Snapshot of a Deadly Embrace: The Caspase-1-GSDMD Interface

The mechanism and promising therapeutic strategy of diabetic cardiomyopathy dysfunctions: Focus on pyroptosis

Diabetes is a major risk factor for cardiovascular diseases, and myocardial damage caused by hyperglycemia is the main cause of heart failure. However, there is still a lack of systematic understanding of myocardial damage caused by diabetes. At present, we believe that the cellular inflammatory damage caused by hyperglycemia is one of the causes of diabetic cardiomyopathy. Pyroptosis, as a proinflammatory form of cell death, is closely related to the occurrence and development of diabetic cardiomyopathy. Therefore, this paper focuses on the important role of inflammation in the occurrence and development of diabetic cardiomyopathy. From the perspective of pyroptosis, we summarize the pyroptosis of different types of cells in diabetic cardiomyopathy and its related signaling pathways. It also summarizes the treatment of diabetic cardiomyopathy, hoping to provide methods for the prevention and treatment of diabetic cardiomyopathy by inhibiting pyroptosis.

Role of pyroptosis in the pathogenesis of various neurological diseases

Pyroptosis, an inflammatory programmed cell death process, has recently garnered significant attention due to its pivotal role in various neurological diseases. This review delves into the intricate molecular signaling pathways governing pyroptosis, encompassing both caspase-1 dependent and caspase-1 independent routes, while emphasizing the critical role played by the inflammasome machinery in initiating cell death. Notably, we explore the Nucleotide-binding domain leucine-rich repeat (NLR) containing protein family, the Absent in melanoma 2-like receptor family, and the Pyrin receptor family as essential activators of pyroptosis. Additionally, we comprehensively examine the Gasdermin family, renowned for their role as executioner proteins in pyroptosis. Central to our review is the interplay between pyroptosis and various central nervous system (CNS) cell types, including astrocytes, microglia, neurons, and the blood-brain barrier (BBB). Pyroptosis emerges as a significant factor in the pathophysiology of each cell type, highlighting its far-reaching impact on neurological diseases. This review also thoroughly addresses the involvement of pyroptosis in specific neurological conditions, such as HIV infection, drug abuse-mediated pathologies, Alzheimer's disease, and Parkinson's disease. These discussions illuminate the intricate connections between pyroptosis, chronic inflammation, and cell death in the development of these disorders. We also conducted a comparative analysis, contrasting pyroptosis with other cell death mechanisms, thereby shedding light on their unique aspects. This approach helps clarify the distinct contributions of pyroptosis to neuroinflammatory processes. In conclusion, this review offers a comprehensive exploration of the role of pyroptosis in various neurological diseases, emphasizing its multifaceted molecular mechanisms within various CNS cell types. By elucidating the link between pyroptosis and chronic inflammation in the context of neurodegenerative disorders and infections, it provides valuable insights into potential therapeutic targets for mitigating these conditions.

Inflammasome and pyroptosis in autoimmune liver diseases

Autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC), and IgG4-related sclerosing cholangitis (IgG4-SC) are the four main forms of autoimmune liver diseases (AILDs), which are all defined by an aberrant immune system attack on the liver. Most previous studies have shown that apoptosis and necrosis are the two major modes of hepatocyte death in AILDs. Recent studies have reported that inflammasome-mediated pyroptosis is critical for the inflammatory response and severity of liver injury in AILDs. This review summarizes our present understanding of inflammasome activation and function, as well as the connections among inflammasomes, pyroptosis, and AILDs, thus highlighting the shared features across the four disease models and gaps in our knowledge. In addition, we summarize the correlation among NLRP3 inflammasome activation in the liver-gut axis, liver injury, and intestinal barrier disruption in PBC and PSC. We summarize the differences in microbial and metabolic characteristics between PSC and IgG4-SC, and highlight the uniqueness of IgG4-SC. We explore the different roles of NLRP3 in acute and chronic cholestatic liver injury, as well as the complex and controversial crosstalk between various types of cell death in AILDs. We also discuss the most up-to-date developments in inflammasome- and pyroptosis-targeted medicines for autoimmune liver disorders.

Pyroptosis and Its Role in Cervical Cancer

Pyroptosis, an inflammatory programmed cell death, is characterized by the caspase-mediated pore formation of plasma membranes and the release of large quantities of inflammatory mediators. In recent years, the morphological characteristics, induction mechanism and action process of pyroptosis have been gradually unraveled. As a malignant tumor with high morbidity and mortality, cervical cancer is seriously harmful to women's health. It has been found that pyroptosis is closely related to the initiation and development of cervical cancer. In this review the mechanisms of pyroptosis and its role in the initiation, progression and treatment application of cervical cancer are summarized and discussed.

NLRP3 Inflammasome/Pyroptosis: A Key Driving Force in Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM), a serious diabetic complication, is a kind of low-grade inflammatory cardiovascular disorder. Due to the high risk of morbidity and mortality, DCM has demanded the attention of medical researchers worldwide. The pathophysiological nature of DCM is intricate, and the genesis and development of which are a consequence of the coaction of many factors. However, the exact pathogenesis mechanism of DCM remains unclear. Pyroptosis is a newly identified programmed cell death (PCD) that is directly related to gasdermin D(GSDMD). It is characterized by pore formation on the cell plasma membrane, the release of inflammatory mediators, and cell lysis. The initiation of pyroptosis is closely correlated with NOD-like receptor 3 (NLRP3) activation, which activates caspase-1 and promotes the cleaving of GSDMD. In addition to adjusting the host’s immune defense, NLRP3 inflammasome/pyroptosis plays a critical role in controlling the systemic inflammatory response. Recent evidence has indicated that NLRP3 inflammasome/pyroptosis has a strong link with DCM. Targeting the activation of NLRP3 inflammasome or pyroptosis may be a hopeful therapeutic strategy for DCM. The focus of this review is to summarize the relevant mechanisms of pyroptosis and the relative contributions in DCM, highlighting the potential therapeutic targets in this field.

VX-765 ameliorates renal injury and fibrosis in diabetes by regulating caspase-1-mediated pyroptosis and inflammation

INTRODUCTION

As a lytic inflammatory cell death, pyroptosis has been recently described but has not been unequivocally elucidated in diabetic nephropathy (DN). VX-765 is a safe and effective inhibitor of caspase-1, that was well tolerated in a phase II clinical trial in patients with epilepsy, but its application in DN is still undefined.

MATERIALS AND METHODS

Immunoblot, co-immunoprecipitation, confocal microscope and flow cytometry were used to analyze the effects of glucose on pyroptosis in renal tubular epithelia (HK-2). In vitro, selective caspase-1 inhibitors VX-765 and Z-YVAD-FMK were administered. Pyroptosis and fibrogenesis were determined by immunoblot, ELISA, cytotoxicity assay and flow cytometry. In vivo, diabetic mice were administered with 100 mg/kg VX-765. Renal function, pathological changes, and the expressions of NLRC4, GSDMD, IL-1β, collagen I, fibronectin and CD45 in renal cortex were evaluated.

RESULTS

We identified NLRC4 as a sensor for caspase-1 activation. Moreover, we provided morphological and molecular evidence for pyroptosis in glucose-stressed tubular cells, including ballooned cell membrane, caspase-1 immunoreactivity, GSDMD cleavage, and the release of inflammatory cytokine and cellular contents. All these effects were prevented by treatment with VX-765 or Z-YVAD-FMK, confirming that caspase-1 effectively regulates the occurrence of pyroptosis in HK-2 cells. In vivo, treatment of diabetic animals with VX-765 ameliorated renal function, suppressed inflammatory cell infiltration and pyroptosis-associated protein expression, and mitigated tubulointerstitial fibrosis.

CONCLUSIONS

This work revealed that caspase-1-mediated pyroptosis drives renal inflammation and fibrosis in diabetes. Our results are the first demonstration of VX-765 representing a promising therapeutic opportunity for alleviating the progression of DN.

Pyroptosis by caspase-11 inflammasome-Gasdermin D pathway in autoimmune diseases

Inflammasomes are a group of supramolecular complexes primarily comprise a sensor, adaptor protein and an effector. Among them, canonical inflammasomes are assembled by one specific pattern recognition receptor, the adaptor protein apoptosis-associated speck-like protein containing a CARD and procaspase-1. Murine caspase-11 and its human ortholog caspase-4/5 are identified as cytosolic sensors which directly responds to LPS. Once gaining access to cytosol, LPS further trigger inflammasome activation in noncanonical way. Downstream pore-forming Gasdermin D is a pyroptosis executioner. Emerging evidence announced in recent years demonstrate the vital role played by caspase-11 non-canonical inflammasome in a range of autoimmune diseases. Pharmacological ablation of caspase-11 and its related effector results in potent therapeutic effects. Though recent advances have highlighted the potential of caspase-11 as a drug target, the understanding of caspase-11 molecular activation and regulation mechanism remains to be limited and thus hampered the discovery and progression of novel inhibitors. Here in this timeline review, we explored how caspase-11 get involved in the pathogenesis of autoimmune diseases, we also collected the reported small-molecular caspase-11 inhibitors. Moreover, the clinical implications and therapeutic potential of caspase-11 inhibitors are discussed. Targeting non-canonical inflammasomes is a promising strategy for autoimmune diseases treatment, while information about the toxicity and physiological disposition of the promising caspase-11 inhibitors need to be supplemented before they can be translated from bench to bedside.