Association Between Gasdermin A and Gasdermin B Polymorphisms and Susceptibility to Adult and Childhood Asthma Among Jordanians

Impavido attenuates inflammation, reduces atherosclerosis, and alters gut microbiota in hyperlipidemic mice

Impavido (Miltefosine) is an FDA-approved drug for treating leishmaniasis and primary amebic meningoencephalitis. We have shown previously that Miltefosine increased cholesterol release and dampened Nlrp3 inflammasome assembly in macrophages. Here, we show that Miltefosine reduced LPS-induced choline uptake by macrophages, and attenuated Nlrp3 inflammasome assembly in mice. Miltefosine-fed mice showed reduced plasma IL-1β in a polymicrobial cecal slurry model of systemic inflammation. Miltefosine-fed mice showed increased reverse cholesterol transport to the plasma, liver, and feces. Hyperlipidemic apoE^-/- mice fed with WTD + Miltefosine showed significantly reduced weight gain and markedly reduced atherosclerotic lesions versus mice fed with WTD. The 16S rDNA sequencing and analysis of gut microbiota showed marked alterations in the microbiota profile of Miltefosine-fed hyperlipidemic apoE^-/- versus control, with the most notable changes in Romboutsia and Bacteriodes species. Taken together, these data indicate that Miltefosine causes pleiotropic effects on lipid metabolism, inflammasome activity, atherosclerosis, and the gut microbiota.

Association between 17q21 variants and asthma predisposition in Pashtun population from Pakistan

OBJECTIVE

Asthma is a heterogeneous and genetically complex respiratory disease, and more than 300 million people are affected worldwide. In this study, frequencies of four SNPs (rs3816470, rs7216389, rs8067378, rs12603332) in chromosome 17q21 region were analyzed and their relationship with the asthma susceptibility, in the Pashtun population of Khyber Pakhtunkhwa province (KPK) of Pakistan were investigated.

METHODS

DNA samples from 500 subjects (asthma cases/controls) were genotyped by Sanger sequencing. Chi-square tests, logistic regression analysis, linkage disequilibrium, and haplotype analysis techniques were applied to study the association of the SNPs with asthma.

RESULTS

Genetic models, including recessive, dominant, co-dominant, over-dominant, and additive, were tested. The frequencies of alleles T/T at rs3816470 (OR = 1.91; 95%CI = 1.15-3.18; p = .011*) and rs7216389 (OR = 2.14; 95%CI = 1.21-3.79; p = .0076*), A/A at rs 8067378 (OR = 1.89; 95%CI = 1.17-3.06; p = .0081*), C/C at rs12603332 (OR = 1.97; 95%CI = 1.18-3.27; p = .008*), under recessive models, respectively, were significantly (p-values < .0125) associated with asthma susceptibility. The frequencies of T/T genotype in rs3816470 (OR = 6.01; 95%CI = 2.48-14.60; p = .000147*), and rs7216389 (OR = 5.05; 95%CI = 1.79-14.21; p = .003296*), and C/C at rs12603332 (OR = 2.64; 95%CI = 1.11-6.32; p = .019063*), were significantly (p-values < .0125) associated with asthma susceptibility in Pashtun women by stratified analysis based on age and gender. Similarly, three unique haplotypes were found associated with disease development and protective effect in female and male subjects. Linkage disequilibrium analysis presented a strong linkage (≥80%) between SNP variants and predicted their co-inheritance in the studied population.

CONCLUSION

The 17q21 variants (rs3816470, rs7216389, rs12603332) were found significantly (p-values < .0125) associated with asthma predisposition in the Pashtun population of KPK exclusively in the female asthmatic cases.

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GSDM gene polymorphisms regulate the IgE level in asthmatic patients

Background

Gasdermin A (GSDMA) and gasdermin B (GSDMB) have been associated with childhood and adult asthma in many populations including the Jordanian population. It is also known that IgE plays a crucial role in various allergic disorders, such elevated levels of total serum IgE were detected in asthma and allergic rhinitis. IgE immunoglobulin is responsible for the release of numerous inflammatory mediators, such as histamine and prostaglandins, from mast cells in asthmatic patients.

Objective

In this study, single nucleotide polymorphisms of GSDMA (rs7212938, T/G) and GSDMB (rs7216389, T/C) in Jordanian population were investigated for their association with total IgE levels in serum of asthmatic children and adult subjects.

Methods

The genetic polymorphism analysis for SNPs was performed using the polymerase chain reaction (PCR)/restriction fragment length polymorphism method (RFLP). Three analysis models were applied to the genotype data: co-dominant, dominant and recessive.

Results

Our data demonstrate a significant correlation between GSDMB genetic SNP (rs7216389) and the total IgE serum level. Where one minor allele in the GSDMB gene is sufficient to induce significant changes in the IgE serum levels and plays a role in the pathogenesis of asthma in asthmatic children of the Jordanian population. Suggesting that this polymorphism might have a protective effect against asthma risk. While the presence of the GSDMB polymorphism alone might not be sufficient to associate with the high risk of developing asthma or responding to it in adults in Jordanian population.

Conclusion

In conclusion, the current study confirms the significant association of GSDMB genetic SNP (rs7216389) with IgE levels in asthma patients in Jordanian population, while no significant correlation of GSDMA and IgE level was found in both child and adult asthmatic patients.

Chemical Modulation of Gasdermin-Mediated Pyroptosis and Therapeutic Potential

Pyroptosis, a lytic form of programmed cell death, both stimulates effective immune responses and causes tissue damage. Gasdermin (GSDM) proteins are a family of pore-forming executors of pyroptosis. While the most-studied member, GSDMD, exerts critical functions in inflammasome biology, emerging evidence demonstrates potential broad relevance for GSDM-mediated pyroptosis across diverse pathologies. In this review, we describe GSDM biology, outline conditions where inflammasomes and GSDM-mediated pyroptosis represent rational therapeutic targets, and delineate strategies to manipulate these central immunologic processes for the treatment of human disease.

GSDMD-mediated pyroptosis: a critical mechanism of diabetic nephropathy

Pyroptosis is a recently identified mechanism of programmed cell death related to Caspase-1 that triggers a series of inflammatory reactions by releasing several proinflammatory factors such as IL-1β and IL-18. The process is characterised by the rupture of cell membranes and the release of cell contents through the mediation of gasdermin (GSDM) proteins. GSDMD is an important member of the GSDM family and plays a critical role in the two pathways of pyroptosis. Diabetic nephropathy (DN) is a microvascular complication of diabetes and a major cause of end-stage renal disease. Recently, it was revealed that GSDMD-mediated pyroptosis plays an important role in the occurrence and development of DN. In this review, we focus on two types of kidney cells, tubular epithelial cells and renal podocytes, to illustrate the mechanism of pyroptosis in DN and provide new ideas for the prevention, early diagnosis and molecular therapy of DN.

Punching Holes in Cellular Membranes: Biology and Evolution of Gasdermins

The gasdermin (GSDM) family has evolved as six gene clusters (GSDMA-E and Pejvakin, PJVK), and GSDM proteins are characterized by a unique N-terminal domain (N-GSDM). With the exception of PJVK, the N-GSDM domain is capable of executing plasma membrane permeabilization. Depending on the cell death modality, several protease- and kinase-dependent mechanisms directly regulate the activity of GSDME and GSDMD, the two most widely expressed and best-studied GSDMs. We provide an overview of all GSDMs in terms of biological function, tissue expression, activation, regulation, and structure. In-depth phylogenetic analysis reveals that GSDM genes show many gene duplications and deletions, suggesting that strong evolutionary forces and a unique position of the PJVK gene are associated with the occurrence of complex inner-ear development in vertebrates.

Association between Gasdermin A, Gasdermin B Polymorphisms and Allergic Rhinitis Amongst Jordanians

BACKGROUND

Gasdermin A (GSDMA) and Gasdermin B (GSDMB) have been associated with childhood and to a lesser extent with adult asthma in many populations. In this study, we investigate whether there is an association between GSDMA (rs7212938, T/G) and GSDMB (rs7216389, T/C) at locus 17q21.2 and risk of Allergic Rhinitis among Jordanians. Also, we aimed to determine if there is an association between such polymorphisms and the IgE level.

METHODS

The study included 112 rhinitis patients and 111 Healthy controls. Gasdermin A (GSDMA) (rs7212938, T/G) and Gasdermin B (rs7216389, T/C) polymorphisms were genotyped using the PCRRFLP method.

RESULTS

On the genotype level, three analysis models were applied namely co-dominant, dominant and recessive genotypes. GSDMB CC genotype was found to have a significant protective effect against allergic Rhinitis (< 0.05). cc genotype was also significantly associated with higher IgE level among the studied population.

CONCLUSION

The GSDMB CC of homozygous minor genotype showed a protective effect against Allergic rhinitis. It also was found to be significantly associated with lower IgE level among the studied population. No association was found between GSDMA with the risk of allergic Rhinitis.

GSDME and its role in cancer: From behind the scenes to the front of the stage

Gasdermin E (GSDME), a gene originally involved in hereditary hearing loss, has been associated with several types of cancer in the last two decades. Recently, GSDME was identified as a pore-forming molecule, which is activated following caspase-3-mediated cleavage resulting in so-called secondary necrosis following apoptotic cell death, or in primary necrotic cell death without an apoptotic phase, so-called pyroptosis-like. This implication in cell death execution suggests its potential role as a tumor suppressor. GSDME also exhibited a cancer type-specific differential methylation pattern between tumor tissues and normal cells, implying GSDME gene methylation as both a pan-cancer and cancer type-specific detection biomarker. A bit paradoxically, GSDME protein expression is considered to be less suited as biomarker, and although its ablation does not protect the cell against eventual cell death, its protein expression might still operate in tumor immunogenicity due to its capacity to induce (secondary) necrotic cell death, which has enhanced immunogenic properties. Additionally, GSDME gene expression has been shown to be associated with favorable prognosis following chemotherapy, and it could therefore be a potential predictive biomarker. We provide an overview of the different associations between GSDME gene methylation, gene expression and tumorigenesis, and explore their potential use in the clinic. Our review only focuses on GSDME and summarizes the current knowledge and most recent advances on GSDME's role in cancer formation, its potential as a biomarker in cancer and on its promising role in immunotherapies and antitumor immune response.

Gasdermins: pore-forming activities and beyond

Gasdermins (GSDMs) belong to a protein superfamily that is found only in vertebrates and consists of GSDMA, GSDMB, GSDMC, GSDMD, DFNA5 (a.k.a. GSDME) and DFNB59 (a.k.a. Pejvakin (PJVK)) in humans. Except for DFNB59, all members of the GSDM superfamily contain a conserved two-domain structure (N-terminal and C-terminal domains) and share an autoinhibitory mechanism. When the N-terminal domain of these GSDMs is released, it possesses pore-forming activity that causes inflammatory death associated with the loss of cell membrane integrity and release of inflammatory mediators. It has also been found that spontaneous mutations occurring in the genes of GSDMs have been associated with the development of certain autoimmune disorders, as well as cancers. Here, we review the current knowledge of the expression profile and regulation of GSDMs and the important roles of this protein family in inflammatory cell death, tumorigenesis and other related diseases.

Association of IL-4 Polymorphisms with Allergic Rhinitis in Jordanian Population

Background and objectives: Allergic rhinitis has complex patterns of inheritance, and single nucleotide polymorphisms, a common genetic variation in a population, exert a significant role in allergic rhinitis pathology. The current study aimed to investigate the association of Interleukin-4 (IL-4) polymorphisms with allergic rhinitis. Materials and Methods: Our study included 158 patients with allergic rhinitis and 140 healthy controls from Jordan that were genotyped for IL-4 single nucleotide polymorphisms (SNPs) C-589T (rs2243250) and T-2979G (rs2227284) using restriction fragment length polymorphism-polymerase chain reaction. Statistical analysis was conducted using IBM SPSS Statistics version 24 software. Results: The results showed that the allelic frequency of the minor alleles was 0.19 and 0.67 for C-589T (rs2243250) and T-2979G (rs2227284) in the allergic rhinitis patients, respectively, while it was 0.18 for C-589T (rs2243250) and 0.64 T-2979G (rs2227284) in the control group. The homozygous (TT) genotype of C-589T (rs2243250) was significantly associated with allergic rhinitis (p < 0.05), while there was no association of any of T-2979G (rs2227284) genotypes with allergic rhinitis. Conclusions: The results of this study indicate that genetic inter-population variation precipitates the differences in the percentages of many diseases among populations, including allergic rhinitis.

Birth weight is not causally associated with adult asthma: results from instrumental variable analyses

The association between lower birth weight and childhood asthma is well established. However, it remains unclear whether the influence of lower birth weight on asthma can persist into adulthood. We conducted a Mendelian randomization analysis to assess the causal relationship of birth weight (~140,000 individuals) on the risk of adult asthma (~62,000 individuals). We estimated the causal effect of birth weight to be 1.00 (95% CI 0.98~1.03, p = 0.737) using the genetic risk score method. We did not observe nonlinear relationship or gender difference for the estimated causal effect. With the inverse-variance weighted method, the causal effect of birth weight on adult asthma was estimated to be 1.02 (95% CI 0.84~1.24, p = 0.813). Additionally, the iMAP method provides no additional genome-wide evidence supporting the causal effects of birth weight on adult asthma. Our results were robust against various sensitivity analyses, and MR-PRESSO and MR-Egger regression showed that no instrument outliers and no horizontal pleiotropy were likely to bias the results. Overall, our study provides no evidence for the fetal origins of diseases hypothesis for adult asthma, implying that the impact of birth weight on asthma in years of children and adolescents does not persist into adult and previous findings may be biased by confounders.

'Hints' in the killer protein gasdermin D: unveiling the secrets of gasdermins driving cell death

Pyroptosis is a lytic form of cell death distinguished from apoptosis, ferroptosis, necrosis, necroptosis, NETosis, oncosis, pyronecrosis and autophagy. Proinflammatory caspases cleave a gasdermin D (GSDMD) protein to generate a 31 kDa N-terminal domain. The cleavage relieves the intramolecular inhibition on the gasdermin-N domain, which then moves to the plasma membrane to exhibit pore-forming activity. Thus, GSDMD acts as the final and direct executor of pyroptotic cell death. Owing to the selective targeting of the inner leaflet of the plasma membrane with the pore-forming that determines pyroptotic cell death, GSDMD could be a potential target to control cell death or extracellular bacterial infections. Intriguingly, other gasdermin family members also share similar N-terminal domains, but they present different cell death programs. Herein, we summarize features and functions of the novel player proteins in cell death, including GSDMD triggering pyroptosis, Gsdma3/GSDMA initiating autophagy/apoptosis and DFNA5 inducing apoptosis/secondary necrosis. The gasdermin N terminus appears to be a novel pore-forming protein. This provides novel insight into the underlying roles and mechanisms of lytic or nonlytic forms of programmed cell death, as well as their potential applications in inflammation-associated diseases.