Current Pharmaceutical Design - Volume 29, Issue 10, 2023

The fast global aging of people worldwide is a crucial demographic trend. According to evidence, Americans aged 65 and above will compose 21.6% of the population by 2040. During the aging process, the kidney undergoes gradual functional decrease, which turned out to be a forthcoming problem in clinical practice. Age-related decrease in renal function, evaluated by total glomerular filtration rate (GFR), which has been shown to drop by approximately 5-10% per decade after the age of 35. The sustaining extended period renal homeostasis is the main purpose of any therapeutic options intended for delaying or even reversing the aging kidney. The renal transplant has been regarded as the common alternative for kidney replacement therapy for elderly patients with end-stage renal disease (ESRD). In the last few years, considerable progress has been made to find novel therapeutic options for alleviating renal aging, in particular, calorie restriction and pharmacologic therapy. Nicotinamide N-methyltransferase is an enzyme responsible for generating N1-Methylnicotinamide (MNAM), notorious for its anti-diabetic, anti-thrombotic, and anti-inflammatory activity. MNAM is one of the important factors regarded as in vivo probes for evaluating the activity of some renal drug transporters. Furthermore, it has been shown to have therapeutic potential in the pathogenesis of proximal tubular cell damage and tubulointerstitial fibrosis. In this article, in addition to addressing the role of MNAM in renal function, we also explained its anti-aging effects. We conducted an in-depth investigation of the urinary excretion of MNAM and its metabolites, especially N1-methyl-2-pyridone-5- carboxamide (2py) in RTR. The excretion of MNAM and its metabolite, 2py, was inversely correlated with the risk of all-cause mortality in renal transplant recipients (RTR), independent of possible confounders. Therefore, we have shown that the reason for the lower mortality rate in RTR who had higher urinary excretion of MNAM and 2py may be related to the anti- aging effects of MNAM through transiently generating low levels of reactive oxygen species, stress resistance and the activation of antioxidant defense pathways.

Recently, breast cancer has reached the highest incident rate amongst all the reported cancers, and one of its variants, known as triple-negative breast cancer (TNBC), is deadlier compared to the other types of breast cancer due to a lack of feasible diagnostic techniques. Advancements in nanotechnology have paved the way to formulate several nanocarriers with the ability to deliver anticancer drugs effectively and selectively to cancer cells with minimum side effects to non-cancerous cells. Nanotheranostics is a novel approach that can be used in the diagnosis of disease along with therapeutic effects. Currently, various imaging agents, such as organic dyes, radioactive agents, upconversion nanoparticles, various contrasting agents, quantum dots, etc., are being explored for the imaging of internal organs or to examine drug distribution. Furthermore, ligand-targeted nanocarriers, which have the potential to target cancer sites, are being used as advanced agents for cancer theranostic applications, including the identification of various metastatic sites of the cancerous tumor. This review article discusses the need for theranostic application in breast cancer with various imaging techniques, the latest nanotheranostic carriers in breast cancer, and related safety and toxicity issues, as well as highlights the importance of nanotheranostics in breast cancer, which could be helpful in deciphering questions related to nanotheranostic systems.

Colorectal cancer (CRC) is currently the second most prevalent cancer diagnosed in women and the third most common kind of cancer in men. Despite tremendous efforts and advancements in diagnostic approaches and treatment options, the mortality rate of CRC accounts for around one million each year globally. The five-year survival rate of CRC is reported to be approximately 14 percent for patients diagnosed at an advanced stage. Due to its significant associated mortality and morbidity, diagnostic tools to identify the disease at its early stages are urgently required. Early diagnosis may lead to better outcomes. The gold standard approach for CRC diagnosis is colonoscopy with biopsy. However, it is an invasive process with a risk of complications and discomfort for the patient. Moreover, it is usually performed in symptomatic or high-risk individuals and therefore, asymptomatic patients might be missed. Thus, alternative non-invasive diagnostic techniques are required to improve CRC outcomes. The new era of personalized medicine is identifying novel biomarkers associated with overall survival and clinical outcomes. Recently, liquid biopsy, a minimally invasive analysis of body fluid biomarkers, has gained attention for diagnosis, evaluation of prognosis, and follow-up of patients with CRC. Several previous studies have demonstrated that this novel approach allows for better understanding of CRC tumor biology and leads to an improvement in clinical outcomes. Here, we explain the enrichment and detection methods of circulating biomarkers, including CTCs, ctDNA, miRNA, lncRNA, and circRNA. Furthermore, we provide an overview on their clinical potential as diagnostic, prognostic, and predictive biomarkers for CRC.

Non-coding RNAs (ncRNAs) are emerging as important regulators in various pathological conditions, including human cancers. NcRNAs exert potentially crucial effects on cell cycle progression, proliferation, and invasion in cancer cells by targeting various cell cycle-related proteins at transcriptional and post-transcriptional levels. As one of the key cell cycle regulatory proteins, p21 is involved in various processes, including the cellular response to DNA damage, cell growth, invasion, metastasis, apoptosis, and senescence. P21 has been shown to have either a tumor-suppressive or oncogenic effect depending on the cellular localization and posttranslational modifications. P21 exerts a significant regulatory effect on both G1/S and G2/M checkpoints by regulating the function of cyclin-dependent kinase enzymes (CDKs) or interacting with proliferating cell nuclear antigen (PCNA). P21 has an important effect on the cellular response to DNA damage by separating DNA replication enzymes from PCNA and inhibiting DNA synthesis resulting in G1 phase arrest. Furthermore, p21 has been shown to negatively regulate the G2/M checkpoint through the inactivation of cyclin-CDK complexes. In response to any cell damage caused by genotoxic agents, p21 exerts its regulatory effects by nuclear preservation of cyclin B1-CDK1 and preventing their activation. Notably, several ncRNAs, including lncRNAs and miRNAs, have been shown to be involved in tumor initiation and progression through the regulation of the p21 signaling axis. In this review, we discuss the miRNA/lncRNA-dependent mechanisms that regulate p21 and their effects on gastrointestinal tumorigenesis. A better understanding of the regulatory effects of ncRNAs on the p21 signaling may help to discover novel therapeutic targets in gastrointestinal cancer.

Helicobacter pylori and Cryptococcus ssp. are pathogenic ureolytic microorganisms that cause several disorders in the host organism and, in severe cases, lead to death. Both infections have the urease enzyme as a key virulence factor since they use its ability to produce ammonia to soften the inhospitable pH to which they are subjected. In this review, we describe two ureases as possible molecular targets for drug discovery and provide insights for developing potent inhibitors against ureases from these pathogenic microorganisms through computer-aided drug discovery approaches, such as structure-based drug design (SBDD) and structure-activity relationship (SAR). The SAR studies have indicated several essential subunits and groups to be present in urease inhibitors that are critical for inhibitory activity against H. pylori or Cryptococcus spp. Since the threedimensional structure of C. neoformans urease has yet to be determined experimentally, the plant urease of Canavalia ensiformis was used in this study due to its structural similarity. Therefore, in the SBDD context, FTMap and FTSite analyses were performed to reveal characteristics of the urease active sites in two protein data bank files (4H9M, Canavalia ensiformis, and 6ZJA, H. pylori). Finally, a docking-based analysis was performed to explore the best inhibitors described in the literature to understand the role of the ligand interactions with the key residues in complex ligand-urease stabilization, which can be applied in the design of novel bioactive compounds.

Background: Neuromyelitis optica (NMO) is a severe neurological demyelinating autoimmune disease affecting the optic nerves and spinal cord. The binding of neuromyelitis optica immunoglobulin G (NMO- IgG) and aquaporin-4 (AQP4) on the surface of astrocytes in the serum and cerebrospinal fluid is the main pathogenesis of NMO. Currently, therapeutic strategies for NMO include a reduction of the secondary inflammation response and the number of NMO-IgG, which can only alleviate clinical symptoms rather than fundamentally preventing a series of pathological processes caused by NMO-IgG binding to AQP4. Objective: The purpose of this study was to investigate the blocking effect of melanthioidine on the binding of NMO-IgG to AQP4 and its potential cytotoxicity. Methods: The current study developed a cell-based high-throughput screening approach to identify a molecular blocker of NMO-IgG binding to AQP4 using the Chinese hamster lung fibroblast (V79) cells expressing M23- AQP4. By screening ~400 small molecules, we identified melanthioidine with blocking effects without affecting AQP4 expression or its water permeability. Results: Melanthioidine effectively blocked the binding of NMO-IgG to AQP4 in immunofluorescence assays and reduced complement-dependent cytotoxicity against both NMO-IgG/complement-treated Fischer rat thyroid- AQP4 cells and primary astrocytes. The docking computations identified the putative sites of blocker binding at the extracellular surface of AQP4. Conclusion: This study serves as proof of a potential NMO therapy by using a small-molecule blocker to target NMO pathogenesis.