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result(s) for
"Datta, Amrita"
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High-throughput screening identified selective inhibitors of exosome biogenesis and secretion: A drug repurposing strategy for advanced cancer
2018
Targeting exosome biogenesis and release may have potential clinical implications for cancer therapy. Herein, we have optimized a quantitative high throughput screen (qHTS) assay to identify compounds that modulate exosome biogenesis and/or release by aggressive prostate cancer (PCa) CD63-GFP-expressing C4-2B cells. A total of 4,580 compounds were screened from the LOPAC library (a collection of 1,280 pharmacologically active compounds) and the NPC library (NCGC collection of 3,300 compounds approved for clinical use). Twenty-two compounds were found to be either potent activators or inhibitors of intracellular GFP signal in the CD63-GFP-expressing C4-2B cells. The activity of lead compounds in modulating the secretion of exosomes was validated by a tunable resistive pulse sensing (TRPS) system (qNano-IZON) and flow cytometry. The mechanism of action of the lead compounds in modulating exosome biogenesis and/or secretion were delineated by immunoblot analysis of protein markers of the endosomal sorting complex required for transport (ESCRT)-dependent and ESCRT-independent pathways. The lead compounds tipifarnib, neticonazole, climbazole, ketoconazole, and triademenol were validated as potent inhibitors and sitafloxacin, forskolin, SB218795, fenoterol, nitrefazole and pentetrazol as activators of exosome biogenesis and/or secretion in PC cells. Our findings implicate the potential utility of drug-repurposing as novel adjunct therapeutic strategies in advanced cancer.
Journal Article
Repurposing ketoconazole as an exosome directed adjunct to sunitinib in treating renal cell carcinoma
by
Moustafa, Ahmed A.
,
Barata, Pedro C.
,
Abdel-Mageed, Asim B.
in
631/154
,
631/154/1438
,
631/154/555
2021
Renal Cell Carcinoma (RCC) is the most common form of kidney cancer, with clear cell RCC (ccRCC) representing about 85% of all RCC tumors. There are limited curable treatments available for metastatic ccRCC because this disease is unresponsive to conventional targeted systemic pharmacotherapy. Exosomes (Exo) are small extracellular vesicles (EVs) secreted from cancer cells with marked roles in tumoral signaling and pharmacological resistance. Ketoconazole (KTZ) is an FDA approved anti-fungal medication which has been shown to suppress exosome biogenesis and secretion, yet its role in ccRCC has not been identified. A time-course, dose-dependent analysis revealed that KTZ selectively decreased secreted Exo in tumoral cell lines. Augmented Exo secretion was further evident by decreased expression of Exo biogenesis (Alix and nSMase) and secretion (Rab27a) markers. Interestingly, KTZ-mediated inhibition of Exo biogenesis was coupled with inhibition of ERK1/2 activation. Next, selective inhibitors were employed and showed ERK signaling had a direct role in mediating KTZ’s inhibition of exosomes. In sunitinib resistant 786-O cells lines, the addition of KTZ potentiates the efficacy of sunitinib by causing Exo inhibition, decreased tumor proliferation, and diminished clonogenic ability of RCC cells. Our findings suggest that KTZ should be explored as an adjunct to current RCC therapies.
Journal Article
TNFα and IL-1β modify the miRNA cargo of astrocyte shed extracellular vesicles to regulate neurotrophic signaling in neurons
2018
Astrocytes are known to be critical regulators of neuronal function. However, relatively few mediators of astrocyte to neuron communication have been identified. Recent advancements in the biology of extracellular vesicles have begun to implicate astrocyte derived extracellular vesicles (ADEV) as mediators of astrocyte to neuron communication, suggesting that alterations in the release and/or composition of ADEVs could influence gliotransmission. TNFα and IL-1β are key mediators of glial activation and neuronal damage, but the effects of these cytokines on the release or molecular composition of ADEVs is unknown. We found that ADEVs released in response to IL-1β (ADEV-IL-1β) and TNFα (ADEV-TNFα) were enriched with miRNAs that target proteins involved in neurotrophin signaling. We confirmed that miR-125a-5p and miR-16-5p (both enriched in ADEV-IL-1β and ADEV-TNFα) targeted NTKR3 and its downstream effector Bcl2. Downregulation of these targets in neurons was associated with reductions in dendritic growth, dendritic complexity, reduced spike rates, and burst activity. Molecular interference of miR-125a-5p and miR-16-5p prevented ADEV-IL-1β from reducing dendritic complexity, spike, and burst rates. These findings suggest that astrocytes respond to inflammatory challenge by modifying the miRNA cargo of ADEVs to diminish the activity of target neurons by regulating the translational expression of proteins controlling programs essential for synaptic stability and neuronal excitability.
Journal Article
Isolation, characterisation and detection of breath-derived extracellular vesicles
2020
The physical characterisation, capture and detection of extracellular vesicles (EVs) and exosomes derived from breath condensate is reported. Breath-derived EVs were isolated from breath condensate and captured on a gold substrate using two complimentary methods. The characterised and isolated EVs were detected using surface plasmon resonance (SPR) and electrochemical impedance spectroscopy (EIS). EIS was done using aptamers as a targeting moiety and showed a larger change in resistance between dilute concentrations of EVs (less than 7 μg/mL).This is the first report of EVs and exosomes isolated and characterised from breath. In addition, EVs from a non-invasive and easily available source such as breath opens up further avenues in the detection of pulmonary diseases.
Journal Article
Perceptions of Digital Health App Usage Among Women Attending Obstetrics and Gynecology Outpatient Department in a Tertiary Care Setting
by
Kaushik, Jaya Shankar
,
Malakar, Himangshu
,
Datta, Amrita
in
Digital technology
,
Gynecology
,
Health facilities
2025
Introduction Digitalization is transforming healthcare, with tools like digital health apps and platforms becoming integral. India's Ayushman Bharat Digital Mission (ABDM) aims to create a digitally empowered healthcare system, utilizing the Ayushman Bharat Health Account (ABHA) for seamless access to health services. This study evaluates patients' perceptions of digital healthcare services, specifically ABHA, in a tertiary care setting, and identifies factors influencing adoption. Methods A cross-sectional study was conducted over six months (September 2024-March 2025) among 250 women (aged 18-80) attending the Obstetrics and Gynecology outpatient department (OPD). A validated questionnaire assessed patient perceptions of ABHA registration and digital health records. Demographic data and awareness of digital platforms were collected. Statistical analysis included descriptive statistics, chi-square tests, and logistic regression. Results The mean age of participants was 28 ± 3.2 years. Awareness of digital platforms varied, with 125 (60%) being aware of digital India platforms, 87 (35%) of ABHA, and 50 (20%) of the Swasthya app. The majority of participants (100 (40%)) belonged to the upper lower class of the Kuppuswamy socioeconomic scale. Overall, patients reported high satisfaction with ABHA registration (satisfaction index (SI) = 87.9), perceiving it as simple and efficient. Logistic regression showed no significant influence of age, education, socioeconomic status, or ABHA awareness on digital health app usage. However, the scan and share feature had a lower SI (78.7). Discussion While patients generally viewed ABHA positively, awareness gaps and usability challenges, particularly with the scan and share feature, were identified. Socioeconomic factors did not significantly impact adoption, suggesting effective integration of ABDM into public healthcare. Targeted educational programs and technological improvements are necessary to enhance digital health literacy and adoption. Conclusion This study highlights the importance of addressing awareness and usability barriers to optimize digital health adoption in tertiary care settings. Enhancing patient education and improving digital interfaces can improve healthcare delivery through digital platforms.
Journal Article
DPTIP, a newly identified potent brain penetrant neutral sphingomyelinase 2 inhibitor, regulates astrocyte-peripheral immune communication following brain inflammation
2018
Brain injury and inflammation induces a local release of extracellular vesicles (EVs) from astrocytes carrying proteins, RNAs, and microRNAs into the circulation. When these vesicles reach the liver, they stimulate the secretion of cytokines that mobilize peripheral immune cell infiltration into the brain, which can cause secondary tissue damage and impair recovery. Recent studies suggest that suppression of EV biosynthesis through neutral sphingomyelinase 2 (nSMase2) inhibition may represent a new therapeutic strategy. Unfortunately, currently available nSMase2 inhibitors exhibit low potency (IC
50
≥ 1 μM), poor solubility and/or limited brain penetration. Through a high throughput screening campaign of >365,000 compounds against human nSMase2 we identified 2,6-
D
imethoxy-4-(5-
P
henyl-4-
T
hiophen-2-yl-1H-
I
midazol-2-yl)-
P
henol (DPTIP), a potent (IC
50
30 nM), selective, metabolically stable, and brain penetrable (AUC
brain
/AUC
plasma
= 0.26) nSMase2 inhibitor. DPTIP dose-dependently inhibited EV release in primary astrocyte cultures. In a mouse model of brain injury conducted in GFAP-GFP mice, DPTIP potently (10 mg/kg IP) inhibited IL-1β-induced astrocyte-derived EV release (51 ± 13%; p < 0.001). This inhibition led to a reduction of cytokine upregulation in liver and attenuation of the infiltration of immune cells into the brain (80 ± 23%; p < 0.01). A structurally similar but inactive analog had no effect
in vitro
or
in vivo
.
Journal Article
Women, development, caste, and violence in rural Bihar, India
2020
This article focuses on the contradictions that exist between economic development and gender equity in India. It deploys concepts of cultural violence and symbolic hegemony to understand how gender and caste-based violence is normalized and institutionalized over time through cultural norms. It also uses an intersectional lens to examine the layers of marginalization and oppression. Based on field studies in rural Bihar, it shows that despite development gains, old forms of gender-based discrimination and violence such as son-preference, dowry, witch-hunting, and discriminatory practices associated with menstruation persist. It notes that there are new forms of violence used by the upper caste groups against the lower ones when the latter resist and refuse to continue performing traditional caste-based tasks. We argue that this refusal by lower caste women can be seen as symbolic resistance against historically defined norms of caste. The emerging patterns of violence discussed in the paper need a more concerted and nuanced exploration of reconfigurations of relations within and between caste groups, as well as the cultural and social contexts in which changes are taking place.
Journal Article
MicroRNA-142 Reduces Monoamine Oxidase A Expression and Activity in Neuronal Cells by Downregulating SIRT1
by
Fox, Howard S.
,
Yelamanchili, Sowmya V.
,
Datta Chaudhuri, Amrita
in
Amine oxidase (flavin-containing)
,
Analysis
,
Brain
2013
Aberrant expression of microRNAs (miRs) has been implicated in the pathogenesis of several neurodegenerative disorders. In HIV-associated neurocognitive disorders (HAND), miR-142 was found to be upregulated in neurons and myeloid cells in the brain. We investigated the downstream effects of chronic miR-142 upregulation in neuronal cells by comparing gene expression in stable clones of the human neuroblastoma cell line BE(2)M17 expressing miR-142 to controls. Microarray analysis revealed that miR-142 expression led to a reduction in monoamine oxidase (MAO) A mRNA, which was validated by qRT-PCR. In addition to the mRNA, the MAOA protein level and enzyme activity were also reduced. Examination of primary human neurons revealed that miR-142 expression indeed resulted in a downregulation of MAOA protein level. Although MAOA is not a direct target of miR-142, SIRT1, a key transcriptional upregulator of MAOA is, thus miR-142 downregulation of MAOA expression is indirect. MiR-142 induced decrease in MAOA expression and activity may contribute to the changes in dopaminergic neurotransmission reported in HAND.
Journal Article
Nrf1 and Nrf2 Transcription Factors Regulate Androgen Receptor Transactivation in Prostate Cancer Cells
by
Abdel-Mageed, Asim B.
,
Freeman, Michael L.
,
Datta, Amrita
in
Analysis of Variance
,
Androgen receptors
,
Androgens
2014
Despite androgen deprivation therapy (ADT), persistent androgen receptor (AR) signaling enables outgrowth of castration resistant prostate cancer (CRPC). In prostate cancer (PCa) cells, ADT may enhance AR activity through induction of oxidative stress. Herein, we investigated the roles of Nrf1 and Nrf2, transcription factors that regulate antioxidant gene expression, on hormone-mediated AR transactivation using a syngeneic in vitro model of androgen dependent (LNCaP) and castration resistant (C4-2B) PCa cells. Dihydrotestosterone (DHT) stimulated transactivation of the androgen response element (ARE) was significantly greater in C4-2B cells than in LNCaP cells. DHT-induced AR transactivation was coupled with higher nuclear translocation of p65-Nrf1 in C4-2B cells, as compared to LNCaP cells. Conversely, DHT stimulation suppressed total Nrf2 levels in C4-2B cells but elevated total Nrf2 levels in LNCaP cells. Interestingly, siRNA mediated silencing of Nrf1 attenuated AR transactivation while p65-Nrf1 overexpression enhanced AR transactivation. Subsequent studies showed that Nrf1 physically interacts with AR and enhances AR's DNA-binding activity, suggesting that the p65-Nrf1 isoform is a potential AR coactivator. In contrast, Nrf2 suppressed AR-mediated transactivation by stimulating the nuclear accumulation of the p120-Nrf1 which suppressed AR transactivation. Quantitative RT-PCR studies further validated the inductive effects of p65-Nrf1 isoform on the androgen regulated genes, PSA and TMPRSS2. Therefore, our findings implicate differential roles of Nrf1 and Nrf2 in regulating AR transactivation in PCa cells. Our findings also indicate that the DHT-stimulated increase in p65-Nrf1 and the simultaneous suppression of both Nrf2 and p120-Nrf1 ultimately facilitates AR transactivation in CRPC cells.
Journal Article