Apoptotic Regulators Research Articles

Cardioprotective effects of liposomal resveratrol in diabetic rats: unveiling antioxidant and anti-inflammatory benefits

ABSTRACT As a consequence of chronic hyperglycemia, diabetes complications and tissue damage are exacerbated. There is evidence that natural phytochemicals, including resveratrol, a bioactive polyphenol, may be able to reduce oxidative stress and improve insulin sensitivity. However, resveratrol's limited bioavailability hampers its therapeutic effectiveness. By using liposomes, resveratrol may be better delivered into the body and be more bioavailable. The objective of this study was to assess the cardioprotective potential of liposome-encapsulated resveratrol (LR) in a streptozotocin-induced (STZ) diabetic rat model. Adult male Wistar rats were categorized into five groups: control, diabetic, resveratrol-treated (40 mg/kg), liposomal resveratrol (LR)-treated (20 mg/kg) and liposomal resveratrol (LR)-treated (40 mg/kg) for a five-week study period. We compared the effects of LR to those of resveratrol (40 mg/kg) on various parameters, including serum levels of cardiac markers, tissue levels of pro-inflammatory cytokines, nuclear transcription factor, oxidative stress markers, and apoptotic markers. LR treatment in STZ-diabetic rats resulted in notable physiological improvements, including blood glucose regulation, inflammation reduction, oxidative stress mitigation, and apoptosis inhibition. LR effectively lowered oxidative stress and enhanced cardiovascular function. It also demonstrated a remarkable ability to suppress NF-kB-mediated inflammation by inhibiting the pro-inflammatory cytokines TNF-α and IL-6. Additionally, LR restored the antioxidant enzymes, catalase and glutathione peroxidase, thereby effectively counteracting oxidative stress. Notably, LR modulated apoptotic regulators, including caspase, Bcl2, and Bax, suggesting a role in regulating programmed cell death. These biochemical alterations were consistent with improved structural integrity of cardiac tissue as revealed by histological examination. In comparison, resveratrol exhibited lower efficacy at an equivalent dosage. Liposomal resveratrol shows promise in alleviating hyperglycemia-induced cardiac damage in diabetes. Further research is warranted to explore its potential as a therapeutic agent for diabetic cardiovascular complications and possible cardioprotective effects.

Immobilization of Membrane-Associated Protein Complexes on SERS-Active Nanomaterials for Structural and Dynamic Characterization.

Exploring the structural basis of membrane proteins is significant for a deeper understanding of protein functions. In situ analysis of membrane proteins and their dynamics, however, still challenges conventional techniques. Here we report the first attempt to immobilize membrane protein complexes on surface-enhanced Raman scattering (SERS)-active supports, titanium dioxide-coated silver (Ag@TiO2) nanoparticles. Biocompatible immobilization of microsomal monooxygenase complexes is achieved through lipid fission and fusion. SERS activity of the Ag@TiO2 nanoparticles enables in situ monitoring of protein-protein electron transfer and enzyme catalysis in real time. Through SERS fingerprints of the monooxygenase redox centers, the correlations between these protein-ligand interactions and reactive oxygen species generation are revealed, providing novel insights into the molecular mechanisms underlying monooxygenase-mediated apoptotic regulation. This study offers a novel strategy to explore structure-function relationships of membrane protein complexes and has the potential to advance the development of novel reactive oxygen species-inducing drugs for cancer therapy.

Evaluation of Annona muricata Linn Leaves Extracts from Maceration and Ultrasonic-Assisted Methods for Anticancer Activity on HLFa Cells

Non-small cell lung cancer (NSCLC) is a deadly kind of cancer that contributes significantly to the global cancer mortality rate. It is distinguished by a significant level of malignancy and unfavourable prognosis. The molecular pathways responsible for tumour invasion and migration in NSCLC are not fully understood, despite their widespread occurrence and significant consequences. Moreover, the ability of cancer cells to withstand the effects of chemical treatments presents a substantial obstacle in the creation of successful treatment approaches for NSCLC. Annona muricata Linn (A. muricata) is known to possess powerful anticancer bioactive components. A. muricata extracts have demonstrated significant therapeutic potential among a wide range of botanical compounds. However, the specific molecular interactions of the plant have not yet been revealed. This study aims to evaluate the anticancer potential of A. muricata leaves extracts on the NSCLC cell line and compare the efficacy of two different extraction methods, namely maceration extraction (ME) and ultrasonic-assisted extraction (UAE). Results showed that ME demonstrated significantly higher antioxidant activity compared to UAE, with respective percentages of 81.4% and 29.4%. However, the UAE extract demonstrated more pronounced cytotoxic effects on the NSCLC cell line (HLFa) with an IC50 value of 139.6 µg/ml, indicating a stronger antiproliferative effect on cancer cell. Both ME and UAE extracts reduced nitrite release in HLFa cell supernatants, with the ME extract showing superior activity. Treatment with ME and UAE also resulted in the activation of Caspase3/7, indicating the induction of apoptosis in HLFa cells compared to the untreated control. The extracts and Cisplatin differ approximately 0.3-fold in caspase 3/7 activation though it was not statistically significant. This activation suggests that both extraction methods effectively initiate the apoptotic cascade which is crucial for the elimination of cancer cells. Furthermore, the UAE extract significantly reduced BCL-2 mRNA levels (p<0.05). The significant reduction in BCL-2, a protein that prevents apoptosis reflect the extract’ ability to modulate key apoptotic regulators with the most significant activity when UAE extracts were used. In summary, A.muricata leaves extracts obtained through both ME and UAE methods exhibited promising anticancer effects against NSCLC, with UAE extracts exhibiting superior activity. These findings pave the way for further investigations into the use of A.muricata in cancer treatment and the development of new therapeutic agents based on its properties.

The Anti-Leukemic Activities of Campesterol and Α-Tocopherol Against BCL-2 Target through Computational Drug Design Approaches.

Heterogeneous Acute Myeloid Leukemia (AML) causes substantial worldwide morbidity and death. AML is characterized by excessive proliferation of immature myeloid cells in the bone marrow and impaired apoptotic regulator expression. B-Cell Lymphoma 2 (BCL-2), an anti-apoptotic protein overexpressed in AML, promotes leukemic cell survival and chemoresistance. Thus, reducing BCL-2 may treat AML. Anticancer activities are found in Aloe barbadensis Miller (Aloe vera). Thus, this work used molecular modeling to assess Aloe vera bioactive chemicals as BCL-2 inhibitors. Molecular docking simulation showed that all identified Aloe vera phytocompounds have strong BCL-2 binding affinities (-6.7 to -8.7 kcal/mol). Campesterol and α-tocopherol were identified as promising compounds for BCL-2 inhibitor research based on their drug-likeness, pharmacokinetics, and toxicity profiles. The stability and conformational of the BCL-2-compound complexes showed that the compounds were stable in BCL-2's binding pocket. Campesterol and α-tocopherol are promising BCL-2 inhibitors that might become effective anti-leukemic therapies with additional in vitro and in vivo research.

7092 Blocking of Aggressive Tumor Progression of Anaplastic Thyroid Cancer by p53

Abstract Disclosure: E. Hwang: None. R. Chari: None. T. Kimura: None. S. Cheng: None. Background: Anaplastic thyroid cancer (ATC) is the most aggressive form of thyroid cancer, with very limited treatment options. Patients succumb to death within 6-12 months after diagnosis. It has been observed that mutations of p53, occurring as tumorigenesis progresses, is associated with the aggressiveness of ATC. The present studies tested the hypothesis that wild type p53 (WTp53) could block tumor progression and mitigate its aggressiveness. Methods: We used human 8505C cells as a model, derived from human ATC tumors, harboring BRAFV600E mutation and one allele of mutated p53C742G. We re-expressed WTp53 or mutant p53C742G into 8505C cells (8505C-WTp53 or 8505C-MTp53 cells, respectively) via lentiviral transduction. We analyzed the effects of exogenous expressed WTp53 and mutant p53 on cell proliferation, apoptosis, and migration in vitro and the progression of tumors in vivo mouse xenograft models. Results: We showed that p53 proteins were more abundantly expressed in 8505C-WTp53 or 8505C-MTp53 cells than the parental 8505C cells. Using WTp53 luciferase reporter (PG-13), we demonstrated that the expressed WTp53 was functional as the transcription activity of p53 was higher than the parental 8505C cells. Consistently, in 8505C-MTp53, the reporter activity of PG-13 was not detected. The expressed WTp53 inhibited cell proliferation and decreased cell migration. Immunohistochemical analysis (IHC) showed decreased proliferation marker Ki67 and increased cleaved caspase-3, indicating the induction of apoptosis in 8505C-WTp53 cells. Importantly, we found that the NIS expression was increased in 8505C-WTp53 cells, but not in 8505C-MTp53 cells, as compared with 8505C cells. Xenograft studies showed that tumor progression was inhibited in nude mice injected with 8505C-WTp53 cells as compared with tumors induced by 8505C parental cells and 8505C-MTp53 cells. Consistent with in vitro findings, IHC demonstrated decreased proliferation marker Ki67 and increased cleaved caspase-3 proteins in tumors induced by 8505C-WTp53 cells. Furthermore, the expression of apoptotic regulators such as BAX and PUMA, known as p53 target genes, were elevated in 8505C-WTp53 cultured cells and in 8505C-WTp53-induced tumors, indicating induction of apoptosis. Conclusions: Our findings showed that the aggressiveness of ATC, caused by mutant p53 in late stage of tumor progression, can be mitigated by exogenous expression of WTp53. These results provided new insights into the deleterious actions of mutation of p53 in ATC tumor development. Importantly, our studies revealed that targeting p53 in ATC could be considered as a potential therapeutic opportunity. Presentation: 6/3/2024

Survival advantage of native and engineered T cells is acquired by mitochondrial transfer from mesenchymal stem cells

BackgroundApoptosis, a form of programmed cell death, is critical for the development and homeostasis of the immune system. Chimeric antigen receptor T (CAR-T) cell therapy, approved for hematologic cancers, retains several limitations and challenges associated with ex vivo manipulation, including CAR T-cell susceptibility to apoptosis. Therefore, strategies to improve T-cell survival and persistence are required. Mesenchymal stem/stromal cells (MSCs) exhibit immunoregulatory and tissue-restoring potential. We have previously shown that the transfer of umbilical cord MSC (UC-MSC)-derived mitochondrial (MitoT) prompts the genetic reprogramming of CD3+ T cells towards a Treg cell lineage. The potency of T cells plays an important role in effective immunotherapy, underscoring the need for improving their metabolic fitness. In the present work, we evaluate the effect of MitoT on apoptotis of native T lymphocytes and engineered CAR-T cells.MethodsWe used a cell-free approach using artificial MitoT (Mitoception) of UC-MSC derived MT to peripheral blood mononuclear cells (PBMCs) followed by RNA-seq analysis of CD3+ MitoTpos and MitoTneg sorted cells. Target cell apoptosis was induced with Staurosporine (STS), and cell viability was evaluated with Annexin V/7AAD and TUNEL assays. Changes in apoptotic regulators were assessed by flow cytometry, western blot, and qRT-PCR. The effect of MitoT on 19BBz CAR T-cell apoptosis in response to electroporation with a non-viral transposon-based vector was assessed with Annexin V/7AAD.ResultsGene expression related to apoptosis, cell death and/or responses to different stimuli was modified in CD3+ T cells after Mitoception. CD3+MitoTpos cells were resistant to STS-induced apoptosis compared to MitoTneg cells, showing a decreased percentage in apoptotic T cells as well as in TUNEL+ cells. Additionally, MitoT prevented the STS-induced collapse of the mitochondrial membrane potential (MMP) levels, decreased caspase-3 cleavage, increased BCL2 transcript levels and BCL-2-related BARD1 expression in FACS-sorted CD3+ T cells. Furthermore, UC-MSC-derived MitoT reduced both early and late apoptosis in CAR-T cells following electroporation, and exhibited an increasing trend in cytotoxic activity levels.ConclusionsArtificial MitoT prevents STS-induced apoptosis of human CD3+ T cells by interfering with the caspase pathway. Furthermore, we observed that MitoT confers protection to apoptosis induced by electroporation in MitoTpos CAR T-engineered cells, potentially improving their metabolic fitness and resistance to environmental stress. These results widen the physiological perspective of organelle-based therapies in immune conditions while offering potential avenues to enhance CAR-T treatment outcomes where their viability is compromised.

A review on the functional characteristics of the c-Myeloproliferative Leukaemia (c-MPL) gene and its isoforms.

The c-MPL-TPO axis regulates hematopoiesis by activating various signalling cascades, including JAK/STAT, MAPK/ERK, and PIK3/AKT. Here, we have summarized how TPO is regulated by c-MPL and, how mutations in the c-MPL regulate hematopoiesis. We also focus on its non-hematological regulatory role in diseases like Unstable Angina and pathways like DNA damage repair, skeletal homeostasis, & apoptotic regulation of neurons/HSCs at the embryonic state. We discuss the therapeutic efficiency of c-MPL and, its potential to be developed as a bio-marker for detecting metastasis and development of chemo-resistance in various cancers, justifying the multifaceted nature of c-MPL. We have also highlighted the importance of c-MPL isoforms and their stoichiometry in controlling the HSC quiescent and proliferative state. The regulation of the ratio of different isoforms through gene-therapy can open future therapeutic avenues. A systematic understanding of c-MPL-isoforms would undoubtedly take one step closer to facilitating c-MPL from basic-research towards translational medicine.

CXCR4 as a therapeutic target in acute myeloid leukemia.

Extensive research on the CXCL12-CXCR4 axis in acute myeloid leukemia (AML) has resulted in the incorporation of novel anti-leukemia drugs targeting this axis into therapeutic strategies. However, despite this progress, a comprehensive and up-to-date review addressing the role of the CXCL12-CXCR4 axis in AML's oncogenic processes is lacking. In this review, we examine its molecular aspects influencing cancer progression, such as its impact on autonomous proliferation, apoptotic regulation, chemoresistance mechanisms, and interactions with non-leukemic cells such as MSCs and Treg cells. Additionally, we explore clinical implications, including prognosis, correlation with WBC count, blast count in the bone marrow and peripheral blood, as well as its association with FLT3-ITD, NPM1 mutations, and FAB classification. Finally, this paper extensively discusses drugs that specifically target the CXCL12-CXCR4 axis, including plerixafor/AMD3100, ulocuplumab, peptide E5, and motixafortide, shedding light on their potential therapeutic value in the treatment of AML.

Piperine Enhances the Anticancer Effects of Cisplatin on Tongue Squamous Cell Carcinoma Cell Line by Inducing Cell Apoptosis.

Oral squamous cell carcinoma is ranked as the predominant type of head and neck squamous cell carcinoma, comprising roughly 90% of all oral cancer cases. Natural products have proven to be highly valuable as complementary, or adjunctive in the treatment of cancer. Piperine, a natural compound derived from Piper nigrum, demonstrates anti-proliferative and anti-neoplastic effects across various types of cancer. This study focused on assessing the cytotoxic effect of piperine in conjunction with cisplatin within the OSCC cell line. In this in-vitro study, cultured OSCC cells were divided into four groups: a control group (untreated), a group exposed solely to piperine, a group exposed solely to cisplatin, and a group receiving both piperine and cisplatin. Cell viability was determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide (MTT) assay technique. Additionally, flow cytometric analysis was employed to examine cell cycle progression and apoptosis. Assessment of reactive oxygen species activity, morphological changes, and nuclear area factor measurements were carried out. Expression of the apoptotic regulator Bax was assessed through western blotting analysis. Piperine has cytotoxic and apoptotic effects in a concentration-dependent manner. Piperine in combination with cisplatin exhibited a synergistic effect, resulting in more pronounced inhibition of cell viability in OSCC cells compared to using piperine and cisplatin alone. Piperine and cisplatin for 24 h induced apoptosis strongly by increasing Bax protein and ROS activity. Combining piperine with cisplatin demonstrated a greater effectiveness in triggering apoptosis in OSCC cells compared to using cisplatin alone, allowing for a reduction.

Mitochondria−endoplasmic reticulum crosstalk in apoptosis: The interactions of cytochrome c with monooxygenase and its reductase

The crosstalk between endoplasmic reticulum and mitochondria is of significance in apoptosis, in which cytochrome b5 (Cyt b5) is thought to be a major target for cytochrome c (Cyt c) upon its release from the mitochondria. In the absence of Cyt b5, the role of interactions of Cyt c with CYP-dependent monooxygenase system in apoptotic regulation was explored in this study. NADPH-dependent and Cyt c-induced formation of reactive oxygen species (ROS) and NADPH-independent Cyt c unfolding were revealed. With the aid of a CPR inhibitor and CYP antibodies, the interactions among Cyt c, cytochrome P450 reductase (CPR) and cytochrome P450 (CYP) are evidenced, which are found crucial for monooxygenase-derived ROS formation. The underlying structural basis of Cyt c−CYP complex was unveiled by molecular dynamics simulations. This study provides novel insights into how Cyt c regulates ROS formation through the interactions with CPR and CYP, and is implicated for a deeper understanding of the regulation mechanism in the mitochondria–endoplasmic reticulum apoptotic pathway.

Antioxidant Defenses, Oxidative Stress Responses, and Apoptosis Modulation in Spontaneous Abortion: An Immunohistochemistry Analysis of First-Trimester Chorionic Villi.

Oxidative stress (OS) and apoptosis are critical factors in placental development and function. Their interplay influences trophoblast proliferation, differentiation, and invasion, as well as vascular development. An imbalance between these processes can lead to pregnancy-related disorders such as preeclampsia, intrauterine growth restriction, and even spontaneous abortion. Our study seeks to elucidate the associations between preventive antioxidant/protective OS response factors-glutathione (GSH), MutT Homolog 1 (MTH1), and apoptotic regulation modulators-tumor protein p53 and B-cell lymphoma (Bcl-2) transcripts, in the context of spontaneous abortion (30 samples) versus elective termination of pregnancy (20 samples), using immunohistochemistry (IHC) to determine their proteomic expression in chorionic villi within abortive fetal placenta tissue samples. Herein, comparative statistical analyses revealed that both OS response factors, GSH and MTH1, were significantly under-expressed in spontaneous abortion cases as compared to elective. Conversely, for apoptotic regulators, p53 expression was significantly higher in spontaneous abortion cases, whereas Bcl-2 expression was significantly lower in spontaneous abortion cases. These findings suggest that a strong pro-apoptotic signal is prevalent within spontaneous abortion samples, alongside reduced anti-apoptotic protection, depleted antioxidant defenses and compromised oxidative DNA damage prevention/repair, as compared to elective abortion controls. Herein, our hypothesis that OS and apoptosis are closely linked processes contributing to placental dysfunction and spontaneous abortion was thus seemingly corroborated. Our results further highlight the importance of maintaining redox homeostasis and apoptotic regulation for a successful pregnancy. Understanding the mechanisms underlying this interplay is essential for developing potential therapies to manage OS, promote placentation, and avoid unwanted apoptosis, ultimately improving pregnancy outcomes. Antioxidant supplementation, modulation of p53 activity, and the enhancement of DNA repair mechanisms may represent potential approaches to mitigate OS and apoptosis in the placenta. Further research is needed to explore these strategies and their efficacy in preventing spontaneous abortion.

Mitochondrial chaperon TNF-receptor- associated protein 1 as a novel apoptotic regulator conferring susceptibility to Pneumocystis jirovecii pneumonia.

Molecular chaperons stabilize protein folding and play a vital role in maintaining tissue homeostasis. To this intent, mitochondrial molecular chaperons may be involved in the regulation of oxidative phosphorylation and apoptosis during stress events such as infections. However, specific human infectious diseases relatable to defects in molecular chaperons have yet to be identified. To this end, we performed whole exome sequencing and functional immune assessment in a previously healthy Asian female, who experienced severe respiratory failure due to Pneumocystis jiroveci pneumonia and non-HIV-related CD4 lymphocytopenia. This revealed that a chaperon, the mitochondrial paralog of HSP90, TRAP1, may have been involved in the patient's susceptibility to an opportunistic infection. Two rare heterozygous variants in TRAP1, E93Q, and A64T were detected. The patient's peripheral blood mononuclear cells displayed diminished TRAP1 expression, but had increased active, cleaved caspase-3, caspase-7, and elevated IL-1β production. Transfection of A64T and E93Q variants in cell lines yielded decreased TRAP1 compared to transfected wildtype TRAP1 and re-capitulated the immunotypic phenotype of enhanced caspase-3 and caspase-7 activity. When infected with live P. jiroveci, the E93Q or A64T TRAP1 mutant expressing cells also exhibited reduced viability. Patient cells and cell lines transfected with the TRAP1 E93Q/A64T mutants had impaired respiration, glycolysis, and increased ROS production. Of note, co-expression of E93Q/A64T double mutants caused more functional aberration than either mutant singly. Taken together, our study uncovered a previously unrecognized role of TRAP1 in CD4+ lymphocytopenia, conferring susceptibility to opportunistic infections.

Mitigation of Deoxynivalenol (DON)- and Aflatoxin B1 (AFB1)-Induced Immune Dysfunction and Apoptosis in Mouse Spleen by Curcumin.

In the context of the potential immunomodulatory properties of curcumin in counteracting the detrimental effects of concurrent exposure to Deoxynivalenol (DON) and Aflatoxin B1 (AFB1), a comprehensive 28-days trial was conducted utilizing 60 randomly allocated mice divided into four groups. Administration of curcumin at a dosage of 5 mg/kg body weight in conjunction with DON at 0.1 mg/kg and AFB1 at 0.01 mg/kg body weight was undertaken to assess its efficacy. Results indicated that curcumin intervention demonstrated mitigation of splenic structural damage, augmentation of serum immunoglobulin A (IgA) and immunoglobulin G (IgG) levels, elevation in T lymphocyte subset levels, and enhancement in the mRNA expression levels of pro-inflammatory cytokines TNF-α, IFN-γ, IL-2, and IL-6. Furthermore, curcumin exhibited a suppressive effect on apoptosis in mice, as evidenced by decreased activity of caspase-3 and caspase-9, reduced expression levels of pro-apoptotic markers Bax and Cytochrome-c (Cyt-c) at both the protein and mRNA levels, and the maintenance of a balanced expression ratio of mitochondrial apoptotic regulators Bax and Bcl-2. Collectively, these findings offer novel insights into the therapeutic promise of curcumin in mitigating immunosuppression and apoptotic events triggered by mycotoxin co-exposure.

In vitro cancer cell line luminescence-based validation of anticancer phytocompounds obtained from Leucas biflora against HELA cervical and A549 lung cancer cells.

Current research aims to screen the anticancer prospective of Leucas biflora phytocompounds against apoptotic regulator target protein essential for cancer progression. In gas chromatography-mass spectrometry analysis major phytocompounds such as tetracosahexaene, squalene, phytol, 22-stigmasten-3-one, stigmasterol, fluorene, and 1,4-dihydro were identified in ethanolic leaf extract of Leucas biflora. In vitro, the free radical scavenging potential of ethanolic leaf extract of Leucas biflora was examined through its DPPH and ABTS radical scavenging potential IC50 value 15.35 and 13.20 μg/ml, respectively. Dose-dependent cytotoxicity was monitored against both A549 lung cancer and HELA cervical cancer cells. Leucas biflora ethanolic leaf extract highly reduces the cell viability of both HELA and A549 cells in in vitro cytotoxicity assays. Leucas biflora ethanolic extract produces 23.76% and 29.76% viability rates against A549 lung and HELA cervical cancer cell lines, and their IC50 values differ slightly at 95.80 and 90.40 μg/ml, respectively. In molecular docking analysis lung cancer target protein-ligand complex 5Y9T-16132746 showed a maximum score of -14 kcal/mol by exhibiting stable binding affinity and interactions among all screened complexes. Based on docking score nine phytocompounds from Leucas biflora and two reference standard drugs were chosen for further analysis. Further validation reveals that the fluorene, 1,4-dihydro possess good ADMET, Bioactivity and density functional theory indices.

Transcriptomic Hallmarks of Hypoxic-Ischemic Brain Injury: Insights from an in Vitro Model.

Hypoxic-ischemic injury of neurons is a pathological process observed in several neurological conditions, including ischemic stroke and neonatal hypoxic-ischemic brain injury (HIBI). An optimal treatment strategy for these conditions remains elusive. The present study delved deeper into the molecular alterations occurring during the injury process in order to identify potential therapeutic targets. Oxygen-glucose deprivation/reperfusion (OGD/R) serves as an established in vitro model for the simulation of HIBI. This study utilized RNA sequencing to analyze rat primary hippocampal neurons that were subjected to either 0.5 or 2 h of OGD, followed by 0, 9, or 18 h of reperfusion. Differential expression analysis was conducted to identify genes dysregulated during OGD/R. Time-series analysis was used to identify genes exhibiting similar expression patterns over time. Additionally, functional enrichment analysis was conducted to explore their biological functions, and protein-protein interaction (PPI) network analyses were performed to identify hub genes. Quantitative real-time polymerase chain reaction (qRT-PCR) was used for validation of hub-gene expression. The study included a total of 24 samples. Analysis revealed distinct transcriptomic alterations after OGD/R processes, with significant dysregulation of genes such as Txnip, Btg2, Egr1 and Egr2. In the OGD process, 76 genes, in two identified clusters, showed a consistent increase in expression; functional analysis showed involvement of inflammatory responses and signaling pathways like tumor necrosis factor (TNF), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and interleukin 17 (IL-17). PPI network analysis suggested that Ccl2, Jun, Cxcl1, Ptprc, and Atf3 were potential hub genes. In the reperfusion process, 274 genes, in three clusters, showed initial upregulation followed by downregulation; functional analysis suggested association with apoptotic processes and neuronal death regulation. PPI network analysis identified Esr1, Igf-1, Edn1, Hmox1, Serpine1, and Spp1 as key hub genes. qRT-PCR validated these trends. The present study provides a comprehensive transcriptomic profile of an in vitro OGD/R process. Key hub genes and pathways were identified, offering potential targets for neuroprotection after hypoxic ischemia.

Ginkgetin improved experimental colitis by inhibiting intestinal epithelial cell apoptosis through EGFR/PI3K/AKT signaling.

Excessive apoptosis of intestinal epithelial cells leads to intestinal barrier dysfunction, which is not only one of the pathological features of inflammatory bowel disease (IBD) but also a therapeutic target. A natural plant extract, Ginkgetin (GK), has been reported to have anti-apoptotic activity, but its role in IBD is unknown. This study aimed to explore whether GK has anti-colitis effects and related mechanisms. An experimental colitis model induced by dextran sulfate sodium (DSS) was established, and GK was found to relieve colitis in DSS-induced mice as evidenced by improvements in weight loss, colon shortening, Disease Activity Index (DAI), macroscopic and tissue scores, and proinflammatory mediators. In addition, in DSS mice and TNF-α-induced colonic organoids, GK protected the intestinal barrier and inhibited intestinal epithelial cell apoptosis, by improving permeability and inhibiting the number of apoptotic cells and the expression of key apoptotic regulators (cleaved caspase 3, Bax and Bcl-2). The underlying mechanism of GK's protective effect was explored by bioinformatics, rescue experiments and molecular docking, and it was found that GK might directly target and activate EGFR, thereby interfering with PI3K/AKT signaling to inhibit apoptosis of intestinal epithelial cells invivo and invitro. In conclusion, GK inhibited intestinal epithelial apoptosis in mice with experimental colitis, at least in part, by activating EGFR and interfering with PI3K/AKT activation, explaining the underlying mechanism for ameliorating colitis, which may provide new options for the treatment of IBD.

Abstract A010: Proteasome inhibitors induce a BAX and BAK independent, non-canonical apoptosis

Abstract In the intrinsic pathway of apoptosis, death stimuli (including drugs, cellular stress, viral infections, etc.) trigger the oligomerization of BAX and BAK resulting in pore formation in the outer mitochondrial membrane to release cytochrome c from the intermembrane space. The released cytochrome c then activates APAF-1 and CASPASE9 to form a 1.4 MDa complex known as apoptosome, which recruits and activates downstream caspases that dismantle the cell. However, we have found that proteasome inhibition leads to a BAX and BAK independent apoptotic cell death. We show using immunofluorescence, fluorogenic assays, and flow cytometry that the proteasome inhibitors, bortezomib and MG-132, trigger a caspase dependent cell death that requires the apoptosome components APAF-1 and CASPASE9, but not cytochrome c. Furthermore, size exclusion chromatography revealed that unlike classical death stimuli, which induce the mega-dalton canonical apoptosome fomation, proteasome inhibitors induce a minor shift in APAF-1, forming a smaller, non-canonical apoptosome. Current efforts are focused on the identification of the APAF-1 activator. Our results indicate the existence of a non-canonical caspase-dependent cell death pathway, which could be a novel therapeutic target in malignancies by bypassing the BCL-2 family of apoptotic regulators. Citation Format: Tresor O Mukiza, Ricardo Enrique-Rodriguez, Amit Budhraja, Lauren Brakefield, Tudor Moldoveanu, Joseph T Opferman. Proteasome inhibitors induce a BAX and BAK independent, non-canonical apoptosis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Expanding and Translating Cancer Synthetic Vulnerabilities; 2024 Jun 10-13; Montreal, Quebec, Canada. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(6 Suppl):Abstract nr A010.

Structural basis of substrate recognition and allosteric activation of the proapoptotic mitochondrial HtrA2 protease

The mitochondrial serine protease HtrA2 is a human homolog of the Escherichia coli Deg-proteins exhibiting chaperone and proteolytic roles. HtrA2 is involved in both apoptotic regulation via its ability to degrade inhibitor-of-apoptosis proteins (IAPs), as well as in cellular maintenance as part of the cellular protein quality control machinery, by preventing the possible toxic accumulation of aggregated proteins. In this study, we use advanced solution NMR spectroscopy methods combined with biophysical characterization and biochemical assays to elucidate the crucial role of the substrate recognizing PDZ domain. This domain regulates the protease activity of HtrA2 by triggering an intricate allosteric network involving the regulatory loops of the protease domain. We further show that divalent metal ions can both positively and negatively modulate the activity of HtrA2, leading to a refined model of HtrA2 regulation within the apoptotic pathway.

Identification of modules and key genes associated with breast cancer subtypes through network analysis

Breast cancer is the most common malignancy in women around the world. Intratumor and intertumoral heterogeneity persist in mammary tumors. Therefore, the identification of biomarkers is essential for the treatment of this malignancy. This study analyzed 28,143 genes expressed in 49 breast cancer cell lines using a Weighted Gene Co-expression Network Analysis to determine specific target proteins for Basal A, Basal B, Luminal A, Luminal B, and HER2 ampl breast cancer subtypes. Sixty-five modules were identified, of which five were characterized as having a high correlation with breast cancer subtypes. Genes overexpressed in the tumor were found to participate in the following mechanisms: regulation of the apoptotic process, transcriptional regulation, angiogenesis, signaling, and cellular survival. In particular, we identified the following genes, considered as hubs: IFIT3, an inhibitor of viral and cellular processes; ETS1, a transcription factor involved in cell death and tumorigenesis; ENSG00000259723 lncRNA, expressed in cancers; AL033519.3, a hypothetical gene; and TMEM86A, important for regulating keratinocyte membrane properties, considered as a key in Basal A, Basal B, Luminal A, Luminal B, and HER2 ampl breast cancer subtypes, respectively. The modules and genes identified in this work can be used to identify possible biomarkers or therapeutic targets in different breast cancer subtypes.

18‑α‑glycyrrhetinic acid induces apoptosis in gingival fibroblasts exposed to phenytoin.

Phenytoin (PHT)-induced gingival overgrowth is caused by the increased proliferation and reduced apoptosis of gingival fibroblasts in inflammatory gingiva. Licorice has long been used as a component of therapeutic preparations. It inhibits cell proliferation, induces cell apoptosis and has anti-inflammatory effects. 18-α-glycyrrhetinic acid (18α-GA), the active compound in licorice, promotes apoptosis in various types of cells. The present study determined whether 18α-GA affects apoptosis in gingival fibroblasts exposed to PHT. The present study aimed to establish a basis for the therapeutic application of 18α-GA to treat the gingival overgrowth induced by PHT. Human gingival fibroblasts from healthy donors were cultured to semi-confluence and then stimulated in serum-free DMEM containing PHT with or without 18α-GA for subsequent experiments. Apoptotic cells were detected by ELISA. Analysis of the distribution of cell cycle phases and the apoptotic cell population was performed by flow cytometry. The expression levels of mRNAs and proteins of apoptotic regulators were measured using reverse transcription-quantitative PCR and western blotting, respectively. Caspase (CASP) activities were assessed by an ELISA. Treatment with 18α-GA markedly increased the number of apoptotic cells, reduced BCL2 mRNA expression, increased CASP2 and receptor (TNFRSF)-interacting serine-threonine kinase 1 (RIPK1) domain containing adaptor with death domain, Fas (TNFRSF6)-associated via death domain, RIPK1, tumor necrosis factor receptor superfamily; member 1A, TNF receptor-associated factor 2, CASP2, CASP3 and CASP9 mRNA expression, and also upregulated the protein expression levels and activities of caspase-2, caspase-3 and caspase-9. These results demonstrated that 18α-GA induced apoptosis through the activation of the Fas and TNF pathways in the death receptor signaling pathway in gingival fibroblasts treated with PHT. 18α-GA exhibited therapeutic potential for the treatment of PHT-induced gingival overgrowth.