Chlorogenic acid ameliorates memory dysfunction via attenuating frontal lobe oxidative stress and apoptosis in diabetic rat model.

Background/aim: Diabetes mellitus, characterized by hyperglycemia, causes various complications, one of which is memory dysfunction. The frontal lobe is known to be responsible for impaired memory function due to hyperglycemia and is associated with oxidative stress-mediated neuronal cell apoptosis. Chlorogenic acid (CGA) is reported to have neuroprotective effects. However, its effect on the frontal lobe in diabetes mellitus (DM) rats is not widely known. This research aimed to elucidate the effect of CGA on the mRNA expressions of SOD1, SOD2, p53, and Bcl-2 in the frontal lobe of DM rats. Materials and methods: Thirty male Wistar rats (2-month-old, 150-200 gBW) were randomly divided into six groups: C (control), DM1.5 (1.5-month DM), DM2 (2-month DM), CGA12.5, CGA25 and CGA50 (DM+CGA 12.5, 25, and 50 mg/kgBW, respectively). A single dose of streptozotocin (60 mg/kgBW) was intraperitoneally injected. Intraperitoneal CGA injection was administered daily for DM1.5 rats for 14 days. Path length was measured in the Morris water maze (MWM) probe test. After termination, the frontal lobes were carefully harvested for RNA extraction. Reverse transcriptase PCR was performed to examine the mRNA expression of SOD1, SOD2, p53, and Bcl-2. Results: The DM2 group demonstrated significant shorter path length on the MWM probe test and significantly lower mRNA expression of SOD1 and Bcl-2, compared to the C group. After CGA administration, the CGA25 group showed a significantly shorter path length than the C group. The CGA12.5 and CGA25 groups had significantly higher mRNA expression of SOD1 than the DM1.5 group. Compared to the DM1.5 and DM2 groups, SOD2 mRNA expression of the administration of all three CGA doses increased markedly. Furthermore, Bcl-2 mRNA expression was significantly increased in the CGA12.5 and CGA50 groups, compared with the DM2 group. Conclusion: Chlorogenic acid might improve memory function through upregulation of frontal lobes' SOD1, SOD2, and Bcl-2 mRNA expression in DM rats.

The ameliorative effect of carvacrol on sodium arsenite-induced hepatotoxicity in rats: Possible role of Nrf2/HO-1, RAGE/NLRP3, Bax/Bcl-2/Caspase-3, and Beclin-1 pathways.

Arsenic is a toxic environmental pollutant heavy metal, and one of its critical target tissues in the body is the liver. Carvacrol is a natural phytocompound that stands out with its antioxidant, anti-inflammatory, and antiapoptotic properties. The current study aims to investigate the protective feature of carvacrol against sodium arsenite-induced liver toxicity. Thirty-five Sprague-Dawley male rats were divided into five groups: Control, Sodium arsenite (SA), CRV, SA + CRV25, and SA + CRV50. Sodium arsenite was administered via oral gavage at a dose of 10 mg/kg for 14 days, and 30 min later, CRV 25 or 50 mg/kg was administered via oral gavage. Oxidative stress, inflammation, apoptosis, autophagy damage pathways parameters, and liver tissue integrity were analyzed using biochemical, molecular, western blot, histological, and immunohistological methods. Carvacrol decreased sodium arsenite-induced oxidative stress by suppressing malondialdehyde levels and increasing superoxide dismutase, catalase, glutathione peroxidase activities, and glutathione levels. Carvacrol reduced inflammation damage by reducing sodium arsenite-induced increased levels of NF-κB and the cytokines (TNF-α, IL-1ß, IL-6, RAGE, and NLRP3) it stimulates. Carvacrol also reduced sodium arsenite-induced autophagic (Beclin-1, LC3A, and LC3B) and apoptotic (P53, Apaf-1, Casp-3, Casp-6, Casp-9, and Bax) parameters. Carvacrol preserved sodium arsenite-induced impaired liver tissue structure. Carvacrol alleviated toxic damage by reducing sodium arsenite-induced increases in oxidative stress, inflammation, apoptosis, and autophagic damage parameters in rat liver tissues. Carvacrol was also beneficial in preserving liver tissue integrity.

Contribution of A1 to macrophage survival in cooperation with MCL-1 and BCL-XL in a murine cell model of myeloid differentiation.

Myeloid cells are the first line of defence against pathogens. Mitochondrial apoptosis signalling is a crucial regulator of myeloid cell lifespan and modulates the function of myeloid cells. The anti-apoptotic protein BCL-2-family protein BCL2A1/A1/BFL-1 is strongly upregulated in inflammation in macrophages. We analysed the contribution of A1 to apoptosis regulation in a conditional system of in vitro differentiation of murine macrophages from immortalised progenitors. We disabled the expression of A1 by targeting all murine A1 isoforms in the genome. Specific inhibitors were used to inactivate other anti-apoptotic proteins. Macrophage progenitor survival mainly depended on the anti-apoptotic proteins MCL-1, BCL-XL and A1 but not BCL-2. Deletion of A1 on its own had little effect on progenitor cell survival but was sensitised to cell death induction when BCL-XL or MCL-1 was neutralised. In progenitors, A1 was required for survival in the presence of the inflammatory stimulus LPS. Differentiated macrophages were resistant to inhibition of single anti-apoptotic proteins, but A1 was required to protect macrophages against inhibition of either BCL-XL or MCL-1; BCL-2 only had a minor role in these cells. Cell death by neutralisation of anti-apoptotic proteins completely depended on BAX with a small contribution of BAK only in progenitors in the presence of LPS. A1 and NOXA appeared to stabilise each other at the posttranscriptional level suggesting direct binding. Co-immunoprecipitation experiments showed the binding of A1 to NOXA and BIM. Interaction between A1 and Noxa may indirectly prevent neutralisation and destabilization of MCL-1. Our findings suggest a unique role for A1 as a modulator of survival in the macrophage lineage in concert with MCL-1 and BCL-XL, especially in a pro-inflammatory environment.

Relapse and resistance in acute myeloid leukemia post venetoclax: improving second lines therapy and combinations.

INTRODUCTION: The combined use of the BCL-2 inhibitor venetoclax with azacitidine now is the standard of care for patients with acute myeloid leukemia (AML) unfit for intensive chemotherapy with outcomes exceeding those achieved with hypomethylating agents alone. Venetoclax in combination with intensive chemotherapy is also increasingly used both as frontline as well as salvage therapy. However, resistance to and relapse after venetoclax-based therapies are of major concern and outcomes after treatment failure remain poor. AREAS COVERED: A comprehensive search was performed using PubMed database (up to April 2024). Studies evaluating venetoclax-based combination treatments in AML and studies assessing markers of response and resistance to venetoclax were investigated. We summarize the status of venetoclax-based therapies in the frontline and relapsed/refractory setting with focus on the main mechanisms of resistance to BCL-2 inhibition. Further, strategies to overcome resistance including combinatorial regimens of hypomethylating agent (HMA) + venetoclax + inhibitors targeting actionable mutations like IDH1/2 or FLT3-ITD and the introduction of novel agents like menin-inhibitors are addressed. EXPERT OPINION: Although venetoclax is reshaping the treatment of unfit and fit AML patients, prognosis of patients after HMA/VEN failure remains dismal, and strategies to abrogate primary and secondary resistance are an unmet clinical need.

BCL2 expression is enriched in advanced prostate cancer with features of lineage plasticity.

The widespread use of potent androgen receptor signaling inhibitors (ARSIs) has led to an increasing emergence of AR-independent castration-resistant prostate cancer (CRPC), typically driven by loss of AR expression, lineage plasticity, and transformation to prostate cancers (PCs) that exhibit phenotypes of neuroendocrine or basal-like cells. The anti-apoptotic protein BCL2 is upregulated in neuroendocrine cancers and may be a therapeutic target for this aggressive PC disease subset. There is an unmet clinical need, therefore, to clinically characterize BCL2 expression in metastatic CRPC (mCRPC), determine its association with AR expression, uncover its mechanisms of regulation, and evaluate BCL2 as a therapeutic target and/or biomarker with clinical utility. Here, using multiple PC biopsy cohorts and models, we demonstrate that BCL2 expression is enriched in AR-negative mCRPC, associating with shorter overall survival and resistance to ARSIs. Moreover, high BCL2 expression associates with lineage plasticity features and neuroendocrine marker positivity. We provide evidence that BCL2 expression is regulated by DNA methylation, associated with epithelial-mesenchymal transition, and increased by the neuronal transcription factor ASCL1. Finally, BCL2 inhibition had antitumor activity in some, but not all, BCL2-positive PC models, highlighting the need for combination strategies to enhance tumor cell apoptosis and enrich response.

Deubiquitinating enzyme USP28 inhibitor AZ1 alone and in combination with cisplatin for the treatment of non-small cell lung cancer.

Lung cancer is one of the most common malignant tumors. Despite decades of research, the treatment of lung cancer remains challenging. Non-small cell lung cancer (NSCLC) is the primary type of lung cancer and is a significant focus of research in lung cancer treatment. The deubiquitinase ubiquitin-specific protease 28 (USP28) plays a role in the progression of various tumors and serves as a potential therapeutic target. This study aims to determine the role of USP28 in the progression of NSCLC. We examined the impact of the USP28 inhibitor AZ1 on the cell cycle, apoptosis, DNA damage response, and cellular immunogenicity in non-small cell lung cancer. We observed that AZ1 and siUSP28 induce DNA damage, leading to the activation of Noxa-mediated mitochondrial apoptosis. The dsDNA and mtDNA released from DNA damage and mitochondrial apoptosis activate tumor cell immunogenicity through the cGAS-STING signaling pathway. Simultaneously, targeting USP28 promotes the degradation of c-MYC, resulting in cell cycle arrest and inhibition of DNA repair. This further promotes DNA damage-induced cell apoptosis mediated by the Noxa protein, thereby enhancing tumor cell immunogenicity mediated by dsDNA and mtDNA. Moreover, we found that the combination of AZ1 and cisplatin (DDP) can enhance therapeutic efficacy, thereby providing a new strategy to overcome cisplatin resistance in NSCLC. These findings suggest that targeting USP28 and combining it with cisplatin are feasible strategies for treating NSCLC.

SETD1B mutations confer apoptosis resistance and BCL2 independence in B cell lymphoma.

The translocation t(14;18) activates BCL2 and is considered the initiating genetic lesion in most follicular lymphomas (FL). Surprisingly, FL patients fail to respond to the BCL2 inhibitor, Venetoclax. We show that mutations and deletions affecting the histone lysine methyltransferase SETD1B (KMT2G) occur in 7% of FLs and 16% of diffuse large B cell lymphomas (DLBCL). Deficiency in SETD1B confers striking resistance to Venetoclax and an experimental MCL-1 inhibitor. SETD1B also acts as a tumor suppressor and cooperates with the loss of KMT2D in lymphoma development in vivo. Consistently, loss of SETD1B in human lymphomas typically coincides with loss of KMT2D. Mechanistically, SETD1B is required for the expression of several proapoptotic BCL2 family proteins. Conversely, inhibitors of the KDM5 histone H3K4 demethylases restore BIM and BIK expression and synergize with Venetoclax in SETD1B-deficient lymphomas. These results establish SETD1B as an epigenetic regulator of cell death and reveal a pharmacological strategy to augment Venetoclax sensitivity in lymphoma.

Apoptosis Regulation in Dental Pulp Cells and PD-1/PD-L1 Expression Dynamics Under Ozone Exposure - A Pilot Approach.

This study aimed to determine the effect of ozone on the expression of Bax and Bcl-2 genes in dental pulp cells. Additionally, the programmed cell death protein 1, programmed death-ligand 1, and CD200 antigens were determined in lymphocytes to assess their surface expression. Dental pulp cells were cultured from extracted healthy third molars and characterized as dental pulp stromal cells. Gene expression of Bcl-2 and Bax was analyzed at 0 s, 6 s, and 12 s of ozone exposure using real-time PCR. Lymphocytes from dental pulp were subjected to ozone exposure for 12 s and PD-1, PD-L1, and CD200/CD200R expression was analyzed by flow cytometry. Upon exposure to ozone for 6 s, the Bcl-2 expression decreased significantly to -0.09, and at 12 s, it increased significantly to 0.3. Bax gene expression level increased significantly to 0.188 after 6 s exposure, and at 12 s, to 0.16. Lymphocytes exposed to ozone for 12 s showed minimal changes in PD-1, PD-L1, and CD200/CD200R expression levels, indicating that oxidative stress does not impact the signaling pathways regulating these molecules. The significant upregulation of Bcl-2 at 12 s highlights the cells' effort to protect themselves from prolonged oxidative stress, possibly tipping the balance toward cell survival and tissue repair. However, the absence of changes in PD-1 and PD-L1 expression on lymphocytes under oxidative stress suggests that these molecules are not sensitive to oxidative stress in this context.

[Effect of Pterostilbene Regulating Nuclear Factor E2-Related Factor 2 on Apoptosis of Colon Cancer Cells in Vitro].

Objective To investigate the effects of pterostilbene on human colon cancer LoVo cells and study the regulatory mechanism of nuclear factor E2-related factor 2 (Nrf2) in the process of pterostilbene acting on LoVo cells. Methods LoVo cells were treated with different concentrations (5,10,20,40,60,80,100 µmol/L) of pterostilbene.Cell viability,migration,invasion,and apoptosis were examined by CCK-8,scratch,Transwell,and TUNEL assays,respectively.The mitochondrial membrane potential was measured by the mitochondrial membrane potential assay kit with JC-1.The reactive oxygen species level was measured by 2',7'-dichlorofluorescein diacetate.The protein levels of Nrf2,phosphorylated Nrf2,heme oxygenase 1,and apoptotic proteins (Bcl2 and Bax) were determined by Western blotting.In addition,cell viability,Nrf2 expression,and apoptosis rate were determined after co-application of the Nrf2-specific agonist sulforaphane. Results Compared with the control group,40,60,80,100 µmol/L pterostilbene reduced the viability of LoVo cells (P=0.014,P<0.001,P<0.001,P<0.001).Pterostilbene at 5,10,20 µmol/L did not show effects on cell viability but inhibited cell migration (P=0.008,P<0.001,P<0.001) and invasion (all P<0.001).Pterostilbene at 40,60,80 µmol/L increased apoptosis (P=0.014,P<0.001,P<0.001),promoted mitochondrial membrane potential depolarization (P=0.026,P<0.001,P<0.001) and reactive oxygen species accumulation (all P<0.001),and down-regulated the expression of phosphorylated Nrf2 (P=0.030,P<0.001,P<0.001),heme oxygenase 1 (P=0.015,P<0.001,P<0.001),and Bcl2 (P=0.039,P<0.001,P<0.001) in LoVo cells.Pterostilbene at 60,80 µmol/L down-regulated Nrf2 expression (P=0.001,P<0.001) and up-regulated Bax expression (both P<0.001).The application of sulforaphane reversed the effects of pterostilbene on cell viability (P<0.001),apoptosis (P<0.001),and Nrf2 expression (P=0.022). Conclusion Pterostilbene is a compound that can effectively inhibit colon cancer cells by inhibiting the Nrf2 pathway.

Enhanced ER protein processing gene expression increases rAAV yield and full capsid ratio in HEK293 cells.

The recombinant adeno-associated virus (rAAV) vector is among the most promising viral vectors in gene therapy. However, the limited manufacturing capacity in human embryonic kidney (HEK) cells is a barrier to rAAV commercialization. We investigated the impact of endoplasmic reticulum (ER) protein processing and apoptotic genes on transient rAAV production in HEK293 cells. We selected four candidate genes based on prior transcriptomic studies: XBP1, GADD34 / PPP1R15A, HSPA6, and BCL2. These genes were stably integrated into HEK293 host cells. Traditional triple-plasmid transient transfection was used to assess the vector production capability and the quality of both the overexpressed stable pools and the parental cells. We show that the overexpression of XBP1, HSPA6, and GADD34 increases rAAV productivity by up to 100% and increases specific rAAV productivity by up to 78% in HEK293T cells. Additionally, more prominent improvement associated with ER protein processing gene overexpression was observed when parental cell productivity was high, but no substantial variation was detected under low-producing conditions. We also confirmed genome titer improvement across different serotypes (AAV2 and AAV8) and different cell lines (HEK293T and HEK293); however, the extent of improvement may vary. This study unveiled the importance of ER protein processing pathways in viral particle synthesis, capsid assembly, and vector production. KEY POINTS: • Upregulation of endoplasmic reticulum (ER) protein processing (XBP1, HSPA6, and GADD34) leads to a maximum 100% increase in rAAV productivity and a maximum 78% boost in specific rAAV productivity in HEK293T cells • The enhancement in productivity can be validated across different HEK293 cell lines and can be used for the production of various AAV serotypes, although the extent of the enhancement might vary slightly • The more pronounced improvements linked to overexpressing ER protein processing genes were observed when parental cell productivity was high, with minimal variation noted under low-producing conditions.

Glutaminase 1 plays critical roles in myelodysplastic syndrome and acute myeloid leukemia cells.

BACKGROUND: Myelodysplastic syndrome (MDS) features bone marrow failure and a heightened risk of evolving into acute myeloid leukemia (AML), increasing with age and reducing overall survival. Given the unfavorable outcomes of MDS, alternative treatments are necessary. Glutamine, the most abundant amino acid in the blood, is metabolized first by the enzyme glutaminase (GLS). OBJECTIVES: To investigate whether GLS is involved in the progression of MDS. The efficacy of GLS inhibitors (CB839 or IPN60090) and BCL2 inhibitor venetoclax was also examined. METHODS: We employed GLS inhibitors (CB839, IPN60090) and the BCL2 inhibitor venetoclax, prepared as detailed. MDS and AML cell lines were cultured under standard and modified (hypoxic, glutamine-free) conditions. Viability, proliferation, and caspase activity were assessed with commercial kits. RT-PCR quantified gene expression post-shRNA transfection. Mitochondrial potential, ATP levels, proteasome activity, and metabolic functions were evaluated using specific assays. Statistical analyses (t-tests, ANOVA) validated the findings. RESULTS: The glutamine-free medium inhibited the growth of MDS cells. GLS1 expression was higher in AML cells than in normal control samples (GSE15061), whereas GLS2 expression was not. Treatment of MDS and AML cells for 72 h was inhibited in a dose-dependent manner by GLS inhibitors. Co-treatment with the B-cell lymphoma 2 (BCL2) inhibitor venetoclax and GLS inhibitors increased potency. Cells transfected with GLS1 short hairpin RNA showed suppressed proliferation under hypoxic conditions and increased sensitivity to venetoclax. CONCLUSIONS: Targeting glutaminolysis and BCL2 inhibition enhances the therapeutic efficacy and has been proposed as a novel strategy for treating high-risk MDS and AML.

Association of both BCL2 positive and negative follicular lymphoma to clasical Hodgkin lymphoma and/or gray zone lymphoma.

We present a series of 9 follicular lymphomas that progressed/transformed into classical Hodgkin lymphoma (CHL). Three cases of CHL showed a syncytial pattern (SCHL) making the differential diagnosis to Gray zone lymphoma (GZL) challenging. None of these three cases presented in the mediastinum. Based in all molecular data analyzed (BCL2/BCL6 FISH studies, IgH PCR and TNGS with a customized gene panel) we did find clonal relationship between the BCL2-positive FL cases and their CHL components in all cases. The three SCHL/GZL cases showed an activated phenotype according to Hans algorithm, presented the t(14; 18)(q32; q21), two out of three showed B cell markers and all expressed CD30 and p53. Interestingly, we identified three BCL2-negative FL cases with a further diagnosis of CHL expanding the spectrum of these association. In one of these three cases a different mutational profile was found in both the FL and the CHL components. All this data together suggests that CHL associated to BCL2-positive FL could be originated in a common progenitor cell (CPC) that give rise to both FL and CHL, acquiring this last component further genetic events in a linear fashion. On the other hand, no clonal relationship between CHL and BCL2-negative FL could be found, suggesting a fortuity association. Nevertheless, ample series of cases studied with more sensitive techniques are needed to confirm our hypothesis.

Induction of Apoptotic Signaling Pathways by 3' methyl ATP in Different Malignant Cells: in vitro Study.

Extracellular ATP is a dynamic signaling molecule that modulates myriad of cellular functions through P2 purinergic receptors activation and is cytotoxic to a variety of cells at high concentration. But the mechanism of this extracellular ATP/ATP analogs- elicited cytotoxicity is not fully understood. In this study we aim to investigate whether there is differential sensitivity towards induction of apoptosis by ATP analogs (2'-Me ATP and 3'-Me ATP) and its effect on receptor mediated or extrinsic and mitochondria mediated or intrinsic apoptotic signaling pathways. Our findings demonstrated that the IC50 values for 2'-Me ATP and 3'-Me ATP were 3mM and 2mM, respectively, in Hep2, and SiHa cells. The downregulation of anti-apoptotic proteins Bcl-2 and Bcl-xL, along with a significant increase in the expression of the pro-apoptotic protein Bax (p<0.05), indicated the involvement of both pro- and anti-apoptotic factors in HeP2 cells, whereas in SiHa cells, a downregulation of anti-apoptotic proteins Bcl-2 and Bcl-xL was observed, whereas the expression level of the pro-apoptotic protein Bax remained unaffected. Furthermore, an upregulation of p53 and apoptosis-inducing factor (AIF) was observed in HeP2 cells (p<0.05) whereas, an upregulation of p53 was observed while no change was seen on the level of apoptosis inducing factor (AIF) was observed in SiHa cells. Additionally, there was a notable rise in caspase-3 and -9 activities, PARP cleavage, and the release of cytochrome c (p<0.05) from the mitochondria to the cytosol in both cells. Collectively, our study suggests that 3'-Me ATP induces apoptosis in Hep2 and SiHa cells through the intrinsic mitochondrial pathway.

Association between NKILA and some apoptotic gene expression in atherosclerosis.

Oxidized light-density lipoprotein (ox-LDL) causes endothelial dysfunction, which is an important determinant of atherogenesis, and subsequently leads to apoptosis. Atherosclerosis is one of the most significant cardiovascular diseases (CVDs) threatening human health and causes death worldwide. Recently, long noncoding RNAs (lncRNAs) have been suggested to involved in vascular biology. Ox-LDL activates nuclear factor kappa-B (NF-κB), and NF-κB interacting lncRNA (NKILA) inhibits NF-κB signaling. In this study, the hypothesis is that NKILA may regulate endothelial cell (EC) apoptosis and, therefore, play a role in the pathogenesis of atherosclerosis. This hypothesis is based on the knowledge that EC apoptosis contributes to atherosclerosis development and that NKILA has become a prominent lncRNA in CVDs. The expression of Bcl-2-associated X protein (BAX), caspase 9 (CASP9), cytochrome c (Cyt c, CYCS), apoptotic protease activating factor 1 (APAF1), and B-cell lymphoma 2 (BCL-2) genes in human umbilical vein endothelial cells (HUVEC) treated with ox-LDL and transfected with NKILA siRNA was analyzed using quantitative reverse transcription polymerase chain reaction (RT-qPCR). BAX, CASP9, CYCS, APAF1, and BCL-2 gene expression was downregulated in ox-LDL and NKILA siRNA-treated HUVEC. In addition, when threshold/quantification cycle (Cq) values of NKILA gene expression increased, Cq values of BAX, CASP9, APAF1, and BCL-2 gene expression increased statistics significantly. The expression detection of all these genes, resulting from NKILA gene silencing, may provide guidance for epigenetic studies on EC apoptosis in atherosclerosis.

A New Class of Gold(I) NHC Complexes with Proapoptotic and Resensitizing Properties towards Multidrug Resistant Leukemia Cells Overexpressing BCL-2.

From previous studies, it is evident that metal-organic gold(I) complexes have antiproliferative activities. The aim of this study is not only to find new anticancer agents but also to overcome existing cytostatic resistance in cancer cells. The synthesis and medicinal evaluation of two cationic 1,3-disubstituted gold(I) bis-tetrazolylidene complexes 1 and 2 are reported. To determine apoptosis-inducing properties of the complexes, DNA fragmentation was measured using propidium iodide staining followed by flow cytometry. Gold(I) complex 1 targets explicitly malignant cells, effectively inhibiting their growth and selectively inducing apoptosis without signs of necrosis. Even in cells resistant to common treatments such as doxorubicin, it overcomes multidrug resistance and sensitizes existing drug-resistant cells to common cytostatic drugs. It is assumed that gold(I) complex 1 involves the mitochondrial pathway in apoptosis and targets members of the BCL-2 family, enhancing its potential as a therapeutic agent in cancer treatment.

Proteasome inhibition induces apoptosis through simultaneous inactivation of MCL-1/BCL-XL by NOXA independent of CHOP and JNK pathways.

Proteasome inhibitors have been employed in the treatment of relapsed multiple myeloma and mantle cell lymphoma. The observed toxicity caused by proteasome inhibitors is a universal phenotype in numerous cancer cells with different sensitivity. In this study, we investigate the conserved mechanisms underlying the toxicity of the proteasome inhibitor bortezomib using gene editing approaches. Our findings utilizing different caspase knocking out cells reveal that bortezomib induces classic intrinsic apoptosis by activating caspase-9 and caspase-3/7, leading to pore-forming protein GSDME cleavage and subsequent lytic cell death or called secondary necrosis, a phenotype also observed in many apoptosis triggers like TNFα plus CHX, DTT and tunicamycin treatment in HeLa cells. Furthermore, through knocking out of nearly all BH3-only proteins including BIM, BAD, BID, BMF and PUMA, we demonstrate that NOXA is the sole BH3-only protein responsible for bortezomib-induced apoptosis. Of note, NOXA is well known for selectively binding to MCL-1 and A1, but our studies utilizing different BH3 mimetics as well as immunoprecipitation assays indicate that, except for the constitutive interaction of NOXA with MCL-1, the accumulation of NOXA after bortezomib treatment allows it to interact with BCL-XL, then simultaneous relieving suppression on apoptosis by both anti-apoptotic proteins BCL-XL and MCL-1. In addition, though bortezomib-induced significant ER stress and JNK activation were observed in the study, further genetic depletion experiments prove that bortezomib-induced apoptosis occurs independently of ER stress-related apoptosis factor CHOP and JNK. In summary, these results provide a solid conclusion about the critical role of NOXA in inactivation of BCL-XL except MCL-1 in bortezomib-induced apoptosis.

miR-29a expression negatively correlates with Bcl-2 levels in colorectal cancer and is correlated with better prognosis.

MicroRNAs (miRNAs) are a class of small non-coding RNAs that act as important regulators of gene expression, involved in various biological pathways. Aberrant miRNAs expression is associated with the onset and progression of colorectal cancer (CRC). The aim of this study was to investigate the correlation between five miRNAs (miR-29a, miR-101, miR-125b, miR-146a, and miR-155), found to be deregulated in tissue samples of CRC patients, and clinicopathological characteristics and histological markers. Analysis of histological markers was performed by immunohistochemical staining of tumour tissues with Ki-67, p53, CD34, and Bcl-2. Our findings revealed a significant negative correlation between miR-29a expression and Bcl-2 levels. Furthermore, high miR-29a expression was associated with a lower incidence of distant metastasis in CRC patients. We observed negative correlations between miR-101 expression and the number of lymph nodes with metastasis, as well as the size of the largest metastasis; miR-125b expression and lymphovascular invasion; and miR-155 expression and mucus presence. Our survival analysis demonstrated that high miR-29a expression correlated with better progression-free survival of CRC patients, underscoring its potential as a prognostic marker. Our study unveiled intricate relationships between specific miRNA expressions and clinicopathological features in CRC, highlighting the potential utility of miR-29a as a valuable prognostic biomarker.

Aquaporin 1 confers apoptosis resistance in pulmonary arterial smooth muscle cells from the SU5416 hypoxia rat model.

Pulmonary hypertension (PH) arises from increased pulmonary vascular resistance due to contraction and remodeling of the pulmonary arteries. The structural changes include thickening of the smooth muscle layer from increased proliferation and resistance to apoptosis. The mechanisms underlying apoptosis resistance in PH are not fully understood. In cancer cells, high expression of aquaporin 1 (AQP1), a water channel, is associated with apoptosis resistance. We showed AQP1 protein was expressed in pulmonary arterial smooth muscle cells (PASMCs) and upregulated in preclinical PH models. In this study, we used PASMCs isolated from control male rats and the SU5416 plus hypoxia (SuHx) model to test the role of AQP1 in modulating susceptibility to apoptosis. We found the elevated level of AQP1 in PASMCs from SuHx rats was necessary for resistance to apoptosis and that apoptosis resistance could be conferred by increasing AQP1 in control PASMCs. In exploring the downstream pathways involved, we found AQP1 levels influence the expression of Bcl-2, with enhanced AQP1 levels corresponding to increased Bcl-2 expression, reducing the ratio of BAX to Bcl-2, consistent with apoptosis resistance. These results provide a mechanism by which AQP1 can regulate PASMC fate.

Protective Effect of Memantine on Cisplatin-Induced Ototoxicity: An In Vitro Study.

HYPOTHESIS: Memantine, an N -methyl- d -aspartate receptor antagonist, is widely used to treat Alzheimer's disease and has been found to have potential neuroprotective effects. In this study, we evaluated the protective effects of memantine against cisplatin-induced ototoxicity. BACKGROUND: Cisplatin is a widely used anticancer drug for various cancers; however, its use is limited by its side effects, including ototoxicity. Several drugs have been developed to reduce cisplatin toxicity. In this study, we treated cisplatin-damaged cochlear hair cells with memantine and evaluated its protective effects. METHOD: House Ear Institute Organ of Corti 1 (HEI-OC1) cells and cochlear explants were treated with cisplatin or memantine. Cell viability, apoptotic patterns, reactive oxygen species (ROS) production, Bcl-2/caspase-3 activity, and cell numbers were measured to evaluate the anti-apoptotic and antioxidative effects of memantine. RESULT: Memantine treatment significantly improved cell viability and reduced cisplatin-induced apoptosis in auditory cells. Bcl-2/caspase-3 activity was also significantly increased, suggesting anti-apoptotic effects against cisplatin-induced ototoxicity. CONCLUSION: Our results suggest that memantine protects against cisplatin-induced ototoxicity in vitro, providing a potential new strategy for preventing hearing loss in patients undergoing cisplatin chemotherapy.