Current Research in Pharmacology and Drug Discovery最新文献

Diabetic retinopathy (DR) is a primary microvascular complication of diabetes mellitus and a vision-threatening condition. Vascular endothelial growth factor (VEGF) induces neovascularization and causes metabolic damage to the retinal and choroidal vasculature in diabetic patients. Existing drug screening models and treatment strategies for DR need to be refined through the establishment of relevant pre-clinical models, which may enable development of effective and safe therapies. The present study discusses the development of an in-vitro three-dimensional (3D) spheroid model, using RF/6A choroid-retinal vascular endothelial cells, to closely mimic the in-vivo disease condition. Compact, reproducibly-sized, viable and proliferating RF/6A spheroids were fabricated, as confirmed by microscopy, live/dead assay, cell proliferation assay and histological staining. In-vitro angiogenesis was studied by evaluating individual effects of VEGF and an anti-VEGF monoclonal antibody, Bevacizumab, and their combination on cellular proliferation and 3D endothelial sprout formation. VEGF stimulated angiogenic sprouting while Bevacizumab demonstrated a dose-dependent anti-angiogenic effect, as determined from the cellular proliferation observed and extent and length of sprouting. These investigations validated the potential of RF/6A spheroids in providing an alternative-to-animal, pathophysiologically-relevant model to facilitate pre-clinical and biomedical research related to DR.

Background

Patients with inflammatory bowel disease (IBD) often require the use of immunosuppressant medications that increase infection risk, leading to concerns over the safe use of IBD medications during the Coronavirus 19 (COVID-19) pandemic.

Objectives

To summarize available evidence on the safety and appropriate use of IBD medications during the COVID-19 pandemic, particularly in regard to risk of severe COVID-19 outcomes such as hospitalization, respiratory failure, or death for patients on IBD therapeutics.

Conclusions

The majority of IBD medications are safe to continue during the COVID-19 pandemic, with a few notable exceptions. Patients with IBD who do not have COVID-19 should continue their prescribed IBD therapies, although steroids are associated with severe COVID-19 outcomes and should be weaned when possible. Corticosteroids should be tapered and discontinued when possible in patients with IBD who test positive for COVID-19 as well. Patients with IBD who test positive for COVID-19 should hold biologics, thiopurines, methotrexate, and tofacitinib for at least 2 weeks, and those who have symptoms should not restart these medications until symptom resolution. During the COVID-19 pandemic, all patients with IBD should continue to follow public health guidance including social distancing, masking, and COVID-19 vaccination recommendations.

Over the past few decades, thyroid cancer has become one of the most common types of endocrine cancer, contributing to an increase in prevalence. In the year 2020, there were 586,202 newly diagnosed cases of thyroid cancer around the world. This constituted approximately 3.0% of all patients diagnosed with cancer. The World Health Organization reported that there will be 2.3 million women receiving treatment for breast cancer in 2020, with 685,000. Despite the fact that carcinoma is one of the world's leading causes of death, there is still a paucity of information about its biology. MicroRNAs (miRNAs; miRs) are non-coding RNAs that can reduce gene expression by cleaving the 3′ untranslated regions of mRNA. These factors make them a potential protein translation inhibitor. Diverse biological mechanisms implicated in the genesis of cancer are modulated by miRNA. The investigation of global miRNA expression in cancer showed regulatory activity through up regulation and down-regulation in several cancers, including thyroid cancer and breast cancer. In thyroid cancer, miRNA influences several cancers related signaling pathways through modulating MAPK, PI3K, and the RAS pathway. In breast cancer, the regulatory activity of miRNA was played through the cyclin protein family, protein kinases and their inhibitors, and other growth promoters or suppressors, which modulated cell proliferation and cell cycle progression. This article's goal is to discuss key miRNA expressions that are involved in the development of thyroid and breast cancer as well as their therapeutic manipulation for these two specific cancer types.

Background

Plumbagin, a natural phenolic compound is investigated for response against blood pressure and vascular reactivity.

Methodology

Blood pressure lowering effects were observed by in-vivo invasive evaluation in normotensive rats, and in-vitro experimentation to measure changes of tension in isolated rat aorta and contractility in atria.

Results

The percentage decrease in mean arterial pressure (MAP) observed with plumbagin intravenously at doses of 0.1, 0.5, 1, 5, 10 ​μg/kg in normotensive rats was 7.16 ​± ​2.35, 15.5 ​± ​5.62, 19.5 ​± ​5.27, 26 ​± ​6.67, 34.33 ​± ​8.80, respectively. Plumbagin exerted vasorelaxant effects in rat aorta, unaffected by the removal of vascular endothelium, and _L-NAME and methylene blue pretreatment. Plumbagin completely inhibited phenylephrine (1 ​μM) and High K⁺ (80 ​mM) induced contractions. Similar to a Ca⁺² channel antagonist, plumbagin caused a rightward shift in the Ca⁺² concentration-response-curves (CRCs), resembling nifedipine. Pre-incubation with plumbagin, significantly suppressed contractions induced by phenylephrine in Ca⁺²-free medium via disrupting Ca⁺² release from intracellular stores. No change in vasorelaxant response was observed with the addition of potassium channel blockers, TEA and BaCl₂. In rat atrial strips, plumbagin exerted significant negative inotropic and chronotropic effects. No significant change was observed with atropine and atenolol pretreatment, so the effect appeared independent of muscarinic and beta-adrenergic receptors.

Conclusion

This study suggests the blood pressure lowering effects of plumbagin. That could be contributed by a decrease in vascular resistance via calcium antagonism, interferences in calcium efflux, and depressive effects on the rate and force of cardiac contraction. Further studies would be necessary to probe deeper into the underlying mechanisms.

The mammalian target of rapamycin (mTOR) plays an important role in the aggressiveness and therapeutic resistance of many cancers. Targeting mTOR continues to be under clinical investigation for cancer therapy. Despite the notable clinical success of mTOR inhibitors in extending the overall survival of patients with certain malignancies including metastatic renal cell carcinomas (RCCs), the overall impact of mTOR inhibitors on cancers has been generally disappointing and attributed to various compensatory responses. Here we provide the first report that expression of the Notch ligand Jagged-1 (JAG1), which is associated with aggressiveness of RCCs, is induced by several inhibitors of mTOR (rapamycin (Rap), BEZ235, KU-0063794) in human clear cell RCC (ccRCC) cells. Using both molecular and chemical inhibitors of PI3K, Akt, and TGF-β signaling, we provide evidence that the induction of JAG1 expression by mTOR inhibitors in ccRCC cells depends on the activation of Akt and occurs through an ALK5 kinase/Smad4-dependent mechanism. Furthermore, we show that mTOR inhibitors activate Notch1 and induce the expression of drivers of epithelial-mesenchymal transition, notably Hic-5 and Slug. Silencing JAG1 with selective shRNAs blocked the ability of KU-0063794 and Rap to induce Hic-5 in ccRCC cells. Moreover, Rap enhanced TGF-β-induced expression of Hic-5 and Slug, both of which were repressed in JAG1-silenced ccRCC cells. Silencing JAG1 selectively decreased the motility of ccRCC cells treated with Rap or TGF-β1. Moreover, inhibition of Notch signaling with γ-secretase inhibitors enhanced or permitted mTOR inhibitors to suppress the motility of ccRCC cells. We suggest targeting JAG1 may enhance therapeutic responses to mTOR inhibitors in ccRCCs.

Curcumin is a well-recognized antioxidant phytoactive isolated from the rhizomes of Curcuma longa. Numerous landmark investigations have proved the antioxidant and hepatoprotective potential of curcumin. The aim of present study was to target curcumin loaded nanocarriers to hepatocytes using asialoglycoprotein receptors targeting strategy. Mannose, a water-soluble carbohydrate, was hydrophobized by anchoring stearylamine with an objective to conjugate mannose on the surface of curcumin loaded nanostructured lipid carriers for targeting asialoglycoprotein receptors on hepatocytes. Mannose conjugated stearylamine was synthesized and characterized using various analytical techniques. The synthesized targeting ligand was incorporated curcumin loaded nanostructured lipid carriers and characterized by photon correlation spectroscopy. Zeta potential measurement was used to confirm the conjugation of the synthesized ligand to the surface of drug-loaded nanostructured lipid carriers. CCl₄ induced hepatotoxicity in male Wistar rats was used as an experimental animal model to evaluate the hepatoprotective potential of formulated drug encapsulated nanostructured lipid carriers. The hepatoprotective potential was assessed by measuring serum liver injury markers and oxidative stress parameters in the liver post–mitochondrial supernatant. Mannose conjugated nanostructured lipid carriers showed acceptable particle size which revealed its suitability for hepatocyte targeting. In addition to this, mannose conjugated nanocarriers revealed significantly better (p ​< ​0.05) reduction of serum liver injury markers and proinflammatory cytokines compared to the unconjugated one which confirmed hepatocytes targeting potential of the synthesized ligand. Asialoglycoprotein receptors targeting could be a landmark strategy for hepatocyte targeting. Thus, the synthesized mannose anchored stearylamine could be a promising novel targeting ligand having hepatocyte targeting potential.

Background

Patients with ulcerative proctitis represent a sub-group of ulcerative colitis patients with specific characteristics. Disease-related symptoms, endoscopic findings and patient's personality perspectives create a difficult-to-assess condition in certain cases.

Objectives

To summarize available evidence on the management of refractory ulcerative proctitis and provide insights in treatment options.

Results

/Conclusion: Topical therapy plays a central role due to the location of the disease. However, well-established treatment options may become exhausted in a considerable proportion of ulcerative proctitis patients, indicating the need to advance to more potent therapies in order to induce and maintain clinical response and remission in these refractory cases. Systemic corticosteroids, thiopurines, calcineurin inhibitors, biologic agents and small molecules have all been tested with variable success rates. Investigational interventions as well as surgical procedures are kept as the ultimate resort in multi-treatment resistant cases. Identifying early prognostic factors that herald a disabling disease progression will help in optimizing treatment and avoiding surgery.

Since its inception in late December 2020 in China, novel coronavirus has affected the global socio-economic aspect. Currently, the world is seeking safe and effective treatment measures against COVID-19 to eradicate it. Many established drug molecules are tested against SARS-CoV-2 as a part of drug repurposing where some are proved effective for symptomatic relief while some are ineffective. Drug repurposing is a practical strategy for rapidly developing antiviral agents. Many drugs are presently being repurposed utilizing basic understanding of disease pathogenesis and drug pharmacodynamics, as well as computational methods. In the present situation, drug repurposing could be viewed as a new treatment option for COVID-19. Several new drug molecules and biologics are engineered against SARS-CoV-2 and are under different stages of clinical development. A few biologics drug products are approved by USFDA for emergency use in the covid management. Due to continuous mutation, many of the approved vaccines are not much efficacious to render the individual immune against opportunistic infection of SARS-CoV-2 mutants. Hence, there is a strong need for the cogent therapeutic agent for covid management. In this review, a consolidated summary of the therapeutic developments against SARS-CoV-2 are depicted along with an overview of effective management of post COVID-19 complications.

Background

Many of the atypical antipsychotics induce metabolic side effects, limiting their use in clinical practice. Alpha-lipoic acid (ALA) was proposed as a new approach in schizophrenia to improve metabolic effects of atypical antipsychotics. The aim of the study is to evaluate the effect of ALA on metabolic and clinical parameters among schizophrenic subjects.

Methods

15 schizophrenic subjects, in stable atypical antipsychotic monotherapy were included in the study. ALA was administrated at the oral daily dose of 600 ​mg/d in addition to antipsychotic therapy. Metabolic, clinical, and psychopathological parameters were measured at typical antipsychotics. e initial screening, and after 12 weeks.

Results

ALA produced a statistically significant reduction in QTc (p ​= ​0.012), blood glucose (p ​= 0.005), AST (p ​= ​0.021), γGT (p ​= ​0.035), CPK (p ​= ​0.005) and prolactinaemia (p ​= ​0.026). In contrast, there was a significant increase in HbA1c (p ​= ​0.026). No effects on body weight and blood lipid levels (triglycerides, total cholesterol, HDL, LDL) emerged.

Conclusions

ALA treatment appeared to be effective for reducing diabetes risk, liver functionality parameters, hyperprolactinaemia and QTC interval. ALA appears to be safe as adjunctive components in schizophrenia.

Organ damage and pathological disease states lead to the rapid release of microRNAs (miRNAs), a class of endogenous small non-coding RNAs, into the blood circulation. Because secreted miRNAs can be detected in biologic fluids such as plasma, they are currently being explored as promising non-invasive biomarkers of infectious and non-infectious diseases. Malaria remains a major global health challenge but still the potential of miRNAs has not been explored extensively in the context of malaria compared to other diseases. Here, we highlight important miRNAs found during different phases of the malaria life cycle in the anopheline vector and the human host. We have also put forward our opinion on how malaria parasite-stage-specific miRNAs can be incorporated into new diagnostic and prognostic tools to detect carrier mosquitoes and infected patients. In addition, we have emphasised the potential of miRNAs to be used as new therapeutics to treat severe malaria patients, an unresearched area of malaria control.