New C(4)- and C(1)-derivatives of furo[3,4-c]pyridine-3-ones and related compounds: evidence for site-specific inhibition of the constitutive proteasome and its immunoisoform.

A set of 18 new C(4) and C(1) derivatives of nor-cerpegin (1,1-dimethyl furo[3,4-c]pyridine-3-one), 6 model compounds (γ- and δ-lactones) and 20 furo- or thieno[2,3-d]-pyrimidine-4-one related compounds were designed and synthesized. Each compound was assayed for inhibition of CT-L, T-L and PA proteolytic activities of 20S constitutive proteasome (c20S). Most performant compounds were also assayed on 20S immunoproteasome (i20S). Compound 10 with a benzylamino group at C(4) and dimethylated at C(1) of the furopyridine ring was the most efficient PA site-specific inhibitor of the c20S (IC50(cPA) of 600nM) without noticeable inhibition of the i20S PA site (iPA). In silico docking assays for 10 at the iPA catalytic site revealed the absence of poses normally observed for this compound and related ones at the constitutive PA site (cPA). The thieno[2,3-d]pyrimidine-4-one 40 was T-L site-specific with a mild inhibition of both c20S and i20S in vitro (IC50(cT-L) of 9.9µM and IC50(iT-L) of 6.7µM). In silico docking assays of 40 at T-L sites of c20S and i20S revealed almost identical first rank poses in the two types of sites with no possibility left for nucleophilic attack by Thr1 as observed for the fused furopyridine-3-one 10.

Assessment the value of Pyroptosis-Associated Gasdermin family genes in hepatocellular carcinoma: A Multi-Omics Comprehensive Analysis.

Background: Hepatocellular carcinoma (HCC) is one of the common primary cancers of the liver worldwide and leading cause of mortality. Gasdermins (GSDMs) family genes play an important role in the regulation of the normal physiological processes and have been implicated in multiple diseases. However, little is known about the relationship between different GSDMs proteins and HCC. The aim of this study was to explore the potential relationship between the expression, prognosis, genetic variation and immune infiltration of GSDMs family genes and HCC. Methods: We used different bioinformatics common public databases such as GSCA, GEPIA, UALCAN, HPA, Kaplan-Meier Plotter, LinkedOmics, GeneMANIA, STRING, cBioPortal, TIMER and TISIDB to analyze the differential expression of the different GSDMs, prognostic value, genetic alterations, immune cell infiltration and their functional networks in HCC patients. Results: All the members of the GSDMs family exhibited elevated mRNA expression levels in LIHC compared to the normal tissues, while only GSDMB, GSDMD and GSDME showed enhanced protein expression. The mRNA expression of most GSDMs members was found to be elevated in HCC patients at stages I-III (clinical stage) compared to the normal subjects. The expression of GSDMD was correlated with OS and DSS of patients, whereas GSDME was correlated with OS, DSS and RFS of patients. Gene amplification was observed to be main mode of variation in members of the GSDMs family. KEGG pathway analysis showed that genes associated with different members of the GSDMs family were enriched in the pathways of S. aureus infection, intestinal immunity, ribosome and protein assembly, oxidative phosphorylation, osteoclast differentiation and Fc gamma (γ) R-mediated phagocytosis. In addition, expression of both GSDMA and GSDME were found to be correlated most significantly with infiltration of immune cells, while GSDMA and GSDME somatic cell copy number alteration (CAN) were correlated significantly with the infiltration of immune cells. All GSDMs were noted to be associated with distinct subtypes of immune cells, except GSDMC. Conclusions: Our findings have provided useful insights to better understand the roles and functions of GSDMs in HCC that can provide novel direction for developing therapeutic modalities for HCC, including immunotherapy.

C1 and N5 derivatives of cerpegin: synthesis of a new series based on structure-activity relationships to optimize their inhibitory effect on 20S proteasome.

Thirty-two new derivatives of cerpegin (1,1,5-trimethylfuro[3,4-c]pyridine-3,4-dione) were designed and synthesized in high yield by a new method, combining several C(1) and N(5) substituents. All compounds were tested for their inhibitory effect on the CT-L, T-L and PA proteolytic activities of a purified mammalian 20S proteasome. Only one molecule inhibited both CT-L and PA activities. Sixteen molecules specifically inhibited PA at the micromolar range, out of which fourteen had IC50 values around 5 µM and two had IC50 values closer to 2 µM. Except in one case, neither calpain I nor cathepsin B was inhibited. In silico docking suggests a unique mode of binding of the most efficient compounds to the ß1 catalytic site (PA activity) in relation to the chemical nature of C(1) substituents.

A Longitudinal Study of the Relationship of Adiponectin with Reproduction in Infertile Women Undergoing IVF/ICSI Treatment, and an Experimental Study in Human Granulosa Cells.

This study investigated the roles of adiponectin in IVF treatment during Phase I (the basal stage before gonadotropin administration), Phase II (approximately 8 days after gonadotropin administration), and Phase III (on the ovum pick-up day), as well as the effects of adiponectin on CYP19A1 and the FSH receptor (FSHR) mRNA expression in a human granulosa-like tumor cell line (KGN). In human subjects (a longitudinal study, n = 30), blood samples were collected in all phases, while follicular fluid (FF) was only collected in Phase III. The participants were classified into successful and unsuccessful groups based on the determination of fetal heartbeats. KGN cells were treated with adiponectin/FSH/IGF-1 (an experimental study, n = 3). There was no difference in the adiponectin levels between successful and unsuccessful pregnancies in the FF (Phase III) and in serum (all phases), as well as among the three phases in both groups. Serum FSH (Phase I) was positively associated with serum adiponectin in the unsuccessful group, but it had a negative association in the successful group (all phases). Serum adiponectin and serum FSH (Phase I) were positively correlated in the unsuccessful group, whereas they were negatively correlated (all phases) in the successful group. The serum adiponectin levels (Phase III) were significantly higher than in the FF in unsuccessful pregnancies, but there was no difference in successful pregnancies. FF adiponectin concentrations were negatively correlated with serum LH in successful subjects. In KGN cells, adiponectin had no influence on CYP19A1 and FSHR mRNA expression. High adiponectin levels in serum compared to FF (Phase III) in unsuccessful subjects might negatively impact IVF treatment.

Roles of kisspeptin in IVF/ICSI-treated infertile women and in human granulosa cells.

Kisspeptin, a crucial central regulator of reproduction, has been used as a trigger in in vitro fertilization (IVF) treatment. This study aimed to investigate the roles of kisspeptin in IVF treatment in infertile females (n = 30); and in steroidogenesis in human granulosa-like tumor cell line (KGN). In the human study, blood was collected at three time points including (1) the beginning of gonadotropin stimulation (Phase I), (2) around eight days after gonadotropin stimulation (Phase II), and (3) on the day of ovum pick-up (Phase III). Follicular fluid (FF) was collected at Phase III. Serum human chorionic gonadotropin (hCG) was measured 15 days after embryo transfer and fetal heart beats were determined around 42 days of menstrual cycle to classify the subjects into successful and unsuccessful groups. FF kisspeptin levels were higher in successful compared with unsuccessful subjects (P < 0.01). Kisspeptin levels were significantly higher in FF than in serum in successful subjects (P < 0.05) but were comparable in unsuccessful subjects. Serum kisspeptin was comparable among three phases in the successful group but its levels in Phase III were significantly lower compared with Phase I in the unsuccessful group (P < 0.01). Serum kisspeptin in Phase II/III had positive correlations with serum E2 in Phases II and III and the outcomes of IVF/intracytoplasmic sperm injection (ICSI) treatment including serum hCG levels. For the cell experiment (n = 3), kisspeptin treatment in the presence of FSH together with IGF-1 enhanced CYP19A1 (aromatase) mRNA expression compared with control. FSH alone increased aromatase concentrations in the supernatant compared with control and kisspeptin at the dose of 10-2 mmol/L with FSH enhanced aromatase concentrations in the supernatant compared with FSH alone (P < 0.001 all). In conclusion, kisspeptin enhanced aromatase expression and secretion and was associated with positive outcomes of IVF/ICSI treatment. Further studies regarding supplementation of kisspeptin could reveal its beneficial effects on IVF/ICSI treatment.

Plasma gp96 is a Novel Predictive Biomarker for Severe COVID-19.

Early and effective identification of severe coronavirus disease 2019 (COVID-19) may allow us to improve the outcomes of associated severe acute respiratory illness with fever and respiratory symptoms. This study analyzed plasma concentrations of heat shock protein gp96 in nonsevere (including mild and typical) and severe (including severe and critical) patients with COVID-19 to evaluate its potential as a predictive and prognostic biomarker for disease severity. Plasma gp96 levels that were positively correlated with interleukin-6 (IL-6) levels were significantly elevated in COVID-19 patients admitted to the hospital but not in non-COVID-19 patients with less severe respiratory impairment. Meanwhile, significantly higher gp96 levels were observed in severe than nonsevere patients. Moreover, the continuous decline of plasma gp96 levels predicted disease remission and recovery, whereas its persistently high levels indicated poor prognosis in COVID-19 patients during hospitalization. Finally, monocytes were identified as the major IL-6 producers under exogenous gp96 stimulation. Our results demonstrate that plasma gp96 may be a useful predictive and prognostic biomarker for disease severity and outcome of COVID-19. IMPORTANCE Early and effective identification of severe COVID-19 may allow us to improve the outcomes of associated severe acute respiratory illness with fever and respiratory symptoms. Some heat shock proteins (Hsps) are released during oxidative stress, cytotoxic injury, and viral infection and behave as danger-associated molecular patterns (DAMPs). This study analyzed plasma concentrations of Hsp gp96 in nonsevere and severe patients with COVID-19. Significantly higher plasma gp96 levels were observed in severe than those in nonsevere patients, and its persistently high levels indicated poor prognosis in COVID-19 patients. The results demonstrate that plasma gp96 may be a useful predictive and prognostic biomarker for disease severity and outcome of COVID-19.

Toward the first class of suicide inhibitors of kallikreins involved in skin diseases.

The inhibition of kallikreins 5 and 7, and possibly kallikrein 14 and matriptase, (that initiates the kallikrein proteolytic cascade) constitutes an innovative way to treat some skin diseases such as Netherton syndrome. We present here the inhibitory properties of coumarin-3-carboxylate derivatives against these enzymes. Our small collection of these versatile organic compounds was enriched by newly synthesized derivatives in order to obtain molecules selective against one, two, three enzymes or acting on the four ones. We evidenced a series of compounds with IC50 values in the nanomolar range. A suicide mechanism was observed against kallikrein 7 whereas the inactivation was either definitive (suicide type) or transient for kallikreins 5 and 14, and matriptase. Most of these potent inhibitors were devoid of cytotoxicity toward healthy human keratinocytes. In situ zymography investigations on skin sections from human kallikrein 5 transgenic mouse revealed significant reduction of the global proteolytic activity by several compounds.

Bisbenzimidazole derivatives as potent inhibitors of the trypsin-like sites of the immunoproteasome core particle.

In this study, a monomeric (MB) and a dimeric (DB) bisbenzimidazoles were identified as novel proteasome inhibitors of the trypsin-like activity located on ß2c sites of the constitutive 20S proteasome (IC50 values at 2-4 µM range). Remarkably, they were further shown to be 100- and 200-fold more potent inhibitors of the immunoproteasome trypsin-like activity (ß2i sites, IC50=24 nM) than of the homologous constitutive activity. Molecular models of inhibitor/enzyme complexes in the two types of trypsin-like sites and corresponding computed binding energy values corroborated kinetic data. Different binding modes were suggested for MB and DB to the ß2c and ß2i trypsic sites. Each pointed to better contacts of the ligand inside the ß2i active site than for ß2c site. MB and DB represent the first selective inhibitors of the immunoproteasome trypsin-like activity described to date and can be considered as prototypes for inhibiting this activity.

Identification by in silico and in vitro screenings of small organic molecules acting as reversible inhibitors of kallikreins.

Netherton syndrome is caused by loss-of-function mutations in SPINK5 encoding the Kazal-type inhibitor LEKTI-1 leading to dysregulation of proteolytic cascades involving several kallikreins. We used both structure-based and ligand-based virtual screening computations to identify commercially available non-covalent inhibitors of human kallikrein 5 (hK5), a serine protease (trypsin-like) that plays a central role in the initiation of the molecular cascades leading to the Netherton syndrome phenotype. The efficacy and mechanism of inhibition of the identified new families of organic compounds were analyzed not only for hK5 but also on other proteases implicated in the cascades (hK7, hK14 and matriptase). These inhibitors are nontoxic on healthy human keratinocytes and are structurally different from traditional serine protease inhibitors validating their potential utility as initial hits to control proteolytic disorders observed in dermatological pathologies such as Netherton syndrome.

Novel organic proteasome inhibitors identified by virtual and in vitro screening.

Proteasome inhibition is a promising strategy for treating cancers. Herein, we report the discovery of novel drug-like inhibitors of mammalian proteasome 20S using a multistep structure-based virtual ligand screening strategy. Sulfone- or piperazine-containing hits essentially belong to the under-represented class of noncovalent and nonpeptidic proteasome inhibitors. Several of our compounds act in the micromolar range and are cytotoxic on human tumoral cell lines. Optimization of these molecules could lead to better anticancer therapy.