Current Molecular Pharmacology - Current Issue

Glucoregulatory protein 94 (Grp94) is necessary for the post-viral life cycle and plays a quality control role in viral proteins, but the role of Grp94 in regulating viral replication in host cells is not well known. Therefore, finding a compound that can regulate Grp94 will help us to study the mechanism of viral replication. Previously, we synthesized a coumarin pyrazoline derivative HCP1 that is an effective inhibitor of Grp94. We suppose that HCP1 may inhibit viral replication.

This study aimed to investigate the effect of HCP1 on the replication ability of Senecavirus A (SVA), so as to provide a target and a leading compound for revealing the pathogenic mechanism of the virus and developing antiviral drugs.

Rat cell lines BHK-21 and porcine cell lines PK-15 were infected with SVA, and the infected cells were treated with different concentrations of HCP1. The cell viability (CCK-8), virus titer (TCID50), autophagy level, and Grp94 expression were measured.

The results showed that a low concentration of HCP1 decreased viral titer and viral load in BHK-21 and PK-15 cells, and 5μM HCP1 significantly decreased the expression of SVA VP2 protein. In addition, SVA infection can lead to an increased level of autophagy, and HCP1 can inhibit host cell autophagy caused by SVA infection, thereby inhibiting viral replication and infection.

These findings reveal that Grp94 is a key factor in controlling SVA replication, and its inhibitor HCP1 suppresses SVA replication by inhibiting the increase of Grp94 protein level and autophagy induced by SVA. This study will contribute to the development of a new class of small-molecule antiviral drugs.

Our previous work has demonstrated significant effects on the oxidative stress response, mitochondrial function, and oxidative phosphorylation in the livers and intestines of p300 S89A knockin (S89AKI) mice. We now show that this mutation is also associated with brain metabolic defects and neuronal differentiation.

p300 S89A edited P19 cells, and S89AKI mice demonstrated metabolic and neuronal differentiation defects based on proteomic, cell biological and PET imaging studies.

The metabolic and differentiation defects associated with the p300 S89A knockin mutation could be corrected both in vitro and in vivo utilizing the small molecule CBP/beta-catenin antagonist ICG-001.

Rebalancing the equilibrium between CBP/β-catenin versus p300/β-catenin associated transcription, utilizing the small molecule CBP/beta-catenin antagonist ICG-001, enhances mitochondrial oxidative phosphorylation, metabolic function, and neuronal differentiation and may be able to ameliorate the cognitive decline seen in neurodegenerative disorders, including Alzheimer’s Disease.

Physalin B (PB) is one of the main active compounds of Solanaceae plants, with a wide range of biological activities. PB reportedly has the potential to treat Alzheimer’s disease (AD).

In this study, we investigated the effect of PB on Tau phosphorylation and cell apoptosis using Tau-expressing HEK293 cells (HEK293/Tau) as a cellular model.

The optimum concentration of PB to treat HEK293/Tau cells was determined using the CCK-8 assay. Additionally, the expression of FoxO1, Tau-5, p-Tau (T231, S262, and S404), ERK, p-ERK, GSK-3β, and p-GSK-3β was detected using western blotting to determine the effect of PB on Tau phosphorylation. The apoptosis rate was detected using flow cytometry, and the expression of Bax and Bcl-2 was detected using western blotting and verified using real-time quantitative polymerase chain reaction (RT-qPCR). Moreover, cells were transfected with FoxO1 siRNA to downregulate FoxO1 expression, and the expression of the above-mentioned proteins was detected to verify the effect of PB on Tau phosphorylation and cell apoptosis.

After 24 h of PB treatment, the phosphorylation levels of Tau at S404, S262, and T231 sites decreased significantly, and the activities of GSK-3β and ERK were inhibited. PB also reduced cell apoptosis by reducing the expression of Bax and increasing the expression of Bcl-2. In addition, PB decreased Tau phosphorylation and cell apoptosis by upregulating FoxO1.

The natural compound PB exhibited a protective effect in the AD cell model by increasing FoxO1 expression and reducing Tau phosphorylation and cell apoptosis.

Liver fibrosis is associated with the activation of hepatic stellate cells (HSCs). Inhibition of HSCs activation is a strategy for alleviating hepatic fibrogenesis. CD73 is involved in liver disease development, while the mechanism remains unclear.

This study aimed to investigate the effect of CD73 targeting inhibition on liver fibrosis.

Intraperitoneal injection of CCl4 was used to induce liver fibrosis in mice models. Adenosine 5′-(α, β-methylene) diphosphate sodium salt (APCP) was used for CD73 blockade. The siRNA was used to induce CD73 knockdown in HSCs. LX2 and HSC-T6 were used to investigate the role of CD73 in HSCs activation in vitro.

The results showed that APCP treatment could alleviate hepatic fibrosis. In fibrotic liver tissues, CD73 exhibited a positive correlation with markers of HSCs activation. Furthermore, APCP treatment and CD73 knockdown could inhibit HSCs (LX2 and HSC-T6) activation and proliferation. By using RNA sequencing of liver tissues from control, CCl4-mice, and APCP-treated mice, 851 genes that were significantly changed in CCl4 mice (vs. control) were reversed by APCP treatment. These genes were mainly enriched in cell division-associated biological processes. Moreover, we found that CD73 might be associated with autophagy in HSCs. In fibrotic liver tissues and HSCs, ATG5 and Beclin1 expression could be downregulated by CD73 knockdown and APCP treatment.

This study demonstrated the effects and mechanism of CD73 in HSCs activation and proliferation, which presents the therapeutical potential of CD73 blockage for liver fibrosis.

Esophageal carcinoma (ESCA) is a common malignancy characterized by high morbidity and mortality. Our work managed to dissect the modulatory mechanism of E2F1/miR-29c-3p/COL11A1 in the malignant progression and sensitivity of ESCA cells to sorafenib.

Via bioinformatics approaches, we identified the target miRNA. Subsequently, CCK-8, cell cycle analysis, and flow cytometry were used to check the biological influences of miR-29c-3p on ESCA cells. TransmiR, mirDIP, miRPathDB, and miRDB databases were used as tools for the prediction of upstream transcription factors and downstream genes of miR-29c-3p. The targeting relationship of genes was detected via RNA immunoprecipitation and chromatin immunoprecipitation, which was further validated by dual-luciferase assay. Finally, in vitro experiments revealed the way E2F1/miR-29c-3p/COL11A1 affected sorafenib’s sensitivity, and in vivo experiments were used to verify the way E2F1 and sorafenib impacted ESCA tumor growth.

miR-29c-3p, downregulated in ESCA, could suppress ESCA cell viability, arrest the cell cycle in the G0/G1 phase, and impel apoptosis. E2F1 was found to be upregulated in ESCA and it could abate the transcriptional activity of miR-29c-3p. COL11A1 was found to be a downstream target of miR-29c-3p to enhance cell viability, induce cell cycle arrest in S phase, and constrain apoptosis. Cellular and animal experiments together demonstrated that E2F1 abated the sorafenib’s sensitivity of ESCA cells via miR-29c-3p/COL11A1.

E2F1 affected the viability, cell cycle, and apoptosis of ESCA cells by modulating miR-29c-3p/COL11A1, and it attenuated the sensitivity of ESCA cells to sorafenib, shedding new light on the treatment of ESCA.

The first clinically evaluated CBP/β-catenin antagonist, PRI-724, displayed an excellent safety profile administered intravenously via continuous infusion. Eisai recently disclosed a third-generation, orally available, reportedly CBP/β-catenin antagonist, E7386. However, several structural features and the reported cytotoxicity of E7386 were unexpected for a specific CBP/β-catenin antagonist. Therefore, we undertook a comparison of E7386 versus the highly specific bona fide CBP/β-catenin antagonists, ICG-001 and C82, the active agents derived from the prodrug PRI-724.

CBP/β-catenin antagonists rebalance the equilibrium between CBP/β-catenin and p300/β-catenin dependent transcription and may be able to treat or prevent many diseases of aging via maintenance of somatic stem cell pool and regulating mitochondrial function and metabolism involved in differentiation and immune cell function. The safety, efficacy, and therapeutic potential of the specific CBP/β-catenin antagonists, ICG-001, and the second-generation compound, C82, the active agent derived from the pro-drug PRI-724, have been studied extensively in a variety of preclinical disease models and in the clinic for oncology and hepatic fibrosis. However, the lack of oral bioavailability has hampered the further development of PRI-724. Thus, Eisai recently proposed a third-generation, orally available, reportedly CBP/β-catenin antagonist E7386. Here, we have performed a comparative analysis of E7386 with the highly specific bona fide CBP/β-catenin antagonists, ICG-001 and C82.

We utilized a series of previously validated biochemical and transcriptional assays to investigate the selective targeting of the CBP/β-catenin interaction in conjunction with global transcriptional profiling to compare the three small molecules, ICG-001, C82, and E7386.

Our data cast significant doubt that the mechanism of action of E7386 is via specific CBP/β-catenin antagonism.

It can thus be concluded that E7386 is not a specific CBP/β-catenin antagonist.

Circular RNAs (circRNAs) have a vital role in the occurrence of numerous cancers. However, its function and pattern of expression in cervical cancer (CC) remain unclear. This research aims to investigate the hsa_circ_000002’s regulatory mechanism in CC.

Hsa_circ_0000021, miR-3940-3p, and KPNA2 expression levels were estimated through qRT-PCR. Nuclear/cytoplasmic separation was conducted to find the subcellular location of hsa_circ_0000021. Western blot was done to estimate the levels of KPNA2 protein. CCK-8, BrdU, wound healing, transwell, and tumor xenograft assays were performed to study how hsa_circ_0000021/miR-3940-3P/KPNA2 function affect CC. Hsa_circ_0000021’s targeting relationships with miR-3940-3p and KPNA2 were ascertained through RIP and luciferase experiments.

Hsa_circ_0000021 and KPNA2 were overexpressed and inversely associated with the levels of miR-3940-3p in CC. Knocking down either hsa_circ_0000021 or KPNA2 repressed the growth of CC tumors as well as the proliferation, invasion, and migration of CC cells. Silencing miR-3940-3p promoted the malignant proliferation of CC cells. Regarding its mechanism, hsa_circ_0000021 affected the malignant CC cell proliferation via the sponging of miR-3940-3p, which targeted KPNA2.

Hsa_circ_0000021 regulates the miR-3940-3p/KPNA2 axis to promote CC occurrence. This potentially is a novel target for CC treatment.

Over the last several decades, the AcrAB and OqxAB efflux pumps have been found to cause multidrug resistance (MDR) in various bacteria, most notably Klebsiella pneumoniae. Antibiotic resistance surges with increased expression of the acrAB and oqxAB efflux pumps.

In accordance with CLSI guidelines, a disk diffusion test was carried out using 50 K. pneumoniae isolates obtained from various clinical samples. CT was computed in treated samples and compared to a susceptible ciprofloxacin strain (A111). The final finding is presented as the fold change in the target gene's expression in treated samples relative to a control sample (A111), normalized to a reference gene. As ∆∆CT = 0 and 2 to the power of 0 = 1, relative gene expression for reference samples is often set to 1

The highest rates of resistance were recognized with cefotaxime (100%), cefuroxime (100%), cefepime (100%), levofloxacin (98%), trimethoprim-sulfamethoxazole (80%), and gentamicin (72%), whereas imipenem (34%) had the lowest rates. Overexpression of acrA and acrB, oqxA and oqxB, regulators marA, soxS, and rarA were greater in ciprofloxacin-resistant isolates compared to the reference strain (strain A111). There was also a moderate connection between ciprofloxacin MIC and acrAB gene expression and a moderate connection between ciprofloxacin MIC and oqxAB gene expression.

This work provides a deeper knowledge of the role of efflux pump genes, particularly acrAB and oqxAB, as well as transcriptional regulators marA, soxS, and rarA, in bacterial resistance to ciprofloxacin.

Diabetic mellitus is responsible for triggering many conditions, such as neuropathy, nephropathy, and retinopathy. Hyperglycemia leads to the development of oxidative stress conditions, activation of pathways, and generation of metabolites, leading to complications like neuropathy and nephropathy.

This paper aims to discuss the mechanism of actions, pathways, and metabolites triggered due to the development of neuropathy and nephropathy post-long-haul diabetes in patients. The therapeutic targets are also highlighted, proving to be a potential cure for such conditions.

Research works were searched from international and national databases with keywords like “diabetes,” “diabetic nephropathy,” “NADPH,” “oxidative stress,” “PKC,” “Molecular mechanisms,” “ cellular mechanisms,” “complications of diabetes,” and “factors.” The databases searched were PubMed, Scopus, Directory of open access journals, Semantic Scholar, Core, Europe PMC, EMBASE, Nutrition, FSTA- Food Science and Technology, Merck Index, Google Scholar, PubMed, Science Open, MedlinePlus, Indian citation index, World Wide Science, and Shodhganga.

Pathways causing protein kinase C (PKC) activation, free radical injury, oxidative stress, and aggravating the conditions of neuropathy and nephropathy were discussed. In diabetic neuropathy and nephropathy, neurons and nephrons are affected to the extent that their normal physiology is disturbed, thus leading to further complications and conditions of loss of nerve sensation in diabetic neuropathy and kidney failure in diabetic nephropathy.

Current treatment options available for the management of diabetic neuropathy are anticonvulsants, antidepressants, and topical medications, including capsaicin. According to AAN guidelines, pregabalin is recommended as the first line of therapy, whereas other drugs currently used for treatment are gabapentin, venlafaxine, opioids, amitriptyline, and valproate.

Drug targets for treating diabetic neuropathy must suppress the activated polyol pathways, kinase C, hexosamine, and other pathways, which amplify neuroinflammation. Targeted therapy must focus on the reduction of oxidative stress and proinflammatory cytokines and suppression of neuroinflammation, NF-κB, AP-1, etc.

Potential drug targets must be considered for new research on the treatment of neuropathy and nephropathy conditions.