Journal of Biosciences最新文献

Rare diseases, also known as orphan diseases, are diseases with low occurrence in the population. Developing orphan drugs is challenging because of inadequate financial and scientific resources and insufficient subjects to run clinical trials. With advances in genome sequencing technologies, emergence of cell and gene therapies, and the latest developments in regulatory pathways, some orphan drugs that have curative potential have been approved. In India, due to its large population and resource crunch, developing orphan drugs is phenomenally challenging. After adopting the Orphan Drug Act, the US-FDA has continuously made advances in regulatory pathways for orphan drugs. Particularly, n-of-one clinical trials have been successful in some cases. India has recently adopted policies that have impacted the long-neglected rare-disease ecosystem; however, there is no clear regulatory path for orphan drug development in India. We have proposed a multi-pronged approach involving close collaboration between the government, regulatory bodies, industries, and patient advocacy groups to boost orphan drug development in India. We believe that rapidly evolving technologies and business models can enable better and faster development of novel orphan drugs in India and other resource-constrained countries.

GNE myopathy is a rare genetic neuromuscular disease that is caused due to mutations in the GNE gene responsible for sialic acid biosynthesis. Foot drop is the most common initial symptom observed in GNE myopathy patients. There is slow progressive muscle weakness in the lower and upper extremities while the quadriceps muscles are usually spared. The exact pathophysiology of the disease is unknown. Besides sialic acid biosynthesis, recent studies suggest either direct or indirect involvement of GNE in other cellular functions such as protein aggregation, apoptosis, ER stress, cell migration, HSP70 chaperone activity, autophagy, muscle atrophy, and myogenesis. Both animal and in vitro cell-based model systems are generated to elucidate the mechanism of GNE myopathy and evaluate the efficacy of therapies. The many therapeutic avenues explored include supplementation with sialic acid derivatives or precursors and gene therapy. Recent studies suggest other therapeutic options such as modulators of HSP70 chaperone (BGP-15), cofilin activator (CGA), and ligands like IGF-1 that may help to rescue cellular defects due to GNE dysfunction. This review provides an overview of the pathophysiology associated with GNE function in the cell and promising therapeutic leads to be explored for future drug development.

Cell type-specific expression of genes plays a pivotal role in the development and evolution of multicellular organisms over millions of years. The majority of regulatory control resides within the non-coding regions of the genome, referred to as 'dark matter', which contains cis-regulatory modules. These cis-regulatory modules function collectively and can impact gene expression even when located far from the target gene, exhibiting context-specific behaviour. Consequently, the cis-regulatory code governing gene expression patterns is intricate, in contrast to the universally understood genetic code. This overview centres on the current knowledge regarding cis-regulatory elements, primarily enhancers and their role in governing the spatiotemporal gene expression patterns, and how they have evolved and adapted across different species.

Stomatal guard cells are unique in that they have more mitochondria than chloroplasts. Several reports emphasized the importance of mitochondria as the major energy source during stomatal opening. We re-examined their role during stomatal closure. The marked sensitivity of stomata to both menadione (MD) and methyl viologen (MV) demonstrated that both mitochondria and chloroplasts helped to promote stomatal closure in Arabidopsis. As in the case of abscisic acid (ABA), a plant stress hormone, MD and MV induced stomatal closure at micromolar concentration. All three compounds generated superoxide and H₂O₂, as indicated by fluorescence probes, BES-So-AM and CM-H₂DCFDA, respectively. Results from tiron (a superoxide scavenger) and catalase (an H₂O₂ scavenger) confirmed that both the superoxide and H₂O₂ were requisites for stomatal closure. Co-localization of the superoxide and H₂O₂ in mitochondria and chloroplasts using fluorescent probes revealed that exposure to MV initially triggered higher superoxide and H2O2 generation in mitochondria. In contrast, MD elevated superoxide/H2O2 levels in chloroplasts. However, with prolonged exposure, MD and MV induced ROS production in other organelles. We conclude that ROS production in mitochondria and chloroplasts leads to stomatal closure. We propose that stomatal guard cells can be good models for examining inter-organellar interactions.

Adult muscle tissue largely comprised of differentiated myofibers also harbors quiescent muscle-resident stem cells (MuSCs) that are responsible for its maintenance, repair and regeneration. Emerging evidence suggests that quiescent MuSCs exhibit a specific metabolic state, which is regulated during physiological and pathological alterations. However, a detailed understanding of the metabolic state of quiescent MuSCs and its alteration during activation and repair is lacking. Direct profiling of MuSCs in vivo is challenging because the cells are rare and dispersed, while isolation and enrichment leads to their activation and loss of quiescence. In this study, we employed 1H-nuclear magnetic resonance (NMR) spectroscopy to profile metabolites in an established culture model of quiescent MuSC-derived myoblasts and compared with activated, proliferative and differentiated muscle cells to determine the state-specific metabolome. We report that the proliferating and differentiated cells are highly enriched in metabolites involved in energy generation, the quiescent state is enriched in metabolites related to phospholipid catabolism (glycerophosphocholine and choline) and depleted for phosphocholine which is enriched in proliferating cells. We propose that the ratio of these metabolites may be useful as a biomarker of MuSC quiescence.

Noradrenaline (NA) and serotonin (5-HT) induce nociception and antinociception. This antagonistic effect can be explained by the dose and type of activated receptors. We investigated the existence of synergism between the noradrenergic and serotonergic systems during peripheral antinociception. The paw pressure test was performed in mice that had increased sensitivity by intraplantar injection of prostaglandin E₂ (PGE₂). Noradrenaline (80 ng) administered intraplantarly induced an antinociceptive effect, that was reversed by the administration of selective antagonists of serotoninergic receptors 5-HT_1B isamoltan, 5-HT_1D BRL15572, 5-HT_2A ketanserin, 5-HT₃ ondansetron, but not by selective receptor antagonist 5-HT₇ SB-269970. The administration of escitalopram, a serotonin reuptake inhibitor, potentiated the antinociceptive effect at a submaximal dose of NA. These results, indicate the existence of synergism between the noradrenergic and serotonergic systems in peripheral antinociception in mice.

Amyloids interact with plasma membranes. Extracellular amyloids cross the plasma membrane barrier. Internalized extracellular amyloids are reported to trigger amyloidogenesis of endogenous proteins in recipient cells. To what extent these extracellular and intracellular amyloids perturb the plasma membrane proteome is not investigated. Using α-synuclein as a model amyloid protein, we performed membrane shaving followed by mass spectrometry experiments to identify the conformational changes in cell surface proteins after extracellular amyloid challenge. We also performed membrane proteomics after the biogenesis of intracellular α-synuclein amyloids. Our results suggest that promiscuous interactions with extracellular amyloids stochastically alter the conformation of plasma membrane proteins. This affects the biological processes through the plasma membrane and results in loss of cell viability. Cells that survive the extracellular amyloid shock can grow normally and gradually develop intracellular amyloids which do not directly impact the plasma membrane proteome and associated biological processes. Thus, our results suggest that α-synuclein amyloids can damage the plasma membrane and related processes during cell-to-cell transfer and not during their intracellular biogenesis.

Ever since language and script evolved, humans have documented their own lives, their business transactions, the lives of animals and of plants, and the movements of the stars. The earliest recorded diary was kept by Merer, who lived at the time of the construction of the Great Pyramid of Giza; Merer writes about the Tura limestone that he loaded on his boat to take down the Nile to the site of pyramid construction. This was nearly 4500 years ago. Before this, and since then, besides written documentation, oral traditions in the form of stories have served to provide a sense of the times, and have given us, our ancestors' descendants, the history of their experimentation with food, medicine, clothing and shelter.

Lafora disease (LD) is a life-threatening autosomal recessive and progressive neurodegenerative disorder that primarily affects adolescents, resulting in mortality within a decade of onset. The symptoms of LD include epileptic seizures, ataxia, dementia, and psychosis. The underlying pathology involves the presence of abnormal glycogen inclusions in neurons and other tissues, which may contribute to neurodegeneration. LD is caused by loss-of-function mutations in either the EPM2A gene or the NHLRC1 gene. These two genes, respectively, code for laforin phosphatase and malin ubiquitin ligase, and are thought to function, as a functional complex, in diverse cellular pathways. One of the major pathways affected in LD is glycogen metabolism; defects here lead to abnormally higher levels of glycogen and its hyperphosphorylation and aggregation, resulting in the formation of Lafora inclusion bodies. Currently, there is no effective therapy for LD. Studies, particularly from animal models, provide distinct insights into the fundamental mechanisms of diseases and potential avenues for therapeutic interventions. The purpose of this review is to present a comprehensive overview of our current knowledge regarding the disease, its genetics, the animal models that have been developed, and the therapeutic strategies that are being developed based on an understanding of the disease mechanism.

Rare genetic diseases are rare by themselves with prevalence of 1 in 25,000, but collectively they are a significant cause of morbidity and mortality. Till date, collectively there are more than 9,000 rare diseases documented, which impose a devastating impact on patients, their families, and the healthcare system, including enormous societal burden. Obtaining a conclusive diagnosis for a patient with a rare genetic disease can be long and gruelling. For some patients it takes months or years to receive a definite diagnosis, and around 50% of the patients remain undiagnosed even with expert clinical and advanced high-end laboratory investigations. Owing to the large population and practice of consanguinity the Indian population is a pool of indigenous variants and unreported phenotypes or diseases. A mission program on pediatric rare diseases is an unparalleled initiative to study unique clinical conditions via the use of latest state-of-art technologies and with the combination of a mulit-omics approach. Our initiative will not only provide diagnosis to patients with rare disease but also build a platform for translational research for rare disease screening, management, and treatment.