Pyroptosis: shedding light on the mechanisms and links with cancers

METTL3-mediated m6A modification enhances lncRNA H19 stability to promote endothelial cell inflammation and pyroptosis to aggravate atherosclerosis

This study explored the impact of N6-methyladenosine (m6A) modification on the regulation of long noncoding RNA (lncRNA) and atherosclerosis progression. An atherosclerosis cell model was established by treating human aortic endothelial cells (HAECs) with oxidized low-density lipoprotein. Additionally, an atherosclerotic animal model was developed using ApoE-/- C57BL/6 male mice fed a high-fat diet. Both models were employed to assess the expression changes of proteins associated with m6A modification. First, the effect of m6A modification writer protein methyltransferase-like 3 (METTL3) knockdown on changes in the level of pyroptosis in HAECs was investigated, and bioinformatic analysis confirmed that lncRNA H19 (H19) was the potential target of m6A modification. RNA-binding protein immunoprecipitation assays were subsequently performed to explore the interaction between H19 and the m6A writer protein METTL3, as well as the reader protein recombinant insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2). Finally, the effect of H19 expression on pyroptosis levels in HAECs was evaluated. In the aortas of atherosclerosis mice, overall m6A levels were significantly elevated compared with controls (p < .05), with METTL3 and METTL14 mRNA and protein levels notably increased (p < .05). Similarly, ox-LDL-treated HAECs showed a significant rise in m6A levels, along with increased METTL3 and METTL14 expression (p < .05). METTL3 knockdown in HAECs led to decreased pyroptosis, as evidenced by reduced lactate dehydrogenase release and lower levels of IL-1β, IL-18, and IL-6 (p < .05). Overexpression of H19 reversed these effects, indicating METTL3's role in promoting atherosclerosis by stabilizing H19 through m6A modification. H19 was the primary target lncRNA molecule of METTL3-mediated m6A modification in the pathogenesis of atherosclerosis. METTL3-mediated m6A modification regulated H19 expression, thereby aggravating atherosclerosis by activating pyroptosis.

NLRP3 inhibitor combined with Yimusake improves erectile dysfunction in rats with diabetes mellitus through the attenuation of pyroptosis

Erectile dysfunction (ED) is a prevalent complication associated with diabetes mellitus (DM), yet pharmacological treatments for diabetes-related erectile dysfunction (DMED) continue to be inadequate in clinical settings. Our previous studies have indicated that there is a close correlation between ED and pyroptosis, but the specific mechanism remains unclear. In this study, we sought to explore the therapeutic effects of DMED through the modulation of NLRP3, aiming to elucidate its potential molecular mechanisms. The DMED rat model was established via intraperitoneal injection of streptozotocin. The rats were randomly assigned to the control group, the DMED group, the Yimusake group, the MCC950 (NLRP3 inhibitor) group, and the MCC950+Yimusake group. Erectile function of rats was observed by measuring intracavernosal pressure (ICP) and mean arterial pressure (MAP). HE staining was performed to observe the histopathological changes in penile; immunofluorescence was performed to measure the level of CD31 (Platelet endothelial cell adhesion molecule-1) in penile. Besides, immunohistochemistry, RT-qPCR and Western blot were performed to demonstrate the expression of NLRP3, caspase-1, IL-1β and eNOS. After treatment with the MCC950 and Yimusake, the number of blood sinusoids and small vessels significantly reduced in penile tissue; NLRP3, caspase-1, IL-1β proteins and mRNA expression decreased, eNOS protein and mRNA expression increased. Compare with the Y group and the MCC950 group, MCC950+Yimusake group had a more significant effect. MCC950 and Yimusake might potentially suppress pyroptosis in the penile tissue of DMED rats by modulating the NLRP3/caspase-1 pathway, thus enhancing erectile function. This discovery could offer a promising therapeutic approach for individuals with DMED.

Non-coding RNAs as key regulators of Gasdermin-D mediated pyroptosis in cancer therapy

Pyroptosis is an inflammatory programed cell death process that plays a crucial role in cancer therapeutic, while Gasdermin-D is a critical effector protein for pyroptosis execution. This review discusses the intricate interactions between Gasdermin-D and some non-coding RNAs (lncRNA, miRNA, siRNA) and their potential application in the regulation of pyroptosis as an anticancer therapy. Correspondingly, these ncRNAs significantly implicate in Gasdermin-D expression and function regarding the pyroptosis pathway. Functioning as competing endogenous RNAs (ceRNAs), these ncRNAs might regulate Gasdermin-D at the molecular level, underlying fatal cell death caused by cancer and tumor propagation. Therefore, these interactions appeal to therapeutics, offering new avenues for cancer treatment. It address this research gap by discussing the possible roles of ncRNAs as mediators of gasdermin-D regulation. It suggest therapeutic strategies based on the current research findings to ensure the interchange between the ideal pyroptosis and cancer cell death.

Research progress on the effect of pyroptosis on the occurrence, development, invasion and metastasis of colorectal cancer

Pyroptosis is a type of programmed cell death mediated by gasdermines (GSDMs). The N-terminal domain of GSDMs forms pores in the plasma membrane, causing cell membrane rupture and the release of cell contents, leading to an inflammatory response and mediating pyrodeath. Pyroptosis plays an important role in inflammatory diseases and malignant tumors. With the further study of pyroptosis, an increasing number of studies have shown that the pyroptosis pathway can regulate the tumor microenvironment and antitumor immunity of colorectal cancer and is closely related to the occurrence, development, treatment and prognosis of colorectal cancer. This review aimed to explore the molecular mechanism of pyroptosis and the role of pyroptosis in the occurrence, development, treatment and prognosis of colorectal cancer (CRC) and to provide ideas for the clinical diagnosis and treatment of CRC.

Harnessing pyroptosis for lung cancer therapy: The impact of NLRP3 inflammasome activation

Lung cancer is still a global health challenge in terms of high incidence, morbidity, and mortality. Recent scientific studies have determined that pyroptosis, a highly inflammatory form of programmed cell death, can be identified as a potential lung cancer therapeutic target. The NLRP3 inflammasome acts as a critical mediator in this process and, upon activation, activates multiprotein complex formation as well as caspase-1 activation. This process, triggered by a release of pro-inflammatory cytokines, results in pyroptotic cell death. Also, the relationship between the NLRP3 inflammasome and lung cancer was justified by its influence on tumour growth or metastasis. The molecular pathways produce progenitive mediators and remake the tissue. Finally, targeting NLRP3 inflammasome for pyroptosis induction and inhibition of its activation appears to be a promising lung cancer treatment approach. This technique makes cancer treatment more promising and personalized. This review explores the role of NLRP3 inflammasome activation and its possibilities in lung cancer treatment.

Oridonin exerts anticonvulsant profile and neuroprotective activity in epileptic mice by inhibiting NLRP3-mediated pyroptosis

BACKGROUND

Epilepsy is a chronic disabling disease poorly controlled by available antiseizure medications. Oridonin, a bioactive alkaloid with anti-inflammatory properties and neuroprotective effects, can inhibit the increased excitability of neurons caused by glutamate accumulation at the cellular level. However, whether oridonin affects neuronal excitability and whether it has antiepileptic potential has not been reported in animal models or clinical studies.

METHOD

Pentylenetetrazol was injected into mice to create a model of chronic epilepsy. Seizure severity was assessed using the Racine scale, and the duration and latency of seizures were observed. Abnormal neuronal discharge was detected using electroencephalography, and neuronal excitability was assessed using calcium imaging. Damage to hippocampal neurons was evaluated using Hematoxylin-Eosin and Nissl staining. The expression of the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome and other pyroptosis-related proteins was determined using western blotting and immunofluorescence. A neuronal pyroptosis model was established using the supernatant of BV2 cells treated with lipopolysaccharide and adenosine triphosphate to stimulate hippocampal neurons.

RESULTS

Oridonin (1 and 5 mg/kg) reduced neuronal damage, increased the latency of seizures, and shortened the duration of fully kindled seizures in chronic epilepsy model mice. Oridonin decreased abnormal discharge during epileptic episodes and suppressed increased neuronal excitability. In vitro experiments showed that oridonin alleviated pyroptosis in hippocampal HT22 neurons.

CONCLUSION

Oridonin exerts neuroprotective effects by inhibiting pyroptosis through the NLRP3/caspase-1 pathway in chronic epilepsy model mice. It also reduces pyroptosis in hippocampal neurons in vitro, suggesting its potential as a therapy for epilepsy.

Targeting regulated cell death (RCD) in hematological malignancies: Recent advances and therapeutic potential

Regulated cell death (RCD) is a form of cell death that can be regulated by numerous biomacromolecules. Accumulating evidence suggests that dysregulated expression and altered localization of related proteins in RCD promote the development of cancer. Targeting subroutines of RCD with pharmacological small-molecule compounds is becoming a promising therapeutic avenue for anti-tumor treatment, especially in hematological malignancies. Herein, we summarize the aberrant mechanisms of apoptosis, necroptosis, pyroptosis, PANoptosis, and ferroptosis in hematological malignancies. In particular, we focus on the relationship between cell death and tumorigenesis, anti-tumor immunotherapy, and drug resistance in hematological malignancies. Furthermore, we discuss the emerging therapeutic strategies targeting different RCD subroutines. This review aims to summarize the significance and potential mechanisms of RCD in hematological malignancies, along with the development and utilization of pertinent therapeutic strategies.

B355252 Suppresses LPS-Induced Neuroinflammation in the Mouse Brain

B355252 is a small molecular compound known for potentiating neural growth factor and protecting against neuronal cell death induced by glutamate in vitro and cerebral ischemia in vivo. However, its other biological functions remain unclear. This study aims to investigate whether B355252 suppresses neuroinflammatory responses and cell death in the brain. C57BL/6j mice were intraperitoneally injected with a single dosage of lipopolysaccharide (LPS, 1 mg/kg) to induce inflammation. B355252 (1 mg/kg) intervention was started two days prior to the LPS injection. The animal behavioral changes were assessed pre- and post-LPS injections. The animal brains were harvested at 4 and 24 h post-LPS injection, and histological, biochemical, and cytokine array outcomes were examined. Results showed that B355252 improved LPS-induced behavioral deterioration, mitigated brain tissue damage, and suppressed the activation of microglial and astrocytes. Furthermore, B355252 reduced the protein levels of key pyroptotic markers TLR4, NLRP3, and caspase-1 and inhibited the LPS-induced increases in IL-1β, IL-18, and cytokines. In conclusion, B355252 demonstrates a potent anti-neuroinflammatory effect in vivo, suggesting that its potential therapeutic value warrants further investigation.

IL-1β induced down-regulation of miR-146a-5p promoted pyroptosis and apoptosis of corneal epithelial cell in dry eye disease through targeting STAT3

AIM

To elaborate the underlying mechanisms by which IL-1β promote progression of Dry eye disease(DED) through effect on pyroptosis and apoptosis of corneal epithelial cells(CECs).

METHODS

400 mOsM solutions were used to establish the DED model (hCECs- DED). RT-qPCR was performed to measure IL-1β mRNA and miR-146a-5p in CECs. Western blotting was performed to measure STAT3, GSDMD, NLRP3, and Caspase-1 levels. Cell counting kit-8 assay was adopted to check cell viability. Apoptosis was detected by flow cytometry. ELISAs were performed to determine IL-18, IL-33 and LDH. The luciferase test detects targeting relationships.

RESULTS

After treatment with 400 mOsM solution, cell viability decreased and apoptosis increased. Compared with hCECs, IL-1β was increased and miR-146a-5p was decreased in hCECs-DED. At the same time, GSDMD, NLRP3, Caspase-1, IL-18, IL-33 and LDH were significantly higher in hCECs-DED than in hCECs, while IL-1β silencing reversed this effect. In addition, IL-1β negatively regulated miR-146a-5p. MiR-146a-5p mimics eliminated the inhibition of hCECs-DED pyroptosis and apoptosis caused by IL-1β silencing. At the same time, miR-146a-5p reduced STAT3 levels in hCECs.

CONCLUSION

Highly expressed IL-1β promoted pyroptosis and apoptosis of hCECs- DED through downregulated miR-146a-5p and inhibited STAT3.

Harnessing Pyroptosis for Cancer Immunotherapy

Cancer immunotherapy is a novel pillar of cancer treatment that harnesses the immune system to fight tumors and generally results in robust antitumor immunity. Although immunotherapy has achieved remarkable clinical success for some patients, many patients do not respond, underscoring the need to develop new strategies to promote antitumor immunity. Pyroptosis is an immunostimulatory type of regulated cell death that activates the innate immune system. A hallmark of pyroptosis is the release of intracellular contents such as cytokines, alarmins, and chemokines that can stimulate adaptive immune activation. Recent studies suggest that pyroptosis promotes antitumor immunity. Here, we review the mechanisms by which pyroptosis can be induced and highlight new strategies to induce pyroptosis in cancer cells for antitumor defense. We discuss how pyroptosis modulates the tumor microenvironment to stimulate adaptive immunity and promote antitumor immunity. We also suggest research areas to focus on for continued development of pyroptosis as an anticancer treatment. Pyroptosis-based anticancer therapies offer a promising new avenue for treating immunologically 'cold' tumors.