Antimicrobial Evaluation of a Set of Heterobicyclic Methylthiadiazole Hydrazones: Synthesis, Characterization, and SAR Studies

To exploit the potential antimicrobial activities of azabicyclic skeleton based compounds, a set of 2r,4c-diaryl-3-azabicyclo[3.3.1]­nonan-9-one-4-methyl-1,2,3-thiadazole-5-carbonyl hydrazones were synthesized. Unambiguous structural elucidation has been carried out by investigating IR, H¹, C¹³ NMR, and elemental analysis. 2D NMR spectra (¹H–¹H COSY, HSQC, HMBC, and NOESY) were recorded for a representative compound, <b>12</b>, to confirm the proposed structure for <b>9</b>–<b>15</b>. Antimicrobial activity assessment of synthesized hydrazones <b>9</b>–<b>15</b> has been evaluated by screening against selective strains. Both bacteria and fungi of various forms along with standard drug have been taken for the analysis. Difference in the potency of activity against the strains has been evaluated on the basis of SAR, and it has been revealed that substitution of electron-withdrawing halogens (chloro, fluoro, and bromo) at para positions of the phenyl (<b>10</b>, <b>12</b>, and <b>13</b>) enhanced the antifungal and antibacterial activities against tested organisms compared to other hydrazone derivatives

Kidney Damage in Long COVID: Studies in Experimental Mice

Simple Summary In this study, we investigated the long-term effects of COVID-19 on the kidneys using mice infected with a similar coronavirus. We examined markers in the kidneys related to inflammation, scarring, and damage. We identified that certain markers linked to scarring and inflammation remained high in the mice’s kidneys even after the initial infection, suggesting kidney damage. However, other markers did not show significant changes (e.g., mRNA levels of TNFR-1, WFDC2, B2M, likely due to factors influencing their half-life and translation rate). To explore treatments, we tested a drug called SPIKENET (SPK), a 15-amino acid synthetic peptide, that blocks the virus from attaching and entering cells. When we gave SPK to the mice, it decreased the certain marker levels in their kidneys in both the group of mice that were treated shortly after infection and the group that received treatment a year after the infection. These findings indicate that kidney scarring may begin early in COVID-19 and that targeting specific markers and proteins with treatments like SPK could help prevent kidney damage in both early and long-term COVID-19 cases.Abstract Signs and symptoms involving multiple organ systems which persist for weeks or months to years after the initial SARS-CoV-2 infection (also known as PASC or long COVID) are common complications of individuals with COVID-19. We recently reported pathophysiological changes in various organs post-acute infection of mice with mouse hepatitis virus-1 (MHV-1, a coronavirus) (7 days) and after long-term post-infection (12 months). One of the organs severely affected in this animal model is the kidney, which correlated well with human studies showing kidney injury post-SARS-CoV-2 infection. Our long-term post-infection pathological observation in kidneys includes the development of edema and inflammation of the renal parenchyma, severe acute tubular necrosis, and infiltration of macrophages and lymphocytes, in addition to changes observed in both acute and long-term post-infection, which include tubular epithelial cell degenerative changes, peritubular vessel congestion, proximal and distal tubular necrosis, hemorrhage in the interstitial tissue, and vacuolation of renal tubules. These findings strongly suggest the possible development of renal fibrosis, in particular in the long-term post-infection. Accordingly, we investigated whether the signaling system that is known to initiate the above-mentioned changes in kidneys in other conditions is also activated in long-term post-MHV-1 infection. We found increased TGF-β1, FGF23, NGAL, IL-18, HIF1-α, TLR2, YKL-40, and B2M mRNA levels in long-term post-MHV-1 infection, but not EGFR, TNFR1, BCL3, and WFDC2. However, only neutrophil gelatinase-associated lipocalin (NGAL) increased in acute infection (7 days). Immunoblot studies showed an elevation in protein levels of HIF1-α, TLR-2, and EGFR in long-term post-MHV-1 infection, while KIM-1 and MMP-7 protein levels are increased in acute infection. Treatment with a synthetic peptide, SPIKENET (SPK), which inhibits spike protein binding, reduced NGAL mRNA in acute infection, and decreased TGF-β1, BCL3 mRNA, EGFR, HIF1-α, and TLR-2 protein levels long-term post-MHV-1 infection. These findings suggest that fibrotic events may initiate early in SARS-CoV-2 infection, leading to pronounced kidney fibrosis in long COVID. Targeting these factors therapeutically may prevent acute or long-COVID-associated kidney complications

Helicobacter pylori pathogen inhibits cellular responses to oncogenic stress and apoptosis.

Helicobacter pylori (H. pylori) is a common gastric pathogen that infects approximately half of the world's population. Infection with H. pylori can lead to diverse pathological conditions, including chronic gastritis, peptic ulcer disease, and cancer. The latter is the most severe consequence of H. pylori infection. According to epidemiological studies, gastric infection with H. pylori is the strongest known risk factor for non-cardia gastric cancer (GC), which remains one of the leading causes of cancer-related deaths worldwide. However, it still remains to be poorly understood how host-microbe interactions result in cancer development in the human stomach. Here we focus on the H. pylori bacterial factors that affect the host ubiquitin proteasome system. We investigated E3 ubiquitin ligases SIVA1 and ULF that regulate p14ARF (p19ARF in mice) tumor suppressor. ARF plays a key role in regulation of the oncogenic stress response and is frequently inhibited during GC progression. Expression of ARF, SIVA1 and ULF proteins were investigated in gastroids, H. pylori-infected mice and human gastric tissues. The role of the H. pylori type IV secretion system was assessed using various H. pylori isogenic mutants. Our studies demonstrated that H. pylori infection results in induction of ULF, decrease in SIVA1 protein levels, and subsequent ubiquitination and degradation of p14ARF tumor suppressor. Bacterial CagA protein was found to sequentially bind to SIVA1 and ULF proteins. This process is regulated by CagA protein phosphorylation at the EPIYA motifs. Downregulation of ARF protein leads to inhibition of cellular apoptosis and oncogenic stress response that may promote gastric carcinogenesis

Protein adduction causes non-mutational inhibition of p53 tumor suppressor

p53 is a key tumor suppressor that is frequently mutated in human tumors. In this study, we investigated how p53 is regulated in precancerous lesions prior to mutations in the p53 gene. Analyzing esophageal cells in conditions of genotoxic stress that promotes development of esophageal adenocarcinoma, we find that p53 protein is adducted with reactive isolevuglandins (isoLGs), products of lipid peroxidation. Modification of p53 protein with isoLGs diminishes its acetylation and binding to the promoters of p53 target genes causing modulation of p53-dependent transcription. It also leads to accumulation of adducted p53 protein in intracellular amyloid-like aggregates that can be inhibited by isoLG scavenger 2-HOBA in vitro and in vivo. Taken together, our studies reveal a posttranslational modification of p53 protein that causes molecular ag-gregation of p53 protein and its non-mutational inactivation in conditions of DNA damage that may play an important role in human tumorigenesis

Protein adduction causes non-mutational inhibition of p53 tumor suppressor

Summary: p53 is a key tumor suppressor that is frequently mutated in human tumors. In this study, we investigated how p53 is regulated in precancerous lesions prior to mutations in the p53 gene. Analyzing esophageal cells in conditions of genotoxic stress that promotes development of esophageal adenocarcinoma, we find that p53 protein is adducted with reactive isolevuglandins (isoLGs), products of lipid peroxidation. Modification of p53 protein with isoLGs diminishes its acetylation and binding to the promoters of p53 target genes causing modulation of p53-dependent transcription. It also leads to accumulation of adducted p53 protein in intracellular amyloid-like aggregates that can be inhibited by isoLG scavenger 2-HOBA in vitro and in vivo. Taken together, our studies reveal a posttranslational modification of p53 protein that causes molecular aggregation of p53 protein and its non-mutational inactivation in conditions of DNA damage that may play an important role in human tumorigenesis