Idiopathic pulmonary fibrosis is a fatal lung disorder in which the etiology and pathogenesis are still unobvious. Effective treatments are urgently needed considering that lung transplantation is the only treatment that could improve outcomes. This study aimed to investigate the therapeutic significance of the dual administration of pimitespib, an HSP90 inhibitor, and nifuroxazide, a STAT3 inhibitor, against bleomycin-induced pulmonary fibrosis in rats. Our results revealed that pimitespib/nifuroxazide inhibited bleomycin-induced alterations in the structure and the function of the lungs. They demonstrated significant decreases in the BALF total and differential cell counts, LDH activity, and total protein. Concurrently, there was a reduction in the accumulation of collagen as proved by decreased hydroxyproline and the gene expression of COL1A1 accompanied by lower levels of PDGF-BB, TIMP-1, and TGF-β. The levels of IL-6 were also downregulated. Pimitespib-induced inhibition of HSP90 led to subsequent inhibition of HIF-1α and STAT3 client proteins since the closed HSP90 would not enclose its client proteins. Therefore, pimitespib resulted in the repression of HIF-1α/CREB-p300 HAT as well as the STAT3/CREB-p300 HAT nuclear interactions. On the other hand, nifuroxazide resulted in a notable decline in pSTAT3 and HIF-1α levels. Subsequently, the combined effects of both drugs led to a substantial reduction in ECM deposition. Herein, pimitespib augmented nifuroxazide-induced disruption in the IL-6/STAT3/HIF-1α autocrine loop. Our findings also disclose that this novel loop is a promising therapeutic attack site for possible pulmonary fibrosis repression studies. Therefore, the use of pimitespib/nifuroxazide embodies an evolutionary perspective in managing pulmonary fibrosis.

Ulcerative colitis (UC) is a chronic inflammatory life-threatening and premalignant disorder with no cure that even might end up with surgical removal of a large section or even all of the colon. It is characterized by relapsing-remitting courses of intestinal inflammation and mucosal damage in which oxidative stress and exaggerated inflammatory response play a significant role. Most of the current medications to maintain remission are symptomatic and have many adverse reactions. Therefore, the potential for improved management of patients with UC continues to increase. Yet, the benefits of using the antiarthritic agent diacetylrhein to counteract inflammation in UC are still obscure. Hence, our study was designed to explore its potential role in UC using a model of dextran sodium sulfate-induced acute colitis in rats. Our results revealed that diacetylrhein targeted the NLRP3 and inhibited the inflammasome assembly. Consequently, caspase-1 activity and the inflammatory cytokines IL-1β and IL-18 were inhibited leading to a curbed pyroptosis process. Additionally, diacetylrhein revealed a significant antiapoptotic potential as revealed by the levels of pro-apoptotic and anti-apoptotic proteins. Concomitant to these effects, diacetylrhein also interrupted NFκB signals leading to improved microscopic features of inflamed colon and decreased colon weight to length ratio, indices of disease activity, and macroscopic damage. Additionally, a reduction in the myeloperoxidase activity, IL-6, and TGF-β alongside an increase in the gene expression of Ocln and ZO-1 were detected. To conclude diacetylrhein showed a significant antioxidant and anti-inflammatory potential and therefore might represent a promising agent in the management of acute UC.

Post-COVID syndrome comprises persistent neuropsychiatric manifestations for more than 12 weeks after recovery from acute SARS-CoV-2 infection, yet its underlying pathophysiology is unclear. Ferroptosis, an iron-dependent form of cell death with three hallmarks, iron dysregulation, antioxidant failure, and lipid peroxidation, seems to be involved in COVID-19/post-COVID-19 pathophysiology. Here, we administered the SARS-CoV-2 spike protein S1 subunit intranasally to K18-hACE2 transgenic mice and quantified ferroptotic marker protein expression in four brain regions (hippocampus, prefrontal cortex, cerebellum, and olfactory bulb) at 2, 6, and 12 weeks post-administration, alongside ultrastructural assessment by transmission electron microscopy (TEM) that was limited to the hippocampus and prefrontal cortex. Two-way ANOVA revealed region- and time-dependent modulation of iron-handling, antioxidant, and lipid peroxidation markers. In the hippocampus, FPN1 was significantly increased at 2 weeks, while TFR1 showed a time-dependent pattern without significant week-specific differences. In the prefrontal cortex, DMT1 significantly increased at 2 weeks, and GPx4 showed an overall treatment effect with a trend of increase at 6 weeks. The cerebellum exhibited early increases in FPN1 and GPx4 and a delayed increase in MDA-conjugated proteins. In the olfactory bulb, FPN1 increased at 12 weeks, with GPx4 showing an overall treatment effect and an early trend of decrease. TEM identified ferroptosis-consistent features in the hippocampus and prefrontal cortex at all time points. These findings suggest that spike protein exposure may be associated with time-dependent and brain-region-specific alterations of ferroptosis-related markers. These preliminary findings are based on a limited sample size, which needs further research to elucidate the clinical implication and to study the mechanism in more depth as well as future validation with pharmacological inhibitors.