ABSTRACT
Background: A cytokine storm is a serious clinical condition that complicates infectious diseases, for example, coronavirus disease 2019 (COVID-19), and non-infectious diseases such as autoimmune diseases and cancer and may often lead to death. The patients who are affected by the cytokine storm are almost always severe/critical and at risk for acute respiratory distress syndrome or eventually death. Pro-inflammatory cytokines such as interleukin 6 (IL-6), IL-1 beta, and tumor necrosis factor alpha (TNF-alpha) have been repeatedly shown to be related to the COVID-19 disease severity and mortality. In this study, our objective was to evaluate the attenuated effect of rivastigmine (RA) in a cytokine storm in Swiss Albino mice in which the cytokine storm was induced by lipopolysaccharide (LPS) and to explore their effects on IL-1 beta, IL-6, and TNF-alpha levels. Method(s): This study was carried with 60 male Swiss albino mice that were divided equally and randomly into six groups as follows: *Group AH: Apparently healthy control group which received no induction, not treated. *Group LPS: Induced using LPS at 5 mg/kg and no treatment administered. *Group DMSO: Induced and treated with 1% dimethyl sulfoxide (DMSO). *Group RA: Induced and treated with 0.5 mg/kg RA. *Group MPA: Induced and treated with 50 mg/kg methylprednisolone (MPA). *Group RMPA: Induced and treated with 0.25 mg/kg rivastigmine and 25 mg/kg of methylprednisolone. All the mice were treated with drugs or vehicles for three consecutive days before LPS induction. The mice were then injected with LPS intraperitoneally at a dosage of 5 mg/kg for systematic inflammatory stimulation. After 48 hours of LPS induction, all the mice were euthanized by light anesthesia with chloroform, and blood was collected for the quantitative determination of IL-1beta, IL-6, and TNF-alpha levels using the enzyme-linked immunosorbent assay (ELISA) technique. Result(s): Administration of LPS to Swiss albino mice caused a significant elevation of IL-1beta, IL-6, and TNF-alpha levels than in the healthy control group. Significant reduction of these parameters were observed in the RA and MPA groups when compared with those in the non-treated group. Conclusion(s): RA was found to be effective in attenuating the induced cytokine storm by suppressing IL-1beta, IL-6, and TNF-alpha levels, and the results with RA were comparable to that of MPA. A combination of half-doses of both RA and MPA administered together shows no obvious advantage when compared with that of each of them alone.Copyright © 2022 Mansoor, Raghif, licensee HBKU Press
ABSTRACT
Background: A cytokine storm is a serious clinical condition that complicates infectious diseases, for example, coronavirus disease 2019 (COVID-19), and non-infectious diseases such as autoimmune diseases and cancer and may often lead to death. The patients who are affected by the cytokine storm are almost always severe/critical and at risk for acute respiratory distress syndrome or eventually death. Pro-inflammatory cytokines such as interleukin 6 (IL-6), IL-1 beta, and tumor necrosis factor alpha (TNF-α) have been repeatedly shown to be related to the COVID-19 disease severity and mortality. In this study, our objective was to evaluate the attenuated effect of rivastigmine (RA) in a cytokine storm in Swiss Albino mice in which the cytokine storm was induced by lipopolysaccharide (LPS) and to explore their effects on IL-1 β, IL-6, and TNF-α levels. Methods: This study was carried with 60 male Swiss albino mice that were divided equally and randomly into six groups as follows: •Group AH: Apparently healthy control group which received no induction, not treated. •Group LPS: Induced using LPS at 5 mg/kg and no treatment administered. •Group DMSO: Induced and treated with 1% dimethyl sulfoxide (DMSO). •Group RA: Induced and treated with 0.5 mg/kg RA. •Group MPA: Induced and treated with 50 mg/kg methylprednisolone (MPA). •Group RMPA: Induced and treated with 0.25 mg/kg rivastigmine and 25 mg/kg of methylprednisolone. All the mice were treated with drugs or vehicles for three consecutive days before LPS induction. The mice were then injected with LPS intraperitoneally at a dosage of 5 mg/kg for systematic inflammatory stimulation. After 48 hours of LPS induction, all the mice were euthanized by light anesthesia with chloroform, and blood was collected for the quantitative determination of IL-1β, IL-6, and TNF-α levels using the enzyme-linked immunosorbent assay (ELISA) technique. Results: Administration of LPS to Swiss albino mice caused a significant elevation of IL-1β, IL-6, and TNF-α levels than in the healthy control group. Significant reduction of these parameters were observed in the RA and MPA groups when compared with those in the non-treated group. Conclusion: RA was found to be effective in attenuating the induced cytokine storm by suppressing IL-1β, IL-6, and TNF-α levels, and the results with RA were comparable to that of MPA. A combination of half-doses of both RA and MPA administered together shows no obvious advantage when compared with that of each of them alone.
ABSTRACT
Background: Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has been responsible for the global pandemic and disease known as COVID-19. Clinical studies have found >50% of COVID-19 patients report gastrointestinal (GI) symptoms, with some studies suggesting longer viral clearance in patients with GI symptoms. SARS-CoV-2 utilizes angiotensin-converting enzyme 2 (ACE2) as a receptor for viral attachment and intracellular entry, which is expressed in the intestine, making the GI tract a potential route of infection. Aim: To determine the effect of microbial colonization on colonic ACE2 expression using a humanized mouse model. Methods: Human stool was collected from healthy volunteers and individuals with irritable bowel syndrome, a common gastrointestinal disorder, and fecal slurries were prepared. 4-6 week old female Swiss-Webster mice (N=6/group) were gavaged with fecal slurries and maintained in sterile ex-isolator cages for 6 weeks. Posthumanization stool was collected along with proximal colonic tissue. Shotgun metagenomics was done on mouse pellets. RNAseq on tissue performed at a depth of 20 million reads/ sample using NovaSeq 6000. MAP-Rseq workflow using the mm10 genome was done to identify differentially expressed genes. Associations of ACE2 expression with α –diversity between microbiome from healthy and irritable bowel syndrome humanized mice was done using linear modeling with compositional associations assessed using PERMANOVA (BrayCurtis distance). To identify taxa associated with ACE2 expression, a permutation-based approach using the F-statistic of a linear model was used with false discovery rate (FDR) to correct for multiple testing. Results: Humanized mice demonstrated significantly lower colonic ACE2 expression compared to the germ-free mice (333.4 ± 191.1 vs. 1914 4 ± 309.9, FDR<0.001). However, ACE2 expression was similar post-humanization across all mouse groups regardless of stool used for humanization, despite decreased diversity in stool from irritable bowel syndrome patients and compositional differences from healthy volunteer stool. No associations between microbiome α-diversity (Shannon p=0.825, observed p= 0.400, InvSimpson p=0.512), β-diversity (p=0.568) or individual taxa were seen with ACE2 expression. Conclusions: Commensal microbial colonization significantly suppresses colonic ACE2 expression. However, in this pilot study, mice colonized with dysbiotic and healthy microbial communities had similar ACE2 expression. Future studies will have to explore the role of commensal microbes on gastrointestinal expression of ACE2 which may in turn reflect predisposition for infection or intestinal involvement with SARS-CoV-2. Supported by DK103911, DK120745.