantly improve the pathological damage of myocardial tissue in VMC rats, and its mechanism may be related to improving the expression of myocardium-related proteins Caspase-3 and Caspase-9, inhibiting oxidative stress response, and down-regulating Cav-3 and Smad3 gene expression in myocardial tissue of VMC rats.

Synthesis, crystal structure and antiproliferative mechanisms of gallium(iii) complexes with benzoylpyridine thiosemicarbazones

We have prepared six thiosemicarbazone ligands and synthesized the corresponding Ga(iii) complexes. The antitumor activity of the ligand increases with its lipophilicity, and the antitumor activity of the Ga(iii) complexes is affected by the ligands. Since C6 has the highest anticancer proliferative activity (0.14 ± 0.01 μM) against HepG-2 (Human hepatocarcinoma cell line), we characterized its structure by X-ray single crystal diffraction and explored its antiproliferation mechanism. Anti-tumor mechanism results show that Ga(iii) complex (C6) promoted HepG-2 cell cycle arrest in the G1 phase by regulating the expression of cell cycle-associated proteins (Cdk 2, cyclin A and cyclin E). Ga(iii) complex (C6) promotes apoptosis by consuming intracellular iron, enhancing intracellular reactive oxygen species (ROS), activating caspase-3/9, releasing cytochromes and apoptotic protease activating factor-1 (apaf-1).

Pro-Oxidant Therapeutic Activities of Cerium Oxide Nanoparticles in Colorectal Carcinoma Cells

Given that basal levels of reactive oxygen species (ROS) are higher in cancer cells, there is a growing school of thought that endorses pro-oxidants as potential chemotherapeutic agents. Intriguingly, cerium oxide (CeO2) nanoparticles can manifest either anti- or pro-oxidant activity as a function of differential pH of various subcellular localizations. In an acidic pH environment, for example, in extracellular milieu of cancer cells, CeO2 would function as a pro-oxidant. Based on this concept, the present study is designed to investigate the pro-oxidant activities of CeO2 in human colorectal carcinoma cell line (HCT 116). For comparison, we have also studied the effect of ceria nanoparticles on human embryonic kidney (HEK 293) cells. Dose-dependent viability of cancerous as well as normal cells has been assessed by treating them independently with CeO2 nanoparticles of different concentrations (5-100 μg/mL) in the culture media. The half maximal inhibitory concentration (IC50) of nanoceria for HCT 116 is found to be 50.48 μg/mL while that for the HEK 293 cell line is 92.03 μg/mL. To understand the intricate molecular mechanisms of CeO2-induced cellular apoptosis, a series of experiments have been conducted. The apoptosis-inducing ability of nanoceria has been investigated by Annexin V-FITC staining, caspase 3/9 analysis, cytochrome c release, intracellular ROS analysis, and mitochondrial membrane potential analysis using flow cytometry. Experimental data suggest that CeO2 treatment causes DNA fragmentation through enhanced generation of ROS, which ultimately leads to cellular apoptosis through the p53-dependent mitochondrial signaling pathway.

The Bcl-2 Family: Ancient Origins, Conserved Structures, and Divergent Mechanisms

Intrinsic apoptosis, the response to intracellular cell death stimuli, is regulated by the interplay of the B-cell lymphoma 2 (Bcl-2) family and their membrane interactions. Bcl-2 proteins mediate a number of processes including development, homeostasis, autophagy, and innate and adaptive immune responses and their dysregulation underpins a host of diseases including cancer. The Bcl-2 family is characterized by the presence of conserved sequence motifs called Bcl-2 homology motifs, as well as a transmembrane region, which form the interaction sites and intracellular location mechanism, respectively. Bcl-2 proteins have been recognized in the earliest metazoans including Porifera (sponges), Placozoans, and Cnidarians (e.g., Hydra). A number of viruses have gained Bcl-2 homologs and subvert innate immunity and cellular apoptosis for their replication, but they frequently have very different sequences to their host Bcl-2 analogs. Though most mechanisms of apoptosis initiation converge on activation of caspases that destroy the cell from within, the numerous gene insertions, deletions, and duplications during evolution have led to a divergence in mechanisms of intrinsic apoptosis. Currently, the action of the Bcl-2 family is best understood in vertebrates and nematodes but new insights are emerging from evolutionarily earlier organisms. This review focuses on the mechanisms underpinning the activity of Bcl-2 proteins including their structures and interactions, and how they have changed over the course of evolution.

Long non-coding RNA NEAT1/miR-193a-3p regulates LPS-induced apoptosis and inflammatory injury in WI-38 cells through TLR4/NF-κB signaling

Pneumonia is a primary pulmonary infection disease with a high morbidity and mortality worldwide. Identification of key long non-coding RNAs (lncRNAs) facilitates to the development of effective therapeutic targets for pneumonia. LncRNA NEAT1 was vital and functional in inflammatory diseases but has not been studied in pneumonia. The aim of this study was to investigate the role of NEAT1 in pneumonia and explore its potential mechanism. Lipopolysaccharide (LPS) was applied into WI-38 cells to establish cell model of pneumonia. Cells were transfected with shRNA-NEAT1, miR-193a-3p or negative control. Real time quantitative PCR and western blot were performed to detect mRNA level and protein expression, respectively. Cell counting kit-8 (CCK-8) assay was performed to detect cell viability. Flow cytometry analysis was performed to determine cell apoptosis. Cell viability was significantly declined and cell apoptosis was increased in LPS-treated WI-38 cells. NEAT1 was upregulated under LPS treatment and NEAT1 inhibition significantly improved cell viability, decreased cell apoptosis and the production of inflammatory cytokines. The expression level of miR-193a-3p was regulated by NEAT1, and NEAT1 reversed miR-193a-3p overexpression-alleviated inflammatory injury that include inflammation and apoptosis induced by LPS. Further, NEAT1 and miR-193a-3p regulated the activity of Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) signaling. Therefore, NEAT1 may function as a ceRNA by sponging miR-193a-3p to regulate the activation of TLR4/NF-κB signaling to alleviate inflammation and apoptosis of WI-38 cells induced by LPS, thus influencing the development of pneumonia. Our findings implied that NEAT1 might serve as a neoteric therapy target for pneumonia.