BCL-2 family proteins: changing partners in the dance towards death. Cell Death Differ. 2018;25:65-80. [PMID: 29149100 PMCID: PMC5729540 DOI: 10.1038/cdd.2017.186]

Synergistic cytotoxicity of decitabine and YM155 in leukemia cells through upregulation of SLC35F2 and suppression of MCL1 and survivin expression

The hypomethylation agent decitabine (DAC), in combination with other apoptosis inducers, is considered a potential modality for cancer treatment. We investigated the mechanism underlying the combined cytotoxicity of DAC and YM155 in acute myeloid leukemia (AML) cells because of increasing evidence that YM155 induces apoptosis in cancer cells. Co-administration of DAC and YM155 resulted in synergistic cytotoxicity in AML U937 cells, which was characterized by the induction of apoptosis, NOXA-dependent degradation of MCL1 and survivin, and depolarization of mitochondria. Restoration of MCL1 or survivin expression attenuated DAC/YM155-induced U937 cell death. DAC initiated AKT and p38 MAPK phosphorylation in a Ca2+/ROS-dependent manner, thereby promoting autophagy-mediated degradation of β-TrCP mRNA, leading to increased Sp1 expression. DAC-induced Sp1 expression associated with Ten-eleven-translocation (TET) dioxygenases and p300 was used to upregulate the expression of SLC35F2. Simultaneously, the activation of p38 MAPK induced by DAC, promoted CREB-mediated NOXA expression, resulting in survivin and MCL1 degradation. The synergistic cytotoxicity of DAC and YM155 in U937 cells was dependent on elevated SLC35F2 expression. Additionally, YM155 facilitated DAC-induced degradation of MCL1 and survivin. A similar mechanism explained DAC/YM155-mediated cytotoxicity in AML HL-60 cells. Our data demonstrated that the synergistic cytotoxicity of DAC and YM155 in AML cell lines U937 and HL-60 is dependent on AKT- and p38 MAPK-mediated upregulation of SLC35F2 and p38 MAPK-mediated degradation of survivin and MCL1. This indicates that a treatment regimen that amalgamates YM155 and DAC may be beneficial for AML.

Novel Bis(2-cyanoacrylamide) Linked to Sulphamethoxazole: Synthesis, DNA Interaction, Anticancer, ADMET, Molecular Docking, and DFT Studies

In the light of advancement and potential extensive use of medication design and therapy, new bis(cyanoacrylamides) incorporating sulphamethoxazole derivatives (7 a-7 f) were synthesized and confirmed by different spectral tools. In vitro anticancer activity towards different human cancer cells (HCT116, MDA-MB-231 and A549) was assessed using MTT assay. Among all derivatives, 4C- and 6C-spacer derivatives (7 e and 7 f) had the most potent growth inhibitory activities against HCT116 cells with IC50 values of 39.7 and 28.5 μM, respectively. 7 e and 7 f induced apoptosis and suppressed migration of HCT116 cells. These compounds also induced a significant increase in caspase-3 and CDH1 activities, and a downregulation of Bcl2 using ELISA. pBR322 DNA cleavage activities of cyanoacrylamides were determined using agarose gel electrophoresis. Furthermore, 7 e and 7 f showed good DNA and BSA binding affinities using different spectroscopic techniques. Furthermore, molecular docking for 7 e and 7 f was performed to anticipate their binding capabilities toward various proteins (Bcl2, CDH1 and BSA). The docking results were well correlated with those of experimental results. Additionally, density functional theory and ADMET study were performed to evaluate the molecular and pharmacokinetic features of 7 e and 7 f, respectively. Thus, this work reveals promising antitumor lead compounds that merit future research and activity enhancement.

Cell-specific modulation of mitochondrial respiration and metabolism by the pro-apoptotic Bcl-2 family members Bax and Bak

Proteins from the Bcl-2 family play an essential role in the regulation of apoptosis. However, they also possess cell death-unrelated activities that are less well understood. This prompted us to study apoptosis-unrelated activities of the Bax and Bak, pro-apoptotic members of the Bcl-2 family. We prepared Bax/Bak-deficient human cancer cells of different origin and found that while respiration in the glioblastoma U87 Bax/Bak-deficient cells was greatly enhanced, respiration of Bax/Bak-deficient B lymphoma HBL-2 cells was slightly suppressed. Bax/Bak-deficient U87 cells also proliferated faster in culture, formed tumours more rapidly in mice, and showed modulation of metabolism with a considerably increased NAD+/NADH ratio. Follow-up analyses documented increased/decreased expression of mitochondria-encoded subunits of respiratory complexes and stabilization/destabilization of the mitochondrial transcription elongation factor TEFM in Bax/Bak-deficient U87 and HBL-2 cells, respectively. TEFM downregulation using shRNAs attenuated mitochondrial respiration in Bax/Bak-deficient U87 as well as in parental HBL-2 cells. We propose that (post)translational regulation of TEFM levels in Bax/Bak-deficient cells modulates levels of subunits of mitochondrial respiratory complexes that, in turn, contribute to respiration and the accompanying changes in metabolism and proliferation in these cells.

BCL-2 Modulates IRE1α Activation to Attenuate Endoplasmic Reticulum Stress and Pulmonary Fibrosis

BCL-2 family members are known to be implicated in survival in numerous biological settings. Here, we provide evidence that in injury and repair processes in lungs, BCL-2 mainly acts to attenuate endoplasmic reticulum (ER) stress and limit extracellular matrix accumulation. Days after an intratracheal bleomycin challenge, mice lose a fraction of their alveolar type II epithelium from terminal ER stress driven by activation of the critical ER sensor and stress effector IRE1α. This fraction is dramatically increased by BCL-2 inhibition, because IRE1α activation is dependent on its physical association with the BCL-2-proapoptotic family member BAX, and we found BCL-2 to disrupt this association in vitro. In vivo, navitoclax (a BCL-2/BCL-xL inhibitor) given 15-21 days after bleomycin challenge evoked strong activation of IRE-1α in mesenchymal cells and markers of ER stress, but not apoptosis. Remarkably, after BCL-2 inhibition, bleomycin-exposed mice demonstrated persistent collagen accumulation at Day 42, compared with resolution in controls. Enhanced fibrosis proved to be due to the RNAase activity of IRE1α downregulating MRC2 mRNA and protein, a mediator of collagen turnover. The critical role of MRC2 was confirmed in precision-cut lung slice cultures of Day-42 lungs from bleomycin-exposed wild-type and MRC2 null mice. Soluble and tissue collagen accumulated in precision-cut lung slice cultures from navitoclax-treated, bleomycin-challenged mice compared with controls, in a manner nearly identical to that of challenged but untreated MRC2 null mice. Thus, apart from mitochondrial-based antiapoptosis, BCL-2 functions to attenuate ER stress responses, fostering tissue homeostasis and injury repair.

MYC Oncogene: A Druggable Target for Treating Cancers with Natural Products

Various diseases, including cancers, age-associated disorders, and acute liver failure, have been linked to the oncogene, MYC. Animal testing and clinical trials have shown that sustained tumor volume reduction can be achieved when MYC is inactivated, and different combinations of therapeutic agents including MYC inhibitors are currently being developed. In this review, we first provide a summary of the multiple biological functions of the MYC oncoprotein in cancer treatment, highlighting that the equilibrium points of the MYC/MAX, MIZ1/MYC/MAX, and MAD (MNT)/MAX complexes have further potential in cancer treatment that could be used to restrain MYC oncogene expression and its functions in tumorigenesis. We also discuss the multifunctional capacity of MYC in various cellular cancer processes, including its influences on immune response, metabolism, cell cycle, apoptosis, autophagy, pyroptosis, metastasis, angiogenesis, multidrug resistance, and intestinal flora. Moreover, we summarize the MYC therapy patent landscape and emphasize the potential of MYC as a druggable target, using herbal medicine modulators. Finally, we describe pending challenges and future perspectives in biomedical research, involving the development of therapeutic approaches to modulate MYC or its targeted genes. Patients with cancers driven by MYC signaling may benefit from therapies targeting these pathways, which could delay cancerous growth and recover antitumor immune responses.

Generation of two human induced pluripotent stem cell lines with BAX and BAK1 double knock-out using CRISPR/Cas9

Bcl-2-associated X protein (BAX) and Blc-2 homologous antagonist killer 1 (BAK) are two pro-apoptotic members of BCL2 family. Here, two BAX/BAK double knock-out human induced pluripotent stem cell lines (iPSC) we generated using CRISPR-Cas9 to generate apoptosis incompetent cell lines. The resulting cell lines were karyotypically normal, had typical morphology and expressed typical markers for the undifferentiated state.

A pyrazolopyridine as a novel AhR signaling activator with anti-breast cancer properties in vitro and in vivo

Breast cancer is one of the main causes of malignancy-related deaths globally and has a significant impact on women's quality of life. Despite significant therapeutic advances, there is a medical need for targeted therapies in breast cancer. Aryl hydrocarbon receptor (AhR), a ligand-dependent transcription factor mediates responses to environment stimuli, is emerging as a unique pleiotropic target. Herein, a combined molecular simulation and in vitro investigations identified 3-(3-fluorophenyl)-1H-pyrazolo[3,4-b]pyridine (3FPP) as a novel AhR ligand in T47D and MDA-MB-231 breast cancer cells. Its agonistic effects induced formation of the AhR-AhR nuclear translocator (Arnt) heterodimer and prompted its binding to the penta-nucleotide sequence, called xenobiotic-responsive element (XRE) motif. Moreover, 3FPP augmented the promoter-driven luciferase activities and expression of AhR-regulated genes encoding cytochrome P450 1A1 (CYP1A1) and microRNA (miR)-212/132 cluster. It reduced cell viability, migration, and invasion of both cell lines through AhR signaling. These anticancer properties were concomitant with reduced levels of B-cell lymphoma 2 (BCL-2), SRY-related HMG-box4 (SOX4), snail family zinc finger 2 (SNAI2), and cadherin 2 (CDH2). In vivo, 3FPP suppressed tumor growth and activated AhR signaling in an orthotopic mouse model. In conclusion, our results introduce the fused pyrazolopyridine 3FPP as a novel AhR agonist with AhR-specific anti-breast cancer potential in vitro and in vivo.

Development and crystal structures of a potent second-generation dual degrader of BCL-2 and BCL-xL

Overexpression of BCL-xL and BCL-2 play key roles in tumorigenesis and cancer drug resistance. Advances in PROTAC technology facilitated recent development of the first BCL-xL/BCL-2 dual degrader, 753b, a VHL-based degrader with improved potency and reduced toxicity compared to previous small molecule inhibitors. Here, we determine crystal structures of VHL/753b/BCL-xL and VHL/753b/BCL-2 ternary complexes. The two ternary complexes exhibit markedly different architectures that are accompanied by distinct networks of interactions at the VHL/753b-linker/target interfaces. The importance of these interfacial contacts is validated via functional analysis and informed subsequent rational and structure-guided design focused on the 753b linker and BCL-2/BCL-xL warhead. This results in the design of a degrader, WH244, with enhanced potency to degrade BCL-xL/BCL-2 in cells. Using biophysical assays followed by in cell activities, we are able to explain the enhanced target degradation of BCL-xL/BCL-2 in cells. Most PROTACs are empirically designed and lack structural studies, making it challenging to understand their modes of action and specificity. Our work presents a streamlined approach that combines rational design and structure-based insights backed with cell-based studies to develop effective PROTAC-based cancer therapeutics.

A p53 score derived from TP53 CRISPR/Cas9 HMCLs predicts survival and reveals a major role of BAX in the response to BH3 mimetics

ABSTRACT

To establish a strict p53-dependent gene-expression profile, TP53-/- clones were derived from TP53+/+ and TP53-/mut t(4;14) human myeloma cell lines (HMCLs) using CRISPR/Cas9 technology. From the 17 dysregulated genes shared between the TP53-/- clones from TP53+/+ HMCLs, we established a functional p53 score, involving 13 genes specifically downregulated upon p53 silencing. This functional score segregated clones and myeloma cell lines as well as other cancer cell lines according to their TP53 status. The score efficiently identified samples from patients with myeloma with biallelic TP53 inactivation and was predictive of overall survival in Multiple Myeloma Research Foundation-coMMpass and CASSIOPEA cohorts. At the functional level, we showed that among the 13 genes, p53-regulated BAX expression correlated with and directly affected the MCL1 BH3 mimetic S63845 sensitivity of myeloma cells by decreasing MCL1-BAX complexes. However, resistance to S63845 was overcome by combining MCL1 and BCL2 BH3 mimetics, which displayed synergistic efficacy. The combination of BH3 mimetics was effective in 97% of patient samples with or without del17p. Nevertheless, single-cell RNA sequencing analysis showed that myeloma cells surviving the combination had lower p53 score, showing that myeloma cells with higher p53 score were more sensitive to BH3 mimetics. Taken together, we established a functional p53 score that identifies myeloma cells with biallelic TP53 invalidation, demonstrated that p53-regulated BAX is critical for optimal cell response to BH3 mimetics, and showed that MCL1 and BCL2 BH3 mimetics in combination may be of greater effectiveness for patients with biallelic TP53 invalidation, for whom there is still an unmet medical need.

Chemotherapy-initiated cysteine-rich protein 61 decreases acute B-lymphoblastic leukemia chemosensitivity

PURPOSE

Chemoresistance is a major challenge for acute lymphoblastic leukemia (ALL) treatment. Cysteine-rich protein 61 (Cyr61) plays an important role in drug resistance modulation of tumor cells, and Cyr61 levels are increased in the bone marrow of patients with ALL and contribute to ALL cell survival. However, the effect of Cyr61 on B cell acute lymphoblastic leukemia (B-ALL) cell chemosensitivity and the regulatory mechanisms underlying Cyr61 production in bone marrow remain unknown.

METHODS

Nalm-6 and Reh human B-ALL cell lines were used in this study. Cyr61 levels were assessed using quantitative real-time PCR (qRT-PCR), western blot analysis, and enzyme-linked immunosorbent assay. The effect of Cyr61 on B-ALL cell chemosensitivity to daunorubicin (DNR) was evaluated using cell viability and flow cytometry analyses. The regulatory mechanisms of Cyr61 production in bone marrow were examined using qRT-PCR and western blot analysis.

RESULTS

Cyr61 knockdown and overexpression increased and decreased the chemosensitivity of B-ALL cells to DNR, respectively. Cyr61 attenuated chemotherapeutic drug-induced apoptosis by upregulating B cell lymphoma-2. Notably, DNR induced DNA damage response and increased Cyr61 secretion in B-ALL cells through the ataxia telangiectasia mutated (ATM)-dependent nuclear factor kappa B pathway.

CONCLUSION

DNR induces Cyr61 production in B-ALL cells, and increased Cyr61 levels reduce the chemosensitivity of B-ALL cells. Consequently, targeting Cyr61 or related ATM signaling pathway may present a promising treatment strategy to enhance the chemosensitivity of patients with B-ALL.

Stroke in the Time of Circadian Medicine

Time-of-day significantly influences the severity and incidence of stroke. Evidence has emerged not only for circadian governance over stroke risk factors, but also for important determinants of clinical outcome. In this review, we provide a comprehensive overview of the interplay between chronobiology and cerebrovascular disease. We discuss circadian regulation of pathophysiological mechanisms underlying stroke onset or tolerance as well as in vascular dementia. This includes cell death mechanisms, metabolism, mitochondrial function, and inflammation/immunity. Furthermore, we present clinical evidence supporting the link between disrupted circadian rhythms and increased susceptibility to stroke and dementia. We propose that circadian regulation of biochemical and physiological pathways in the brain increase susceptibility to damage after stroke in sleep and attenuate treatment effectiveness during the active phase. This review underscores the importance of considering circadian biology for understanding the pathology and treatment choice for stroke and vascular dementia and speculates that considering a patient's chronotype may be an important factor in developing precision treatment following stroke.

Roles and mechanisms of aberrant alternative splicing in melanoma - implications for targeted therapy and immunotherapy resistance

BACKGROUND

Despite advances in therapeutic strategies, resistance to immunotherapy and the off-target effects of targeted therapy have significantly weakened the benefits for patients with melanoma.

MAIN BODY

Alternative splicing plays a crucial role in transcriptional reprogramming during melanoma development. In particular, aberrant alternative splicing is involved in the efficacy of immunotherapy, targeted therapy, and melanoma metastasis. Abnormal expression of splicing factors and variants may serve as biomarkers or therapeutic targets for the diagnosis and prognosis of melanoma. Therefore, comprehensively integrating their roles and related mechanisms is essential. This review provides the first detailed summary of the splicing process in melanoma and the changes occurring in this pathway.

CONCLUSION

The focus of this review is to provide strategies for developing novel diagnostic biomarkers and summarize their potential to alter resistance to targeted therapies and immunotherapy.

MCL1 inhibition targets Myeloid Derived Suppressors Cells, promotes antitumor immunity and enhances the efficacy of immune checkpoint blockade

Immune checkpoint inhibitors (ICIs) are now the first-line treatment for patients with advanced melanoma. Despite promising clinical results, many patients fail to respond to these therapies. BH3 mimetics, a novel class of small molecule inhibitors that bind and inhibit anti-apoptotic members of the BCL2 family proteins such as BCL2 or MCL1, have been very successful in treating hematologic malignancies. However, there are limited studies on the immunomodulatory role of the BH3 mimetics. Several factors contribute to ICI resistance including myeloid-derived suppressor cells (MDSCs) that exert immunosuppressive effects through direct and indirect inhibition of antitumor immunity. Thus, targeting MDSCs to enhance antitumor immunity has the potential to enhance the efficacy of ICIs. In this study, we show that the MCL1 inhibitor S64315 reduces melanoma tumor growth in an immune cell-dependent manner in mice. Specifically, S64315 enhances antitumor immunity by reducing MDSC frequency and by promoting the activity of CD8+T cells. Additionally, human MDSCs are 10 times more sensitive to S64315 than cutaneous melanoma lines. Further, we found that a higher expression of MCL1 is associated with poor survival for patients treated with anti-PD-1. Finally, combining S64315 and anti-PD-1 significantly slowed tumor growth compared to either agent alone. Together, this proof-of-concept study demonstrates the potential of combining an MCL1 inhibitor with anti-PD-1 in the treatment of melanoma. It justifies the further development of next generation MCL1 inhibitors to improve efficacy of ICIs in treating malignant melanoma.

Modes of Interactions with DNA/HSA Biomolecules and Comparative Cytotoxic Studies of Newly Synthesized Mononuclear Zinc(II) and Heteronuclear Platinum(II)/Zinc(II) Complexes toward Colorectal Cancer Cells

A series of mono- and heteronuclear platinum(II) and zinc(II) complexes with 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine ligand were synthesized and characterized. The DNA and protein binding properties of [ZnCl2(terpytBu)] (C1), [{cis-PtCl(NH3)2(μ-pyrazine)ZnCl(terpytBu)}](ClO4)2 (C2), [{trans-PtCl(NH3)2(μ-pyrazine)ZnCl(terpytBu)}](ClO4)2 (C3), [{cis-PtCl(NH3)2(μ-4,4'-bipyridyl)ZnCl(terpytBu)}](CIO4)2 (C4) and [{trans-PtCl(NH3)2(μ-4,4'-bipyridyl)ZnCl(terpytBu)}](CIO4)2 (C5) (where terpytBu = 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine), were investigated by electronic absorption, fluorescence spectroscopic, and molecular docking methods. Complexes featuring transplatin exhibited lower Kb and Ksv constant values compared to cisplatin analogs. The lowest Ksv value belonged to complex C1, while C4 exhibited the highest. Molecular docking studies reveal that the binding of complex C1 to DNA is due to van der Waals forces, while that of C2-C5 is due to conventional hydrogen bonds and van der Waals forces. The tested complexes exhibited variable cytotoxicity toward mouse colorectal carcinoma (CT26), human colorectal carcinoma (HCT116 and SW480), and non-cancerous mouse mesenchymal stem cells (mMSC). Particularly, the mononuclear C1 complex showed pronounced selectivity toward cancer cells over non-cancerous mMSC. The C1 complex notably induced apoptosis in CT26 cells, effectively arrested the cell cycle in the G0/G1 phase, and selectively down-regulated Cyclin D.

A billion years of evolution manifest in nanosecond protein dynamics

Protein dynamics form a critical bridge between protein structure and function, yet the impact of evolution on ultrafast processes inside proteins remains enigmatic. This study delves deep into nanosecond-scale protein dynamics of a structurally and functionally conserved protein across species separated by almost a billion years, investigating ten homologs in complex with their ligand. By inducing a photo-triggered destabilization of the ligand inside the binding pocket, we resolved distinct kinetic footprints for each homolog via transient infrared spectroscopy. Strikingly, we found a cascade of rearrangements within the protein complex which manifest in time points of increased dynamic activity conserved over hundreds of millions of years within a narrow window. Among these processes, one displays a subtle temporal shift correlating with evolutionary divergence, suggesting reduced selective pressure in the past. Our study not only uncovers the impact of evolution on molecular processes in a specific case, but has also the potential to initiate a field of scientific inquiry within molecular paleontology, where species are compared and classified based on the rapid pace of protein dynamic processes; a field which connects the shortest conceivable time scale in living matter (10[Formula: see text] s) with the largest ones (10[Formula: see text] s).

Study on the Efficacy and Potential Mechanism of Topical Shen Bai Hair Growing Decoction against Androgenetic Alopecia Based on Ultrahigh Performance Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry and RNA-seq

Androgenetic alopecia (AGA) is a major problem that can happen to people of all ages, leading to psychological problems, such as anxiety and depression. Topical Shen Bai hair growing decoction (TSBHGD) is based on the pathogenesis of AGA, combined with Traditional Chinese Medicine theory, improved by the Tianjin Academy of Traditional Chinese Medicine Affiliated Hospital according to its clinical treatment experience. This study was designed to demonstrate the therapeutic efficacy of TSBHGD against AGA, analyze the chemical components of TSBHGD as well as the skin-retained and blood-retained components in mice after topical administration of TSBHGD, and clarify the mechanism of its therapeutic efficacy. It was demonstrated that TSBHGD could suppress TNF-α and IL-6 levels and improve pathological phenomena such as hair loss, reduced follicle density, and dermal thickness caused by testosterone solution. Totally 35 components were identified in TSBHGD extracts, 12 skin-retained components were identified in drug-containing skin, and 7 blood-retained components were identified in drug-containing plasma, according to ultrahigh performance liquid chromatography quadrupole time-of-flight mass spectrometry. Transcriptomic sequencing revealed that some of the genes in AGA mice had altered expression patterns, which could be reversed by TSBHGD. Through network pharmacology analysis, it was found that TSBHGD mainly regulated eight signaling pathways, among which the apoptosis signaling pathway ranked first with a significance of 0.00149. Finally, both Bcl-2 and Caspase family proteins in the apoptosis signaling pathway were examined by Western blot. It was confirmed that TSBHGD could inhibit the apoptosis level in AGA mice's skin tissue to exert an anti-AGA effect. This will facilitate the development of new-generation herbal compound formulas with precise efficacy and provide novel ideas for AGA therapy.

Traditional Chinese medicine and its active substances reduce vascular injury in diabetes via regulating autophagic activity

Due to its high prevalence, poor prognosis, and heavy burden on healthcare costs, diabetic vascular complications have become a significant public health issue. Currently, the molecular and pathophysiological mechanisms underlying diabetes-induced vascular complications remain incompletely understood. Autophagy, a highly conserved process of lysosomal degradation, maintains intracellular homeostasis and energy balance via removing protein aggregates, damaged organelles, and exogenous pathogens. Increasing evidence suggests that dysregulated autophagy may contribute to vascular abnormalities in various types of blood vessels, including both microvessels and large vessels, under diabetic conditions. Traditional Chinese medicine (TCM) possesses the characteristics of "multiple components, multiple targets and multiple pathways," and its safety has been demonstrated, particularly with minimal toxicity in liver and kidney. Thus, TCM has gained increasing attention from researchers. Moreover, recent studies have indicated that Chinese herbal medicine and its active compounds can improve vascular damage in diabetes by regulating autophagy. Based on this background, this review summarizes the classification, occurrence process, and related molecular mechanisms of autophagy, with a focus on discussing the role of autophagy in diabetic vascular damage and the protective effects of TCM and its active compounds through the regulation of autophagy in diabetes. Moreover, we systematically elucidate the autophagic mechanisms by which TCM formulations, individual herbal extracts, and active compounds regulate diabetic vascular damage, thereby providing new candidate drugs for clinical treatment of vascular complications in diabetes. Therefore, further exploration of TCM and its active compounds with autophagy-regulating effects holds significant research value for achieving targeted therapeutic approaches for diabetic vascular complications.

Starvation-induced autophagy modulates spermatogenesis and sperm quality in Nile tilapia

Spermatogenesis is a finely regulated process that involves the interaction of several cellular mechanisms to ensure the proper development and maturation of germ cells. This study assessed autophagy contribution and its relation to apoptosis in fish spermatogenesis during starvation. To that end, Nile tilapia males were subjected to 0 (control), 7, 14, 21, and 28 days of starvation to induce autophagy. Testes samples were obtained for analyses of spermatogenesis by histology, electron microscopy, immunohistochemistry, and western blotting. Sperm quality was assessed using a computer-assisted sperm analysis (CASA) system. Data indicated a significant reduction in gonadosomatic index, seminiferous tubule area, and spermatozoa proportion in fish subject to starvation compared to the control group. Immunoblotting revealed a reduction of Bcl2 and Beclin 1 associated with increased Bax and Caspase-3, mainly after 21 and 28 days of starvation. LC3 and P62 indicated reduced autophagic flux in these starvation times. Immunolabeling for autophagic and apoptotic proteins occurred in all development stages of the germ cells, but protein expression varied throughout starvation. Beclin 1 and Cathepsin D decreased while Bax and Caspase-3 increased in spermatocytes, spermatids, and spermatozoa after 21 and 28 days. Autophagic and lysosomal proteins colocalization indicated the fusion of autophagosomes with lysosomes and lysosomal degradation in spermatogenic cells. The CASA system indicated reduced sperm motility and velocity in animals subjected to 21 and 28 days of starvation. Altogether, the data support autophagy acting at different spermatogenesis stages in Nile tilapia, with decreased autophagy and increased apoptosis after 21 and 28 days of starvation, which results in a decrease in the spermatozoa number and sperm quality.

Programmed nanocarrier loaded with paclitaxel and dual-siRNA to reverse chemoresistance by synergistic therapy

Paclitaxel (PTX) is commonly used in clinical tumor therapy. However, chemoresistance and the inducement of tumor metastasis severely affect the efficacy of PTX. To develop a treatment strategy to reverse chemoresistance, the co-delivery of PTX and small interfering RNA with nanocarriers were programmed in this study. The carrier we have programmed exhibits excellent safety, stability, and delivery efficiency for co-delivery of siRNA and PTX. After rapid release of siRNA, PTX could be released within 72 h. The siBcl-xL and siMcl-1 inhibited cell migration decreased the mitochondrial membrane potential, and induced the release of reactive oxygen species while synergistically functioning with the antineoplastic effects of PTX. Our strategy reduced IC50 values by 2-5-fold in different cell lines, and the results of flow cytometry confirmed increased apoptosis rates and effectively inhibited cell migration. Synergistic therapy effectively reversed chemoresistance in PTX-resistant breast cancer cells. Similarly, the synergistic administration strategy showed significant sensitizing effects in vivo. Our study demonstrates the combined application of multiple synergistic antitumor administration strategies.

Sublethal engagement of apoptotic pathways in residual cancer

Cytotoxic chemo-, radio-, and targeted therapies frequently elicit apoptotic cancer cell death. Mitochondrial outer membrane permeabilization (MOMP) is a critical, regulated step in this apoptotic pathway. The residual cancer cells that survive treatment serve as the seeds of eventual relapse and are often functionally characterized by their transient tolerance of multiple therapeutic treatments. New studies suggest that, in these cells, a sublethal degree of MOMP, reflective of incomplete apoptotic commitment, is widely observed. Here, we review recent evidence that this sublethal MOMP drives the aggressive features of residual cancer cells while templating a host of unique vulnerabilities, highlighting how failed apoptosis may counterintuitively enable new therapeutic strategies to target residual disease (RD).

Different concentrations of betaxolol switch cell fate between necroptosis, apoptosis, and senescence in human corneal stromal cells

Betaxolol is commonly used to manage glaucoma in clinical practice. However, its long-term use may damage the cornea. Thus, the cytotoxicity and mechanisms of betaxolol in human corneal stromal cells (HCSCs) warrant further study. In this study, we used in vitro HCSCs and in vivo rabbit corneal models to investigate betaxolol cytotoxic effects and mechanism of action. At near-clinical concentrations (0.28% and 0.14%), betaxolol inhibited caspase-8 activity, activated receptor-interacting protein kinase (RIPK)1, RIPK3, and mixed-spectrum kinase-like domain (MLKL), and phosphorylated MLKL to induce necroptosis in HCSCs. Similarly, moderate concentrations of betaxolol (0.07%-0.0175%) activated caspase-8 to trigger the exogenous apoptotic pathway. Through the intrinsic apoptotic pathway, betaxolol upregulated the expression of Bcl-2 family apoptotic proteins Bax and Bad and downregulated that of anti-apoptotic proteins Bcl-2 and Bcl-xL. This subsequently disrupted the mitochondrial membrane potential and cytoplasmic transfer of cytochrome c and apoptosis-inducing factor, activated caspase-9, and induced apoptosis in HCSCs. Furthermore, continuous treatment with low betaxolol concentrations (0.00875%) for three generations of HCSCs prevented apoptosis by promoting the expression of Bcl-xL and suppressing that of Bax. However, its toxic effects initiated cellular senescence by increasing reactive oxygen species, leading to the disruption of energy metabolism and DNA damage. Finally, clinical concentrations of betaxolol had a pro-apoptotic effect on rabbit corneal stromal cells in vivo. These results suggest that betaxolol induces cytotoxicity in a concentration-dependent manner in HCSCs, and that caspase-8 and Bcl-2 family proteins may be critical switches in the conversion of different HCSC death mechanisms.

Evaluation of the cytotoxic activity of sorafenib-loaded camel milk casein nanoparticles against hepatocarcinoma cells

Sorafenib, a multikinase inhibitor is used to treat hepatocellular and renal carcinoma. However, a low solubility impedes its bioavailability and thus, effectiveness. This study aims to enhance its effectiveness by using novel camel milk casein nanoparticles as a delivery system. This study evaluates the cytotoxicity of sorafenib encapsulated in camel milk casein nanoparticles against human hepatocarcinoma cells (HepG2 cells) in vitro. Optimal drug loaded nanoparticles were stable for 1 month, had encapsulation efficiency of 96%, exhibited a particle size of 230 nm, zeta potential of -14.4 and poly disparity index of 0.261. Treatment with it led to cell morphology and DNA fragmentation as a characteristic of apoptosis. Flow cytometry showed G1 phase arrest of cell cycle and 26% increased apoptotic cells population upon treatment as compared to control. Sorafenib-loaded casein nanoparticles showed 6-fold increased ROS production in HepG2 cells as compared to 4-fold increase shown by the free drug. Gene and protein expression studies done by qPCR and western blotting depicted upregulation of tumor suppressor gene p53, pro-apoptotic Bax, and caspase-3 along with downregulated anti-apoptotic Bcl-2 gene and protein expression which further emphasized death by apoptosis. It is concluded regarding the feasibility of these casein nanoparticles as a delivery system with enhanced therapeutic outcomes against hepatocellular carcinoma cells.

Ursolic acid alleviates paclitaxel-induced peripheral neuropathy through PPARγ activation

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) reduces the overall quality of life and leads to interruption of chemotherapy. Ursolic acid, a triterpenoid naturally which presents in fruit peels and in many herbs and spices, can function as a peroxisome proliferator-activated receptor γ (PPARγ) agonist, and has been widely used as an herbal medicine with a wide spectrum of pharmacological activities, including anti-cancer, anti-inflammatory and neuroprotective effect.

METHODS

We used a phenotypic drug screening approach to identify ursolic acid as a potential neuroprotective drug in vitro and in vivo and carried out additional biochemical experiments to identify its mechanism of action.

RESULTS

Our study demonstrated that ursolic acid reduced neurotoxicity and cell apoptosis induced by pacilitaxel, resulting in an improvement of CIPN. Moreover, we explored the potential mechanisms of ursolic acid on CIPN. As a result, ursolic acid inhibited CHOP (C/EBP Homologous Protein) expression, indicating the endoplasmic reticulum (ER) stress suppression, and regulating CHOP related apoptosis regulator (the Bcl2 family) to reverse pacilitaxel induced apoptosis. Moreover, we showed that the therapeutic effect of ursolic acid on the pacilitaxel-induced peripheral neuropathy is PPARγ dependent.

CONCLUSIONS

Taken together, the present study suggests ursolic acid has potential as a new PPARγ agonist targeting ER stress-related apoptotic pathways to ameliorate pacilitaxel-induced peripheral neuropathic pain and nerve injury, providing new clinical therapeutic method for CIPN.

14-3-3-η interacts with BCL-2 to protect human endothelial progenitor cells from ox-LDL-triggered damage

Oxidized low-density lipoprotein (ox-LDL) causes dysfunction of endothelial progenitor cells (EPCs), and we recently reported that 14-3-3-η can attenuate the damage triggered by ox-LDL in EPCs. However, the molecular mechanisms by which 14-3-3-η protects EPCs from the damage caused by ox-LDL are not fully understood. In this study, we observed that the expression of 14-3-3-η and BCL-2 were downregulated in ox-LDL-treated EPCs. Overexpression of 14-3-3-η in ox-LDL-treated EPC significantly increased BCL-2 level, while knockdown of BCL-2 reduced 14-3-3-η expression and mitigated the protective effect of 14-3-3-η on EPCs. In addition, we discovered that 14-3-3-η colocalizes and interacts with BCL-2 in EPCs. Taken together, these data suggest that 14-3-3-η protects EPCs from ox-LDL-induced damage by its interaction with BCL-2.

Rational Formulation of targeted ABT-737 nanoparticles by self-assembled polypeptides and designed peptides

Here we present the development of nanoparticles (NPs) formulations specifically designed for targeting the antiapoptotic Bcl-2 proteins on the outer membrane of mitochondria with the drug agent ABT-737. The NPs which are self-assembled by the natural polypeptide poly gamma glutamic acid (ϒPGA) and a designed cationic and amphiphilic peptide (PFK) have been shown to target drugs toward mitochondria. In this study we systematically developed the formulation of such NPs loaded with the ABT-737 and demonstrated the cytotoxic effect of the best identified formulation on MDA-MB-231 cells. Our findings emphasize the critical role of solutions pH and the charged state of the components throughout the formulation process as well as the concentrations of the co-components and their mixing sequence, in achieving the most stable and effective cytotoxic formulation. Our study highlights the potential versatility of designed peptides in combination with biopolymers for improving drug delivery formulations and enhance their targeting abilities.

Cold atmospheric plasma stabilizes mismatch repair for effective, uniform treatment of diverse colorectal cancer cell types

Mismatch Repair (MMR) mechanisms play a pivotal role in rectifying DNA replication errors and maintaining the stability of DNA microsatellite structure. Colorectal cancer (CRC) can be characterized into microsatellite stability (MSS) and microsatellite instability (MSI) subtypes based on the functionality of MMR. MSI CRC notably exhibits enhanced chemotherapy resistance, attributable to diminished MMR-related protein expression. Cold atmospheric plasma (CAP) has emerged as a promising treatment modality, demonstrating efficacy in inducing apoptosis in various cancer cells. However, the therapeutic impact of CAP on MSI colorectal cancer, and the underlying mechanisms remain elusive. In this study, we investigated the effects of CAP on MSI (MC38, HCT116, and LOVO) and MSS (CT26 and HT29) CRC cell lines. We are probing into the products of CAP treatment. Our findings indicate that CAP treatment induces comparable effects on apoptosis, reactive oxygen species (ROS), and reactive nitrogen species (RNS), as well as the expression of apoptosis-related proteins in both MSI and MSS cells. Mechanistically, CAP treatment led to an elevation in the expression of mismatch repair proteins (MLH1 and MSH2), particularly in MSI cells, which notably have been proven to facilitate the activation of apoptosis-related proteins. Collectively, our study reveals that CAP enhances apoptotic signaling and induces apoptosis in MSI colorectal cancer cells by upregulating the expression of MMR-related proteins, thereby reinforcing MMR stabilization.

Dietary intervention reverses molecular markers of hepatocellular senescence in the GAN diet-induced obese and biopsy-confirmed mouse model of NASH

BACKGROUND

Hepatocellular senescence may be a causal factor in the development and progression of non-alcoholic steatohepatitis (NASH). The most effective currently available treatment for NASH is lifestyle intervention, including dietary modification. This study aimed to evaluate the effects of dietary intervention on hallmarks of NASH and molecular signatures of hepatocellular senescence in the Gubra-Amylin NASH (GAN) diet-induced obese (DIO) and biopsy-confirmed mouse model of NASH.

METHODS

GAN DIO-NASH mice with liver biopsy-confirmed NASH and fibrosis received dietary intervention by switching to chow feeding (chow reversal) for 8, 16 or 24 weeks. Untreated GAN DIO-NASH mice and chow-fed C57BL/6J mice served as controls. Pre-to-post liver biopsy histology was performed for within-subject evaluation of NAFLD Activity Score and fibrosis stage. Terminal endpoints included blood/liver biochemistry, quantitative liver histology, mitochondrial respiration and RNA sequencing.

RESULTS

Chow-reversal promoted substantial benefits on metabolic outcomes and liver histology, as demonstrated by robust weight loss, complete resolution of hepatomegaly, hypercholesterolemia, elevated transaminase levels and hepatic steatosis in addition to attenuation of inflammatory markers. Notably, all DIO-NASH mice demonstrated ≥ 2 point significant improvement in NAFLD Activity Score following dietary intervention. While not improving fibrosis stage, chow-reversal reduced quantitative fibrosis markers (PSR, collagen 1a1, α-SMA), concurrent with improved liver mitochondrial respiration, complete reversal of p21 overexpression, lowered γ-H2AX levels and widespread suppression of gene expression markers of hepatocellular senescence.

CONCLUSIONS

Dietary intervention (chow reversal) substantially improves metabolic, biochemical and histological hallmarks of NASH and fibrosis in GAN DIO-NASH mice. These benefits were reflected by progressive clearance of senescent hepatocellular cells, making the model suitable for profiling potential senotherapeutics in preclinical drug discovery for NASH.

In situ architecture of Opa1-dependent mitochondrial cristae remodeling

Cristae membrane state plays a central role in regulating mitochondrial function and cellular metabolism. The protein Optic atrophy 1 (Opa1) is an important crista remodeler that exists as two forms in the mitochondrion, a membrane-anchored long form (l-Opa1) and a processed short form (s-Opa1). The mechanisms for how Opa1 influences cristae shape have remained unclear due to lack of native three-dimensional views of cristae. We perform in situ cryo-electron tomography of cryo-focused ion beam milled mouse embryonic fibroblasts with defined Opa1 states to understand how each form of Opa1 influences cristae architecture. In our tomograms, we observe a variety of cristae shapes with distinct trends dependent on s-Opa1:l-Opa1 balance. Increased l-Opa1 levels promote cristae stacking and elongated mitochondria, while increased s-Opa1 levels correlated with irregular cristae packing and round mitochondria shape. Functional assays indicate a role for l-Opa1 in wild-type apoptotic and calcium handling responses, and show a compromised respiratory function under Opa1 imbalance. In summary, we provide three-dimensional visualization of cristae architecture to reveal relationships between mitochondrial ultrastructure and cellular function dependent on Opa1-mediated membrane remodeling.

Magnetic nanoparticles for ferroptosis cancer therapy with diagnostic imaging

Ferroptosis offers a novel method for overcoming therapeutic resistance of cancers to conventional cancer treatment regimens. Its effective use as a cancer therapy requires a precisely targeted approach, which can be facilitated by using nanoparticles and nanomedicine, and their use to enhance ferroptosis is indeed a growing area of research. While a few review papers have been published on iron-dependent mechanism and inducers of ferroptosis cancer therapy that partly covers ferroptosis nanoparticles, there is a need for a comprehensive review focusing on the design of magnetic nanoparticles that can typically supply iron ions to promote ferroptosis and simultaneously enable targeted ferroptosis cancer nanomedicine. Furthermore, magnetic nanoparticles can locally induce ferroptosis and combinational ferroptosis with diagnostic magnetic resonance imaging (MRI). The use of remotely controllable magnetic nanocarriers can offer highly effective localized image-guided ferroptosis cancer nanomedicine. Here, recent developments in magnetically manipulable nanocarriers for ferroptosis cancer nanomedicine with medical imaging are summarized. This review also highlights the advantages of current state-of-the-art image-guided ferroptosis cancer nanomedicine. Finally, image guided combinational ferroptosis cancer therapy with conventional apoptosis-based therapy that enables synergistic tumor therapy is discussed for clinical translations.

To be or not to be: The active inference of suicide

Suicide presents an apparent paradox as a behavior whose motivation is not obvious since its outcome is non-existence and cannot be experienced. To address this paradox, we propose to frame suicide in the integrated theory of stress and active inference. We present an active inference-based cognitive model of suicide as a type of stress response hanging in cognitive balance between predicting self-preservation and self-destruction. In it, self-efficacy emerges as a meta-cognitive regulator that can bias the model toward either survival or suicide. The model suggests conditions under which cognitive homeostasis can override physiological homeostasis in motivating self-destruction. We also present a model proto-suicidal behavior, programmed cell death (apoptosis), in active inference terms to illustrate how an active inference model of self-destruction can be embodied in molecular mechanisms and to offer a hypothesis on another puzzle of suicide: why only humans among brain-endowed animals are known to practice it.

A New Benzo[6,7]oxepino[3,2-b] Pyridine Derivative Induces Apoptosis in Canine Mammary Cancer Cell Lines

CMC is the most frequently diagnosed cancer and one of the leading causes of death in non-spayed female dogs. Exploring novel therapeutic agents is necessary to increase the survival rate of dogs with CMC. MPOBA is a BZOP derivative that has a significant anticancer effect in a human cell line. The main goal of this study was to investigate the anticancer properties of MPOBA against two CMC cell lines (REM134 and CMGT071020) using a 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, a wound healing assay, a transwell migration assay, an Annexin V-FITC apoptosis assay with a flow cytometry analysis, a mRNA expression analysis using quantitative real-time PCR (qRT-PCR), and an immunohistochemistry (IHC). According to the accumulated studies, MPOBA caused significant concentration- and time-dependent reductions in cell proliferation and cell migration and induced apoptosis in both CMC cell lines. In gene expression analysis, nine canine genes, including TP53, BCL-2, BAX, epidermal growth factor receptor (EGFR), snail transcription factor (SNAIL), snail-related zinc-finger transcription factor (SLUG), TWIST, E-cadherin, and N-cadherin, were investigated. The mRNA expression results revealed that MPOBA induced upregulation of TP53 and overexpression of the pro-apoptotic gene BAX, together with an inhibition of BCL-2. Moreover, MPOBA also suppressed the mRNA expression levels of SNAIL, EGFR, and N-cadherin and induced upregulation of E-cadherin, crucial genes related to the epithelial-to-mesenchymal transition (EMT). However, there was no significant difference in the IHC results of the expression patterns of vimentin (VT) and cytokeratin (CK) between MPOBA-treated and control CMC cells. In conclusion, the results of the present study suggested that MPOBA exhibited significant anticancer activity by inducing apoptosis in both CMCs via upregulation of TP53 and BAX and downregulation of BCL-2 relative mRNA expression. MPOBA may prove to be a potential candidate drug to be further investigated as a therapeutic agent for CMC.

Mitochondrial-mediated apoptosis as a therapeutic target for FNC (2'-deoxy-2'-b-fluoro-4'-azidocytidine)-induced inhibition of Dalton's lymphoma growth and proliferation

PURPOSE

T-cell lymphomas, refer to a diverse set of lymphomas that originate from T-cells, a type of white blood cell, with limited treatment options. This investigation aimed to assess the efficacy and mechanism of a novel fluorinated nucleoside analogue (FNA), 2'-deoxy-2'-β-fluoro-4'-azidocytidine (FNC), against T-cell lymphoma using Dalton's lymphoma (DL)-bearing mice as a model.

METHODS

Balb/c mice transplanted with the DL tumor model received FNC treatment to study therapeutic efficacy against T-cell lymphoma. Behavioral monitoring, physiological measurements, and various analyses were conducted to evaluate treatment effects for mechanistic investigations.

RESULTS

The results of study indicated that FNC prevented DL-altered behavior parameters, weight gain and alteration in organ structure, hematological parameters, and liver enzyme levels. Moreover, FNC treatment restored organ structures, attenuated angiogenesis, reduced DL cell viability and proliferation through apoptosis. The mechanism investigation revealed FNC diminished MMP levels, induced apoptosis through ROS induction, and activated mitochondrial-mediated pathways leading to increase in mean survival time of DL mice. These findings suggest that FNC has potential therapeutic effects in mitigating DL-induced adverse effects.

CONCLUSION

FNC represents an efficient and targeted treatment strategy against T-cell lymphoma. FNC's proficient ability to induce apoptosis through ROS generation and MMP reduction makes it a promising candidate for developing newer and more effective anticancer therapies. Continued research could unveil FNC's potential role in designing a better therapeutic approach against NHL.

Venetoclax Combined with Intensive Chemotherapy: A New Hope for Refractory and/or Relapsed Acute Myeloid Leukemia?

Background. Primary resistance of acute myeloid leukemia (AML) to the conventional 3 + 7 intensive chemotherapy and relapses after first-line chemotherapy are two highly challenging clinical scenarios. In these cases, when allogeneic stem cell transplantation is feasible, patients are usually retreated with other chemotherapeutic regimens, as transplantation is still considered, nowadays, the only curative option. Methods. We discuss the mechanisms behind resistance to chemotherapy and offer a comprehensive review on current treatments of refractory/relapsed AML with a focus on novel approaches incorporating the BCL-2 inhibitor venetoclax. Results. Alas, complete remission rates after salvage chemotherapy remain relatively low, between 30 and 60% at best. More recently, the BCL-2 inhibitor venetoclax was combined either with hypomethylating agents or chemotherapy in refractory/relapsed patients. In particular, its combination with chemotherapy offered promising results by achieving higher rates of remission and bridging a substantial number of patients to transplantation. Conclusions. Venetoclax-based approaches might become, in the near future, the new standard of care for refractory/relapsed AML.

Programmed cell death in tumor immunity: mechanistic insights and clinical implications

Programmed cell death (PCD) is an evolutionarily conserved mechanism of cell suicide that is controlled by various signaling pathways. PCD plays an important role in a multitude of biological processes, such as cell turnover, development, tissue homeostasis and immunity. Some forms of PCD, including apoptosis, autophagy-dependent cell death, pyroptosis, ferroptosis and necroptosis, contribute to carcinogenesis and cancer development, and thus have attracted increasing attention in the field of oncology. Recently, increasing research-based evidence has demonstrated that PCD acts as a critical modulator of tumor immunity. PCD can affect the function of innate and adaptive immune cells, which leads to distinct immunological consequences, such as the priming of tumor-specific T cells, immunosuppression and immune evasion. Targeting PCD alone or in combination with conventional immunotherapy may provide new options to enhance the clinical efficacy of anticancer therapeutics. In this review, we introduce the characteristics and mechanisms of ubiquitous PCD pathways (e.g., apoptosis, autophagy-dependent cell death, pyroptosis and ferroptosis) and explore the complex interaction between these cell death mechanisms and tumor immunity based on currently available evidence. We also discuss the therapeutic potential of PCD-based approaches by outlining clinical trials targeting PCD in cancer treatment. Elucidating the immune-related effects of PCD on cancer pathogenesis will likely contribute to an improved understanding of oncoimmunology and allow PCD to be exploited for cancer treatment.

Augmented mitochondrial apoptotic signaling impairs C2C12 myoblast differentiation following cellular aging through sequential passaging

Aging is associated with the steady decline of several cellular processes. The loss of skeletal muscle mass, termed sarcopenia, is one of the major hallmarks of aging. Aged skeletal muscle exhibits a robust reduction in its regenerative capacity due to dysfunction (i.e., senescence, lack of self-renewal, and impaired differentiation) of resident muscle stem cells, called satellite cells. To replicate aging in vitro, immortalized skeletal muscle cells (myoblasts) can be treated with various agents to mimic age-related dysfunction; however, these come with their own set of limitations. In the present study, we used sequential passaging of mouse myoblasts to mimic impaired differentiation that is observed in aged skeletal muscle. Further, we investigated mitochondrial apoptotic mechanisms to better understand the impaired differentiation in these "aged" cells. Our data shows that sequential passaging (>20 passages) of myoblasts is accompanied with significant reductions in differentiation and elevated cell death. Furthermore, high-passage (HP) myoblasts exhibit greater mitochondrial-mediated apoptotic signaling through mitochondrial BAX translocation, CYCS and AIFM1 release, and caspase-9 activation. Finally, we show that inhibition of mitochondrial outer membrane permeability partly recovered differentiation in HP myoblasts. Together, our findings suggests that mitochondrial apoptotic signaling is a contributing factor to the diminished differentiation that is observed in aged myoblasts.

Yiqi Jiedu decoction attenuates radiation injury of spermatogenic cells via suppressing IκBα/NF-κB pathway-induced excessive autophagy and apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

The prescription of Yiqi Jiedu decoction (YQJD) originated from the classic Chinese herbal prescriptions of Danggui Buxue Decoction and Wuzi Yanzong Pill. A previous study has shown that 4 Gy irradiation induced the apoptosis of spermatocytes and revealed autophagosomes in cells exposed to radiation. YQJD decoction has the effect of preventing radiation injury.

AIM OF THE STUDY

We used spermatocytes (GC-2spd cell line) to investigate the relationship between autophagy and apoptosis of spermatogenic cells after radiation, and the mechanisms of YQJD decoction.

MATERIALS AND METHODS

Establish an in vitro radiation injury model by irradiating GC-2spd cells with 60Co γ-rays (4 Gy or 8 Gy). Autophagy agonists, autophagy inhibitors and YQJD were used to intervene cells. Cell apoptosis and inflammatory factors were measured. NF-κB localization was observed by immunofluorescence. Autophagy and apoptosis-related proteins and IκBα/NF-κB pathway factors were detected.

RESULTS

Ionizing radiation promoted the growth of spermatogenic autophagosomes. After radiation, NF-κB was translocated to the nucleus, inflammatory factors were secreted, and IκBα/NF-κB pathway was activated, which promoted autophagy and apoptosis. YQJD decoction can inhibit the phosphorylation of IκBα/NF-κB pathway related factors, regulate the expression of Beclin-1 and Bcl-2 proteins, and inhibit the occurrence of autophagy and apoptosis of irradiated spermatocyte.

CONCLUSIONS

The research results indicate that ionizing radiation can activate the IκBα/NF-κB signaling pathway in spermatocytes, promote cell autophagy and apoptosis by regulating the expression of Beclin-1 and Bcl-2 factors. The YQJD decoction inhibits the IκBα/NF-κB signaling pathway so as to regulate Beclin-1 and Bcl-2.

Aureusidin ameliorates 6-OHDA-induced neurotoxicity via activating Nrf2/HO-1 signaling pathway and preventing mitochondria-dependent apoptosis pathway in SH-SY5Y cells and Caenorhabditis elegans

Movement disorder Parkinson's disease (PD) is the second most common neurodegenerative disease in the world after Alzheimer's disease, which severely affects the quality of patients' lives and imposes an increasingly heavy socioeconomic burden. Aureusidin is a kind of natural flavonoid compound with anti-inflammatory and anti-oxidant activities, while its pharmacological action and mechanism are rarely reported in PD. This study aimed to explore the neuroprotective effects and potential mechanisms of Aureusidin in PD. The present study demonstrated that Aureusidin protected SH-SY5Y cells from cell damage induced by 6-hydroxydopamine (6-OHDA) via inhibiting the mitochondria-dependent apoptosis and activating the Nrf2/HO-1 antioxidant signaling pathway. Additionally, Aureusidin diminished dopaminergic (DA) neuron degeneration induced by 6-OHDA and reduced the aggregation toxicity of α-synuclein (α-Syn) in Caenorhabditis elegans (C. elegans.) In conclusion, Aureusidin showed a neuroprotective effect in the 6-OHDA-induced PD model via activating Nrf2/HO-1 signaling pathway and prevented mitochondria-dependent apoptosis pathway, and these findings suggested that Aureusidin may be an effective drug for the treatment of PD.

Non-canonical BIM-regulated energy metabolism determines drug-induced liver necrosis

Paracetamol (acetaminophen, APAP) overdose severely damages mitochondria and triggers several apoptotic processes in hepatocytes, but the final outcome is fulminant necrotic cell death, resulting in acute liver failure and mortality. Here, we studied this switch of cell death modes and demonstrate a non-canonical role of the apoptosis-regulating BCL-2 homolog BIM/Bcl2l11 in promoting necrosis by regulating cellular bioenergetics. BIM deficiency enhanced total ATP production and shifted the bioenergetic profile towards glycolysis, resulting in persistent protection from APAP-induced liver injury. Modulation of glucose levels and deletion of Mitofusins confirmed that severe APAP toxicity occurs only in cells dependent on oxidative phosphorylation. Glycolytic hepatocytes maintained elevated ATP levels and reduced ROS, which enabled lysosomal recycling of damaged mitochondria by mitophagy. The present study highlights how metabolism and bioenergetics affect drug-induced liver toxicity, and identifies BIM as important regulator of glycolysis, mitochondrial respiration, and oxidative stress signaling.

Long-term culture induces Bax-dependent apoptosis in rat preimplantation embryos

Although rat preimplantation embryos are necessary for producing genetically modified rats, their in vitro culture remains a challenge. Rat zygotes can develop from the one-cell stage to the blastocyst stage in vitro; however, long-term culture reduces their developmental competence via an unknown mechanism. In this study, we examined how in vitro conditions affect rat preimplantation embryos, which may explain this reduced competence. Comprehensive gene expression analysis showed that genes related to apoptosis and energy metabolism were differentially expressed in rat embryos cultured long-term in vitro compared with those developed in vivo. Furthermore, we found that the expression of Bak1 and Bax, which are responsible for mitochondrial outer membrane permeabilization, were more upregulated in embryos cultured in vitro than those developed in vivo. Similarly, apoptosis-dependent DNA fragmentation was also exacerbated in in vitro culture conditions. Finally, gene disruption using CRISPR/Cas9 showed that Bax, but not Bak1, was responsible for these effects. These findings suggest that long-term in vitro culture induces Bax-dependent apoptosis through the mitochondrial pathway and may provide clues to improve the long-term culture of rat preimplantation embryos for genetic engineering research.

Paraquat and Parkinson's Disease: The Molecular Crosstalk of Upstream Signal Transduction Pathways Leading to Apoptosis

Parkinson's disease (PD) is a heterogeneous disease involving a complex interaction between genes and the environment that affects various cellular pathways and neural networks. Several studies have suggested that environmental factors such as exposure to herbicides, pesticides, heavy metals, and other organic pollutants are significant risk factors for the development of PD. Among the herbicides, paraquat has been commonly used, although it has been banned in many countries due to its acute toxicity. Although the direct causational relationship between paraquat exposure and PD has not been established, paraquat has been demonstrated to cause the degeneration of dopaminergic neurons in the substantia nigra pars compacta. The underlying mechanisms of the dopaminergic lesion are primarily driven by the generation of reactive oxygen species, decrease in antioxidant enzyme levels, neuroinflammation, mitochondrial dysfunction, and ER stress, leading to a cascade of molecular crosstalks that result in the initiation of apoptosis. This review critically analyses the crucial upstream molecular pathways of the apoptotic cascade involved in paraquat neurotoxicity, including mitogenactivated protein kinase (MAPK), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/AKT, mammalian target of rapamycin (mTOR), and Wnt/β-catenin signaling pathways.

Fibre-rich diet attenuates chemotherapy-related neuroinflammation in mice

The gastrointestinal microbiota has received increasing recognition as a key mediator of neurological conditions with neuroinflammatory features, through its production of the bioactive metabolites, short-chain fatty acids (SCFAs). Although neuroinflammation is a hallmark shared by the neuropsychological complications of chemotherapy (including cognitive impairment, fatigue and depression), the use of microbial-based therapeutics has not previously been studied in this setting. Therefore, we aimed to investigate the effect of a high fibre diet known to modulate the microbiota, and its associated metabolome, on neuroinflammation caused by the common chemotherapeutic agent 5-fluorouracil (5-FU). Twenty-four female C57Bl/6 mice were treated with 5-FU (400 mg/kg, intraperitoneal, i.p.) or vehicle control, with or without a high fibre diet (constituting amylose starch; 4.7 % crude fibre content), given one week prior to 5-FU and until study completion (16 days after 5-FU). Faecal pellets were collected longitudinally for 16S rRNA gene sequencing and terminal SCFA concentrations of the caecal contents were quantified using gas chromatography-mass spectrometry (GC-MS). Neuroinflammation was determined by immunofluorescent analysis of astrocyte density (GFAP). The high fibre diet significantly altered gut microbiota composition, increasing the abundance of Bacteroidaceae and Akkermansiaceae (p < 0.0001 and p = 0.0179) whilst increasing the production of propionate (p = 0.0097). In the context of 5-FU, the diet reduced GFAP expression in the CA1 region of the hippocampus (p < 0.0001) as well as the midbrain (p = 0.0216). Astrocyte density negatively correlated with propionate concentrations and the abundance of Bacteroidaceae and Akkermansiaceae, suggesting a relationship between neuroinflammatory and gastrointestinal markers in this model. This study provides the first evidence of the neuroprotective effects of fibre via dietary intake in alleviating the neuroimmune changes seen in response to systemically administered 5-FU, indicating that the microbiota-gut-brain axis is a targetable mediator to reduce the neurotoxic effects of chemotherapy treatment.

Navigated Transcranial Magnetic Stimulation (nTMS) based Preoperative Planning for Brain Tumor Treatment

Transcranial Magnetic Stimulation (TMS) is a non-invasive technique for analyzing the central and peripheral nervous system. TMS could be a powerful therapeutic technique for neurological disorders. TMS has also shown potential in treating various neurophysiological complications, such as depression, anxiety, and obsessive-compulsive disorders, without pain and analgesics. Despite advancements in diagnosis and treatment, there has been an increase in the prevalence of brain cancer globally. For surgical planning, mapping brain tumors has proven challenging, particularly those localized in expressive regions. Preoperative brain tumor mapping may lower the possibility of postoperative morbidity in surrounding areas. A navigated TMS (nTMS) uses magnetic resonance imaging (MRI) to enable precise mapping during navigated brain stimulation. The resulting magnetic impulses can be precisely applied to the target spot in the cortical region by employing nTMS. This review focuses on nTMS for preoperative planning for brain cancer. This study reviews several studies on TMS and its subtypes in treating cancer and surgical planning. nTMS gives wider and improved dimensions of preoperative planning of the motor-eloquent areas in brain tumor patients. nTMS also predicts postoperative neurological deficits, which might be helpful in counseling patients. nTMS have the potential for finding possible abnormalities in the motor cortex areas.

Mitigative potential of kaempferide against polyethylene microplastics induced testicular damage by activating Nrf-2/Keap-1 pathway

Polyethylene microplastics (PE-MPs) are one of the environmental contaminants that instigate oxidative stress (OS) in various organs of the body, including testes. Kaempferide (KFD) is a plant-derived natural flavonol with potential neuroprotective, hepatoprotective, anti-cancer, anti-oxidant and anti-inflammatory properties. Therefore, the present study was designed to evaluate the alleviative effects of KFD against PE-MPs-prompted testicular toxicity in rats. Fourty eight adult male albino rats were randomly distributed into 4 groups: control, PE-MPs-administered (1.5 mgkg-1), PE-MPs (1.5 mgkg-1) + KFD (20 mgkg-1) co-treated and KFD (20 mgkg-1) only treated group. PE-MPs intoxication significantly (P < 0.05) lowered the expression of Nrf-2 and anti-oxidant enzymes, while increasing the expression of Keap-1. The activities of anti-oxidants i.e., catalase (CAT), glutathione reductase (GSR), superoxide dismutase (SOD), hemeoxygene-1 (HO-1) and glutathione peroxidase (GPx) were reduced, besides malondialdehyde (MDA) and reactive oxygen species (ROS) contents were increased significantly (P < 0.05) following the PE-MPs exposure. Moreover, PE-MPs exposure significantly (P < 0.05) reduced the sperm motility, viability and count, whereas considerably (P < 0.05) increased the dead sperm number and sperm structural anomalies. Furthermore, PE-MPs remarkably (P < 0.05) decreased steroidogenic enzymes and Bcl-2 expression, while increasing the expression of Caspase-3 and Bax. PE-MPs exposure significantly (P < 0.05) reduced the levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone, whereas inflammatory indices were increased. PE-MPs exposure also induced significant histopathological damages in the testes. Nevertheless, KFD supplementation significantly (P < 0.05) abrogated all the damages induced by PE-MPs. The findings of our study demonstrated that KFD could significantly attenuate PE-MPs-instigated OS and testicular toxicity, due to its anti-oxidant, anti-inflammatory, androgenic and anti-apoptotic potential.

Role of intrinsic apoptosis in environmental exposure health outcomes

Environmental exposures are linked to diseases of high public health concern, including cancer, neurodegenerative disorders, and autoimmunity. These diseases are caused by excessive or insufficient cell death, prompting investigation of mechanistic links between environmental toxicants and dysregulation of cell death pathways, including apoptosis. This review describes how legacy and emerging environmental exposures target the intrinsic apoptosis pathway to potentially drive pathogenesis. Recent discoveries reveal that dynamic regulation of apoptosis may heighten the vulnerability of healthy tissues to exposures in children, and that apoptotic signaling can guide immune responses, tissue repair, and tumorigenesis. Understanding how environmental toxicants dysregulate apoptosis will uncover opportunities to deploy apoptosis-modulating agents for the treatment or prevention of exposure-linked diseases.

Preventive effects of quercetin against inflammation and apoptosis in cyclophosphamide-induced testicular damage

Objectives

We aimed to investigate the effects of quercetin (QRC) against cyclophosphamide (CP)-induced testicular damage and how it interacts with apoptotic and inflammatory signaling pathways.

Materials and Methods

Forty male Wistar rats were randomly divided into four groups, 10 in each group; Control group (corn oil, intragastrically, 14 days), QRC group (100 mg/kg QRC, dissolved in corn oil, 14 days), CP group (200 mg/kg CP, intraperitoneally, single dose on the 7th day), and CP+QRC group (100 mg/kg QRC, intragastrically, 14 days and 200 mg/kg CP, intraperitoneally, single dose on the 7th day). Animals were sacrificed one day after the last QRC application and the effects of quercetin were evaluated by histological, morphometrical, and hormonal parameters. Also, nuclear factor kappa B (NFkB), nuclear factor erythroid 2 related factor 2 (Nrf2), Bcl-2 associated X protein (Bax), and B-cell lymphoma-2 (Bcl-2) immunoreactivities were evaluated immunohistochemically.

Results

CP increased the testicular weight/body weight ratio, significantly decreasing body weights and testicular weights. All hormone levels were also reduced significantly. Morphometrically, seminiferous tubules diameter and germinal epithelial thickness decreased, while a significant increase was determined in interstitial field width in addition to histological damage. Furthermore, immunohistochemical findings also indicated that NFkB and Bax immunoreactivity were increased in the CP group, whereas significant decrease was seen in Nrf2 and Bcl-2 immunoreactivity. Apoptotic cell and tubule index were reduced in CP. QRC ensured improvement in all findings.

Conclusion

Data showed us, that QRC may have preventive effects in CP-induced testicular damage by acting on NFkB, Nrf2, Bax, and Bcl-2 pathways.

Ginsenoside RK1 improves cognitive impairments and pathological changes in Alzheimer's disease via stimulation of the AMPK/Nrf2 signaling pathway

BACKGROUND

The pathogenesis of Alzheimer's disease (AD) is complex, resulting in unsatisfactory effects of single-target therapeutic drugs. Accumulation evidence suggests that low toxicity multi-target drugs may play effective roles in AD. Ginseng is the root and rhizome of Panax ginseng Meyer, which can be used not only as herbal medicine but also as a functional food to support body functions. Ginsenoside RK1 (RK1), obtained from ginseng plants through high-temperature treatment, has antiapoptotic, antioxidant, anti-inflammatory effects and these events are involved in the development of AD. So, we believe that RK1 may be an effective drug for the treatment of AD.

HYPOTHESIS/PURPOSE

We aimed to investigate the potential protective effects and mechanisms of RK1 in AD.

METHODS

Neuronal damage was detected by MTT assay, LDH assay, immunofluorescence and western blotting. Oxidative stress was measured by JC-1 staining, reactive oxygen species (ROS) staining, superoxide dismutase (SOD) and malonaldehyde (MDA). The cognitive deficit was measured through morris water maze (MWM) and novel object recognition (NOR) tests.

RESULTS

RK1 attenuated Aβ-induced apoptosis, restored mitochondrial membrane potential (ΔΨm), and reduced intracellular levels of ROS in both PC12 cells and primary cultured neurons. In vivo, RK1 significantly improved cognitive deficits and mitigated AD-like pathological features. Notably, RK1 demonstrated superior efficacy compared to the positive control drug, donepezil. Mechanistically, our study elucidates that RK1 modulates the phosphorylation of AMP-activated protein kinase (AMPK) and its downstream target, NF-E2-related factor 2 (Nrf2), leading to the optimization of mitochondrial membrane potential, reduction of ROS levels, and mitigation of AD-like pathology. It's noteworthy that blocking the AMPK signaling pathway attenuated the protective effects of RK1.

CONCLUSION

RK1 demonstrates superior efficacy in alleviating cognitive deficits and mitigating pathological changes compared to donepezil. These findings suggest the potential utility of RK1-based therapies in the development of treatments for AD.

Chitosan biopolymer functionalized with graphene oxide and titanium dioxide with Escin metallic nanocomposites for anticancer potential against colon cancer

Our study produced GO-TiO2-chitosan-escin nanocomposites (GTCEnc), characterized them using physical and biological methods, and evaluated their potential as cancer treatment candidates. Standard protocols were used to produce GTCEnc. Nanocomposites are created using XRD, FTIR, UV-Vis, and PL spectroscopy analysis. The morphology and ultrastructure of nanocomposites were investigated using SEM and TEM. Nanocomposites containing TiO2, GO, chitosan, and escin nanostructures were characterized using diffraction, microscopy, and spectroscopy; the antimicrobial activity of GTCEnc was investigated. Various methods were used to test the anticancer activity of GTCEnc against COLO 205 cell lines, including MTT, EtBr/AO, DAPI, JC-1, Annexin-V/FITC, cell cycle analysis, and activation of pro-apoptotic markers, such as caspase-3, -8, and -9. The nanocomposites were cytotoxic to COLO 205 cells, with an IC50 of 22.68 μg/mL, but not to 293T cells. In cells treated with nanomaterials, cytotoxicity, nuclear damage, apoptosis induction, and free radical production were significantly increased. Our finding suggests that GTCEnc has potent anticancer and antibacterial activity in vitro because of its unique nanocomposite properties and antibacterial and anticancer activity in vitro. Additional research is required to understand the clinical efficacy of these nanocomposites.

Apoptosis and its pathways as targets for intracellular pathogens to persist in cells

Apoptosis is a finely programmed process of cell death in which cells silently dismantle and actively participate in several operations such as immune response, differentiation, and cell growth. It can be initiated by three main pathways: the extrinsic, the perforin granzyme, and the intrinsic that culminate in the activation of several proteins in charge of tearing down the cell. On the other hand, apoptosis represents an ordeal for pathogens that live inside cells and maintain a strong dependency with them; thus, they have evolved multiple strategies to manipulate host cell apoptosis on their behalf. It has been widely documented that diverse intracellular bacteria, fungi, and parasites can interfere with most steps of the host cell apoptotic machinery to inhibit or induce apoptosis. Indeed, the inhibition of apoptosis is considered a virulence property shared by many intracellular pathogens to ensure productive replication. Some pathogens intervene at an early stage by interfering with the sensing of extracellular signals or transduction pathways. Others sense cellular stress or target the apoptosis regulator proteins of the Bcl-2 family or caspases. In many cases, the exact molecular mechanisms leading to the interference with the host cell apoptotic cascade are still unknown. However, intense research has been conducted to elucidate the strategies employed by intracellular pathogens to modulate host cell death. In this review, we summarize the main routes of activation of apoptosis and present several processes used by different bacteria, fungi, and parasites to modulate the apoptosis of their host cells.

Chemical modulation of cytosolic BAX homodimer potentiates BAX activation and apoptosis

The BCL-2 family protein BAX is a major regulator of physiological and pathological cell death. BAX predominantly resides in the cytosol in a quiescent state and upon stress, it undergoes conformational activation and mitochondrial translocation leading to mitochondrial outer membrane permeabilization, a critical event in apoptosis execution. Previous studies reported two inactive conformations of cytosolic BAX, a monomer and a dimer, however, it remains unclear how they regulate BAX. Here we show that, surprisingly, cancer cell lines express cytosolic inactive BAX dimers and/or monomers. Expression of inactive dimers, results in reduced BAX activation, translocation and apoptosis upon pro-apoptotic drug treatments. Using the inactive BAX dimer structure and a pharmacophore-based drug screen, we identify a small-molecule modulator, BDM19 that binds and activates cytosolic BAX dimers and prompts cells to apoptosis either alone or in combination with BCL-2/BCL-XL inhibitor Navitoclax. Our findings underscore the role of the cytosolic inactive BAX dimer in resistance to apoptosis and demonstrate a strategy to potentiate BAX-mediated apoptosis.

A high-throughput screening approach to discover potential colorectal cancer chemotherapeutics: Repurposing drugs to disrupt 14-3-3 protein-BAD interactions

Inducing apoptosis in different types of cancer cells is an effective therapeutic strategy. However, the success of existing chemotherapeutics can be compromised by tumor cell resistance and systemic off-target effects. Therefore, the discovery of pro-apoptotic compounds with minimal systemic side-effects is crucial. 14-3-3 proteins are molecular scaffolds that serve as important regulators of cell survival. Our previous study demonstrated that 14-3-3ζ can sequester BAD, a pro-apoptotic member of the BCL-2 protein family, in the cytoplasm and prevent its translocation to mitochondria to inhibit the induction of apoptosis. Despite being a critical mechanism of cell survival, it is unclear whether disrupting 14-3-3 protein:BAD interactions could be harnessed as a chemotherapeutic approach. Herein, we established a BRET-based high-throughput drug screening approach (Z'-score= 0.52) capable of identifying molecules that can disrupt 14-3-3ζ:BAD interactions. An FDA-approved drug library containing 1971 compounds was used for screening, and the capacity of identified hits to induce cell death was examined in NIH3T3-fibroblasts and colorectal cancer cell lines, HT-29 and Caco-2. Our in vitro results suggest that terfenadine, penfluridol, and lomitapide could be potentially repurposed for treating colorectal cancer. Moreover, our screening method demonstrates the feasibility of identifying pro-apoptotic agents that can be applied towards conditions where aberrant cell growth or function are key determinants of disease pathogenesis.