BH3-only proteins in apoptosis and beyond: an overview

Multilineage-differentiating stress-enduring cells attenuate the cognitive impairment caused by chronic cerebral hypoperfusion in rats

Multilineage-differentiating stress-enduring (Muse) cells are non-tumorigenic pluripotent- like stem cells that can migrate to damaged sites and contribute to tissue repair. Chronic cerebral hypoperfusion (CCH), which mimics vascular dementia, causes hippocampal neuronal degeneration and white matter (WM) damage, which lead to cognitive dysfunction. Currently, there are no effective treatments for it. We evaluated the efficiency of the human-Muse cell-based product CL2020 in treating CCH in rats. A bilateral common carotid artery occlusion was used to induce cognitive dysfunction. Six-weeks after carotid artery occlusion, CL2020 were injected intravenously. Cognitive function was assessed using a Barnes circular maze (BCM) at 3 weeks after CL2020 administration. Histological findings and western blots were assessed at 4 weeks after CL2020 administration. BCM assessment indicated recovery in cognitive function in the CL2020-treated group. Compared with the vehicle, CL2020 targeted the hippocampus, where it decreased neuronal loss and WM damage. CL2020 also promoted angiogenesis and suppressed apoptotic cell death. Western blotting of hippocampal samples revealed the downregulation of pro- apoptotic and the upregulation of anti-apoptotic proteins in the CL2020-treated group. In conclusion, intravenous administration of CL2020 improved the cognitive deficits caused by CCH, partly because of decreased hippocampal neuronal loss and WM damage, and increased angiogenesis in the hippocampus.

Apoptotic proteins in Leishmania donovani: in silico screening, modeling, and validation by knock-out and gene expression analysis

Visceral leishmaniasis, a life-threatening vector-borne illness that disproportionately affects children and elderly immunocompromised people, is a primary tropical neglected disease. No apoptotic partner proteins have yet been reported in Leishmania donovani, while their identification could contribute to knowledge on parasite cell death and the establishment of alternative therapeutics. We searched for mammalian Bcl-2 family protein orthologs and found one anti-apoptotic and two pro-apoptotic orthologs in L. donovani. A pro-death aquaporin protein, due to its characteristic BH3 domain known to interact with pro-apoptotic proteins in mammalian Bcl-2 family proteins, was also included in this study. Molecular docking and molecular dynamics simulations were conducted to assess protein-protein interactions between the identified apoptotic proteins and mimic mammalian intrinsic apoptotic pathways. The results showed that both pro-apoptotic proteins interacted with the hydrophobic pocket of the anti-apoptotic ortholog, forming a stable complex. This interaction may represent a critical event in an apoptotic pathway in L. donovani. To further characterise it, we used CRISPR-Cas9 approaches to target the identified proteins. Pure knocked population mutants, and episomal over-expressing mutant cells were exposed to apoptotic stimuli. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and quantitative expression profiling suggested that these proteins are involved in the parasite's apoptosis and could play a role in its survival.

Human anti-apoptotic Bcl-2 and Bcl-xL proteins protect yeast cells from aging induced oxidative stress

Aging is a degenerative, biological, and time-dependent process that affects all organisms. Yeast aging is a physiological phenomenon characterized by the progressive transformation of yeast cells, resulting in modifications to their viability and vitality. Aging in yeast cells is comparable to that in higher organisms in some respects; however, due to their straightforward and well-characterized genetic makeup, these cells present unique advantages when it comes to researching the aging process. Here, we assessed the impact of human anti-apoptotic Bcl-2 and Bcl-xL proteins on aging using a yeast model. The findings clearly showed that these proteins exhibited remarkable anti-aging properties in yeast cells. Our data indicate that the presence of both proteins enhanced the reproductive survival of aging cells, likely by effecting the components functioning as both pro- and anti-oxidants, depending on the stage of yeast cell lifespan. Both proteins partially protected yeast cells from aging-related morphological deformations and cellular damage during the aging period. In particular, Bcl-xL expressing yeast cells reached the maximum activity levels for almost all of the major antioxidant enzymes and the total antioxidant status on the 8th day of lifespan and could provide effective protection at the latest stage of the investigated aging period. The chemometric data analysis of IR spectra confirmed the findings of the morphological and biochemical analyses. In this regard, specifically, understanding the mechanism of action on the cellular redox state of Bcl-xL in yeast may facilitate comprehension of its indirect antioxidant function in higher eukaryotes.

Insights into the Absence of Lymphoma Despite Fulminant Epstein-Barr Virus Infection in Patients with XIAP Deficiency

X-linked Lymphoproliferative Syndromes (XLP), which arise from mutations in the SH2D1A or XIAP genes, are characterized by the inability to control Epstein-Barr Virus (EBV) infection. While primary EBV infection triggers severe diseases in each, lymphomas occur at high rates with XLP-1 but not with XLP-2. Why XLP-2 patients are apparently protected from EBV-driven lymphomagenesis, in contrast to all other described congenital conditions that result in heightened susceptibility to EBV, remains a key open question. To gain insights, we cross-compared newly EBV infected versus immune stimulated B-cells from XLP-2 patients or upon XIAP CRISPR knockout, relative to healthy controls. XIAP perturbation impeded outgrowth of newly EBV-infected primary human B-cells, though had no impact on proliferation of B-cells stimulated by CD40 ligand and interleukin-21 or upon established EBV-immortalized lymphoblastoid cell lines (LCLs). B-cells from XLP-2 patients or in which XIAP was depleted by CRISPR editing exhibited a markedly lower EBV transformation efficiency than healthy control B-cells. Mechanistically, nascent EBV infection activated p53-mediated apoptosis signaling, whose effects on transforming B-cell death were counteracted by XIAP. In the absence of XIAP, EBV infection triggered high rates of apoptosis, not seen with CD40L/IL-21 stimulation. Moreover, inflammatory cytokines are present at high levels in XLP-2 patient serum with fulminant EBV infection, which heightened apoptosis induction in newly EBV-infected cells. These findings highlight the crucial role of XIAP in supporting early stages of EBV-driven B-cell immortalization and provide insights into the absence of EBV+ lymphoma in XLP-2 patients.

RNA Sequencing Data Analysis of Oligoasthenoteratozoospermia Patients' Sperms and Effects of Curcumin on the Expression of Some Genes during Sperm Cryopreservation and Freeze-Thawing Process

Background

The cause of oligoasthenoteratozoospermia (OAT) is unclear. In this original study, we examined OAT patients' sperm using RNA-sequencing and studied the impact of curcumin on gene expression during sperm cryopreservation and freeze-thawing.

Methods

RNA-seq was performed using the Galaxy Europe server in IKHC (Imam Khomeini Hospital Complex), Tehran, Iran in 2023. Sperm samples were collected from 30 OAT patients and 30 healthy volunteers. Sperm parameters were analyzed, and samples were frozen with 20 μM curcumin at -196 °C for one week. Thawed samples were assessed for sperm parameters, and the expression levels of bax, bak, bcl-2, bclw, casp9, apaf-1, SOD, cat, and GPX4 genes were measured using RT-PCR.

Result

RNA-seq analysis showed increased expression of NANOS1, HSPA6, and ALOXE3 genes, while BHLHE41, Hey1, and PPM1D genes were down-regulated in OAT patients' sperm. Curcumin (20 μM) effectively preserves sperm parameters and motility during cryopreservation in healthy subjects and in OAT patients in particular. Cryopreserved sperm from both OAT patients and healthy individuals exhibited reduced expression of pro-apoptotic genes, increased expression of anti-apoptotic genes, and elevated levels of SOD and GPX4 genes.

Conclusion

Altered expressions of NANOS1, HSPA6, ALOXE3, BHLHE41, Hey1, and PPM1D genes likely contribute to OAT development. Additionally, curcumin protects sperm parameters during cryopreservation for both healthy individuals and OAT patients.

A Comprehensive Insight into Apoptosis: Molecular Mechanisms, Signaling Pathways, and Modulating Therapeutics

Apoptosis, or programmed cell death, is a fundamental biological process essential for maintaining tissue homeostasis. Dysregulation of apoptosis is implicated in a variety of diseases, including cancer, neurodegenerative disorders, and autoimmune conditions. This review provides an in-depth insight into the molecular mechanisms and signaling pathways that regulate apoptosis, highlighting both intrinsic and extrinsic pathways. Additionally, the review explains the tumor microenvironment's influence on apoptosis and its implications for cancer therapy resistance. Understanding the complex interplay between apoptotic signaling and cellular responses is crucial for developing targeted therapies that can effectively manage diseases associated with apoptosis dysregulation. The effects of conventional therapeutics and alternative substances with natural sources such as herbal compounds, alongside vitamins, minerals, and trace elements on cellular homeostasis and disease pathogenesis have been thoroughly investigated. Moreover, recent advances in therapeutic strategies aimed at modulating apoptosis are discussed, with a focus on novel interventions such as nutrition bio shield dietary supplement. These emerging approaches offer potential benefits beyond conventional treatments by selectively targeting apoptotic pathways to inhibit cancer progression and metastasis. By integrating insights from recent studies, this review aims to enhance our understanding of apoptosis and guide future research in developing innovative therapeutic approaches.

The replicative helicase CMG is required for the divergence of cell fates during asymmetric cell division in vivo

We report that the eukaryotic replicative helicase CMG (Cdc45-MCM-GINS) is required for differential gene expression in cells produced by asymmetric cell divisions in C. elegans. We found that the C. elegans CMG component, PSF-2 GINS2, is necessary for transcriptional upregulation of the pro-apoptotic gene egl-1 BH3-only that occurs in cells programmed to die after they are produced through asymmetric cell divisions. We propose that CMG's histone chaperone activity causes epigenetic changes at the egl-1 locus during replication in mother cells, and that these changes are required for egl-1 upregulation in cells programmed to die. We find that PSF-2 is also required for the divergence of other cell fates during C. elegans development, suggesting that this function is not unique to egl-1 expression. Our work uncovers an unexpected role of CMG in cell fate decisions and an intrinsic mechanism for gene expression plasticity in the context of asymmetric cell division.

The pluripotent-to-totipotent state transition in mESCs activates the intrinsic apoptotic pathway through DUX-induced DNA replication stress

The pluripotent mouse embryonic stem cell (mESCs) can transit into the totipotent-like state, and the transcription factor DUX is one of the master regulators of this transition. Intriguingly, this transition in mESCs is accompanied by massive cell death, which significantly impedes the establishment and maintenance of totipotent cells in vitro, yet the underlying mechanisms of this cell death remain largely elusive. In this study, we found that the totipotency transition in mESCs triggered cell death through the upregulation of DUX. Specifically, R-loops are accumulated upon DUX induction, which subsequently lead to DNA replication stress (RS) in mESCs. This RS further activates p53 and PMAIP1, ultimately leading to Caspase-9/7-dependent intrinsic apoptosis. Notably, inhibiting this intrinsic apoptosis not only mitigates cell death but also enhances the efficiency of the totipotency transition in mESCs. Our findings thus elucidate one of the mechanisms underlying cell apoptosis during the totipotency transition in mESCs and provide a strategy for optimizing the establishment and maintenance of totipotent cells in vitro.

Integrated stress response (ISR) activation and apoptosis through HRI kinase by PG3 and other p53 pathway-restoring cancer therapeutics

Restoration of the p53 pathway has been a long-term goal in the field of cancer research to treat tumors with mutated p53 and aggressive clinical behavior. p53 pathway restoration in p53-deficient cancers can be achieved by small molecules via p53-dependent or p53-independent processes. Hereafter p53-independent restoration of p53-pathway-signaling in p53-deficient/mutated tumors is referred to as 'restoration of the p53 pathway'. We compare activation of p53 target genes by novel compounds PG3 and PG3-Oc, that activate p53-target genes in a p53-independent manner, and four mutant p53-activating compounds while Nutlin-3a is used as negative control. PG3 and PG3-Oc upregulate p21, PUMA, and DR5 in five cancer cell lines with various p53 mutational statuses through ATF4 (Activating Transcriptional Factor 4) and integrated stress response (ISR) independent of p53. Mutant p53-targeting compounds induce expression of the 3 major downstream p53 target genes and ATF4 in a highly variable and cell-type-dependent manner. PG3 treatment activates ATF4 through ISR via kinase HRI (Heme-Regulated Inhibitor). ATF4 mediates upregulation of PUMA, p21, and NAG-1/GDF15 (Nonsteroidal anti-inflammatory drug-activated gene 1). We note that PUMA mediates apoptosis through activation of caspase-8 in HT29 cells and potentially caspase-10 in SW480 cells. We provide a novel mechanism engaged by PG3 to induce cell death via the HRI/ATF4/PUMA axis. Our results provide unique insights into the mechanism of action of PG3 as a novel cancer therapeutic targeting p53 pathway-like tumor suppression.

Altered RNA export by SF3B1 mutants confers sensitivity to nuclear export inhibition

SF3B1 mutations frequently occur in cancer yet lack targeted therapies. Clinical trials of XPO1 inhibitors, selinexor and eltanexor, in high-risk myelodysplastic neoplasms (MDS) revealed responders were enriched with SF3B1 mutations. Given that XPO1 (Exportin-1) is a nuclear exporter responsible for the export of proteins and multiple RNA species, this led to the hypothesis that SF3B1-mutant cells are sensitive to XPO1 inhibition, potentially due to altered splicing. Subsequent RNA sequencing after XPO1 inhibition in SF3B1 wildtype and mutant cells showed increased nuclear retention of RNA transcripts and increased alternative splicing in the SF3B1 mutant cells particularly of genes that impact apoptotic pathways. To identify novel drug combinations that synergize with XPO1 inhibition, a forward genetic screen was performed with eltanexor treatment implicating anti-apoptotic targets BCL2 and BCLXL, which were validated by functional testing in vitro and in vivo. These targets were tested in vivo using Sf3b1K700E conditional knock-in mice, which showed that the combination of eltanexor and venetoclax (BCL2 inhibitor) had a preferential sensitivity for SF3B1 mutant cells without excessive toxicity. In this study, we unveil the mechanisms underlying sensitization to XPO1 inhibition in SF3B1-mutant MDS and preclinically rationalize the combination of eltanexor and venetoclax for high-risk MDS.

Dying for a cause: The pathogenic manipulation of cell death and efferocytic pathways

Cell death is a natural consequence of infection. However, although the induction of cell death was solely thought to benefit the pathogen, compelling data now show that the activation of cell death pathways serves as a nuanced antimicrobial strategy that couples pathogen elimination with the generation of inflammatory cytokines and the priming of innate and adaptive cellular immunity. Following cell death, the phagocytic uptake of the infected dead cell by antigen-presenting cells and the subsequent lysosomal fusion of the apoptotic body containing the pathogen serve as an important antimicrobial mechanism that furthers the development of downstream adaptive immune responses. Despite the complexity of regulated cell death pathways, pathogens are highly adept at evading them. Here, we provide an overview of the remarkable diversity of cell death and efferocytic pathways and discuss illustrative examples of virulence strategies employed by pathogens, including oral pathogens, to counter their activation and persist within the host.

Past and present discovery of the BAFF/APRIL system - A bibliometric study from 1999 to 2023

Cytokines from the Tumour Necrosis Factor (TNF) family are important regulators of both physiological and pathological processes. The discovery of novel TNF ligands and receptors, BAFF and APRIL, have opened up new possibilities for scientists to explore the effect of these cytokines on the human immune system. The role of BAFF/APRIL system in B lymphocytes is particularly important for survival and maintenance of homeostasis. Aberrant expression of the system is associated with various immunological disorders. Hence, this study provides a comprehensive overview of the past and present BAFF/APRIL system research development in a bibliometric perspective. To our best knowledge, this is the first ever bibliometric analysis conducted focusing on the BAFF/APRIL system. A total of 1055 relevant documents were retrieved from WoSCC. Microsoft Excel, VOSviewer, and Biblioshiny of R studio were bibliometric tools used to analyse the scientific literature. From 1999, the annual publications showed an upward trend, with Journal of Immunology being the most productive journal. USA leads the race for BAFF/APRIL system research developments. Pascal Schneider, a senior researcher affiliated with University of Lausanne, Switzerland was recognised as the most productive author and institution in the BAFF/APRIL system research field. The research focus transitioned from focusing on the role of the system in B cell biology, to immunological disorders and finally to development of BAFF/APRIL targeting drugs. Despite several studies elucidating briefly the pathway mechanism of BAFF/APRIL system in B-cell selection, substantial research on the mechanism of action in disease models and T cell activation and development of immunomodulating drugs from natural origins remains largely unexplored. Therefore, future research focusing on these areas are crucial for the deeper understanding of the system in disease manifestations and progression allowing a better treatment management for various immunological disorders.

Ashwagandha-Induced Programmed Cell Death in the Treatment of Breast Cancer

The aim of this review is to provide experimental evidence for the programmed-death activity of Ashwagandha (Withania somnifera) in the anti-cancer therapy of breast cancer. The literature search was conducted using online electronic databases (Google Scholar, PubMed, Scopus). Collection schedule data for the review article covered the years 2004-2024. Ashwagandha active substances, especially Withaferin A (WA), are the most promising anti-cancer compounds. WS exerts its effect on breast cancer cells by inducing programmed cell death, especially apoptosis, at the molecular level. Ashwagandha has been found to possess a potential for treating breast cancer, especially estrogen receptor/progesterone receptor (ER/PR)-positive and triple-negative breast cancer.

N6-Methyladenosine Methylation of mRNA in Cell Apoptosis

Apoptosis, a highly controlled homeostatic mechanism that eliminates single cells without destroying tissue function, occurs during growing development and senescence. N6-methyladenosine (m6A), as the most common internal modification of eukaryotic mRNA, fine-tunes gene expression by regulating many aspects of mRNA metabolism, such as splicing, nucleation, stability, translation, and degradation. Remarkably, recent reports have indicated that aberrant methylation of m6A-related RNA may directly or indirectly influence the expression of apoptosis-related genes, thus regulating the process of cell apoptosis. In this review, we summarized the relationship between m6A modification and cell apoptosis, especially its role in the nervous system, and analyzed the limitations of the current research.

14-3-3 Family of Proteins: Biological Implications, Molecular Interactions, and Potential Intervention in Cancer, Virus and Neurodegeneration Disorders

The 14-3-3 family of proteins are highly conserved acidic eukaryotic proteins (25-32 kDa) abundantly present in the body. Through numerous binding partners, the 14-3-3 is responsible for many essential cellular pathways, such as cell cycle regulation and gene transcription control. Hence, its dysregulation has been linked to the onset of critical illnesses such as cancers, neurodegenerative diseases and viral infections. Interestingly, explorative studies have revealed an inverse correlation of 14-3-3 protein in cancer and neurodegenerative diseases, and the direct manipulation of 14-3-3 by virus to enhance infection capacity has dramatically extended its significance. Of these, COVID-19 has been linked to the 14-3-3 proteins by the interference of the SARS-CoV-2 nucleocapsid (N) protein during virion assembly. Given its predisposition towards multiple essential host signalling pathways, it is vital to understand the holistic interactions between the 14-3-3 protein to unravel its potential therapeutic unit in the future. As such, the general structure and properties of the 14-3-3 family of proteins, as well as their known biological functions and implications in cancer, neurodegeneration, and viruses, were covered in this review. Furthermore, the potential therapeutic target of 14-3-3 proteins in the associated diseases was discussed.

Modeling the Binding of Anticancer Peptides and Mcl-1

Mcl-1 (myeloid cell leukemia 1), a member of the Bcl-2 family, is upregulated in various types of cancer. Peptides representing the BH3 (Bcl-2 homology 3) region of pro-apoptotic proteins have been demonstrated to bind the hydrophobic groove of anti-apoptotic Mcl-1, and this interaction is responsible for regulating apoptosis. Structural studies have shown that, while there is high overall structural conservation among the anti-apoptotic Bcl-2 (B-cell lymphoma 2) proteins, differences in the surface groove of these proteins facilitates binding specificity. This binding specificity is crucial for the mechanism of action of the Bcl-2 family in regulating apoptosis. Bim-based peptides bind specifically to the hydrophobic groove of Mcl-1, emphasizing the importance of these interactions in the regulation of cell death. Molecular docking was performed with BH3-like peptides derived from Bim to identify high affinity peptides that bind to Mcl-1 and to understand the molecular mechanism of their interactions. The interactions of three identified peptides, E2gY, E2gI, and XXA1_F3dI, were further evaluated using 250 ns molecular dynamics simulations. Conserved hydrophobic residues of the peptides play an important role in their binding and the structural stability of the complexes. Understanding the molecular basis of interaction of these peptides will assist in the development of more effective Mcl-1 specific inhibitors.

Targeting apoptosis in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most prevalent subtype of renal cancer, accounting for approximately 80% of all renal cell cancers. Due to its exceptional inter- and intratumor heterogeneity, it is highly resistant to conventional systemic therapies. Targeting the evasion of cell death, one of cancer's hallmarks, is currently emerging as an alternative strategy for ccRCC. In this article, we review the current state of apoptosis-inducing therapies against ccRCC, including antisense oligonucleotides, BH3 mimetics, histone deacetylase inhibitors, cyclin-kinase inhibitors, inhibitors of apoptosis protein antagonists, and monoclonal antibodies. Although preclinical studies have shown encouraging results, these compounds fail to improve patients' outcomes significantly. Current evidence suggests that inducing apoptosis in ccRCC may promote tumor progression through apoptosis-induced proliferation, anastasis, and apoptosis-induced nuclear expulsion. Therefore, re-evaluating this approach is expected to enable successful preclinical-to-clinical translation.

Orexins in apoptosis: a dual regulatory role

The orexins, also referred to as hypocretins, are neuropeptides that originate from the lateral hypothalamus (LH) region of the brain. They are composed of two small peptides, orexin-A, and orexin-B, which are broadly distributed throughout the central and peripheral nervous systems. Orexins are recognized to regulate diverse functions, involving energy homeostasis, the sleep-wake cycle, stress responses, and reward-seeking behaviors. Additionally, it is suggested that orexin-A deficiency is linked to sleepiness and narcolepsy. The orexins bind to their respective receptors, the orexin receptor type 1 (OX1R) and type 2 (OX2R), and activate different signaling pathways, which results in the mediation of various physiological functions. Orexin receptors are widely expressed in different parts of the body, including the skin, muscles, lungs, and bone marrow. The expression levels of orexins and their receptors play a crucial role in apoptosis, which makes them a potential target for clinical treatment of various disorders. This article delves into the significance of orexins and orexin receptors in the process of apoptosis, highlighting their expression levels and their potential contributions to different diseases. The article offers an overview of the existing understanding of the orexin/receptor system and how it influences the regulation of apoptosis.

Involvement of Glucosamine 6 Phosphate Isomerase 2 (GNPDA2) Overproduction in β-Amyloid- and Tau P301L-Driven Pathomechanisms

Alzheimer's disease (AD) is a neurodegenerative olfactory disorder affecting millions of people worldwide. Alterations in the hexosamine- or glucose-related pathways have been described through AD progression. Specifically, an alteration in glucosamine 6 phosphate isomerase 2 (GNPDA2) protein levels has been observed in olfactory areas of AD subjects. However, the biological role of GNPDA2 in neurodegeneration remains unknown. Using mass spectrometry, multiple GNPDA2 interactors were identified in human nasal epithelial cells (NECs) mainly involved in intraciliary transport. Moreover, GNPDA2 overexpression induced an increment in NEC proliferation rates, accompanied by transcriptomic alterations in Type II interferon signaling or cellular stress responses. In contrast, the presence of beta-amyloid or mutated Tau-P301L in GNPDA2-overexpressing NECs induced a slowdown in the proliferative capacity in parallel with a disruption in protein processing. The proteomic characterization of Tau-P301L transgenic zebrafish embryos demonstrated that GNPDA2 overexpression interfered with collagen biosynthesis and RNA/protein processing, without inducing additional changes in axonal outgrowth defects or neuronal cell death. In humans, a significant increase in serum GNPDA2 levels was observed across multiple neurological proteinopathies (AD, Lewy body dementia, progressive supranuclear palsy, mixed dementia and amyotrophic lateral sclerosis) (n = 215). These data shed new light on GNPDA2-dependent mechanisms associated with the neurodegenerative process beyond the hexosamine route.

Molecular cloning and characterization of BNIP3 and NIX1/2 and their role in DHA-induced mitophagy and apoptosis in grass carp (Ctenopharyngodon idellus) adipocytes

B-cell lymphoma-2 and adenovirus E1B 19-kDa-interacting protein 3 (BNIP3) and BNIP3 like (BNIP3L or NIX) play a vital role in regulating mitophagy and the intrinsic apoptosis in mammals, but their gene characterizations remain unclear in fish. Herein, bnip3, nix1 and nix2 were isolated and characterized from grass carp (Ctenopharyngodon idellus), which encode peptides of 194, 233 and 222 amino acids, respectively. As typical BH3-only proteins, grass carp BNIP3, NIX1 and NIX2 proteins contain BH3 and C-terminal transmembrane domains for inducing apoptosis. Moreover, the LC3-interacting region motif of BNIP3, NIX1 and NIX2 is also conserved in grass carp. Phylogenetic analyses also demonstrated that nix1 and nix2 may have originated from the genome duplication event. Expression pattern analysis indicated that bnip3, nix1 and nix2 were highest expressed in brain, followed by eye (bnip3) and liver (nix1 and nix2). BNIP3, NIX1 and NIX2 localized to the nucleus and the cytoplasm, with a predominant localization to mitochondria within the cytoplasm. In the present study, we found that 200 μM DHA impaired the mitochondrial function, manifested as the decreased antioxidant ability, cellular ATP content and mitochondrial membrane potential in grass carp adipocytes. In addition, the gene expression and enzyme activities of caspase family were significantly increased in 200 μM DHA group, indicating that adipocyte apoptosis was induced. Meanwhile, DHA increased the gene expression of bnip3, nix1 and nix2 in a dose-dependent manner in grass carp adipocytes. The colocalization of mitochondria and lysosomes was promoted by 200 μM DHA treatment, implying that BNIP3/NIX-related mitophagy was activated in adipocytes. Based on these findings, it can be inferred that BNIP3/NIX-related mitophagy may be involved in the adipocyte apoptosis induced by DHA in grass carp.

Significance of TRAIL/Apo-2 ligand and its death receptors in apoptosis and necroptosis signalling: Implications for cancer-targeted therapeutics

The human immune defensesystem routinely expresses the tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), which is the most prevalent element for antitumor immunity. TRAIL associates with its death receptors (DRs), DR4 (TRAIL-R1), and DR5 (TRAIL-R2), in cancer cells to initiate the intracellular apoptosis cascade. Accordingly, numerous academic institutions and pharmaceutical companies havetried to exploreTRAIL's capacity to kill tumourcells by producing recombinant versions of it (rhTRAIL) or TRAIL receptor agonists (TRAs) [monoclonal antibody (mAb), synthetic and natural compounds, etc.] and molecules that sensitize TRAIL signalling pathway for therapeutic applications. Recently, several microRNAs (miRs) have been found to activate or inhibit death receptor signalling. Therefore, pharmacological regulation of these miRs may activate or resensitize the TRAIL DRs signal, and this is a novel approach for developing anticancer therapeutics. In this article, we will discuss TRAIL and its receptors and molecular pathways by which it induces various cell death events. We will unravel potential innovative applications of TRAIL-based therapeutics, and other investigated therapeutics targeting TRAIL-DRs and summarize the current preclinical pharmacological studies and clinical trials. Moreover, we will also emphasizea few situations where future efforts may be addressed to modulate the TRAIL signalling pathway.

PIM3 Kinase: A Promising Novel Target in Solid Cancers

PIM3 (provirus-integrating Moloney site 3) is a serine/threonine kinase and belongs to the PIM family (PIM1, PIM2, and PIM3). PIM3 is a proto-oncogene that is frequently overexpressed in cancers originating from endoderm-derived tissues, such as the liver, pancreas, colon, stomach, prostate, and breast cancer. PIM3 plays a critical role in activating multiple oncogenic signaling pathways promoting cancer cell proliferation, survival, invasion, tumor growth, metastasis, and progression, as well as chemo- and radiation therapy resistance and immunosuppressive microenvironment. Genetic inhibition of PIM3 expression suppresses in vitro cell proliferation and in vivo tumor growth and metastasis in mice with solid cancers, indicating that PIM3 is a potential therapeutic target. Although several pan-PIM inhibitors entered phase I clinical trials in hematological cancers, there are currently no FDA-approved inhibitors for the treatment of patients. This review provides an overview of recent developments and insights into the role of PIM3 in various cancers and its potential as a novel molecular target for cancer therapy. We also discuss the current status of PIM-targeted therapies in clinical trials.

The power of mumps virus: Matrix protein activates apoptotic pathways in human colorectal cell lines

New therapeutic approaches can significantly impact the control of colorectal cancer (CRC), which is increasing worldwide. In this study, we investigated the potential of targeting viral proteins to combat cancer cells. Specifically, we examined the anticancer potential of the matrix (M) protein of the mumps virus Hoshino strain in SW480 CRC cell lines. To begin, we individually transfected SW480 cells with pcDNA3 plasmids containing the mumps virus M gene. We then investigated the percentage of cell death, caspase activity, and the expression levels of genes involved in apoptosis pathways. Following this, we performed bioinformatics analysis on the M protein to identify any similarities with Bcl-2 family members and their viral homologs. Our diagnostic methods showed that treatment with the mumps M protein induced apoptosis and upregulated the expression and activity of pro-apoptotic proteins in SW480 CRC cells compared to the control and vector groups. Based on our bioinformatics studies, we proposed that the BH3 motif in the M protein may trigger apoptosis in CRC cells by interacting with cellular Bax. Overall, our study showed for the first time that the mumps virus M protein could be considered as a targeted treatment for CRC by inducing apoptotic pathways.

Recent Updates in Venetoclax Combination Therapies in Pediatric Hematological Malignancies

Venetoclax is a strongly effective B-cell lymphoma-2 inhibitor (BCL-2) with an ability to selectively restore the apoptotic potential of cancerous cells. It has been proven that in combination with immunotherapy, targeted therapies, and lower-intensity therapies such as hypomethylating agents (HMAs) or low-dose cytarabine (LDAC), the drug can improve overall outcomes for adult patients with acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), and multiple myeloma (MM), amongst other hematological malignancies, but its benefit in pediatric hematology remains unclear. With a number of preclinical and clinical trials emerging, the newest findings suggest that in many cases of younger patients, venetoclax combination treatment can be well-tolerated, with a safety profile similar to that in adults, despite often leading to severe infections. Studies aim to determine the activity of BCL-2 inhibitor in the treatment of both primary and refractory acute leukemias in combination with standard and high-dose chemotherapy. Although more research is required to identify the optimal venetoclax-based regimen for the pediatric population and its long-term effects on patients' outcomes, it can become a potential therapeutic agent for pediatric oncology.

Genome-Wide Assessment of Shared Genetic Architecture Between Rheumatoid Arthritis and Cardiovascular Diseases

BACKGROUND

Patients with rheumatoid arthritis (RA) have a 2- to 10-fold increased risk of cardiovascular disease (CVD), but the biological mechanisms and existence of causality underlying such associations remain to be investigated. We aimed to investigate the genetic associations and underlying mechanisms between RA and CVD by leveraging large-scale genomic data and genetic cross-trait analytic approaches.

METHODS AND RESULTS

Within UK Biobank data, we examined the genetic correlation, shared genetics, and potential causality between RA (Ncases=6754, Ncontrols=452 384) and cardiovascular diseases (CVD, Ncases=44 238, Ncontrols=414 900) using linkage disequilibrium score regression, cross-trait meta-analysis, and Mendelian randomization. We observed significant genetic correlations of RA with myocardial infarction (rg:0.40 [95% CI, 0.24-0.56), angina (rg:0.42 [95% CI, 0.28-0.56]), coronary heart diseases (rg:0.41 [95% CI, 0.27-0.55]), and CVD (rg:0.43 [95% CI, 0.29-0.57]) after correcting for multiple testing (P<0.05/5). When stratified by frequent use of analgesics, we found increased genetic correlation between RA and CVD among participants without aspirin usage (rg:0.54 [95% CI, 0.30-0.78] for angina; Pvalue=6.69×10-6) and among participants with paracetamol usage (rg:0.75 [95% CI, 0.20-1.29] for myocardial infarction; Pvalue=8.90×10-3), whereas others remained similar. Cross-trait meta-analysis identified 9 independent shared loci between RA and CVD, including PTPN22 at chr1p13.2, BCL2L11 at chr2q13, and CCR3 at chr3p21.31 (Psingle trait<1×10-3 and Pmeta<5×10-8), highlighting potential shared pathogenesis including accelerating atherosclerosis, upregulating oxidative stress, and vascular permeability. Finally, Mendelian randomization estimates showed limited evidence of causality between RA and CVD.

CONCLUSIONS

Our results supported shared genetic pathogenesis rather than causality in explaining the observed association between RA and CVD. The identified shared genetic factors provided insights into potential novel therapeutic target for RA-CVD comorbidities.

Design and Synthesis of Novel 2-Acetamido, 6-Carboxamide Substituted Benzothiazoles as Potential BRAFV600E Inhibitors - In vitro Evaluation of their Antiproliferative Activity

The oncogenic BRAFV600E kinase leads to abnormal activation of the MAPK signaling pathway and thus, uncontrolled cellular proliferation and cancer development. Based on our previous virtual screening studies which issued 2-acetamido-1,3 benzothiazole-6-carboxamide scaffold as active pharmacophore displaying selectivity against the mutated BRAF, eleven new substituted benzothiazole derivatives were designed and synthesized by coupling of 2-acetamidobenzo[d]thiazole-6-carboxylic acid with the appropriate amines in an effort to provide even more efficient inhibitors and tackle drug resistance often developed during cancer treatment. All derived compounds bore the benzothiazole scaffold substituted at position-2 by an acetamido moiety and at position-6 by a carboxamide functionality, the NH moiety of which was further linked through an alkylene linker to a sulfonamido (or amino) aryl (or alkyl) functionality or a phenylene linker to a sulfonamido aromatic (or non-aromatic) terminal pharmacophore in the order -C6 H4 -NHSO2 -R or reversely -C6 H4 -SO2 N(H)-R. These analogs were subsequently biologically evaluated as potential BRAFV600E inhibitors and antiproliferative agents in several colorectal cancer and melanoma cell lines. In all assays applied, one analog, namely 2-acetamido-N-[3-(pyridin-2-ylamino)propyl]benzo[d]thiazole-6-carboxamide (22), provided promising results in view of its use in drug development.

Mitochondrial Dynamics of Bcl-2 Family Proteins during 17-β-Estradiol-Induced Apoptosis Correlate with the Malignancy of Endometrial Cancer Cells

Excessive fat intake leads to an increase in cholesterol. Overexposure to estrogen derived from cholesterol is known to contribute to the malignancy of endometrial adenocarcinomas. However, it is not well understood the relationship between the exposure to estrogen and the malignancy of endometrial adenocarcinomas. We investigated how estrogen affected the malignancy of endometrial cancer cells, specifically HEC1 cells (a moderately differentiated adenocarcinoma) and HEC50B cells (a poorly differentiated adenocarcinoma). Cell viability was decreased by exogenous 17-β-estradiol (E2) in a concentration-dependent manner. E2 disturbed the mitochondrial membrane potentials by changing the localization of the B-cell lymphoma 2 (Bcl-2) family protein; however, there were significant differences in the localization of Bcl-2 family proteins between HEC1 and HEC50B cells. In HEC1 cells, E2 increased the expression of B-cell lymphoma-extra large (Bcl-XL) and the Bcl-2-associated X protein (Bax) and decreased Bcl-2 and Bcl-2-associated death promoter (Bad) expression on the outer mitochondrial membrane. Conversely, E2 increased the expression of Bad and Bax, and it decreased Bcl-2 and Bcl-XL expressions on the outer mitochondrial membrane in HEC50B cells. The disturbance of the mitochondrial membrane potential led to the release of cytochrome c from the mitochondria to the cytosolic space followed by activating caspase-9. After that, caspase-3 was activated and induced apoptosis. These results suggested that the localization of the Bcl-2 family protein observed under E2-induced apoptosis is related to the malignancy of endometrial cancer cells. We hope that the dynamics of Bcl-2 family proteins such as Bcl-XL and Bad will be used to diagnose malignant endometrial adenocarcinomas.

Mitochondrial quality control in health and cardiovascular diseases

Cardiovascular diseases (CVDs) are one of the primary causes of mortality worldwide. An optimal mitochondrial function is central to supplying tissues with high energy demand, such as the cardiovascular system. In addition to producing ATP as a power source, mitochondria are also heavily involved in adaptation to environmental stress and fine-tuning tissue functions. Mitochondrial quality control (MQC) through fission, fusion, mitophagy, and biogenesis ensures the clearance of dysfunctional mitochondria and preserves mitochondrial homeostasis in cardiovascular tissues. Furthermore, mitochondria generate reactive oxygen species (ROS), which trigger the production of pro-inflammatory cytokines and regulate cell survival. Mitochondrial dysfunction has been implicated in multiple CVDs, including ischemia-reperfusion (I/R), atherosclerosis, heart failure, cardiac hypertrophy, hypertension, diabetic and genetic cardiomyopathies, and Kawasaki Disease (KD). Thus, MQC is pivotal in promoting cardiovascular health. Here, we outline the mechanisms of MQC and discuss the current literature on mitochondrial adaptation in CVDs.

Epstein-Barr Virus Encoded BCL2, BHRF1, Downregulates Autophagy by Noncanonical Binding of BECN1

γ-herpesviruses (γHVs) encode BCL2 homologues (vBCL2) that bind the Bcl-2 homology 3 domains (BH3Ds) of diverse proteins, inhibiting apoptosis and promoting host cell and virus survival. vBCLs encoded by Kaposi sarcoma-associated HV (KSHV) and γHV68 downregulate autophagy, a degradative cellular process crucial for homeostasis and innate immune responses to pathogens, by binding to a BH3D in BECN1, a key autophagy protein. Epstein-Barr virus (EBV) encodes a vBCL2 called BHRF1. Here we show that unlike the KSHV and γHV68 vBCL2s, BHRF1 does not bind the isolated BECN1 BH3D. We use yeast two-hybrid assays to identify the minimal region of BECN1 required and sufficient for binding BHRF1. We confirm that this is a direct, albeit weak, interaction via affinity pull-down assays and isothermal titration calorimetry. To understand the structural bases of BHRF1 specificity, we determined the 2.6 Å crystal structure of BHRF1 bound to the BID BH3D, which binds ∼400-times tighter to BHRF1 than does BECN1, and performed a detailed structural comparison with complexes of diverse BH3Ds bound to BHRF1 and to other antiapoptotic BCL2s. Lastly, we used mammalian cell autophagy assays to demonstrate that BHRF1 downregulates autophagy and that a cell-permeable peptide derived from the BID BH3D inhibits BHRF1-mediated downregulation of autophagy. In summary, our results suggest that BHRF1 downregulates autophagy by noncanonical binding of a flexible region of BECN1 that includes but is not limited to the BH3D and that BH3D-derived peptides that bind better to BHRF1 can block downregulation of autophagy by BHRF1.

JNK Cascade-Induced Apoptosis-A Unique Role in GqPCR Signaling

The response of cells to extracellular signals is mediated by a variety of intracellular signaling pathways that determine stimulus-dependent cell fates. One such pathway is the cJun-N-terminal Kinase (JNK) cascade, which is mainly involved in stress-related processes. The cascade transmits its signals via a sequential activation of protein kinases, organized into three to five tiers. Proper regulation is essential for securing a proper cell fate after stimulation, and the mechanisms that regulate this cascade may involve the following: (1) Activatory or inhibitory phosphorylations, which induce or abolish signal transmission. (2) Regulatory dephosphorylation by various phosphatases. (3) Scaffold proteins that bring distinct components of the cascade in close proximity to each other. (4) Dynamic change of subcellular localization of the cascade's components. (5) Degradation of some of the components. In this review, we cover these regulatory mechanisms and emphasize the mechanism by which the JNK cascade transmits apoptotic signals. We also describe the newly discovered PP2A switch, which is an important mechanism for JNK activation that induces apoptosis downstream of the Gq protein coupled receptors. Since the JNK cascade is involved in many cellular processes that determine cell fate, addressing its regulatory mechanisms might reveal new ways to treat JNK-dependent pathologies.

Anticancer Potential of Flavonoids: An Overview with an Emphasis on Tangeretin

Natural compounds with pharmacological activity, flavonoids have been the subject of an exponential increase in studies in the field of scientific research focused on therapeutic purposes due to their bioactive properties, such as antioxidant, anti-inflammatory, anti-aging, antibacterial, antiviral, neuroprotective, radioprotective, and antitumor activities. The biological potential of flavonoids, added to their bioavailability, cost-effectiveness, and minimal side effects, direct them as promising cytotoxic anticancer compounds in the optimization of therapies and the search for new drugs in the treatment of cancer, since some extensively antineoplastic therapeutic approaches have become less effective due to tumor resistance to drugs commonly used in chemotherapy. In this review, we emphasize the antitumor properties of tangeretin, a flavonoid found in citrus fruits that has shown activity against some hallmarks of cancer in several types of cancerous cell lines, such as antiproliferative, apoptotic, anti-inflammatory, anti-metastatic, anti-angiogenic, antioxidant, regulatory expression of tumor-suppressor genes, and epigenetic modulation.

Macrocyclic Carbon-Linked Pyrazoles As Novel Inhibitors of MCL-1

Myeloid cell leukemia-1 (MCL-1) is a member of the antiapoptotic BCL-2 proteins family and a key regulator of mitochondrial homeostasis. Overexpression of MCL-1 is found in many cancer cells and contributes to tumor progression, which makes it an attractive therapeutic target. Pursuing our previous study of macrocyclic indoles for the inhibition of MCL-1, we report herein the impact of both pyrazole and indole isomerism on the potency and overall properties of this family of compounds. We demonstrated that the incorporation of a fluorine atom on the naphthalene moiety was a necessary step to improve cellular potency and that, combined with the introduction of various side chains on the pyrazole, it enhanced solubility significantly. This exploration culminated in the discovery of compounds (Ra)-10 and (Ra)-15, possessing remarkable cellular potency and properties.

Ursolic Acid against Prostate and Urogenital Cancers: A Review of In Vitro and In Vivo Studies

Prostate cancer is the second most diagnosed form of cancer in men worldwide and accounted for roughly 1.3 million cases and 359,000 deaths globally in 2018, despite all the available treatment strategies including surgery, radiotherapy, and chemotherapy. Finding novel approaches to prevent and treat prostate and other urogenital cancers effectively is of major importance. Chemicals derived from plants, such as docetaxel and paclitaxel, have been used in cancer treatment, and in recent years, research interest has focused on finding other plant-derived chemicals that can be used in the fight against cancer. Ursolic acid, found in high concentrations in cranberries, is a pentacyclic triterpenoid compound demonstrated to have anti-inflammatory, antioxidant, and anticancer properties. In the present review, we summarize the research studies examining the effects of ursolic acid and its derivatives against prostate and other urogenital cancers. Collectively, the existing data indicate that ursolic acid inhibits human prostate, renal, bladder, and testicular cancer cell proliferation and induces apoptosis. A limited number of studies have shown significant reduction in tumor volume in animals xenografted with human prostate cancer cells and treated with ursolic acid. More animal studies and human clinical studies are required to examine the potential of ursolic acid to inhibit prostate and other urogenital cancers in vivo.

Therapeutic advancements in targeting BCL-2 family proteins by epigenetic regulators, natural, and synthetic agents in cancer

Cancer is amongst the deadliest and most disruptive disorders, having a much higher death rate than other diseases worldwide. Human cancer rates continue to rise, thereby posing the most significant concerns for medical health professionals. In the last two decades, researchers have gone past several milestones in tackling cancer while gaining insight into the role of apoptosis in cancer or targeting various biomarker tools for prognosis and diagnosis. Apoptosis which is still a topic full of complexities, can be controlled considerably by B-cell lymphoma 2 (BCL-2) and its family members. Therefore, targeting proteins of this family to prevent tumorigenesis, is essential to focus on the pharmacological features of the anti-apoptotic and pro-apoptotic members, which will help to develop and manage this disorder. This review deals with the advancements of various epigenetic regulators to target BCL-2 family proteins, including the mechanism of several microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Similarly, a rise in natural and synthetic molecules' research over the last two decades has allowed us to acquire insights into understanding and managing the transcriptional alterations that have led to apoptosis and treating various neoplastic diseases. Furthermore, several inhibitors targeting anti-apoptotic proteins and inducers or activators targeting pro-apoptotic proteins in preclinical and clinical stages have been summarized. Overall, agonistic and antagonistic mechanisms of BCL-2 family proteins conciliated by epigenetic regulators, natural and synthetic agents have proven to be an excellent choice in developing cancer therapeutics.

p53 and Myofibroblast Apoptosis in Organ Fibrosis

Organ fibrosis represents a dysregulated, maladaptive wound repair response that results in progressive disruption of normal tissue architecture leading to detrimental deterioration in physiological function, and significant morbidity/mortality. Fibrosis is thought to contribute to nearly 50% of all deaths in the Western world with current treatment modalities effective in slowing disease progression but not effective in restoring organ function or reversing fibrotic changes. When physiological wound repair is complete, myofibroblasts are programmed to undergo cell death and self-clearance, however, in fibrosis there is a characteristic absence of myofibroblast apoptosis. It has been shown that in fibrosis, myofibroblasts adopt an apoptotic-resistant, highly proliferative phenotype leading to persistent myofibroblast activation and perpetuation of the fibrotic disease process. Recently, this pathological adaptation has been linked to dysregulated expression of tumour suppressor gene p53. In this review, we discuss p53 dysregulation and apoptotic failure in myofibroblasts and demonstrate its consistent link to fibrotic disease development in all types of organ fibrosis. An enhanced understanding of the role of p53 dysregulation and myofibroblast apoptosis may aid in future novel therapeutic and/or diagnostic strategies in organ fibrosis.

Computational approaches for the design of modulators targeting protein-protein interactions

BACKGROUND

Protein-protein interactions (PPIs) are intriguing targets for designing novel small-molecule inhibitors. The role of PPIs in various infectious and neurodegenerative disorders makes them potential therapeutic targets . Despite being portrayed as undruggable targets, due to their flat surfaces, disorderedness, and lack of grooves. Recent progresses in computational biology have led researchers to reconsider PPIs in drug discovery.

AREAS COVERED

In this review, we introduce in-silico methods used to identify PPI interfaces and present an in-depth overview of various computational methodologies that are successfully applied to annotate the PPIs. We also discuss several successful case studies that use computational tools to understand PPIs modulation and their key roles in various physiological processes.

EXPERT OPINION

Computational methods face challenges due to the inherent flexibility of proteins, which makes them expensive, and result in the use of rigid models. This problem becomes more significant in PPIs due to their flexible and flat interfaces. Computational methods like molecular dynamics (MD) simulation and machine learning can integrate the chemical structure data into biochemical and can be used for target identification and modulation. These computational methodologies have been crucial in understanding the structure of PPIs, designing PPI modulators, discovering new drug targets, and predicting treatment outcomes.

Effect of UV Stress on the Structure and Function of Pro-apoptotic Bid and Anti-apoptotic Bcl-xl proteins

Ultraviolet C (UV-C) radiation induces apoptosis in mammalian cells via the mitochondrion-mediated pathway. The Bcl-2 family of proteins are the regulators of the mitochondrial pathway of apoptosis and appears responsive to UV-C radiation. It is unknown how the structure and, effectively, the function of these proteins are directly impacted by UV-C exposure. Here, we present the effect of UV-C irradiation on the structure and function of pro-apoptotic Bid-FL and anti-apoptotic Bcl-xlΔC proteins. Using a variety of biophysical tools, we show that, following UV-C irradiation, the structures of Bcl-xlΔC and Bid-FL are irreversibly altered. Bcl-xLΔC is found to be more sensitive to UV stress than Bid-FL Interestingly, UV-C exposure shows dramatic chemical shift perturbations in consequence of dramatic structural perturbations (α-helix to β-sheet) in the BH3- binding region, a crucial segment of Bcl-xlΔC. Furter it has been shown that UV-exposed Bcl-xlΔC has reduced efficacy of its interactions with pro-apoptotic tBid.

RASSF1 is identified by transcriptome coordination analysis as a target of ATF4

Evaluation of gene co-regulation is a powerful approach for revealing regulatory associations between genes and predicting biological function, especially in genetically diverse samples. Here, we applied this strategy to identify transcripts that are co-regulated with unfolded protein response (UPR) genes in cultured fibroblasts from outbred deer mice. Our analyses showed that the transcriptome associated with RASSF1, a tumor suppressor involved in cell cycle regulation and not previously linked to UPR, is highly correlated with the transcriptome of several UPR-related genes, such as BiP/GRP78, DNAJB9, GRP94, ATF4, DNAJC3, and CHOP/DDIT3. Conversely, gene ontology analyses for genes co-regulated with RASSF1 predicted a previously unreported involvement in UPR-associated apoptosis. Bioinformatic analyses indicated the presence of ATF4-binding sites in the RASSF1 promoter, which were shown to be operational using chromatin immunoprecipitation. Reporter assays revealed that the RASSF1 promoter is responsive to ATF4, while ablation of RASSF1 mitigated the expression of the ATF4 effector BBC3 and abrogated tunicamycin-induced apoptosis. Collectively, these results implicate RASSF1 in the regulation of endoplasmic reticulum stress-associated apoptosis downstream of ATF4. They also illustrate the power of gene coordination analysis in predicting biological functions and revealing regulatory associations between genes.

Evidence for existence of an apoptosis-inducing BH3-only protein, sayonara, in Drosophila

Cells need to sense stresses to initiate the execution of the dormant cell death program. Since the discovery of the first BH3-only protein Bad, BH3-only proteins have been recognized as indispensable stress sensors that induce apoptosis. BH3-only proteins have so far not been identified in Drosophila despite their importance in other organisms. Here, we identify the first Drosophila BH3-only protein and name it sayonara. Sayonara induces apoptosis in a BH3 motif-dependent manner and interacts genetically and biochemically with the BCL-2 homologous proteins, Buffy and Debcl. There is a positive feedback loop between Sayonara-mediated caspase activation and autophagy. The BH3 motif of sayonara phylogenetically appeared at the time of the ancestral gene duplication that led to the formation of Buffy and Debcl in the dipteran lineage. To our knowledge, this is the first identification of a bona fide BH3-only protein in Drosophila, thus providing a unique example of how cell death mechanisms can evolve both through time and across taxa.

Role of C-terminal domain of Mycobacterium tuberculosis PE6 (Rv0335c) protein in host mitochondrial stress and macrophage apoptosis

PE/PPE proteins of Mycobacterium tuberculosis (Mtb) target the host organelles to dictate the outcome of infection. This study investigated the significance of PE6/Rv0335c protein's unique C-terminal in causing host mitochondrial perturbations and apoptosis. In-silico analysis revealed that similar to eukaryotic apoptotic Bcl2 proteins, Rv0335c had disordered, hydrophobic C-terminal and two BH3-like motifs in which one was located at C-terminal. Also, Rv0335c's N terminal had mitochondrial targeting sequence. Since, C-terminal of Bcl2 proteins are crucial for mitochondria targeting and apoptosis; it became relevant to evaluate the role of Rv0335c's C-terminal domain in modulating host mitochondrial functions and apoptosis. To confirm this, in-vitro experiments were conducted with Rv0335c whole protein and Rv0335c∆Cterm (C-terminal domain deleted Rv0335c) protein. Rv0335c∆Cterm caused significant reduction in mitochondrial perturbations and Caspase-mediated apoptosis of THP1 macrophages in comparison to Rv0335c. However, the deletion of C-terminal domain didn't affect Rv0335c's ability to localize to mitochondria. Nine Ca²⁺ binding residues were predicted within Rv0335c and four of them were at the C-terminal. In-vitro studies confirmed that Rv0335c caused significant increase in intracellular calcium influx whereas Rv0335c∆Cterm had insignificant effect on Ca²⁺ influx. Rv0335c has been reported to be a TLR4 agonist and, we observed a significant reduction in the expression of TLR4-HLA-DR-TNF-α in response to Rv0335c∆Cterm protein also suggesting the role of Rv0335c's C-terminal domain in host-pathogen interaction. These findings indicate the possibility of Rv0335c as a molecular mimic of eukaryotic Bcl2 proteins which equips it to cause host mitochondrial perturbations and apoptosis that may facilitate pathogen persistence.

Targeting Apoptotic Pathway of Cancer Cells with Phytochemicals and Plant-Based Nanomaterials

Apoptosis is the elimination of functionally non-essential, neoplastic, and infected cells via the mitochondrial pathway or death receptor pathway. The process of apoptosis is highly regulated through membrane channels and apoptogenic proteins. Apoptosis maintains cellular balance within the human body through cell cycle progression. Loss of apoptosis control prolongs cancer cell survival and allows the accumulation of mutations that can promote angiogenesis, promote cell proliferation, disrupt differentiation, and increase invasiveness during tumor progression. The apoptotic pathway has been extensively studied as a potential drug target in cancer treatment. However, the off-target activities of drugs and negative implications have been a matter of concern over the years. Phytochemicals (PCs) have been studied for their efficacy in various cancer cell lines individually and synergistically. The development of nanoparticles (NPs) through green synthesis has added a new dimension to the advancement of plant-based nanomaterials for effective cancer treatment. This review provides a detailed insight into the fundamental molecular pathways of programmed cell death and highlights the role of PCs along with the existing drugs and plant-based NPs in treating cancer by targeting its programmed cell death (PCD) network.

Pseudomonas aeruginosa Cytotoxins: Mechanisms of Cytotoxicity and Impact on Inflammatory Responses

Pseudomonas aeruginosa is one of the most virulent opportunistic Gram-negative bacterial pathogens in humans. It causes many acute and chronic infections with morbidity and mortality rates as high as 40%. P. aeruginosa owes its pathogenic versatility to a large arsenal of cell-associated and secreted virulence factors which enable this pathogen to colonize various niches within hosts and protect it from host innate immune defenses. Induction of cytotoxicity in target host cells is a major virulence strategy for P. aeruginosa during the course of infection. P. aeruginosa has invested heavily in this strategy, as manifested by a plethora of cytotoxins that can induce various forms of cell death in target host cells. In this review, we provide an in-depth review of P. aeruginosa cytotoxins based on their mechanisms of cytotoxicity and the possible consequences of their cytotoxicity on host immune responses.

Intrinsic Apoptotic Pathway Genes of Circulating Blood Neutrophils Triggered during HIV Infection and Remained Stimulated in ART Patients

BACKGROUND

The intrinsic apoptotic pathway of neutrophils in Human Immunodeficiency Virus (HIV) infection results in spontaneous neutrophil death. There is a scarcity of data regarding the gene expression of an intrinsic apoptotic pathway of neutrophils in HIV patients.

OBJECTIVE

The objective of this study was to observe the differential expression of some important genes involved in the intrinsic apoptotic pathway of HIV patients, including those who were receiving antiretroviral therapy (ART).

METHODS

Blood samples were collected from asymptomatic, symptomatic, ART receiver HIV patients, and healthy individuals. Total RNA was extracted from neutrophils and subjected to quantitative real-time PCR assay. CD4+T cells and an automated complete blood count were performed.

RESULTS

Among the asymptomatic, symptomatic, and ART receiver HIV patients (n=20 in each group), median CD4+T counts were 633, 98, and 565 cells/ml, and the length of HIV infection in months (± SD) was 24.06 ± 21.36, 62.05 ± 25.51, and 69.2 ± 39.67, respectively. Compared with healthy controls, intrinsic apoptotic pathway genes, i.e., BAX, BIM, Caspase-3, Caspase-9, MCL-1, and Calpain-1, were upregulated to 1.21 ± 0.33, 1.8 ± 0.25, 1.24 ± 0.46, 1.54 ± 0.21, 1.88 ± 0.30, and 5.85 ± 1.34 fold in the asymptomatic group, and even more significantly, i.e., 1.51 ± 0.43, 2.09 ± 1.13, 1.85 ± 1.22, 1.72 ± 0.85, 2.26 ± 1.34, and 7.88 ± 3.31 fold in symptomatic patients, respectively. Despite CD4+ T-cell levels increased in the ART receiver group, these genes did not approach the level of healthy or asymptomatic and remained significantly upregulated.

CONCLUSION

The genes involved in the intrinsic apoptotic pathway in circulating neutrophils during HIV infection were stimulated in vivo, and ART reduced the expression of those upregulated genes but did not return to the level of asymptomatic or healthy individuals.

Coordination of MAPK and p53 dynamics in the cellular responses to DNA damage and oxidative stress

In response to different cellular stresses, the transcription factor p53 undergoes different dynamics. p53 dynamics, in turn, control cell fate. However, distinct stresses can generate the same p53 dynamics but different cell fate outcomes, suggesting integration of dynamic information from other pathways is important for cell fate regulation. To determine how MAPK activities affect p53-mediated responses to DNA breaks and oxidative stress, we simultaneously tracked p53 and either ERK, JNK, or p38 activities in single cells. While p53 dynamics were comparable between the stresses, cell fate outcomes were distinct. Combining MAPK dynamics with p53 dynamics was important for distinguishing between the stresses and for generating temporal ordering of cell fate pathways. Furthermore, cross-talk between MAPKs and p53 controlled the balance between proliferation and cell death. These findings provide insight into how cells integrate signaling pathways with distinct temporal patterns of activity to encode stress specificity and drive different cell fate decisions.

Comprehensive literature review of monkeypox

The current outbreak of monkeypox (MPX) infection has emerged as a global matter of concern in the last few months. MPX is a zoonosis caused by the MPX virus (MPXV), which is one of the Orthopoxvirus species. Thus, it is similar to smallpox caused by the variola virus, and smallpox vaccines and drugs have been shown to be protective against MPX. Although MPX is not a new disease and is rarely fatal, the current multi-country MPX outbreak is unusual because it is occurring in countries that are not endemic for MPXV. In this work, we reviewed the extensive literature available on MPXV to summarize the available data on the major biological, clinical and epidemiological aspects of the virus and the important scientific findings. This review may be helpful in raising awareness of MPXV transmission, symptoms and signs, prevention and protective measures. It may also be of interest as a basis for performance of studies to further understand MPXV, with the goal of combating the current outbreak and boosting healthcare services and hygiene practices.Trial registration: ClinicalTrials.gov identifier: NCT02977715..Trial registration: ClinicalTrials.gov identifier: NCT03745131..Trial registration: ClinicalTrials.gov identifier: NCT00728689..Trial registration: ClinicalTrials.gov identifier: NCT02080767..

Deubiquitinating Enzyme USP12 Regulates the Pro-Apoptosis Protein Bax

The Bax protein is a pro-apoptotic protein belonging to the Bcl-2 family, involved in inducing apoptosis at the mitochondrial level. Regulating the protein levels of Bax is essential to enhancing apoptosis. In the current study, we ascertained the presence of deubiquitinating enzymes (DUBs) associated with Bax by performing the yeast two-hybrid screening (Y2H). We determined that ubiquitin-specific protease 12 (USP12), one of the DUBs, is associated with Bax. The binding of USP12 to Bax shows the interaction as a DUB, which regulates ubiquitination on Bax. Taken together, we believe that USP12 regulates Bax by detaching ubiquitin on K63-linked chains, indicating that USP12 affects the cellular functions of Bax, but it is not related with proteasomal degradation. The half-life of the Bax protein was determined by performing the site-directed mutagenesis of putative ubiquitination sites on Bax (K128R, K189R, and K190R). Of these, Bax (K128R and K190R) showed less ubiquitination; therefore, we compared the half-life of Bax (WT) and Bax K mutant forms in vitro. Interestingly, Bax (K189R) showed a higher ubiquitination level and shorter half-life than Bax (WT), and the (K128R and K190R) mutant form has a longer half-life than Bax (WT).

An integrative systems biology approach to overcome venetoclax resistance in acute myeloid leukemia

The over-expression of the Bcl-2 protein is a common feature of many solid cancers and hematological malignancies, and it is typically associated with poor prognosis and resistance to chemotherapy. Bcl-2-specific inhibitors, such as venetoclax, have recently been approved for the treatment of chronic lymphocytic leukemia and small lymphocytic lymphoma, and they are showing promise in clinical trials as a targeted therapy for patients with relapsed or refractory acute myeloid leukemia (AML). However, successful treatment of AML with Bcl-2-specific inhibitors is often followed by the rapid development of drug resistance. An emerging paradigm for overcoming drug resistance in cancer treatment is through the targeting of mitochondrial energetics and metabolism. In AML in particular, it was recently observed that inhibition of mitochondrial translation via administration of the antibiotic tedizolid significantly affects mitochondrial bioenergetics, activating the integrated stress response (ISR) and subsequently sensitizing drug-resistant AML cells to venetoclax. Here we develop an integrative systems biology approach to acquire a deeper understanding of the molecular mechanisms behind this process, and in particular, of the specific role of the ISR in the commitment of cells to apoptosis. Our multi-scale mathematical model couples the ISR to the intrinsic apoptosis pathway in venetoclax-resistant AML cells, includes the metabolic effects of treatment, and integrates RNA, protein level, and cellular viability data. Using the mathematical model, we identify the dominant mechanisms by which ISR activation helps to overcome venetoclax resistance, and we study the temporal sequencing of combination treatment to determine the most efficient and robust combination treatment protocol.

In this work, we develop a multi-scale systems biology approach to study the mechanisms by which the integrated stress response (ISR) activation helps to overcome venetoclax resistance in acute myeloid leukemia (AML). The multi-scale model enables the integration of RNA-level, protein-level, and cellular viability and proliferation data. The model developed in this work can predict several important features of the resistant AML cell lines that are consistent with experimental data. Further, our integrative systems biology approach led to the determination of the optimal combination treatment protocol.

From the divergence of senescent cell fates to mechanisms and selectivity of senolytic drugs

Senescence is a cellular stress response that involves prolonged cell survival, a quasi-irreversible proliferative arrest and a modification of the transcriptome that sometimes includes inflammatory gene expression. Senescent cells are resistant to apoptosis, and if not eliminated by the immune system they may accumulate and lead to chronic inflammation and tissue dysfunction. Senolytics are drugs that selectively induce cell death in senescent cells, but not in proliferative or quiescent cells, and they have proved a viable therapeutic approach in multiple mouse models of pathologies in which senescence is implicated. As the catalogue of senolytic compounds is expanding, novel survival strategies of senescent cells are uncovered, and variations in sensitivity to senolysis between different types of senescent cells emerge. We propose herein a mechanistic classification of senolytic drugs, based on the level at which they target senescent cells: directly disrupting BH3 protein networks that are reorganized upon senescence induction; downregulating survival-associated pathways essential to senescent cells; or modulating homeostatic processes whose regulation is challenged in senescence. With this approach, we highlight the important diversity of senescent cells in terms of physiology and pathways of apoptosis suppression, and we describe possible avenues for the development of more selective senolytics.

Six new polyoxygenated xanthones from Garcinia cowa and their neuroprotective effects on glutamate-mediated hippocampal neuronal HT22 cell death

Six new polyoxygenated xanthones, garcicowanones F-H (1-3), norcowanol A-B (4-5), and garcinone F (6) along with twelve known compounds 7-18 were obtained from the latex of Garcinia cowa Roxb. ex Choisy. All new compounds have a 1,3,7-trioxygenated or 1,3,6,7-tetraoxygenated xanthone nucleus and differ from majority of xanthones from G. cowa by hydrated side chains. Compounds 1, 7, 8 and 18 exhibited significant neuroprotective effects on glutamate-mediated hippocampal neuronal HT22 cell death. In particular, compound 1 exhibited the most potent neuroprotective effect with >80% cell viability in the concentration range of 2.9-115 µM. Further studies on compound 1 showed that it decreased cellular Ca2+ influx and inhibits cellular reactive oxygen species generation in HT22 cells. A Western blot analysis showed that MAPK phosphorylation, Bax, and AIF translocation dramatically increased upon treatment with 5 mM glutamate and decreased upon a co-treatment with compound 1.

Design, synthesis, and evaluation of a novel series of mono-indolylbenzoquinones derivatives for the potential treatment of breast cancer

Breast cancer is one of the most common cancers in the world, and pro-apototic drugs activating the apoptotic pathway are a strategy for anticancer therapy. To explore new antineoplastic agents, a series of novel mono-indolylbenzoquinone derivatives have been designed and synthesized. Compared with the lead bis-indolylbenzoquinones, most of the novel mono-indolylbenzoquinone derivatives have significantly increased their activity against A549, HeLa, and especially, MDA-MB-231 cell lines. Among them, 10d has the lowest IC50 value of 70 nM on MDA-MB-231 cells. Moreover, its oral toxicity is extremely low with an LD50 value of 374 mg/kg and no obvious liver and kidney damage to mice. 10d down-regulated Bcl-2, up-regulated Bax, and increased the release of cytochrome C, caspase3 and 9. 10d also up-regulated the expression of p53, catalase, and HTRA2/Omi. Therefore, 10d may exert its anticancer activity by activating apoptotic pathway and p53 expression. In vivo, 10d suppressed breast cancer 4T1 tumor growth with 36% inhibition ratio of tumor by intraperitoneal injection in mice. Furthermore, a cross-linked cyanoacrylate (CA)-based local sustained-release drug delivery systems (LSRDDSs) improved 10d anticancer activity to 49.8% inhibition of tumor growth. Taken together, 10d could be a promising drug candidate for clinical development to treat metastatic breast cancer.