Browsing by Author "Aritri Bir"

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Alpha-synuclein interaction with mitochondria is the final mechanism of ferroptotic death induced by erastin in SH-SY5Y cells
(Taylor and Francis Ltd., 2024) Upasana Ganguly; Sukhpal Singh; Aritri Bir; Arindam Ghosh; Sankha Shubhra Chakrabarti; Reena V. Saini; Luciano Saso; Marco Bisaglia; Sasanka Chakrabarti
Ferroptosis has been characterized as a form of iron-dependent regulated cell death accompanied by an accumulation of reactive oxygen species and lipid oxidation products along with typical morphological alterations in mitochondria. Ferroptosis is activated by diverse triggers and inhibited by ferrostatin-1 and liproxstatin-1, apart from iron chelators and several antioxidants, and the process is implicated in multiple pathological conditions. There are, however, certain ambiguities about ferroptosis, especially regarding the final executioner of cell death subsequent to the accumulation of ROS. This study uses a typical inducer of ferroptosis such as erastin on SH-SY5Y cells, and shows clearly that ferroptotic death of cells is accompanied by the loss of mitochondrial membrane potential and intracellular ATP content along with an accumulation of oxidative stress markers. All these are prevented by ferrostatin-1 and liproxstatin-1. Additionally, cyclosporine A prevents mitochondrial alterations and cell death induced by erastin implying the crucial role of mitochondrial permeability transition pore (mPTP) activation in ferroptotic death. Furthermore, an accumulation of α-synuclein occurs during erastin induced ferroptosis which can be inhibited by ferrostatin-1 and liproxstatin-1. When the knock-down of α-synuclein expression is performed by specific siRNA treatment of SH-SY5Y cells, the mitochondrial impairment and ferroptotic death of the cells induced by erastin are markedly prevented. Thus, α-synuclein through the involvement of mPTP appears to be the key executioner protein of ferroptosis induced by erastin, but it needs to be verified if it is a generalized mechanism of ferroptosis by using other inducers and cell lines. © 2024 Informa UK Limited, trading as Taylor & Francis Group.
Ceramide and sphingosine-1-phosphate in cell death pathways: Relevance to the pathogenesis of Alzheimer’s disease
(Bentham Science Publishers B.V., 2016) Sankha Shubhra Chakrabarti; Aritri Bir; Jit Poddar; Maitrayee Sinha; Anirban Ganguly; Sasanka Chakrabarti
The metabolic turnover of sphingolipids produces several signaling molecules that profoundly affect the proliferation, differentiation and death of cells. In particular, an enormous body of information is available that defines the varied role of ceramide and sphingosine-1-phosphate in cell death and survival. This review specifically examines the role of ceramide and sphingosine-1- phosphate in triggering neuronal death in Alzheimer’s disease by analyzing the data from post-mortem studies and experimental research. There is compelling evidence that ceramide plays a key role in the neurodegeneration and amyloidogenesis occurring in the brain in Alzheimer’s disease. Further, it appears that ceramide and amyloid beta protein orchestrate an attack on mitochondria to set in the path-ways of cell death. However, the complexity of metabolic and signaling pathways of sphingolipid derivatives precludes an immediate identification of effective drug targets for the therapy of Alzheimer’s disease. © 2016 Bentham Science Publishers.
Dimethyl-2-oxoglutarate but not antioxidants prevents glucose hypometabolism induced neural cell death: implications in the pathogenesis and therapy of Alzheimer's disease
(Elsevier B.V., 2025) Aman Chauhan; Karanpreet Bhutani; Aritri Bir; Ajay Singh; Sankha Shubhra Chakrabarti; Adesh K. Saini; Sasanka Chakrabarti; Arindam Ghosh
Cerebral glucose hypometabolism is a cardinal molecular signature of Alzheimer's disease, and its role in the pathogenesis of this disorder is under intensive study in both animal and cell-based models. In the current study, we exposed SH-SY5Y cells (human neuroblastoma cell line) over a period of 48 h to DRB18, an inhibitor of multiple glucose transporters, in different concentrations to develop a state of glucose hypometabolism. Under this metabolic insult, in SH-SY5Y cells a profound dose-dependent neural cell death, an increased production of reactive oxygen radicals, mitochondrial membrane depolarization and a depletion of cellular ATP content were noted; these effects were not prevented by lipid-soluble novel antioxidants such as ferrostatin-1 and liproxstatin-1 or by a general water-soluble antioxidant like N-acetylcysteine. However, dimethyl-2-oxoglutarate, the cell-permeable analogue of 2-oxoglutarate (α-ketoglutarate) which can serve as an alternative fuel during glucose hypometabolism partially prevented both mitochondrial impairments and neural cell death. Thus, dimethyl-2-oxoglutarate may be explored further as a potential neuroprotective compound for Alzheimer's disease, and its effect on amyloid beta metabolism and homeostasis should be examined under glucose hypometabolic stress. © 2025 The Authors
Reactive oxygen species, redox signaling and neuroinflammation in Alzheimer’s disease: The NF-κB connection
(Bentham Science Publishers B.V., 2015) Upinder Kaur; Priyanjalee Banerjee; Aritri Bir; Maitrayee Sinha; Atanu Biswas; Sasanka Chakrabarti
Oxidative stress and inflammatory response are important elements of Alzheimer's disease (AD) pathogenesis, but the role of redox signaling cascade and its cross-talk with inflammatory mediators have not been elucidated in details in this disorder. The review summarizes the facts about redox-signaling cascade in the cells operating through an array of kinases, phosphatases and transcription factors and their downstream components. The biology of NF-κB and its activation by reactive oxygen species (ROS) and proinflammatory cytokines in the pathogenesis of AD have been specially highlighted citing evidence both from post-mortem studies in AD brain and experimental research in animal or cell-based models of AD. The possibility of identifying new disease-modifying drugs for AD targeting NF-κBsignaling cascade has been discussed in the end. © 2015 Bentham Science Publishers.