Identifying novel inhibitors targeting Exportin-1 for the potential treatment of COVID-19.

The nuclear export protein 1 (XPO1) mediates the nucleocytoplasmic transport of proteins and ribonucleic acids (RNAs) and plays a prominent role in maintaining cellular homeostasis. XPO1 has emerged as a promising therapeutic approach to interfere with the lifecycle of many viruses. In our earlier study, we proved the inhibition of XPO1 as a therapeutic strategy for managing SARS-COV-2 and its variants. In this study, we have utilized pharmacophore-assisted computational methods to identify prominent XPO1 inhibitors. After several layers of screening, a few molecules were shortlisted for further experimental validation on the in vitro SARS-CoV-2 cell infection model. It was observed that these compounds reduced spike positivity, suggesting inhibition of SARS-COV-2 infection. The outcome of this study could be considered further for developing novel antiviral therapeutic strategies against SARS-CoV-2.

Nanomedicine for glioblastoma: Progress and future prospects.

Glioblastoma is the most aggressive form of brain tumor, accounting for the highest mortality and morbidity rates. Current treatment for patients with glioblastoma includes maximal safe tumor resection followed by radiation therapy with concomitant temozolomide (TMZ) chemotherapy. The addition of TMZ to the conformal radiation therapy has improved the median survival time only from 12 months to 16 months in patients with glioblastoma. Despite these aggressive treatment strategies, patients' prognosis remains poor. This therapeutic failure is primarily attributed to the blood-brain barrier (BBB) that restricts the transport of TMZ from reaching the tumor site. In recent years, nanomedicine has gained considerable attention among researchers and shown promising developments in clinical applications, including the diagnosis, prognosis, and treatment of glioblastoma tumors. This review sheds light on the morphological and physiological complexity of the BBB. It also explains the development of nanomedicine strategies to enhance the permeability of drug molecules across the BBB.

MIF1 and MIF2 Myostatin Peptide Inhibitors as Potent Muscle Mass Regulators.

The use of peptides as drugs has progressed over time and continues to evolve as treatment paradigms change and new drugs are developed. Myostatin (MSTN) inhibition therapy has shown great promise for the treatment of muscle wasting diseases. Here, we report the MSTN-derived novel peptides MIF1 (10-mer) and MIF2 (10-mer) not only enhance myogenesis by inhibiting MSTN and inducing myogenic-related markers but also reduce adipogenic proliferation and differentiation by suppressing the expression of adipogenic markers. MIF1 and MIF2 were designed based on in silico interaction studies between MSTN and its receptor, activin type IIB receptor (ACVRIIB), and fibromodulin (FMOD). Of the different modifications of MIF1 and MIF2 examined, Ac-MIF1 and Ac-MIF2-NH2 significantly enhanced cell proliferation and differentiation as compared with non-modified peptides. Mice pretreated with Ac-MIF1 or Ac-MIF2-NH2 prior to cardiotoxin-induced muscle injury showed more muscle regeneration than non-pretreated controls, which was attributed to the induction of myogenic genes and reduced MSTN expression. These findings imply that Ac-MIF1 and Ac-MIF2-NH2 might be valuable therapeutic agents for the treatment of muscle-related diseases.

Computational screening of camostat and related compounds against human TMPRSS2: A potential treatment of COVID-19.

The global coronavirus pandemic has burdened the human population with mass fatalities and disastrous socio-economic consequences. The frequent occurrence of these new variants has fueled the already prevailing challenge. There is still a necessity for highly effective small molecular agents to prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, we targeted the human transmembrane surface protease TMPRSS2, which is essential for proteolytic activation of SARS-CoV-2. Camostat is a well-known inhibitor of serine proteases and an effective TMPRSS2 inhibitor. A virtual library of camostat-like compounds was computationally screened against the catalytic site of TMPRSS2. Following a sequential in-depth molecular docking and dynamics simulation, we report the compounds that exhibited promising efficacy against TMPRSS2. The molecular docking and MM/PBSA free energy calculation study indicates these compounds carry excellent binding affinity against TMPRSS2 and found them more effective than camostat. The study will open doors for the effective treatment of coronavirus disease 2019.

Deciphering the Role of Autophagy in Treatment of Resistance Mechanisms in Glioblastoma.

Autophagy is a process essential for cellular energy consumption, survival, and defense mechanisms. The role of autophagy in several types of human cancers has been explicitly explained; however, the underlying molecular mechanism of autophagy in glioblastoma remains ambiguous. Autophagy is thought to be a "double-edged sword", and its effect on tumorigenesis varies with cell type. On the other hand, autophagy may play a significant role in the resistance mechanisms against various therapies. Therefore, it is of the utmost importance to gain insight into the molecular mechanisms deriving the autophagy-mediated therapeutic resistance and designing improved treatment strategies for glioblastoma. In this review, we discuss autophagy mechanisms, specifically its pro-survival and growth-suppressing mechanisms in glioblastomas. In addition, we try to shed some light on the autophagy-mediated activation of the cellular mechanisms supporting radioresistance and chemoresistance in glioblastoma. This review also highlights autophagy's involvement in glioma stem cell behavior, underlining its role as a potential molecular target for therapeutic interventions.

Identification of Novel FNIN2 and FNIN3 Fibronectin-Derived Peptides That Promote Cell Adhesion, Proliferation and Differentiation in Primary Cells and Stem Cells.

In recent years, a major rise in the demand for biotherapeutic drugs has centered on enhancing the quality and efficacy of cell culture and developing new cell culture techniques. Here, we report fibronectin (FN) derived, novel peptides fibronectin-based intergrin binding peptide (FNIN)2 (18-mer) and FNIN3 (20-mer) which promote cell adhesion proliferation, and the differentiation of primary cells and stem cells. FNIN2 and 3 were designed based on the in silico interaction studies between FN and its receptors (integrin α5ß1, αvß3, and αIIbß3). Analysis of the proliferation of seventeen-cell types showed that the effects of FNINs depend on their concentration and the existence of expressed integrins. Significant rhodamine-labeled FNIN2 fluorescence on the membranes of HeLa, HepG2, A498, and Du145 cells confirmed physical binding. Double coating with FNIN2 or 3 after polymerized dopamine (pDa) or polymerized tannic acid (pTA) precoating increased HBEpIC cell proliferation by 30-40 percent, suggesting FNINs potently affect primary cells. Furthermore, the proliferation of C2C12 myoblasts and human mesenchymal stem cells (MSCs) treated with FNINs was significantly increased in 2D/3D culture. FNINs also promoted MSC differentiation into osteoblasts. The results of this study offer a new approach to the production of core materials (e.g., cell culture medium components, scaffolds) for cell culture.

Is PF-00835231 a Pan-SARS-CoV-2 Mpro Inhibitor? A Comparative Study.

The COVID-19 outbreak continues to spread worldwide at a rapid rate. Currently, the absence of any effective antiviral treatment is the major concern for the global population. The reports of the occurrence of various point mutations within the important therapeutic target protein of SARS-CoV-2 has elevated the problem. The SARS-CoV-2 main protease (Mpro) is a major therapeutic target for new antiviral designs. In this study, the efficacy of PF-00835231 was investigated (a Mpro inhibitor under clinical trials) against the Mpro and their reported mutants. Various in silico approaches were used to investigate and compare the efficacy of PF-00835231 and five drugs previously documented to inhibit the Mpro. Our study shows that PF-00835231 is not only effective against the wild type but demonstrates a high affinity against the studied mutants as well.

Enzyme targeting strategies for prevention and treatment of cancer: Implications for cancer therapy.

Extensive growth of cancer in humans is a major cause of death. Numerous studies are being conducted to improve the early diagnosis, prevention, and treatment of cancer. Recent technological advancements in medical science and research indicate molecular target therapy holds much promise in cancer treatment. In the past, therapeutic and diagnostic targeting of non-glycolytic and glycolytic enzymes in cancer have been successful, and discoveries of biomarker enzymes in cancer hold promise for therapeutic treatments. In this review, we discuss the roles of several cancer-associated enzymes that could potentially act as therapeutic targets, and place special focus on non-glycolytic and glycolytic enzymes. This review indicates that the targeting of metabolic signaling offers a promising means of developing novel anti-cancer therapies.

ASK1 and its role in cardiovascular and other disorders: available treatments and future prospects.

Introduction: Apoptosis signal-regulating kinase 1 (ASK1), also known as MAP3K5, is a member of mitogen-activated protein kinase kinase kinase (MAP3K) family and is well reported as crucial in the regulation of the JNK and P38 pathways. ASK1 is activated in response to a diverse array of stresses such as endoplasmic reticulum stress, lipopolysaccharides, tumor necrosis factor alpha, and reactive oxygen species. The activation of ASK1 induces various stress responses. Areas covered: Considering ASK1 as an important therapeutic drug target, here we have discussed the role of ASK1 in the progression of various diseases. We have also provided an overview of the available inhibitors for ASK1. The success of computational-based approaches toward ASK1 inhibitor design has also been discussed. Expert opinion: A number of reports have outlined the prominent role of ASK1 in the pathogenesis of several diseases. The discovery of novel ASK1 inhibitors would have a wide range of applications in medical science. In-silico techniques have been successfully used in the design of some novel ASK1 inhibitors. The use of machine learning-based approaches in combination with structure-based virtual screening (SBVS) and ligand-based virtual screening (LBVS) will be helpful toward the development of potent ASK1 inhibitors.

Fibromodulin and regulation of the intricate balance between myoblast differentiation to myocytes or adipocyte-like cells.

Interactions between myoblasts and the surrounding microenvironment led us to explore the role of fibromodulin (FMOD), an extracellular matrix protein, in the maintenance of myoblast stemness and function. Microarray analysis of FMODkd myoblasts and in silico studies were used to identify the top most differentially expressed genes in FMODkd, and helped establish that FMOD-based regulations of integral membrane protein 2a and clusterin are essential components of the myogenic program. Studies in knockout, obese, and diabetic mouse models helped characterize the operation of a novel FMOD-based regulatory circuit that controls myoblast switching from a myogenic to a lipid accumulation fate. FMOD regulation of myoblasts is an essential part of the myogenic program, and it offers opportunities for the development of therapeutics for the treatment of different muscle diseases.-Lee, E. J., Jan, A. T., Baig, M. H., Ahmad, K., Malik, A., Rabbani, G., Kim, T., Lee, I.-K., Lee, Y. H., Park, S.-Y., Choi, I. Fibromodulin and regulation of the intricate balance between myoblast differentiation to myocytes or adipocyte-like cells.

Multi-Spectroscopic Characterization of Human Serum Albumin Binding with Cyclobenzaprine Hydrochloride: Insights from Biophysical and In Silico Approaches.

Cyclobenzaprine hydrochloride (CBH) is a well-known muscle relaxant that is widely used to relieve muscle spasms and other pain associated with acute musculoskeletal conditions. In this study, we elucidated the binding characteristics of this muscle relaxant to human serum albumin (HSA). From a pharmaceutical and biochemical viewpoint, insight into the structure, functions, dynamics, and features of HSA-CBH complex holds great importance. The binding of CBH with this major circulatory transport protein was studied using a combination of biophysical approaches such as UV-VIS absorption, fluorescence quenching, and circular dichroism (CD) spectroscopy. Various in silico techniques, molecular docking and molecular dynamics, were also used to gain deeper insight into the binding. A reduction in the fluorescence intensities of HSA-CBH complex with a constant increase in temperature, revealed the static mode of protein fluorescence quenching upon CBH addition, which confirmed the formation of the HSA-CBH ground state complex. The alteration in the UV-VIS and far-UV CD spectrum indicated changes in both secondary and tertiary structures of HSA upon binding of CBH, further proving CBH binding to HSA. The analysis of thermodynamic parameters ∆H° and ∆S° showed that binding of CBH to HSA was dominated by intermolecular hydrophobic forces. The results of the molecular docking and molecular dynamics simulation studies also confirmed the stability of the complex and supported the experimental results.

Mechanistic Insights into the Antimicrobial Actions of Metallic Nanoparticles and Their Implications for Multidrug Resistance.

Multiple drug-resistant bacteria are a severe and growing public health concern. Because relatively few antibiotics have been approved over recent years and because of the inability of existing antibiotics to combat bacterial infections fully, demand for unconventional biocides is intense. Metallic nanoparticles (NPs) offer a novel potential means of fighting bacteria. Although metallic NPs exert their effects through membrane protein damage, superoxide radicals and the generation of ions that interfere with the cell granules leading to the formation of condensed particles, their antimicrobial potential, and mechanisms of action are still debated. This article discusses the action of metallic NPs as antibacterial agents, their mechanism of action, and their effect on bacterial drug resistance. Based on encouraging data about the antibacterial effects of NP/antibiotic combinations, we propose that this concept be thoroughly researched to identify means of combating drug-resistant bacteria.

Identification of High-Affinity Inhibitors of Cyclin-Dependent Kinase 2 Towards Anticancer Therapy.

Cyclin-dependent kinase 2 (CDK2) is an essential protein kinase involved in the cell cycle regulation. The abnormal activity of CDK2 is associated with cancer progression and metastasis. Here, we have performed structure-based virtual screening of the PubChem database to identify potent CDK2 inhibitors. First, we retrieved all compounds from the PubChem database having at least 90% structural similarity with the known CDK2 inhibitors. The selected compounds were subjected to structure-based molecular docking studies to investigate their pattern of interaction and estimate their binding affinities with CDK2. Selected compounds were further filtered out based on their physicochemical and ADMET properties. Detailed interaction analysis revealed that selected compounds interact with the functionally important residues of the active site pocket of CDK2. All-atom molecular dynamics simulation was performed to evaluate conformational changes, stability and the interaction mechanism of CDK2 in-complex with the selected compound. We found that binding of 6-N,6-N-dimethyl-9-(2-phenylethyl)purine-2,6-diamine stabilizes the structure of CDK2 and causes minimal conformational change. Finally, we suggest that the compound (PubChem ID 101874157) would be a promising scaffold to be further exploited as a potential inhibitor of CDK2 for therapeutic management of cancer after required validation.

Binding of Tolperisone Hydrochloride with Human Serum Albumin: Effects on the Conformation, Thermodynamics, and Activity of HSA.

Tolperisone hydrochloride (TH) has muscle relaxant activity and has been widely used for several years in clinical practice to treat pathologically high skeletal muscle tone (spasticity) and related pains. The current study was designed to explore the binding efficacy of TH with human serum albumin (HSA) using multispectrscopic, calorimetric approach, FRET, esterase-like activity, and a molecular docking method. A reduction in fluorescence emission at 340 nm of HSA was attributed to fluorescence quenching by TH via a static quenching type. Binding constants ( Kb) were evaluated at different temperatures, and obtained Kb values were ∼104 M-1, which demonstrated moderately strong affinity of TH for HSA. A calculated negative Δ G° value indicated spontaneous binding of TH to HSA. Far-UV CD spectroscopy revealed that the α-helix content was increased after TH binding. The binding distance between donor and acceptor was calculated to be 2.11 nm based on Förster's resonance energy transfer theory. ITC results revealed TH interacted with HSA via hydrophobic interactions and hydrogen bonding. The thermal stability of HSA was studied using DSC, and results showed that in the presence of TH the structure of HSA was significantly more thermostable. The esterase-like activity of HSA showed fixed Vmax and increased Km suggesting that TH binds with HSA in a competitive manner. Furthermore, molecular docking results revealed TH binds in the cavity of HSA, that is, subdomain IIA (Sudlow site I), and that it hydrogen bonds with K199 and H242 of HSA. Binding studies of drugs with HSA are potentially useful for elucidating chemico-biological interactions that can be utilized in the drug design, pharmaceutical, pharmacology, and biochemistry fields. This extensive study provides additional insight of ligand binding and structural changes induced in HSA relevant to the biological activity of HSA in vivo.

Fibromodulin: a master regulator of myostatin controlling progression of satellite cells through a myogenic program.

Differentiation of muscle satellite cells (MSCs) involves interaction of the proteins present in the extracellular matrix (ECM) with MSCs to regulate their activity, and therefore phenotype. Herein, we report fibromodulin (FMOD), a member of the proteoglycan family participating in the assembly of ECM, as a novel regulator of myostatin (MSTN) during myoblast differentiation. In addition to having a pronounced effect on the expression of myogenic marker genes [myogenin (MYOG) and myosin light chain 2 (MYL2)], FMOD was found to maintain the transcriptional activity of MSTN Moreover, coimmunoprecipitation and in silico studies performed to investigate the interaction of FMOD helped confirm that it antagonizes MSTN function by distorting its folding and preventing its binding to activin receptor type IIB. Furthermore, in vivo studies revealed that FMOD plays an active role in healing by increasing satellite cell recruitment to sites of injury. Together, these findings disclose a hitherto unrecognized regulatory role for FMOD in MSCs and highlight new mechanisms whereby FMOD circumvents the inhibitory effects of MSTN and triggers myoblast differentiation. These findings offer a basis for the design of novel MSTN inhibitors that promote muscle regeneration after injury or for the development of pharmaceutical agents for the treatment of different muscle atrophies.-Lee, E. J., Jan, A. T., Baig, M. H., Ashraf, J. M., Nahm, S.-S., Kim, Y.-W., Park, S.-Y., Choi, I. Fibromodulin: a master regulator of myostatin controlling progression of satellite cells through a myogenic program.

Biophysical Study on the Interaction between Eperisone Hydrochloride and Human Serum Albumin Using Spectroscopic, Calorimetric, and Molecular Docking Analyses.

Eperisone hydrochloride (EH) is widely used as a muscle relaxant for patients with muscular contracture, low back pain, or spasticity. Human serum albumin (HSA) is a highly soluble negatively charged, endogenous and abundant plasma protein ascribed with the ligand binding and transport properties. The current study was undertaken to explore the interaction between EH and the serum transport protein, HSA. Study of the interaction between HSA and EH was carried by UV-vis, fluorescence quenching, circular dichroism (CD), Fourier transform infrared (FTIR) spectroscopy, Förster's resonance energy transfer, isothermal titration calorimetry and differential scanning calorimetry. Tryptophan fluorescence intensity of HSA was strongly quenched by EH. The binding constants (Kb) were obtained by fluorescence quenching, and results show that the HSA-EH interaction revealed a static mode of quenching with binding constant Kb ≈ 104 reflecting high affinity of EH for HSA. The negative ΔG° value for binding indicated that HSA-EH interaction was a spontaneous process. Thermodynamic analysis shows HSA-EH complex formation occurs primarily due to hydrophobic interactions, and hydrogen bonds were facilitated at the binding of EH. EH binding induces α-helix of HSA as obtained by far-UV CD and FTIR spectroscopy. In addition, the distance between EH (acceptor) and Trp residue of HSA (donor) was calculated 2.18 nm using Förster's resonance energy transfer theory. Furthermore, molecular docking results revealed EH binds with HSA, and binding site was positioned in Sudlow Site I of HSA (subdomain IIA). This work provides a useful experimental strategy for studying the interaction of myorelaxant with HSA, helping to understand the activity and mechanism of drug binding.

Design, synthesis, and evaluation of purine and pyrimidine-based KRAS G12D inhibitors: Towards potential anticancer therapy.

Oncogenic RAS mutations, commonly observed in human tumors, affect approximately 30% of cancer cases and pose a significant challenge for effective cancer treatment. Current strategies to inhibit the KRAS G12D mutation have shown limited success, emphasizing the urgent need for new therapeutic approaches. In this study, we designed and synthesized several purine and pyrimidine analogs as inhibitors for the KRAS G12D mutation. Our synthesized compounds demonstrated potent anticancer activity against cell lines with the KRAS G12D mutation, effectively impeding their growth. They also exhibited low toxicity in normal cells, indicating their selective action against cancer cells harboring the KRAS G12D mutation. Notably, the lead compound, PU1-1 induced the programmed cell death of KRAS G12D-mutated cells and reduced the levels of active KRAS and its downstream signaling proteins. Moreover, PU1-1 significantly shrunk the tumor size in a pancreatic xenograft model induced by the KRAS G12D mutation, further validating its potential as a therapeutic agent. These findings highlight the potential of purine-based KRAS G12D inhibitors as candidates for targeted cancer therapy. However, further exploration and optimization of these compounds are essential to meet the unmet clinical needs of patients with KRAS-mutant cancers.

Combining structure-based pharmacophore modeling and machine learning for the identification of novel BTK inhibitors.

Bruton's tyrosine kinase (BTK) is a critical enzyme which is involved in multiple signaling pathways that regulate cellular survival, activation, and proliferation, making it a major cancer therapeutic target. We applied the novel integrated structure-based pharmacophore modeling, machine learning, and other in silico studies to screen the Korean chemical database (KCB) to identify the potential BTK inhibitors (BTKi). Further evaluation of these inhibitors on three different human cancer cell lines showed significant cell growth inhibitory activity. Among the 13 compounds shortlisted, four demonstrated consistent cell inhibition activity among breast, gastric, and lung cancer cells (IC50 below 3 µM). The selected compounds also showed significant kinase inhibition activity (IC50 below 5 µM). The current study suggests the potential of these inhibitors for targeting BTK malignant tumors.

Development of machine learning models for the screening of potential HSP90 inhibitors.

Heat shock protein 90 (Hsp90) is a molecular chaperone playing a significant role in the folding of client proteins. This cellular protein is linked to the progression of several cancer types, including breast cancer, lung cancer, and gastrointestinal stromal tumors. Several oncogenic kinases are Hsp90 clients and their activity depends on this molecular chaperone. This makes HSP90 a prominent therapeutic target for cancer treatment. Studies have confirmed the inhibition of HSP90 as a striking therapeutic treatment for cancer management. In this study, we have utilized machine learning and different in silico approaches to screen the KCB database to identify the potential HSP90 inhibitors. Further evaluation of these inhibitors on various cancer cell lines showed favorable inhibitory activity. These inhibitors could serve as a basis for future development of effective HSP90 inhibitors.

Probing the Interaction of Selonsertib with Human Serum Albumin: In silico and In vitro Approaches.

INTRODUCTION: Selonsertib, the most recently developed selective inhibitor of apoptosis signal-regulating kinase 1. We elucidated the binding characteristics, mechanism of interaction, and dynamic behaviors of selonsertib with human serum albumin (HSA), a major circulatory transport protein. METHODS: Different biophysical approaches (fluorescence quenching and isothermal titration calorimetry (ITC) were combined with various in silico techniques to examine the binding of selonsertib to HSA. Molecular docking results, analysis of molecular dynamics trajectories, and essential dynamics investigations indicated the stable binding of selonsertib to HSA. Further in vitro studies were performed to validate the observed interaction. RESULTS: ITC results confirmed the robust binding and high affinity of selonsertib and HSA. Likewise, the fluorescence quenching results highlighted the binding affinity of selonsertib and HSA. Collectively, our findings offer deeper insight into the binding mechanism of selonsertib and HSA, emphasizing the selonsertib-mediated structural changes within HSA, along with a comprehensive rationale for the biological transport and accumulation of selonsertib in the blood plasma. CONCLUSION: Therefore, considering the bioavailability and effectiveness of selonsertib, assessing the interactions of this inhibitor with carrier proteins is crucial to elucidate its biological processes at the molecular level. This evidence carries the considerable scientific potential for future drug design.