The corticotropin-releasing factor (CRF) and its type 1 receptor (CRF₁R) play a key role in the regulation of the hypothalamic–pituitary–adrenal (HPA) axis. Dysregulation of the HPA axis is associated with congenital adrenal hyperplasia (CAH) and depression. Non-peptide CRF₁R-selective antagonists displayed antidepressant effects on animal models and are used for the management of CAH. To develop novel non-peptide CRF₁R antagonists, we have previously designed and synthesized a series of substituted pyrimidines. Among these analogs, molecule 43 (M43) binds to CRF₁R with the highest affinity. Based on this finding, we selected M43 for further pharmacological characterization in the present study. The results suggest that M43 is a potent CRF₁R antagonist, blocking the ability of the CRF-related agonist, Tyr⁰-sauvagine, to stimulate (1) cAMP accumulation in HEK 293 cells expressing CRF₁R and (2) the proliferation rate of RAW 264.7 macrophages. Computational studies suggest that the antagonist properties of M43 are mostly attributed to its ability to interact with residues in the allosteric pocket of CRF₁R, comprised of the third, fifth, and sixth transmembrane domain residues, which block activation-associated structural rearrangements of the receptor. Our data will be used to design novel non-peptide CRF₁R antagonists for clinical use.

Hypertrophic cardiomyopathy (HCM) is a heart muscle disease associated with an increased risk for sudden cardiac death (SCD). Cytokeratin 18-based proteins, such as M30 and M65 antigens, are known cell-death biomarkers. M30 antigen is released from cells during apoptosis, and M65 antigen is released during cell death from any cause, such as apoptosis or necrosis. We aimed to study the expression of M30 and M65 antigens in peripheral blood obtained by 46 HCM patients and compare with 27 age- and sex-matched patients without HCM. We also investigated the CK18 expression in myocardium from postmortem HCM hearts. M30 and M65 antigens were significantly increased in the HCM vs. non-HCM group (Μ30: 338 ± 197 U/uL vs. 206 ± 166 U/uL, p = 0.003; M65: 428 ± 224 U/uL vs. 246 ± 214 U/uL, p = 0.001), and HCM patients with a higher expression of these markers (M30: 417 ± 208 vs. 271 ± 162 U/uL, p = 0.011; M65: 518 ± 242 vs. 351 ± 178 U/uL, p = 0.011) had a higher risk for SCD. In HCM, both apoptosis and necrosis are increased, but particularly necrosis (M30/M65 ratio: 0.75 ± 0.09 vs. 0.85 ± 0.02, p < 0.001). CK18 is expressed in the HCM myocardium (1.767 ± 0.412 vs. 0.537 ± 0.383, % of area, p = 0.0058). Therefore, M30 and M65 antigens may be novel biomarkers in HCM.

Background/Objectives: Psoriasis is a chronic, systemic, and multifactorial disease affecting approximately 1–2% of the Caucasian population. It is characterized by distinct histopathological features, including epidermal hyperplasia and infiltration of immune cells into the skin. Despite its high prevalence, the underlying mechanisms driving psoriasis remain incompletely understood. Heat shock proteins (HSPs), particularly HSP70, are known to play key roles in modulating immune responses and inflammation. Although previous studies have examined the involvement of HSPs in dermatological conditions such as psoriasis, current evidence remains inconclusive. In this study, we aimed to elucidate the role of Hsp70 deficiency in the pathogenesis of psoriasis using an in vivo model. Methods: We used male mice that were either genetically normal (Hsp70+/+) or lacked the Hsp70 gene (Hsp70−/−) at 8–12 weeks of age. Psoriasis was induced by applying imiquimod cream daily for 7 days. At the end of this period mice were sacrificed and blood and tissue collected for further analysis. The severity of the psoriasis was evaluated daily using the PASI Score. Results: Hsp70 depletion was accompanied by significantly decreased psoriatic-like skin inflammation, fewer histological abnormalities, and lower PASI scores. Flow cytometry analysis revealed a decrease in LY6C⁺ monocytes and an increase in LY6G⁺ neutrophils infiltration in Hsp70-deficient mice. In addition, HSP60 expression was lower in the absence of HSP70, while HSP90 expression was markedly elevated. Conclusions: These results point to a significant regulatory function of HSP70 in psoriatic inflammation and raise the possibility that it could be a therapeutic target.