Proapoptotic BAX and BAK: a requisite gateway to mitochondrial dysfunction and death

Pharmacological targeting cGAS/STING/NF-κB axis by tryptanthrin induces microglia polarization toward M2 phenotype and promotes functional recovery in a mouse model of spinal cord injury

JOURNAL/nrgr/04.03/01300535-202511000-00031/figure1/v/2024-12-20T164640Z/r/image-tiff The M1/M2 phenotypic shift of microglia after spinal cord injury plays an important role in the regulation of neuroinflammation during the secondary injury phase of spinal cord injury. Regulation of shifting microglia polarization from M1 (neurotoxic and proinflammatory type) to M2 (neuroprotective and anti-inflammatory type) after spinal cord injury appears to be crucial. Tryptanthrin possesses an anti-inflammatory biological function. However, its roles and the underlying molecular mechanisms in spinal cord injury remain unknown. In this study, we found that tryptanthrin inhibited microglia-derived inflammation by promoting polarization to the M2 phenotype in vitro . Tryptanthrin promoted M2 polarization through inactivating the cGAS/STING/NF-κB pathway. Additionally, we found that targeting the cGAS/STING/NF-κB pathway with tryptanthrin shifted microglia from the M1 to M2 phenotype after spinal cord injury, inhibited neuronal loss, and promoted tissue repair and functional recovery in a mouse model of spinal cord injury. Finally, using a conditional co-culture system, we found that microglia treated with tryptanthrin suppressed endoplasmic reticulum stress-related neuronal apoptosis. Taken together, these results suggest that by targeting the cGAS/STING/NF-κB axis, tryptanthrin attenuates microglia-derived neuroinflammation and promotes functional recovery after spinal cord injury through shifting microglia polarization to the M2 phenotype.

SIRT2 inhibition enhances mitochondrial apoptosis in Brucella-infected bovine placental trophoblast cells

Brucella is a successful pathogen that employs a plethora of immune evasion mechanisms. This contributes to pathogenesis and persistence and limits the efficacy of available treatments. An increasing understanding of host‒pathogen interactions suggests that integrating host-directed strategies with existing anti-Brucella treatments could lead to more effective bacterial clearance and a reduction in drug-resistant strains. SIRT2 is a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase found in mammals. It can deacetylate various transcription factors and regulatory proteins, playing crucial roles in host‒pathogen interactions and pathogen infection-induced apoptosis. In this study, we investigated the role of SIRT2 in Brucella-induced cell apoptosis using bovine placental trophoblast cells. Our results indicate that B. abortus A19 infection upregulates SIRT2 protein expression and significantly induces mitochondrial apoptosis in these cells. Furthermore, inhibition of SIRT2 exacerbates B. abortus A19-induced mitochondrial apoptosis and markedly inhibits intracellular bacterial survival. These results prove the role of SIRT2 in Brucella pathogenesis and the mechanism of action.

ASK1 limits kidney glucose reabsorption, growth, and mid-late proximal tubule KIM-1 induction when diabetes and Western diet are combined with SGLT2 inhibition

Selonsertib is an apoptosis signal-regulating kinase 1 inhibitor (ASK1i) that attenuated the decline in creatinine-based estimated GFR in humans with type 2 diabetes and kidney disease but increased the rate of acute kidney injury. This study explored the individual and combined kidney effects of selonsertib and the antihyperglycemic sodium-glucose cotransporter 2 inhibitor (SGLT2i) dapagliflozin in Western diet-fed male Akita mice, a murine model of early type 1 diabetes mellitus showing signs of systemic but no kidney inflammation. ASK1i reduced elevated plasma levels of proinflammatory cytokines/chemokines (IL-6, MCP1/CCL2, KC/CXCL1, and IP-10/CXCL10) without significantly changing hyperglycemia, glomerular hyperfiltration, and albuminuria or affecting the blood glucose and glomerular hyperfiltration-lowering effect of SGLT2i. A potential sign of tubular stress, SGLT2i modestly upregulated kidney cortex transcription of proinflammatory and profibrotic genes and distal tubule injury marker Ngal. Adding ASK1i to SGLT2i lowered the transcription of many of these genes, including Ngal. However, ASK1i enhanced kidney glucose reabsorption independent of SGLT2i, and combined ASK1i + SGLT2i increased kidney weight by 30%. This was associated with and positively correlated with the upregulation of the tubular stress/injury marker KIM-1, primarily in the mid-to-late proximal tubule. Combined ASK1i + SGLT2i increased the tubular injury score but not signs of kidney inflammation or fibrosis beyond a robust increase in kidney mRNA expression of Il6, Ccl2 (Mcp1), and Timp1, associated with increased plasma IL-6 levels. The data support the hypothesis that housekeeping functions of ASK1 limit glucose reabsorption and the associated growth and cellular stress induced in the mid-to-late proximal tubule by combining hyperglycemia and Western diet with SGLT2 inhibition.NEW & NOTEWORTHY Selonsertib is an apoptosis signal-regulating kinase 1 (ASK1) inhibitor that attenuated creatinine-based eGFR decline in humans with type 2 diabetes and kidney disease but increased acute kidney injury rates. Here, we report evidence in a murine model of early type 1 diabetes mellitus that housekeeping functions of ASK1 limit glucose reabsorption and the associated growth and cellular stress induced in the mid-to-late proximal tubule by combining hyperglycemia and Western diet with SGLT2 inhibition.

Involvement of GSK-3β, NF-κB, PPARγ, and apoptosis in amlodipine's anticancer effect in BALB/c mice

Lung cancer is the primary cause of death due to cancer all over the world despite the decrease in the mortality rates from cancer in general. While chemotherapy is a commonly employed treatment for lung cancer, its efficacy is limited due to poor tissue selectivity, inadequate delivery to tumor sites, and associated side effects. The present work aims to assess the potential anti-cancer effectiveness of amlodipine, a calcium channel blocker, on murine lung cancer via modulating GSK-3β, NF-κB, PPARγ, and apoptosis. Lung cancer was induced in BALB/c mice by intraperitoneal injection of 1.5 g/kg in two doses of urethane: once on the 1st and the second on the 60th day of the experiment. Amlodipine was administered orally at a dose of 10 mg/kg/day for the last 28 days of experiment. Relative to urethane group, amlodipine mitigated urethane-induced histopathological abnormalities. It restored oxidant/antioxidant balance by normalizing MDA, GSH, and SOD. Furthermore, it exerted a marked anti-inflammatory effect through downregulating lung MPO, ICAM-1, IL-6, TNF-α, and NF-қB expressions. Amlodipine enhanced apoptosis of cancer cells as evidenced by increasing Bax and decreasing Bcl-2 expression. The anticancer effect of amlodipine was suggested to be mediated through increasing PPARγ and reducing GSK3β and p-GSK3β signaling. Collectively, these results suggest that amlodipine could exert a promising anticancer effect against lung cancer through modulating GSK-3β, NF-κB, PPARγ, and apoptosis. Our findings could be highly significant in clinical settings, offering a valuable adjuvant option for managing lung carcinoma, particularly in patients with cardiovascular disorders.

In-situ Sprayed platelet-derived small extracellular vesicles for the skin flap survival by reducing PANoptosis

Necrosis at the distal end of random skin flaps remains a significant challenge, limiting the clinical application of these flaps in plastic and reconstructive surgery. Inhibiting ischemia/reperfusion (I/R) injury and promoting the formation of neovascular networks are critical preventive strategies. Platelet-derived small extracellular vesicles (PL-sEV) are nanocarriers of growth factors that provide an alternative to clinically used platelet-rich plasma and platelet lysates, offering higher growth factor concentrations and lower immunogenicity. In this study, PANoptosis, a distinct form of inflammatory cell death, was fully characterized in a random skin flap model. Subcutaneous injection of PL-sEV improved ischemic skin flap survival by enhancing blood perfusion and reducing PANoptosis levels. In vitro, PL-sEV inhibited oxygen-glucose deprivation/reoxygenation-induced dysfunction in human umbilical vein endothelial cells. Furthermore, PL-sEV was incorporated into a thermosensitive triblock hydrogel, creating a sprayable delivery system (PLEL@PL-sEV). Mechanistic analysis through RNA sequencing indicated that the protective effects of PL-sEV against PANoptosis likely resulted from its anti-inflammatory properties, particularly via suppression of the NF-κB signaling pathway. This novel hydrogel system demonstrated controlled release of PL-sEV and proved effective in improving skin flap transplantation outcomes.

Re-appraising assays on permeabilized blood cancer cells testing venetoclax or other BH3 mimetic agents selectively targeting pro-survival BCL2 proteins

BH3 mimetic drugs that selectively target the pro-survival BCL2 proteins are highly promising for cancer treatment, most notably for treating blood cancers. Venetoclax, which inhibits BCL2, is now approved for treating chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML). Preferably, robust and validated assays would identify patients most likely to benefit from therapy with venetoclax itself or with inhibitors of other pro-survival proteins. A sophisticated method that has been developed is the BH3 profiling assay. In this assay, permeabilized, instead of intact, cells are treated for a few hours with inhibitors of the pro-survival BCL2 proteins, and the resultant mitochondrial depolarization measured. Sensitivity to a specific inhibitor (e.g., venetoclax or other BH3 mimetics) is then used to infer the reliance of a tumor (e.g., CLL) on one or more pro-survival BCL2 proteins. However, we found that this methodology cannot reliably identify such dependencies. In part, this is because almost all cells express multiple pro-survival BCL2 proteins that restrain BAX and BAK which must be inhibited before mitochondrial depolarization and apoptosis can proceed. Using genetic and pharmacological tools across multiple cell line models of blood cancer, we demonstrated that selective BCL2 inhibitors have important flow-on effects that includes the redistribution of BH3-only proteins to ancillary pro-survival proteins not directly engaged by the inhibitor. These secondary effects, critical to the biological action of selective inhibitors, were not accurately recapitulated in permeabilized cells, probably due to the limited time frame possible in such assays or the altered biophysical conditions when cells are permeabilized. While we could consistently define the sensitivity of a tumor cell to a particular BH3 mimetic drugs using intact cells, this was not reliable with permeabilized cells. These studies emphasize the need to carefully evaluate assays on permeabilized cells undertaken with inhibitors of the pro-survival BCL2 proteins.

Curcumin as a protective agent against chromium and ammonia toxicity using molecular and biochemical approaches in fish

In aquatic ecosystems, metal and ammonia pollution pose major concern as they contaminate the environment and induces toxicity in fish. The present study addresses the toxicity induced by chromium (Cr) and ammonia (NH3) toxicity in fish and investigates the potential of dietary curcumin in mitigating the effects of concurrent exposure to theses stressors in Pangasianodon hypophthalmus. Three isonitrogenous and isocaloric diets were formulated: a control diet (0% curcumin) and two curcumin-supplemented diets containing 0.1% and 0.2% curcumin. Four experimental groups were designed in a completely randomized design: (1) control, (2) concurrent exposure to Cr and NH3 toxicity and fed with control diet, (3) 0.1% curcumin with Cr and NH3 exposure, and (4) 0.2% curcumin with Cr and NH3 exposure. Fish fed with 0.2% curcumin diet, followed by the 0.1% curcumin diet under Cr and NH3 stress, exhibited significantly reduced cortisol levels compared to the control and Cr + NH3 groups. Similarly, the expression of HSP70 and iNOS genes in liver tissue was significantly downregulated in the 0.1% and 0.2% curcumin-fed groups compared to other groups. Concurrent exposure to Cr and NH3 led to a considerable increase in oxidative stress enzyme in liver and kidney tissues, including glutathione S-transferase (GST), catalase (CAT), and superoxide dismutase (SOD). However, dietary supplementation with 0.1% curcumin significantly reduced oxidative stress enzyme activities. The stressors markedly reduced acetylcholinesterase (AChE) activity, but supplementation with 0.1% curcumin restored AChE activity. The expression of stress-related genes such as cytochrome P450 (CYP450), caspase-3a (Cas3a), and tumor necrosis factor-alpha (TNF-α) was noticeably downregulated in the curcumin-fed groups, reducing the impact of Cr + NH3 stress. Furthermore, total immunoglobulin (Ig) levels and growth-related gene expression, including growth hormone (GH) and growth hormone receptor 1 (GHR1), were significantly upregulated in the 0.1% curcumin-fed group under Cr + NH3 stress compared to all other groups. Additionally, myostatin (MYST) gene expression was significantly downregulated in the 0.1% curcumin-fed group. Activities of cellular metabolic and digestive enzymes were significantly improved with curcumin supplementation, mitigating the adverse effects of Cr + NH3 stress compared to the control and other groups. Moreover, Cr bioaccumulation in different fish tissues was reduced in the 0.1% curcumin-fed group. This study highlights the potential of dietary curcumin in mitigating the adverse effects of concurrent Cr and NH3 exposure through gene regulation, thereby improving the physiological and productive performance of Pangasianodon hypophthalmus.

Cytosolic cytochrome c represses ferroptosis

The release of cytochrome c, somatic (CYCS) from mitochondria to the cytosol is an established trigger of caspase-dependent apoptosis. Here, we unveil an unexpected role for cytosolic CYCS in inhibiting ferroptosis-a form of oxidative cell death driven by uncontrolled lipid peroxidation. Mass spectrometry and site-directed mutagenesis revealed the existence of a cytosolic complex composed of inositol polyphosphate-4-phosphatase type I A (INPP4A) and CYCS. This CYCS-INPP4A complex is distinct from the CYCS-apoptotic peptidase activating factor 1 (APAF1)-caspase-9 apoptosome formed during mitochondrial apoptosis. CYCS boosts INPP4A activity, leading to increased formation of phosphatidylinositol-3-phosphate, which prevents phospholipid peroxidation and plasma membrane rupture, thus averting ferroptotic cell death. Unbiased screening led to the identification of the small-molecule compound 10A3, which disrupts the CYCS-INPP4A interaction. 10A3 sensitized cultured cells and tumors implanted in immunocompetent mice to ferroptosis. Collectively, these findings redefine our understanding of cytosolic CYCS complexes that govern diverse cell death pathways.

The protective effects of sesamin on the ileum in superior mesenteric artery ischemia induced in rats

BACKGROUND

Acute mesenteric artery ischemia is recognized as a significant cause of mortality and morbidity, with its incidence increasing with age. This study aims to investigate the efficacy of sesamin in mitigating the histological, immunological, and biochemical damage associated with superior mesenteric artery ischemia and reperfusion (SMA I/R) injury in the ileum.

METHODS

Twenty-eight Sprague-Dawley rats were randomly assigned into four equal groups. Group I (Control group): Received no treatment. Group II (SMA I/R group): Carboxymethylcellulose was mixed with distilled water and administered orally via gavage at a dose of 1 mL/kg/dose for three weeks. At the end of the third week, SMA ischemia was induced for 60 minutes followed by 120 minutes of reperfusion. Group III (Sesamin group): Received sesamin orally at a dose of 30 mg/kg via gavage for three weeks. Group IV (Sesamin + SMA I/R group): Received sesamin followed by SMA I/R.

RESULTS

Serum malondialdehyde (MDA) levels were highest in the SMA I/R group, while lower levels were observed in the Sesamin + SMA I/R group (p<0.05). Similarly, total oxidant status (TOS) was significantly reduced in the Sesamin + SMA I/R group compared to the SMA I/R group (p<0.05). Consistent with these findings, Bax expression, a pro-apoptotic marker, was less intense in the Sesamin + SMA I/R group than in the SMA I/R group.

CONCLUSION

Our findings indicate that the administration of sesamin prior to SMA I/R effectively reduces oxidative damage and prevents histological alterations, as demonstrated by histological, immunohistochemical, and biochemical parameters.

The antiviral BDGR-49 provides protection from lethal, neurotropic Venezuelan equine encephalitis virus intranasal infection in mice

Venezuelan, western, and eastern equine encephalitis virus (VEEV, WEEV, and EEEV) cause a febrile illness that may result in fatal neurological disease in humans and equines. Human infections are typically from mosquito bites, although cases from respiratory exposure in laboratory accidents have been documented. In addition to natural mosquito-borne infection, the potential biothreat inherent in the ability to disseminate these viruses via the respiratory route has driven the development of antiviral drugs for this route of exposure. To address this gap, we tested the prophylactic administration of a novel brain-penetrant, antiviral, BDGR-49, against a lethal intranasal challenge of VEEV, WEEV, or EEEV in BALB/c mouse model. BDGR-49 conferred 100% protection with 6 mg kg-1 twice per day for 6 days for VEEV, but not EEEV or WEEV. By 8 days post-infection (dpi), infectious virus, viral RNA, and viral antigen in the brain of BDGR-49-treated mice were significantly reduced. Brains of VEEV TrD-infected, BDGR-49-treated mice showed a significant reduction in the expression of genes associated with inflammation (IFNB1, TNF, IL6, and CCL5) and cell death (CASP4, GSDMD, PYCARD, and ZBP1). At dpi 14, histopathology showed that neuronal lesions and inflammatory cell infiltrates were essentially absent, and viral antigen was not detected in the brains of VEEV TrD-infected, BDGR-49-treated mice. In summary, although BDGR-49 treatment showed significant promise for the treatment of mice exposed intranasally to VEEV, the more rapid and efficient entry of EEEV and WEEV by this route into the central nervous system will require additional optimization of the dosing regimen.IMPORTANCEProphylactic and therapeutic treatment of viruses that cause encephalitis requires fast-acting drugs that rapidly penetrate the blood-brain barrier. Currently, clinicians have only a limited set of antivirals for the treatment of neurotropic infections such as herpesviruses or HIV-1, and none for alphaviruses, and treatment outcomes remain poor. New medical countermeasures will address the gap in treatment of viral encephalitis such as those caused by the neurotropic alphaviruses and others.

MYBL2 promotes cell proliferation and inhibits cell apoptosis via PI3K/AKT and BCL2/BAX/Cleaved-caspase-3 signaling pathway in gastric cancer cells

The transcription factor MYB proto-oncogene like 2 (MYBL2) has been reported to be involved in the occurrence and development of various tumors, however, its role in gastric cancer (GC) remains to be elucidated. In this study, the Kaplan-Meier plotter was used to evaluate the prognostic value of different MYBL2 expression levels in GC patients. The UALCAN database were applied to analyze the relationships between MYBL2 and clinicopathological characteristics of GC. GC cell proliferation, cell cycle and apoptosis were determined by CCK-8 and flow cytometry assays, and proteins were examined by Western blot analysis. Next, signaling pathway enrichment analysis of MYBL2-related genes and protein expression were analyzed by Gene Set Enrichment Analysis (GSEA) and Western blot assays. The results found that MYBL2 expression was significantly upregulated in GC compared with adjacent non-malignant tissues and associated with poor patient survival, tumor, stages and lymph node metastasis. Forced expression of MYBL2 could promote cell proliferation, resulting in an accelerated S phase progression and inhibiting cell apoptosis in GC cells. Conversely, MYBL2 silencing inhibited cell proliferation, induced G2/M phase arrest and promoted cell apoptosis in GC cells. Mechanistically, Western blot analysis showed that MYBL2 silencing decreased the expression of BCL2 and upregulated the expression of Cleaved-caspase-3 and BAX in HGC-27 cells. Conversely, MYBL2 overexpression in AGS cells resulted in the opposite effects. Furthermore, enforced expression of MYBL2 activated the PI3K/AKT signaling pathway, especially AKT phosphorylation. Additionally, the AKT inhibitor MK2206 significantly reversed the proliferation capacity of GC cells induced by MYBL2 overexpression. Therefore, these results suggest that upregulated expression of MYBL2 contributes to GC cell growth and inhibits cell apoptosis by regulating the PI3K/AKT and BCL2/BAX/Cleaved-caspase-3 signaling pathways in GC cells indicating that MYBL2 may be a new therapeutic target and prognostic marker for GC.

Targeted siRNA Delivery Against RUNX1 Via tFNA: Inhibiting Retinal Neovascularization and Restoring Vessels Through Dll4/Notch1 Signaling

Purpose

To assess the efficacy of tetrahedral framework nucleic acids (tFNAs) as a delivery system for small interfering RNA (siRNA) targeting RUNX1 (siRUNX1) in inhibiting retinal neovascularization (RNV) and restoring vascular integrity via the Dll4/Notch1 signaling pathway.

Methods

tFNAs and tFNAs-siRUNX1 were synthesized using annealing of single-stranded DNAs and characterized by PAGE and high-performance capillary electrophoresis. Human umbilical vein endothelial cells were treated under hypoxic conditions with tFNAs-siRUNX1, and cellular uptake was evaluated using fluorescence microscopy and flow cytometry. Angiogenesis was assessed through EdU proliferation, tube formation, and wound-healing assays. In vivo experiments used oxygen-induced retinopathy (OIR) and laser-induced choroidal neovascularization (CNV) models in mice, with subsequent imaging by optical coherence tomography (OCT) and fundus fluorescence angiography. Gene and protein expression were analyzed by RT-PCR and Western blotting, focusing on the Dll4/Notch1 pathway and apoptosis markers.

Results

tFNAs-siRUNX1 effectively inhibited endothelial cell proliferation, migration, and tube formation in vitro. In OIR and CNV models, it reduced neovascularization, nonperfusion areas, and vascular leakage. The mechanism involved modulation of the Dll4/Notch1 pathway, with decreased Dll4, Notch1, and Hes1 and increased Nts expression. tFNAs-siRUNX1 also reduced endothelial cell apoptosis via the Bcl-2/Bax pathway.

Conclusions

tFNAs-siRUNX1 is a promising delivery system for targeting RNV, inhibiting neovascularization, and restoring retinal vascular integrity, providing a potential therapeutic alternative to anti-VEGF treatments.

Combined effect of mercury and ammonia toxicity and its mitigation through selenium nanoparticles in fish

An experiment was conducted to mitigate mercury and ammonia toxicity (Hg + NH₃) in Oreochromis niloticus (GIFT strain) using selenium nanoparticles (Se-NPs). The Se-NPs were synthesized using green methods, employing fish waste as the substrate. Experimental diets were prepared by supplementing Se-NPs at 0, 0.3, and 0.6 mg kg⁻¹. The oxidative stress enzymes, including catalase (CAT) and glutathione peroxidase (GPx), in the liver and kidney tissues were significantly reduced by Se-NPs at 0.3 and 0.6 mg kg⁻¹ under Hg + NH₃ stress compared to the control and stressor in 20 and 40 day periods. Additionally, superoxide dismutase (SOD) activity in the kidney at 20 days and in the liver at 40 days was significantly reduced by supplementation of Se-NPs under similar conditions. The activity of acetylcholine esterase (AChE), was significantly inhibited by Hg + NH₃ toxicity. Whereas, AChE activity was enhanced by Se-NPs supplementation at 0.3 and 0.6 mg kg⁻¹ during 20 and 40 day intervals. The gene expression of HSP70, iNOS, CYP450, Caspase-3a, and TNFα in liver tissue, and MYST in muscle tissue was upregulated by Hg+NH₃ toxicity. However, this upregulation was significantly downregulated by supplementation of Se-NPs at 0.3 and 0.6 mg kg⁻¹ under Hg + NH₃ stress. Moreover, immunoglobulin (Ig) and growth hormone (GH) levels were noticeably upregulated with Se-NPs compared to the control and Hg+NH₃ stress. The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and malate dehydrogenase (MDH) in liver and gill tissues, were significantly elevated by Hg+NH₃ toxicity, were reduced by Se-NPs diet. Conversely, digestive enzyme activities, including protease, amylase, and lipase, were significantly enhanced by Se-NPs under stress conditions. Dietary supplementation with Se-NPs at 0.3 and 0.6 mg kg⁻¹ improved growth performance parameters such as final weight gain percentage, feed conversion ratio, protein conversion ratio, specific growth rate, daily growth index, and relative feed intake compared to the control and other groups. DNA damage, assessed in terms of tail DNA percentage, was significantly reduced with Se-NPs supplementation. Additionally, mercury detoxification was significantly enhanced with Se-NPs-supplemented diets. In conclusion, this study demonstrates that dietary Se-NPs effectively alleviate the adverse effects of mercury and ammonia toxicity by modulating antioxidant status, enhancing immunomodulation, and mitigating stress biomarker impacts through changes in gene expression in fish.

Conventional chemotherapy: millions of cures, unresolved therapeutic index

In recent decades, millions of patients with cancer have been cured by chemotherapy alone. By 'cure', we mean that patients with cancers that would be fatal if left untreated receive a time-limited course of chemotherapy and their cancer disappears, never to return. In an era when hundreds of thousands of cancer genomes have been sequenced, a remarkable fact persists: in most patients who have been cured, we still do not fully understand the mechanisms underlying the therapeutic index by which the tumour cells are killed, but normal cells are somehow spared. In contrast, in more recent years, patients with cancer have benefited from targeted therapies that usually do not cure but whose mechanisms of therapeutic index are, at least superficially, understood. In this Perspective, we will explore the various and sometimes contradictory models that have attempted to explain why chemotherapy can cure some patients with cancer, and what gaps in our understanding of the therapeutic index of chemotherapy remain to be filled. We will summarize principles which have benefited curative conventional chemotherapy regimens in the past, principles which might be deployed in constructing combinations that include modern targeted therapies.

Impaired inflammatory resolution with severe SARS-CoV-2 infection in leptin knock out obese hamster

Comorbidities, such as obesity, increase the risk of severe COVID-19. However, the mechanisms underlying severe illnesses in individuals with obesity are poorly understood. Here, we used gene-edited leptin knock out (Leptin -/-) obese hamsters to establish a severe infection model. This model exhibits robust viral replication, severe lung lesions, pronounced clinical symptoms, and fatal infection, mirroring severe COVID-19 in patients with obesity. Using single-cell transcriptomics on lung tissues pre- and post-infection, we found that monocyte-derived alveolar macrophages (MD-AM) play a key role in lung hyper-inflammation, including two unique MD-AM cell fate branches specific to Leptin -/- hamsters. Notably, reduced Trem2-dependent efferocytosis pathways in Leptin -/- hamsters indicated weakened inflammation resolution, consistent with the scRNA-seq data from patients with obesity. In summary, our study highlights the obesity-associated mechanisms underlying severe SARS-CoV-2 infections and establishes a reliable preclinical animal model for developing obesity-specific therapeutics for critical COVID-19.

Ferroptosis and PANoptosis under hypoxia pivoting on the crosstalk between DHODH and GPX4 in corneal epithelium

Cell death under stress conditions like hypoxia, involves multiple interconnected pathways. In this study, a stable dihydroorotate dehydrogenase (DHODH) knockdown human corneal epithelial cell line was established to explore the regulation of hypoxic cell death, which was mitigated by various cell death inhibitors, particularly by a lipid peroxyl radical scavenger liproxstatin-1 (Lip-1), suggesting that hypoxic cell death involves crosstalk of ferroptosis and PANoptosis. We discovered that both DHODH and Glutathione peroxidase 4 (GPX4) protected cells from hypoxic death by inhibiting lipid peroxidation, mitochondrial reactive oxygen species (ROS) and maintaining mitochondrial membrane potential. However, upregulation of DHODH suppressed GPX4 upstream, exhibiting a trade-off in the expression levels between DHODH and GPX4 under hypoxia, with DHODH exerting a more decisive impact on cell survival. DHODH knockdown under hypoxia did not significantly alter lipid peroxidation levels, demonstrating the balance between DHODH and GPX4 expression finely regulated cellular ferroptosis homeostasis. This study highlights the complex interplay between ferroptosis and PANoptosis in hypoxic cell death, particularly the dual role of DHODH in regulating both pathways. DHODH is not merely maintaining the quantity of mitochondria but is promoting the selection of mitochondria favorable to cell survival. These findings not only deepen our understanding of cell death but also suggest potential therapeutic strategies for diseases involving oxidative stress and mitochondrial dysfunction.

Triterpenoid phthalimides as selective anti-cancer agents targeting mitochondrial apoptosis

Starting from benzyl 30-oxobetulinate and 30-oxobetulin diacetate, substituted dienes were synthesized and subjected to Diels-Alder reaction, yielding a variety of triterpenoid phthalates, phthalimides, and related derivatives. A total of 55 new compounds were prepared and tested for in vitro cytotoxic activity against eight cancer cell lines and two non-cancerous cell lines. Four compounds with IC50 values of 5 μM or lower were selected for further investigation. These compounds induced apoptosis in CCRF-CEM cells in a concentration-dependent manner, accompanied by mitochondrial depolarization and altered expression of key proteins involved in mitochondrial apoptosis. The compounds also disrupted DNA replication and transcriptional activity. Modulation of key proliferation pathways, including PI3K/Akt and STAT3, further supported the antiproliferative potential of these derivatives. Considering their high cytotoxicity and antiproliferative activity in CCRF-CEM cells, compounds 19, 26, 28, and 30 have been identified as promising candidates for further development.

Elucidating the dual roles of apoptosis and necroptosis in diabetic wound healing: implications for therapeutic intervention

Wound healing is a complex and multistep biological process that involves the cooperation of various cell types. Programmed cell death, including apoptosis and necrotizing apoptosis, plays a crucial role in this process. Apoptosis, a controlled and orderly programmed cell death regulated by genes, helps eliminate unnecessary or abnormal cells and maintain internal environmental stability. It also regulates various cell functions and contributes to the development of many diseases. In wound healing, programmed cell death is essential for removing inflammatory cells and forming scars. On the other hand, necroptosis, another form of programmed cell death, has not been thoroughly investigated regarding its role in wound healing. This review explores the changes and apoptosis of specific cell groups during wound healing after an injury and delves into the potential underlying mechanisms. Furthermore, it briefly discusses the possible mechanisms linking wound inflammation and fibrosis to apoptosis in wound healing. By understanding the relationship between apoptosis and wound healing and investigating the molecular mechanisms involved in apoptosis regulation, new strategies for the clinical treatment of wound healing may be discovered.

The Protective Effect of Nimodipine in Schwann Cells Is Related to the Upregulation of LMO4 and SERCA3 Accompanied by the Fine-Tuning of Intracellular Calcium Levels

Nimodipine is the current gold standard in the treatment of subarachnoid hemorrhage, as it is the only known calcium channel blocker that has been proven to improve neurological outcomes. In addition, nimodipine exhibits neuroprotective properties in vitro under various stress conditions. Furthermore, clinical studies have demonstrated a neuroprotective effect of nimodipine after vestibular schwannoma surgery. However, the molecular mode of action of nimodipine pre-treatment has not been well investigated. In the present study, using real-time cell death assays, we demonstrated that nimodipine not only reduces cell death induced by osmotic and oxidative stress but also protects cells directly at the time of stress induction in Schwann cells. Nimodipine counteracts stress-induced calcium overload and the overexpression of the Cav1.2 calcium channel. In addition, we found nimodipine-dependent upregulation of sarcoplasmic/endoplasmic reticulum calcium ATPase 3 (SERCA3) and LIM domain only 4 (LMO4) protein. Analysis of anti-apoptotic cell signaling showed an inhibition of the pro-apoptotic protein glycogen synthase kinase 3 beta (GSK3β). Nimodipine-treated Schwann cells exhibited higher levels of phosphorylated GSK3β at serine residue 9 during osmotic and oxidative stress. In conclusion, nimodipine prevents cell death by protecting cells from calcium overload by fine-tuning intracellular calcium signaling and gene expression.

Pol II degradation activates cell death independently from the loss of transcription

Pol II-mediated transcription is essential for eukaryotic life. While loss of transcription is thought to be universally lethal, the associated mechanisms promoting cell death are not yet known. Here, we show that death following loss of Pol II is not caused by dysregulated gene expression. Instead, death occurs in response to the loss of Pol II protein itself, specifically loss of the enzymatic subunit, Rbp1. Loss of Pol II exclusively activates apoptosis, and expression of a transcriptionally inactive version of Rpb1 rescues cell viability. Using functional genomics, we identify a previously uncharacterized mechanism that regulates lethality following loss of Pol II, which we call the Pol II Degradation-dependent Apoptotic Response (PDAR). Using the genetic dependencies of PDAR, we identify clinically used drugs that owe their efficacy to a PDAR-dependent mechanism. Our findings unveil a novel apoptotic signaling response that contributes to the efficacy of a wide array of anti-cancer therapies.

Investigating the protective effects of fluvoxamine against sepsis-related acute lung injury through antiapoptotic, anti-inflammatory, and anti-oxidant features in rats

Objectives

Acute lung injury (ALI) is characterized by severe hypoxia and alveolar damage, often caused by oxidative stress, endoplasmic reticulum stress (ERS), and apoptosis. Fluvoxamine (FLV), an antidepressant, has tissue-protective properties through various intracellular mechanisms. This study investigates the anti-inflammatory effects of FLV used as an antidepressant in a lipopolysaccharide (LPS)-induced ALI model.

Materials and Methods

Thirty-two female Wistar Albino rats aged 14-16 weeks and weighing 300-350 g, with 8 animals in each group, were divided into four groups: control, LPS, LPS+FLV, and FLV. After LPS administration, rats were euthanized, and histopathological analysis, immunohistochemistry for tumor necrosis factor-α (TNF-α) and caspase-3 (Cas-3), ELISA for oxidative stress markers, and PCR for CHOP, Cas-12, and Cas-9 gene expressions were conducted.

Results

In the LPS group, lung tissue damage, increased inflammatory cell infiltration, increased Cas-3 and TNF-α expressions, increased oxidative stress markers, and increased CHOP, Cas-9, and Cas-12 mRNA expressions were observed compared to the control group. FLV treatment in the LPS+FLV group significantly reversed these effects in the LPS group.

Conclusion

FLV exhibits protective effects against ALI by mitigating inflammation, ERS, and apoptosis via the CHOP/Cas-9/Cas-12 pathway. Further studies are needed to explore additional pathways and potential clinical applications of FLV.

Mechanistic Insights on Cardioprotective Properties of Ursolic Acid: Regulation of Mitochondrial and Non-mitochondrial Pathways

Ursolic acid, a natural pentacyclic triterpenoid compound, has been shown to have significant cardioprotective effects in various preclinical studies. This article reviews the various mechanisms by which ursolic acid achieves its cardioprotective effects, highlighting its potent anti-oxidant, anti-inflammatory, and anti- apoptotic properties. Ursolic acid upregulates anti-oxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GPx), effectively reducing oxidative stress, thereby decreasing reactive oxygen species (ROS) and improving lipid peroxidation levels. Furthermore, ursolic acid downregulates pro-inflammatory cytokines and inhibits key inflammatory pathways, such as nuclear factor kappa B (NF-κB), which results in its anti-inflammatory effects. These actions help in protecting cardiac tissues from acute and chronic inflammation. Ursolic acid also promotes mitochondrial function and energy metabolism by enhancing mitochondrial biogenesis and reducing dysfunction, which is critical during ischemia-reperfusion (I/R) injury. Additionally, ursolic acid influences multiple molecular pathways, including B-cell leukemia/lymphoma 2 protein (Bcl- 2)/Bcl-2 associated x-protein (Bax), miR-21/extracellular signal-regulated kinase (ERK), and phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt), to reduce cardiomyocyte apoptosis. Collectively, these properties make ursolic acid a promising therapeutic agent for cardiovascular diseases (CVDs), warranting further research and clinical trials to harness its potential fully.

BI1 Activates Autophagy and Mediates TDP43 to Regulate ALS Pathogenesis

Amyotrophic lateral sclerosis (ALS) is the most prevalent motor neuron disease in adults. Currently, there are no known drugs or clinical approaches that have demonstrated efficacy in treating ALS. Mitochondrial function and autophagy have been identified as crucial mechanisms in the development of ALS. While Bax inhibitor 1 (BI1) has been implicated in neurodegenerative diseases, its exact mechanism remains unknown. This study investigates the therapeutic impact of BI1 overexpression on ALS both in vivo and in vitro, revealing its ability to mitigate SOD1G93A-induced apoptosis, nuclear damage, mitochondrial dysfunction, and axonal degeneration of motor neurons. At the same time, BI1 prolongs onset time and lifespan of ALS mice, improves motor function, and alleviates neuronal damage, muscle damage, neuromuscular junction damage among other aspects. The findings indicate that BI1 can inhibit pathological TDP43 morphology and initially stimulate autophagy through interaction with TDP43. This study establishes a solid theoretical foundation for understanding the regulation of autophagy by BI1 and TDP43 while shedding light on the pathogenesis of ALS through their interaction - offering new concepts and targets for clinical implementation and drug development.

Tyrosine Kinase Inhibitor Lenvatinib Causes Cardiotoxicity by Inducing Endoplasmic Reticulum Stress and Apoptosis through Activating ATF6, IRE1α and PERK Signaling Pathways

BACKGROUND

Lenvatinib is a tyrosine kinase inhibitor that can improve progression-free survival in patients with thyroid cancer and hepatocellular carcinoma. However, it is limited by adverse cardiovascular events, including hypertension and cardiac dysfunction. Activation of endoplasmic reticulum stress is involved in cardiomyocyte apoptosis.

OBJECTIVE

This study aimed to confirm whether the cardiotoxicity of lenvatinib is associated with endoplasmic reticulum stress by targeting the activating transcription factor 6 (ATF6), inositol- requiring enzyme 1α (IRE1α) and protein kinase RNA-like ER kinase (PERK) signaling pathways.

METHODS

Male C57/BL6 mice were intragastric administration with 30 mg/kg/day lenvatinib. Electrocardiography (ECG) and echocardiography were used to detect arrhythmias and cardiac function. Neonatal rat cardiomyocytes were treated with lenvatinib for 48h. Cell counting kit (CCK8), 2´,7´-dichlorodihydrofluoresceine diacetate (H2DCFHDA), Hoechst 33258 and dihydrorhodamine 123 were respectively used for evaluating cell viability, the level of reactive oxygen species (ROS), nuclear morphological changes and mitochondrial membrane potential (MMP) level.

RESULTS

Lenvatinib remarkably decreased the posterior wall thickness of left ventricle during diastole and systole but caused little decrease to the left ventricular ejection fraction (LVEF, %). Furthermore, lenvatinib greatly prolonged the corrected QT interval (QTc) and altered the morphology of cardiomyocytes. No significant difference in fibrosis was found in mouse cardiac slices. Lenvatinib upregulates apoptosis-related protein expression. In addition, lenvatinib increased ERS-related proteins expression (GRP78, CHOP, and ATF6) and enhanced PERK phosphorylation. In neonatal rat cardiac myocytes, lenvatinib markedly decreased the viability of cardiomyocytes and induced apoptosis. Furthermore, ROS production increased and MMP decreased. Similar to the mice experiment, lenvatinib caused upregulation of apoptosis-related and ERS-related proteins and increased the phosphorylation levels of PERK and IRE1α.

CONCLUSION

Lenvatinib-induced cardiotoxicity is associated with ERS-induced apoptosis by targeting the ATF6, IRE1α, and PERK signaling pathways.

Homologous recombination promotes non-immunogenic mitotic cell death upon DNA damage

Double-strand breaks (DSBs) can initiate mitotic catastrophe, a complex oncosuppressive phenomenon characterized by cell death during or after cell division. Here we unveil how cell cycle-regulated DSB repair guides disparate cell death outcomes through single-cell analysis of extended live imaging. Following DSB induction in S or G2, passage of unresolved homologous recombination intermediates into mitosis promotes non-immunogenic intrinsic apoptosis in the immediate attempt at cell division. Conversely, non-homologous end joining, microhomology-mediated end joining and single-strand annealing cooperate to enable damaged G1 cells to complete the first cell cycle with an aberrant cell division at the cost of delayed extrinsic lethality and interferon production. Targeting non-homologous end joining, microhomology-mediated end joining or single-strand annealing promotes mitotic death, while suppressing mitotic death enhances interferon production. Together the data indicate that a temporal repair hierarchy, coupled with cumulative DSB load, serves as a reliable predictor of mitotic catastrophe outcomes following genome damage. In this pathway, homologous recombination suppresses interferon production by promoting mitotic lethality.

Pioneering the Battle Against Breast Cancer: The Promise of New Bcl-2 Family

Currently, breast cancer is the most common cancer type, accounting for 1 in every 4 cancer cases. Leading both in mortality and incidence, breast cancer causes 1 in 4 cancer deaths. To decrease the burden of breast cancer, novel therapeutic agents which target the key hallmarks of cancer, are being explored. The Bcl-2 family of proteins has a crucial role in governing cell death, making them an attractive target for cancer therapy. As cancer chemotherapies lead to oncogenic stress, cancer cells upregulate the Bcl-2 family to overcome apoptosis, leading to failure of treatment. To fix this issue, Bcl-2 family inhibitors, which can cause cell death, have been introduced as novel therapeutic agents. Members of this group have shown promising results in in-vitro studies, and some are currently in clinical trials. In this review, we will investigate Bcl-2 family inhibitors, which are already in trials as monotherapy or combination therapy for breast cancer, and we will also highlight the result of in vitro studies of novel Bcl-2 family inhibitors on breast cancer cells. The findings of these studies have yielded encouraging outcomes regarding the identification of novel Bcl-2 family inhibitors. These compounds hold significant potential as efficacious agents for employment in both monotherapy and combination therapy settings.

Eltrombopag restores proliferative capacity and adipose-osteogenic balance of mesenchymal stromal cells in low-risk myelodysplastic syndromes

In low-risk myelodysplastic syndromes (MDS), the proinflammatory signaling is excessive, and the proliferation and differentiation potentials of mesenchymal stromal cells (MSCs) are strongly impaired. Eltrombopag (ELT) has been demonstrated recently effective and relatively safe in low-risk MDS with severe thrombocytopenia. However, its impact on the MDS-MSCs has not been investigated in any detail. Here, for the first time, we investigated the changes induced by ELT in MSCs' viability, proliferation, apoptosis, senescence, multilineage differentiation properties, and stem cell support capacity in low-risk MDS patients. We demonstrated that ELT may act on improving the impaired inflammatory profile and reactivating the downregulated canonical WNT signaling pathway in low-risk MDS, and also restoring the self-renewal capacity and the balance in adipose-osteogenic differentiation of MDS-MSCs.

Effects of Exogenous Tryptophan in Alleviating Transport Stress in Pearl Gentian Grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂)

Live fish transportation plays a crucial role in the commercial fish trade. Consequently, mitigating stress during transportation is essential for enhancing the survival rate of fish and reducing potential financial losses. In this study, the effectiveness was evaluated of exogenous tryptophan in reducing transport stress in hybrid grouper, Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂. Firstly, the groupers were divided into the following five experimental groups: 40 mg/L MS-222 group, 30 mg/L tryptophan, 50 mg/L tryptophan, 70 mg/L tryptophan, and the control group without additives. Followed by transportation simulation, the fish samples were collected before and after transportation for the determination of antioxidant enzyme activities, apoptosis gene, and inflammatory gene expressions. The results indicated that the superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities and malondialdehyde (MDA) levels in all groups were significantly increased, while they were lower in the 50 mg/L Trp treated group compared to the control group (p < 0.05). Compared with the control group in the 50 mg/L Trp, 70 mg/L Trp, and 40 mg/L MS-222-treated groups, serum cortisol and blood glucose levels were significantly increased (p < 0.05), and anti-inflammatory factor (IL-10) gene expression was upregulated and pro-inflammatory factor (IL-1β) gene expression was decreased (p < 0.05). In addition, it was found that the 30 mg/L Trp, 50 mg/L Trp, and 40 mg/L MS-222 treatment groups had less green fluorescence than the control group by measuring the mitochondrial membrane potential, and 50 mg/L Trp and MS-222 showed more red fluorescence in fluorescence images than the other samples at the same sampling time. Therefore, in this study, it was demonstrated that the tryptophan could be used as a new anti-stress agent for hybrid groupers during transport, and additional research is required to identify the specific conditions that yield the best outcomes.

Potent combination benefit of the AKT inhibitor capivasertib and the BCL-2 inhibitor venetoclax in diffuse large B cell lymphoma

The therapeutic potential of targeting PI3K/AKT/PTEN signalling in B-cell malignancies remains attractive. Whilst PI3K-α/δ inhibitors demonstrate clinical benefit in certain B-cell lymphomas, PI3K signalling inhibitors have been inadequate in relapsed/refractory diffuse large B-cell lymphoma (DLBCL) in part, due to treatment related toxicities. Clinically, AKT inhibitors exhibit a differentiated tolerability profile offering an alternative approach for treating patients with B-cell malignancies. To explore how AKT inhibition complements other potential therapeutics in the treatment of DLBCL patients, an in vitro combination screen was conducted across a panel of DLCBL cell lines. The AKT inhibitor, capivasertib, in combination with the BCL-2 inhibitor, venetoclax, produced notable therapeutic benefit in preclinical models of DLBCL. Capivasertib and venetoclax rapidly induced caspase and PARP cleavage in GCB-DLBCL PTEN wildtype cell lines and those harbouring PTEN mutations or reduced PTEN protein, driving prolonged tumour growth inhibition in DLBCL cell line and patient derived xenograft lymphoma models. The addition of the rituximab further deepened the durability of capivasertib and venetoclax responses in a RCHOP refractory DLBCL in vivo models. These findings provide preclinical evidence for the rational treatment combination of AKT and BCL-2 inhibitors using capivasertib and venetoclax respectively alongside anti-CD20 antibody supplementation for treatment of patients with DLBCL.

Cytochrome c and cancer cell metabolism: A new perspective

Cytochrome c is a vital electron carrier in the mitochondrial respiratory chain. When the outer membrane of mitochondria becomes permeable, cytochrome c is discharged into the cytoplasm, where it initiates the intrinsic apoptosis pathway. The complex interaction between cytochrome c and apoptosis protease-activating factor-1 (Apaf-1) leads to the formation of the apoptosome and activation of a cascade of caspases, highlighting the critical role of cytochrome c in controlling cell death mechanisms. Additionally, cytochrome c undergoes post-translational modifications, especially phosphorylation, which intricately regulate its roles in both respiration and apoptosis. These modifications add layers of complexity to how cytochrome c effectively controls cellular functions. cytochrome c becomes a lighthouse in the intricate web of cancer, its expression patterns providing hints about prognosis and paths toward treatment. Reduced levels of cytochrome c have been observed in cancer tissues, indicating a potential inhibition of apoptosis. For instance, in glioma tissues, cytochrome c levels were lower compared to healthy tissues, and this reduction became more pronounced in advanced stages of the disease. However, the role of cytochrome c in cancer becomes more intricate as it becomes intertwined with the metabolic reprogramming of cancer cells. This suggests that cytochrome c plays a crucial role in tumor progression and resistance to treatment. Viewing cytochrome c as a molecular mosaic reveals that it is not merely a protein, but also a central player in determining cellular fate. This realization opens up exciting avenues for potential advancements in cancer diagnosis and treatment strategies. Despite the advancements made, the narrative surrounding cytochrome c remains incomplete, urging further exploration into its complexities and the biological implications linked to cancer. cytochrome c stands as a beacon of hope and a promising target for therapy in the battle against cancer, particularly due to its significant involvement in tumor metabolism. It holds the potential for a future where innovative solutions can be developed to address the intricate challenges of cellular fate. In this review, we have endeavored to illuminate the multifaceted domain of cytochrome c drawing connections among apoptosis, metabolic reprogramming, and the Warburg effect in the context of cancer.

Synthesis of nanohybrid consisting of taurine derived carbon dots and nanoceria for anticancer applications

Here, we first synthesized carbon dots (CDs) from taurine and then a nanohybrid with ceria (CeO2) nanoparticles using thermal decomposition method for checking their antineoplastic efficacy against human triple negative mammary carcinoma cells, MDA-MB-231. The in vitro study demonstrated significant dose-dependent antineoplastic activity of the nanohybrids within a range of concentration from 10 to 50 μg/mL after 48 h of treatment. The cellular morphology analysis clearly depicted substantial amount of cell death which seems to stem from increased intracellular reactive oxygen species (ROS) production. However, the maximum anticancer activity of the nanohybrid as compared to bare CDs and CeO2 is supposed to be due to the combined anticancer effect of both CDs and CeO2 (a well-established antitumor agent). Further we have performed molecular docking study to reveal the anticancer mechanism of CDs which exhibited high binding capacity towards several proapoptotic and antiapoptotic protein molecules. The binding affinity values were found to be - 8.7 kcal/mol, - 7.9 kcal/mol, - 9.6 kcal/mol, - 9.5 kcal/mol, - 12 kcal/mol and - 11.1 kcal/mol for BAD, BCl-2, p53, Caspase-8, Caspase-9 and Caspase-3 respectively. Taken together, our synthesized CDs-CeO2 nanohybrid could be thought as a potential anticarcinogenic option in the field of breast cancer therapeutics.

Unveiling the Mechanism of Protective Effects of Tanshinone as a New Fighter Against Cardiovascular Diseases: A Systematic Review

Tanshinone, a natural compound found in the roots of Salvia miltiorrhiza, has been shown to possess various pharmacological properties, including anti-inflammatory, antioxidant, and cardiovascular protective effects. This article aims to review the literature on the cardiovascular protective effects of tanshinone and its underlying mechanisms. Tanshinone has been demonstrated to improve cardiac function, reduce oxidative stress, and inhibit inflammation in various animal models of cardiovascular diseases. Additionally, it has been shown to regulate multiple signaling pathways involved in the pathogenesis of cardiovascular diseases, such as the PI3K/AKT, MAPK, and NF-κB pathways. Clinical studies have also suggested that tanshinone may have therapeutic potential for treating cardiovascular diseases. In conclusion, tanshinone has emerged as a promising natural compound with significant cardiovascular protective effects, and further research is warranted to explore its potential clinical applications.

Melatonin protects RPE cells from necroptosis and NLRP3 activation via promoting SERCA2-related intracellular Ca2+ homeostasis

BACKGROUND

Melatonin is an antioxidant that also has anti-inflammatory effects. It has been reported to delay the progression of age-related macular degeneration (AMD), however, the mechanism has not been fully recognized.

PURPOSE

The aim of the present study was to investigate the effects of melatonin on sodium iodate (SI)-induced retinal degeneration and elucidate the specific mechanisms, then, provide novel targets in AMD treatment.

METHODS

Retinal degeneration mouse model and in vitro retinal pigment epithelium (RPE) death model were established by SI treatment. Melatonin was administrated intraperitoneally at a concentration of 20, 40 or 80 mg/kg for in vivo study or treated at 48 h before SI treatment. To confirm the therapeutic effects of melatonin on mouse, the retinal structure and visual function were evaluated. The specific cell death rates were determined by CCK-8 assay, PI staining and protein level of RIPK3. The cytosolic or mitochondrial calcium levels were determined by Fluo-4AM or Rhod-2AM staining. Mitochondrial functions including mitochondrial dynamics, mitochondrial membrane potential, or mitochondrial permeability pore opening were evaluated. The proteins involved in endoplasmic reticulum (ER) stress were measured by western blot assay while the genes expression in calcium signaling pathway were measured by RT-qPCR.

RESULTS

We show that melatonin protects RPE cells from necroptosis and NLRP3 inflammasome activation induced by SI. Mechanistically, melatonin suppresses ER stress and intracellular calcium overload triggered by SI through restoring the function of SERCA2. Silencing of SERCA2 or blocking of melatonin receptors inhibit the protective effects of melatonin. Melatonin reduces mitochondrial Ca2+ levels and restores mitochondrial membrane potential. Constant mitochondrial Ca2+ overload directly promote cell necroptosis through mitochondrial fission. Inhibition of mitochondrial fission by Mdivi-1 prevent necroptosis induced by SI without altering the level of mitochondrial Ca2+.

CONCLUSIONS

The results confirmed that melatonin protects RPE cells from SI-induced injury by regulates MT2/SERCA2/Ca2+ axis. This study highlighted the potential of melatonin in the treatment of AMD and elucidated the mechanism and signaling pathway that mediate the protective effects.

Glucose limitation protects cancer cells from apoptosis induced by pyrimidine restriction and replication inhibition

Cancer cells often experience nutrient-limiting conditions because of their robust proliferation and inadequate tumour vasculature, which results in metabolic adaptation to sustain proliferation. Most cancer cells rapidly consume glucose, which is severely reduced in the nutrient-scarce tumour microenvironment. In CRISPR-based genetic screens to identify metabolic pathways influenced by glucose restriction, we find that tumour-relevant glucose concentrations (low glucose) protect cancer cells from inhibition of de novo pyrimidine biosynthesis, a pathway that is frequently targeted by chemotherapy. We identify two mechanisms to explain this result, which is observed broadly across cancer types. First, low glucose limits uridine-5-diphosphate-glucose synthesis, preserving pyrimidine nucleotide availability and thereby prolonging the time to replication fork stalling. Second, low glucose directly modulates apoptosis downstream of replication fork stalling by suppressing BAK activation and subsequent cytochrome c release, key events that activate caspase-9-dependent mitochondrial apoptosis. These results indicate that the low glucose levels frequently observed in tumours may limit the efficacy of specific chemotherapeutic agents, highlighting the importance of considering the effects of the tumour nutrient environment on cancer therapy.

Mechanisms and cross-talk of regulated cell death and their epigenetic modifications in tumor progression

Cell death is a fundamental part of life for metazoans. To maintain the balance between cell proliferation and metabolism of human bodies, a certain number of cells need to be removed regularly. Hence, the mechanisms of cell death have been preserved during the evolution of multicellular organisms. Tumorigenesis is closely related with exceptional inhibition of cell death. Mutations or defects in cell death-related genes block the elimination of abnormal cells and enhance the resistance of malignant cells to chemotherapy. Therefore, the investigation of cell death mechanisms enables the development of drugs that directly induce tumor cell death. In the guidelines updated by the Cell Death Nomenclature Committee (NCCD) in 2018, cell death was classified into 12 types according to morphological, biochemical and functional classification, including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, PARP-1 parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence and mitotic catastrophe. The mechanistic relationships between epigenetic controls and cell death in cancer progression were previously unclear. In this review, we will summarize the mechanisms of cell death pathways and corresponding epigenetic regulations. Also, we will explore the extensive interactions between these pathways and discuss the mechanisms of cell death in epigenetics which bring benefits to tumor therapy.

Multi-omics reveal toxicity mechanisms underpinning nanoplastic in redclaw crayfish (Cherax quadricarinatus)

We investigated the effects of different nanoplastic (NP, size = 100 nm) concentrations on red crayfish (Cherax quadricarinatus) and examined toxicity mechanisms. We established four concentration groups (control (CK): 0 μg/L; Low: 100 μg/L; Medium: 500 μg/L; and High: 1000 μg/L) and analyzed toxicity effects in C. quadricarinatus hepatopancreas using histopathological, transcriptomic, metabolomic, and fluorescence methods. NP exposure caused histological lesions and oxidative stress in hepatopancreas, and also significantly decreased glutathione (GSH) (P < 0.05) but significantly increased malondialdehyde content (MDA) (P < 0.05) in NP-treated groups. By analyzing different metabolic indicators, total cholesterol (T-CHO) content significantly increased (P < 0.05) and triglyceride (TG) content significantly decreased in Medium and High (P < 0.05). Transcriptomic analyses revealed that NPs influenced apoptosis, drug metabolism-cytochrome P450, and P53 signaling pathways. Metabolomic analyses indicated some metabolic processes were affected by NPs, including bile secretion, primary bile acid biosynthesis, and cholesterol metabolism. Caspase 3, 8, and 9 distribution levels in hepatopancreatic tissues were also determined by immunofluorescence; positive caspase staining increased with increased NP concentrations. Additionally, by examining relative Bcl-2, Bax, Apaf-1, and p53 mRNA expression levels, Bcl-2 expression was significantly decreased with increasing NP concentrations; and the expression of Bcl-2 was increasing significantly with the NPs concentration increasing. Bax expression in Low, Medium, and High groups was also significantly higher when compared with the CK group (P < 0.05); with High group levels significantly higher than in Low and Medium groups (P < 0.05). P53 expression was significantly increased in Low, Medium, and High groups (P < 0.05). Thus, NPs induced apoptosis in C. quadricarinatus hepatopancreatic cells, concomitant with increasing NP concentrations. Therefore, we identified mechanisms underpinning NP toxicity in C. quadricarinatus and provide a theoretical basis for exploring NP toxicity in aquatic organisms.

The Immune Escape Strategy of Rabies Virus and Its Pathogenicity Mechanisms

In contrast to most other rhabdoviruses, which spread by insect vectors, the rabies virus (RABV) is a very unusual member of the Rhabdoviridae family, since it has evolved to be fully adapted to warm-blooded hosts and spread directly between them. There are differences in the immune responses to laboratory-attenuated RABV and wild-type rabies virus infections. Various investigations showed that whilst laboratory-attenuated RABV elicits an innate immune response, wild-type RABV evades detection. Pathogenic RABV infection bypasses immune response by antagonizing interferon induction, which prevents downstream signal activation and impairs antiviral proteins and inflammatory cytokines production that could eliminate the virus. On the contrary, non-pathogenic RABV infection leads to immune activation and suppresses the disease. Apart from that, through recruiting leukocytes into the central nervous system (CNS) and enhancing the blood-brain barrier (BBB) permeability, which are vital factors for viral clearance and protection, cytokines/chemokines released during RABV infection play a critical role in suppressing the disease. Furthermore, early apoptosis of neural cells limit replication and spread of avirulent RABV infection, but street RABV strains infection cause delayed apoptosis that help them spread further to healthy cells and circumvent early immune exposure. Similarly, a cellular regulation mechanism called autophagy eliminates unused or damaged cytoplasmic materials and destroy microbes by delivering them to the lysosomes as part of a nonspecific immune defense mechanism. Infection with laboratory fixed RABV strains lead to complete autophagy and the viruses are eliminated. But incomplete autophagy during pathogenic RABV infection failed to destroy the viruses and might aid the virus in dodging detection by antigen-presenting cells, which could otherwise elicit adaptive immune activation. Pathogenic RABV P and M proteins, as well as high concentration of nitric oxide, which is produced during rabies virus infection, inhibits activities of mitochondrial proteins, which triggers the generation of reactive oxygen species, resulting in oxidative stress, contributing to mitochondrial malfunction and, finally, neuron process degeneration.

A lipid signature of BAK-driven apoptotic pore formation

Apoptotic cell death is regulated by the BCL-2 protein family, with clusters of BAK or BAX homodimers driving pore formation in the mitochondrial outer membrane via a poorly understood process. There is growing evidence that, in addition to BAK and BAX, lipids play an important role in pore formation. Towards a better understanding of the lipidic drivers of apoptotic pore formation in isolated mitochondria, two complementary approaches were taken. Firstly, the lipids released during BAK-mediated pore formation were measured with targeted lipidomics, revealing enrichment of long chain polyunsaturated lysophospholipids (LPLs) in the released fraction. In contrast, the BAK protein was not released suggesting that BAK and LPLs locate to distinct microdomains. Secondly, added cholesterol not only prevented pore formation but prevented the clustering of BAK homodimers. Our data lead us to a model in which BAK clustering triggers formation of a separate microdomain rich in LPLs that can progress to lipid shedding and the opening of a lipid-lined pore. Pore stabilisation and growth may be due to BAK dimers then moving to the pore edge. Our BAK-lipid microdomain model supports the heterogeneity of BAK assemblies, and the observed lipid-release signature gives new insight into the genesis of the apoptotic pore.

NFATc4 Knockout Promotes Neuroprotection and Retinal Ganglion Cell Regeneration After Optic Nerve Injury

Retinal ganglion cells (RGCs), neurons transmitting visual information via the optic nerve, fail to regenerate their axons after injury. The progressive loss of RGC function underlies the pathophysiology of glaucoma and other optic neuropathies, often leading to irreversible blindness. Therefore, there is an urgent need to identify the regulators of RGC survival and the regenerative program. In this study, we investigated the role of the family of transcription factors known as nuclear factor of activated T cells (NFAT), which are expressed in the retina; however, their role in RGC survival after injury is unknown. Using the optic nerve crush (ONC) model, widely employed to study optic neuropathies and central nervous system axon injury, we found that NFATc4 is specifically but transiently up-regulated in response to mechanical injury. In the injured retina, NFATc4 immunolocalized primarily to the ganglionic cell layer. Utilizing NFATc4-/- and NFATc3-/- mice, we demonstrated that NFATc4, but not NFATc3, knockout increased RGC survival, improved retina function, and delayed axonal degeneration. Microarray screening data, along with decreased immunostaining of cleaved caspase-3, revealed that NFATc4 knockout was protective against ONC-induced degeneration by suppressing pro-apoptotic signaling. Finally, we used lentiviral-mediated NFATc4 delivery to the retina of NFATc4-/- mice and reversed the pro-survival effect of NFATc4 knockout, conclusively linking the enhanced survival of injured RGCs to NFATc4-dependent mechanisms. In summary, this study is the first to demonstrate that NFATc4 knockout may confer transient RGC neuroprotection and decelerate axonal degeneration after injury, providing a potent therapeutic strategy for optic neuropathies.

Profiling protein-protein interactions to predict the efficacy of B-cell-lymphoma-2-homology-3 mimetics for acute myeloid leukaemia

B-cell-lymphoma-2 (BCL2) homology-3 (BH3) mimetics are inhibitors of protein-protein interactions (PPIs) that saturate anti-apoptotic proteins in the BCL2 family to induce apoptosis in cancer cells. Despite the success of the BH3-mimetic ABT-199 for the treatment of haematological malignancies, only a fraction of patients respond to the drug and most patients eventually develop resistance to it. Here we show that the efficacy of ABT-199 can be predicted by profiling the rewired status of the PPI network of the BCL2 family via single-molecule pull-down and co-immunoprecipitation to quantify more than 20 types of PPI from a total of only 1.2 × 106 cells per sample. By comparing the obtained multidimensional data with BH3-mimetic efficacies determined ex vivo, we constructed a model for predicting the efficacy of ABT-199 that designates two complexes of the BCL2 protein family as the primary mediators of drug effectiveness and resistance, and applied it to prospectively assist therapeutic decision-making for patients with acute myeloid leukaemia. The characterization of PPI complexes in clinical specimens opens up opportunities for individualized protein-complex-targeting therapies.

Cellular ATP demand creates metabolically distinct subpopulations of mitochondria

Mitochondria serve a crucial role in cell growth and proliferation by supporting both ATP synthesis and the production of macromolecular precursors. Whereas oxidative phosphorylation (OXPHOS) depends mainly on the oxidation of intermediates from the tricarboxylic acid cycle, the mitochondrial production of proline and ornithine relies on reductive synthesis1. How these competing metabolic pathways take place in the same organelle is not clear. Here we show that when cellular dependence on OXPHOS increases, pyrroline-5-carboxylate synthase (P5CS)-the rate-limiting enzyme in the reductive synthesis of proline and ornithine-becomes sequestered in a subset of mitochondria that lack cristae and ATP synthase. This sequestration is driven by both the intrinsic ability of P5CS to form filaments and the mitochondrial fusion and fission cycle. Disruption of mitochondrial dynamics, by impeding mitofusin-mediated fusion or dynamin-like-protein-1-mediated fission, impairs the separation of P5CS-containing mitochondria from mitochondria that are enriched in cristae and ATP synthase. Failure to segregate these metabolic pathways through mitochondrial fusion and fission results in cells either sacrificing the capacity for OXPHOS while sustaining the reductive synthesis of proline, or foregoing proline synthesis while preserving adaptive OXPHOS. These findings provide evidence of the key role of mitochondrial fission and fusion in maintaining both oxidative and reductive biosyntheses in response to changing nutrient availability and bioenergetic demand.

Magical role of iron nanoparticles for enhancement of thermal efficiency and gene regulation of fish in response to multiple stresses

The present study addresses the challenges of uncontrolled temperature and pollution in aquatic environments, with a focus on fish ability to tolerate high temperature. The investigation aimed to determine the role of iron nanoparticles (Fe-NPs) in enhancing the thermal tolerance of Pangasianodon hypophthalmus exposed to high-temperature stress, arsenic (As), and ammonia (NH3) toxicity. Fe-NPs were synthesized using green approaches, specifically from fish gill. The dietary Fe-NPs were formulated and supplemented at 10, 15, and 20 mg kg⁻1 of feed. Notably, Fe-NPs at 15 mg kg⁻1 diet significantly reduced the critical thermal minimum (CTmin) (14.44 ± 0.21 °C) and the lethal thermal minimum (LTmin) (13.46 ± 0.15 °C), compared to the control and other treatment groups. Conversely, when Fe-NPs at 15 mg kg⁻1 were supplemented with or without exposure to stressors (As + NH3+T), the critical thermal maximum (CTmax) increased to 47.59 ± 0.16 °C, and the lethal thermal maximum (LTmax) increased to 48.60 ± 0.37 °C, both significantly higher than the control and other groups. A strong correlation was observed between LTmin and CTmin (R2 = 0.90) and between CTmax and LTmax (R2 = 0.98). Furthermore, dietary Fe-NPs at 15 mg kg⁻1 significantly upregulated the expression of stress-related genes, including HSP70, iNOS, Caspase-3a, CYP450, MT, cat, sod, gpx, TNFα, IL, TLR, and Ig. The enhanced thermal tolerance (LTmin and LTmax) can be attributed to these gene regulations, suggesting the mechanistic involvement of Fe-NPs in improving thermal resilience. Overall, the findings demonstrate that dietary supplementation with Fe-NPs, particularly at 15 mg kg⁻1, improves thermal tolerance and stress response in P. hypophthalmus by enhancing gene expression and overall thermal efficiency under stressor conditions.

High-Salt Diet Accelerates Neuron Loss and Anxiety in APP/PS1 Mice Through Serpina3n

High salt (HS) consumption is an independent risk factor for neurodegenerative diseases such as dementia, stroke, and cerebral small vessel disease related to cognitive decline. Recently, Alzheimer's disease-like pathology changes have been reported as consequences of a HS diet in wild-type (wt) mice. However, it has not been revealed how HS diets accelerate the progress of Alzheimer's disease (AD) in APP/PS1 mice. Here, we fed APP/PS1 mice a HS diet or normal diet (ND) for six months; the effects of the HS/ND on wt mice were also observed. The results of our behavior test reveal that the HS diet exacerbates anxiety, β-amyloid overload, neuron loss, and synapse damage in the hippocampi of APP/PS1 mice; this was not observed in HS-treated wt mice. RNA sequencing shows that nearly all serpin family members were increased in the hippocampus of HS-treated APP/PS1 mice. Gene function analysis showed that a HS diet induces neurodegeneration, including axon dysfunction and neuro-ligand-based dysfunction, and regulates serine protein inhibitor activities. The mRNA and protein levels of Serpina3n were dramatically increased. Upregulated Serpina3n may be the key for β-amyloid aggregation and neuronal loss in the hippocampus of HS-treated APP/PS1 mice. Serpina3n inhibition attenuated the anxiety and increased the number of neurons in the hippocampal CA1(cornu ammonis) region of APP/PS1 mice. Our study provides novel insights into the mechanisms by which excessive HS diet deteriorates anxiety in AD mice. Therefore, decreasing daily dietary salt consumption constitutes a pivotal public health intervention for mitigating the progression of neuropathology, especially for old patients and those with neurodegenerative disease.

Modeling doxorubicin-induced-cardiotoxicity through breast cancer patient specific iPSC-derived heart organoid

Heart organoid (HO) technology has successfully overcome the limitations of two-dimensional (2D) disease modeling and drug testing, thereby emerging as a valuable tool in drug discovery for assessing toxicity and efficacy. However, its ability to distinguish drug responses among individuals remain unclear, which is crucial for developing predictive models. We addressed this gap by comparing human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) with human induced pluripotent stem cell-derived heart organoids (hiPSC-HOs) in the context of doxorubicin-induced cardiotoxicity (DIC). For this study, we utilized hiPSCs generated from breast cancer patients who had previously been treated with doxorubicin. By comparing groups with and without DIC, we examined various parameters, including cell viability, mRNA expression, protein expression and electrophysiological variations. The results of our analysis revealed significant differences between these groups, providing insights into hiPSC-HOs as a potential platform for testing differences in drug responses among patients.

Tuina Promotes Repair of Chronic Cervical Muscle Injury by Regulating Satellite Cell Proliferation and Differentiation and Inhibiting Myocyte Apoptosis

Purpose

Chronic cervical muscle injury is the first common cause of the development of cervical spondylosis, and Tuina can effectively promote the repair of chronic cervical muscle injury and alleviate neck pain, but the mechanism behind its efficacy is still unknown. The proliferation and differentiation of muscle satellite cells and the apoptosis of cervical myocytes play important roles in the repair of chronic cervical muscle injuries; therefore, this study aimed to explore the potential mechanisms of Tuina to promote the repair of cervical muscle injuries in terms of the proliferation and differentiation of satellite cells and the apoptosis of myocytes.

Patients and Methods

Twenty-eight Wistar rats were randomly divided into control group, model group, Tuina group, and meloxicam group, with 7 rats in each group. Except for the control group, each group were establish a chronic cervical muscle injury model (CCMI). Meloxicam (0.79 mg/kg) was administered by gavage, and in the Tuina group, pressure was applied to the Fengchi acupoint on the affected side once a day. Morphological changes of cervical muscle tissues were detected by ultrasonic diagnostic instrument and HE staining, electrophysiological recordings of electromyographic changes, apoptosis rate was detected by TUNEL staining, and positive expression of Bax, Bcl-2, IGF-1, MyoD, and Pax-7 were detected by Immunohistochemistry and Western blot.

Results

In CCMI model rats, we observed that the cervical muscle fibers were disorganized, with irregular morphology, and the amplitude of electromyography was significantly weakened, while Tuina could significantly improve these symptoms and effectively promote the repair of chronic cervical muscle injury. Meanwhile, compared with the model group, Tuina could significantly increase the expression levels of IGF-1 (P<0.01) and MyoD (P<0.05) and decrease the expression level of Pax7 (P<0.05). In addition, we found that the number of apoptotic cells in cervical myocytes was reduced after Tuina intervention (P<0.05), and Tuina inhibited the expression of pro-apoptotic factor Bax (P<0.01) and promoted the expression of anti-apoptotic factor Bcl-2 (P<0.05).

Conclusion

Tuina can promote the proliferation and differentiation of satellite cells to repair chronic cervical muscle injury by regulating the expression of Pax7, MyoD, and IGF-1, as well as inhibiting the expression of Bax and promoting the expression of Bcl-2 to ameliorate the apoptosis of cervical myocytes in CCMI model rats.

Genetic knock-in of EIF2AK3 variants reveals differences in PERK activity in mouse liver and pancreas under endoplasmic reticulum stress

Common single-nucleotide variants (SNVs) of eukaryotic translation initiation factor 2 alpha kinase 3 (EIF2AK3) slightly increase the risk of disorders in the periphery and the central nervous system. EIF2AK3 encodes protein kinase RNA-like endoplasmic reticulum kinase (PERK), a key regulator of ER stress. Three exonic EIF2AK3 SNVs form the PERK-B haplotype, which is present in 28% of the global population. Importantly, the precise impact of these SNVs on PERK activity remains elusive. In this study, we demonstrate that PERK-B SNVs do not alter PERK expression or basal activity in vitro and in the novel triple knock-in mice expressing the exonic PERK-B SNVs in vivo. However, the kinase activity of PERK-B protein is higher than that of PERK-A in a cell-free assay and in mouse liver homogenates. Pancreatic tissue in PERK-B/B mice also exhibit increased susceptibility to apoptosis under acute ER stress. Monocyte-derived macrophages from PERK-B/B mice exhibit higher PERK activity than those from PERK-A/A mice, albeit with minimal functional consequences at acute timepoints. The subtle PERK-B-driven effects observed in liver and pancreas during acute stress implicate PERK as a contributor to disease susceptibility. The novel PERK-B mouse model provides valuable insights into ER stress-induced PERK activity, aiding the understanding of the genetic basis of disorders associated with ER stress.

BRD-810 is a highly selective MCL1 inhibitor with optimized in vivo clearance and robust efficacy in solid and hematological tumor models

The MCL1 gene is frequently amplified in cancer and codes for the antiapoptotic protein myeloid cell leukemia 1 (MCL1), which confers resistance to the current standard of care. Therefore, MCL1 is an attractive anticancer target. Here we describe BRD-810 as a potent and selective MCL1 inhibitor and its key design principle of rapid systemic clearance to potentially minimize area under the curve-driven toxicities associated with MCL1 inhibition. BRD-810 induced rapid cell killing within 4 h in vitro but, in the same 4-h window, had no impact on cell viability or troponin I release in human induced pluripotent stem cell-derived cardiomyocytes, even at suprapharmacologic concentrations. In vivo BRD-810 induced efficacy in xenograft hematological and solid tumor models despite the short residence time of BRD-810 in plasma. In totality, our data support the hypothesis that short-term inhibition of MCL1 with BRD-810 can induce apoptosis in tumor cells while maintaining an acceptable safety profile. We, therefore, intend to advance BRD-810 to clinical trials.

Synergistic induction of ferroptosis by targeting HERC1-NCOA4 axis to enhance the photodynamic sensitivity of osteosarcoma

Over the past 30 years, the survival rate for osteosarcoma (OS) has remained stagnant, indicating persistent challenges in diagnosis and treatment. Photodynamic therapy (PDT) has emerged as a novel and promising treatment modality for OS. Despite apoptosis being the primary mechanism attributed to PDT, it fails to overcome issues such as low efficacy and resistance. Ferroptosis, a Fe2+-dependent cell death process, has the potential to enhance PDT's efficacy by increasing reactive oxygen species (ROS) through the Fenton reaction. In this study, we investigated the anti-tumor mechanism of PDT and introduced an innovative therapeutic strategy that synergistically induces apoptosis and ferroptosis. Furthermore, we have identified HERC1 as a pivotal protein involved in the ubiquitination and degradation of NCOA4, while also uncovering a potential regulatory factor involving NRF2. Ultimately, by targeting the HERC1-NCOA4 axis during PDT, we successfully achieved full activation of ferroptosis, which significantly enhanced the anti-tumor efficacy of PDT. In conclusion, these findings provide new theoretical evidence for further characterizing mechanism of PDT and offer new molecular targets for the treatment of OS.

Permeabilization of the outer mitochondrial membrane: Mechanisms and consequences

Permeabilization of the outer mitochondrial membrane is а physiological process that can allow certain molecules to pass through it, such as low molecular weight solutes required for cellular respiration. This process is also important for the development of various modes of cell death. Depending on the severity of this process, cells can die by autophagy, apoptosis, or necrosis/necroptosis. Distinct types of pores can be opened at the outer mitochondrial membrane depending on physiological or pathological stimuli, and different mechanisms can be activated in order to open these pores. In this comprehensive review, all these types of permeabilization, the mechanisms of their activation, and their role in various diseases are discussed.