Substitution of threonine-1351 in the multidrug transporter Cdr1p of Candida albicans results in hypersusceptibility to antifungal agents and threonine-1351 is essential for synergic effects of calcineurin inhibitor FK520

Objectives: Functional characterization of a mutant Candida albicans drug resistance protein (Cdr1p) by overexpression in Saccharomyces cerevisiae. Methods: We overexpressed green fluorescent protein-tagged Cdr1p in S. cerevisiae AD1-8u− host and introduced a point mutation to substitute T1351 with F in Cdr1p. The cells expressing T1351F mutant Cdr1p were analysed for their functional activity using minimum inhibitory concentration, spot assay, and fluconazole efflux. The binding activity of photoaffinity analogues 8-azidoATP, iodoarylazidoprazosin and azidopine to the mutant T1351F Cdr1p was also characterized. Results: The T1351F mutant Cdr1p-expressing cells were susceptible to anisomycin, cycloheximide, fluconazole, miconazole and nystatin. The mutant protein was expressed to the same level as that of native Cdr1p in S. cerevisiae cells and was properly localized to the cell surface. There was also no difference between the mutant variant and the native protein's ability to bind a photoaffinity analogue of ATP, 8-azidoATP, or the radiolabelled photoaffinity agents iodoarylazidoprazosin and azidopine. However, the substitution of T1351 resulted in considerable reduction in its ability to export fluorescent substrate rhodamine 6G. The synergy between calcineurin inhibitors FK520 and azoles was abrogated in cells expressing the T1351F mutant variant of Cdr1p. Conclusions: The results from this study suggest that the T1351 in the predicted transmembrane domain (TMD) 11 of Cdr1p is not only important for drug-substrate transport but also has a role in governing synergy of FK520

Towards the clinical implementation of pharmacogenetics in bipolar disorder.

BackgroundBipolar disorder (BD) is a psychiatric illness defined by pathological alterations between the mood states of mania and depression, causing disability, imposing healthcare costs and elevating the risk of suicide. Although effective treatments for BD exist, variability in outcomes leads to a large number of treatment failures, typically followed by a trial and error process of medication switches that can take years. Pharmacogenetic testing (PGT), by tailoring drug choice to an individual, may personalize and expedite treatment so as to identify more rapidly medications well suited to individual BD patients.DiscussionA number of associations have been made in BD between medication response phenotypes and specific genetic markers. However, to date clinical adoption of PGT has been limited, often citing questions that must be answered before it can be widely utilized. These include: What are the requirements of supporting evidence? How large is a clinically relevant effect? What degree of specificity and sensitivity are required? Does a given marker influence decision making and have clinical utility? In many cases, the answers to these questions remain unknown, and ultimately, the question of whether PGT is valid and useful must be determined empirically. Towards this aim, we have reviewed the literature and selected drug-genotype associations with the strongest evidence for utility in BD.SummaryBased upon these findings, we propose a preliminary panel for use in PGT, and a method by which the results of a PGT panel can be integrated for clinical interpretation. Finally, we argue that based on the sufficiency of accumulated evidence, PGT implementation studies are now warranted. We propose and discuss the design for a randomized clinical trial to test the use of PGT in the treatment of BD

Functional characterization of Candida albicans ABC transporter Cdr1p

In view of the importance of Candida drug resistance protein (Cdr1p) in azole resistance, we have characterized it by overexpressing it as a green fluorescent protein (GFP)-tagged fusion protein (Cdr1p-GFP). The overexpressed Cdr1p-GFP in Saccharomyces cerevisiae is shown to be specifically labeled with the photoaffinity analogs iodoarylazidoprazosin (IAAP) and azidopine, which have been used to characterize the drug-binding sites on mammalian drug-transporting P-glycoproteins. While nystatin could compete for the binding of IAAP, miconazole specifically competed for azidopine binding, suggesting that IAAP and azidopine bind to separate sites on Cdr1p. Cdr1p was subjected to site-directed mutational analysis. Among many mutant variants of Cdr1p, the phenotypes of F774A and ΔF774 were particularly interesting. The analysis of GFP-tagged mutant variants of Cdr1p revealed that a conserved F774, in predicted transmembrane segment 6, when changed to alanine showed increased binding of both photoaffinity analogues, while its deletion (ΔF774), as revealed by confocal microscopic analyses, led to mislocalization of the protein. The mislocalized ΔF774 mutant Cdr1p could be rescued to the plasma membrane as a functional transporter by growth in the presence of a Cdr1p substrate, cycloheximide. Our data for the first time show that the drug substrate-binding sites of Cdr1p exhibit striking similarities with those of mammalian drug-transporting P-glycoproteins and despite differences in topological organization, the transmembrane segment 6 in Cdr1p is also a major contributor to drug substrate-binding site(s)

A conceptually new treatment approach for relapsed glioblastoma: Coordinated undermining of survival paths with nine repurposed drugs (CUSP9) by the International Initiative for Accelerated Improvement of Glioblastoma Care.

To improve prognosis in recurrent glioblastoma we developed a treatment protocol based on a combination of drugs not traditionally thought of as cytotoxic chemotherapy agents but that have a robust history of being well-tolerated and are already marketed and used for other non-cancer indications. Focus was on adding drugs which met these criteria: a) were pharmacologically well characterized, b) had low likelihood of adding to patient side effect burden, c) had evidence for interfering with a recognized, well-characterized growth promoting element of glioblastoma, and d) were coordinated, as an ensemble had reasonable likelihood of concerted activity against key biological features of glioblastoma growth. We found nine drugs meeting these criteria and propose adding them to continuous low dose temozolomide, a currently accepted treatment for relapsed glioblastoma, in patients with recurrent disease after primary treatment with the Stupp Protocol. The nine adjuvant drug regimen, Coordinated Undermining of Survival Paths, CUSP9, then are aprepitant, artesunate, auranofin, captopril, copper gluconate, disulfiram, ketoconazole, nelfinavir, sertraline, to be added to continuous low dose temozolomide. We discuss each drug in turn and the specific rationale for use- how each drug is expected to retard glioblastoma growth and undermine glioblastoma's compensatory mechanisms engaged during temozolomide treatment. The risks of pharmacological interactions and why we believe this drug mix will increase both quality of life and overall survival are reviewed

Plasma membrane calcium ATPase (PMCA4): A housekeeper for RT-PCR relative quantification of polytopic membrane proteins

BACKGROUND: Although relative quantification of real-time RT-PCR data can provide valuable information, one limitation remains the selection of an appropriate reference gene. No one gene has emerged as a universal reference gene and much debate surrounds some of the more commonly used reference genes, such as glyceraldehyde-3-phosphate dehydrogenase (GAPDH). At this time, no gene encoding for a plasma membrane protein serves as a reference gene, and relative quantification of plasma membrane proteins is performed with genes encoding soluble proteins, which differ greatly in quantity and in targeting and trafficking from plasma membrane proteins. In this work, our aim was to identify a housekeeping gene, ideally one that codes for a plasma membrane protein, whose expression remains the same regardless of drug treatment and across a wide range of tissues to be used for relative quantification of real-time RT-PCR data for ATP binding cassette (ABC) plasma membrane transporters. RESULTS: In studies evaluating the expression levels of two commonly used reference genes coding for soluble proteins and two genes coding for membrane proteins, one plasma membrane protein, plasma membrane calcium-ATPase 4 (PMCA4), was comparable to the two reference genes already in use. In addition, PMCA4 expression shows little variation across eight drug-treated cell lines and was found to be superior to GAPDH and HPRT1, commonly used reference genes. Finally, we show PMCA4 used as a reference gene for normalizing ABC transporter expression in a drug-resistant lung carcinoma cell line. CONCLUSION: We have found that PMCA4 is a good housekeeping gene for normalization of gene expression for polytopic membrane proteins including transporters and receptors

Trending Algorithm on Twitter through 2023

Introduction: by doing so, Twitter\u27s trending algorithm sets the benchmark for what online discussion and information flow look like. It must be clearly understood by the researchers and the users as to how it developed and impacted.Objective: this paper discusses the Twitter trending algorithm discussion until 2023, highlighting its aspects and ethical considerations.Method: to demonstrate trend identification, we adopted a cross-sectional approach that involved data mining of trends defined by the Twitter platform from January 2020 to October 2023, applying machine learning techniques. In total, 1,984,544 unique trends were identified in the two cities over the 1584 days of Twitter API research.Results: this research identified that there are many changes in the current trending algorithm regarding Twitter, and current real-time content and users’ participation are the major concerns. The assessed model, known as TrendDetector, predicts the trend of commercials to be 80 %, while the non-commercial trend is assessed to be 60 %. Trend selection was guided by the traffic of tweets, the number of users, and the extent of new content.Conclusions: user-generated activities, content, and spread, as well as the structure and design of the platform, are thus an intricate mix in the case of the trending algorithm on Twitter. It enhances the timely acquisition of information while being associated with preconditions of bias and manipulation. Future research must look at aspects such as the algorithm\u27s transparency and the ethicality of the trends it select

The Rising Cost of Cyberattacks: Trends and Impacts across Industries

Cybersecurity incidents have escalated sharply since 2020, exposing organizations to mounting financial and operational risks. This study quantifies multi-year trends in five major attack classes, calculates the compound annual growth rate (CAGR) of breaches, and evaluates how targeted security spending mitigates losses across eight industries. Secondary data were extracted from authoritative sources (IBM, ENISA, and Ponemon). Descriptive statistics charted incident growth; Pearson correlation assessed the linkage between phishing volume and breach frequency; ordinary least-squares regression measured the effect of network, infrastructure, and identity-access investments on breach counts. Breaches rose at a 28.3% CAGR from 2020 to 2023. Healthcare incurred the highest mean cost per incident (USD 10.9 million in 2023). Phishing volume strongly correlates with breaches (r = 0.97, p < 0.05), while greater outlays on network and infrastructure security were significantly associated with lower breach rates (β = –0.18 and –0.22, respectively; p < 0.05). Unlike prior sector-specific studies, our cross-industry analysis blends global data with inferential modelling, producing actionable benchmarks that help decision-makers allocate limited cybersecurity budgets where they reduce risk most

TRPC1 participates in the HSV-1 infection process by facilitating viral entry

Mammalian transient receptor potential (TRP) channels are major components of Ca2+ signaling pathways and control a diversity of physiological functions. Here, we report a specific role for TRPC1 in the entry of herpes simplex virus type 1 (HSV-1) into cells. HSV-1-induced Ca2+ release and entry were dependent on Orai1, STIM1, and TRPC1. Inhibition of Ca2+ entry or knockdown of these proteins attenuated viral entry and infection. HSV-1 glycoprotein D interacted with the third ectodomain of TRPC1, and this interaction facilitated viral entry. Knockout of TRPC1 attenuated HSV-1-induced ocular abnormality and morbidity in vivo in TRPC1−/− mice. There was a strong correlation between HSV-1 infection and plasma membrane localization of TRPC1 in epithelial cells within oral lesions in buccal biopsies from HSV-1-infected patients. Together, our findings demonstrate a critical role for TRPC1 in HSV-1 infection and suggest the channel as a potential target for anti-HSV therapy.Fil: He, DongXu. Jiangnan University; ChinaFil: Mao, AiQin. Jiangnan University; ChinaFil: Li, YouRan. Jiangnan University; ChinaFil: Tam, SiuCheung. Chinese University Of Hong Kong; Hong KongFil: Zheng, YongTang. Kunming Institute Of Zoology Chinese Academy Of Sciences; ChinaFil: Yao, XiaoQiang. Chinese University Of Hong Kong; Hong KongFil: Birnbaumer, Lutz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Ambudkar, Indu S.. National Institute Of Dental And Craniofacial Research ; Estados UnidosFil: Ma, Xin. Jiangnan University; Chin

Identification of two novel heterodimeric ABC transporters in melanoma:ABCB5β/B6 and ABCB5β/B9

ABCB5 is a member of the ABC transporter superfamily composed of 48 transporters, which have been extensively studied for their role in cancer multidrug resistance and, more recently, in tumorigenesis. ABCB5 has been identified as a marker of skin progenitor cells, melanoma, and limbal stem cells. It has also been associated with multidrug resistance in several cancers. The unique feature of ABCB5 is that it exists as both a full transporter (ABCB5FL) and a half transporter (ABCB5β). Several studies have shown that the ABCB5β homodimer does not confer multidrug resistance, in contrast to ABCB5FL. In this study, using three complementary techniques, (1) nanoluciferase-based bioluminescence resonance energy transfer, (2) coimmunoprecipitation, and (3) proximity ligation assay, we identified two novel heterodimers in melanoma: ABCB5β/B6 and ABCB5β/B9. Both heterodimers could be expressed in High-Five insect cells and ATPase assays revealed that both functional nucleotide-binding domains of homodimers and heterodimers are required for their basal ATPase activity. These results are an important step toward elucidating the functional role of ABCB5β in melanocytes and melanoma.</p