Biology subjects

Karmirian, K.

Publications and source records attributed to Karmirian, K..

9 recordsLinked to original sources

bioRxiv2024

LSD Modulates Proteins Involved in Cell Proteostasis, Energy Metabolism and Neuroplasticity in Human Brain Organoids

Proteomic analysis of human cerebral organoids may reveal how psychedelics regulate biological processes, shedding light on drug-induced changes in the brain. This study elucidates the proteomic alterations induced by lysergic acid diethylamide (LSD) in human cerebral organoids. By employing high-resolution mass spectrometry-based proteomics, we quantitatively analyzed the differential abundance of proteins in cerebral organoids exposed to LSD. Our findings indicate changes in proteostasis, energy metabolism, and neuroplasticity-related pathways. Specifically, LSD exposure led to alterations in protein synthesis, folding, autophagy, and proteasomal degradation, suggesting a complex interplay in the regulation of neural cell function. Additionally, we observed modulation in glycolysis and oxidative phosphorylation, crucial for cellular energy management and synaptic function. In support of the proteomic data, complementary experiments demonstrated LSDs potential to enhance neurite outgrowth in vitro, confirming its impact on neuroplasticity. Collectively, our results provide a comprehensive insight into the molecular mechanisms through which LSD may affect neuroplasticity and potentially contribute to therapeutic effects for neuropsychiatric disorders.

neuroscience↗

bioRxiv2021

Age-linked suppression of lipoxin A4 mediates cognitive deficits in mice and humans

Age increases the risk for cognitive impairment and is the single major risk factor for Alzheimers disease (AD), the most prevalent form of dementia in the elderly. The pathophysiological processes triggered by aging that render the brain vulnerable to dementia involve, at least in part, changes in inflammatory mediators. Here we show that lipoxin A4 (LXA4), a lipid mediator of inflammation resolution known to stimulate endocannabinoid signaling in the brain, is reduced in the aging central nervous system. We demonstrate that genetic suppression of 5-lipoxygenase (5-LOX), the enzyme mediating LXA4 synthesis, promotes learning impairment in mice. Conversely, administration of exogenous LXA4 attenuated cytokine production and memory loss induced by inflammation in mice. We further show that cerebrospinal fluid LXA4 is reduced in patients with dementia and positively associates with memory performance, brain-derived neurotrophic factor (BDNF), and AD-linked amyloid-. Our findings suggest that reduced LXA4 levels may lead to vulnerability to age-related cognitive disorders and that promoting LXA4 signaling may comprise an effective strategy to prevent early cognitive decline in AD.

neuroscience↗

bioRxiv2021

Proteomic changes induced by harmine in human brain organoids reveal signaling pathways related to neuroprotection

Harmine is a {beta}-carboline found in Banisteriopsis caapi, a constituent of ayahuasca brew. Ayahuasca is consumed as a beverage in native Americans sacred rituals and in religious ceremonies in Brazil. Throughout the years, the beneficial effects of ayahuasca to improve mental health and life quality have been reported, which propelled the investigation of its therapeutic potential to target neurological disorders such as depression and anxiety. Indeed, antidepressant effects of ayahuasca have been described, raising the question of which cellular mechanisms might underlie those effects. Previous animal studies describe potential neuroprotective mechanisms of harmine, including anti-inflammatory and antioxidant activities, and neurotrophin signaling activation. However, the cellular and molecular mechanisms modulated by harmine in human models remain less investigated. Here we analyzed the short-term changes in the proteome of human brain organoids treated with harmine using shotgun mass spectrometry. Harmine upregulates proteins related to synaptic vesicle cycle, cytoskeleton-dependent intracellular transport, cell cycle, glucose transporter-4 translocation, and neurotrophin signaling pathway. In addition, protein expression levels of Akt and phosphorylated CREB were increased after 24 hour-treatment. Our results shed light on the potential mechanisms that may underlie harmine-induced neuroprotective effects.

cell biology↗

bioRxiv2021

DYRK1A role in microtubule-based axonal transport regulates the retrograde dynamics of APP vesicles in human neurons

In Alzheimers Disease (AD) the abnormal intracellular distribution of the amyloid precursor protein (APP) affects its processing and, consequently, the generation of A{beta}. Axonal transport plays key roles in the neuronal distribution of APP. The dual-specificity-tyrosine phosphorylation-regulated-kinase-1A (DYRK1A) has been associated with AD onset since its overexpression was found in Down syndrome and sporadic AD patients. Experimental evidence confirmed that APP and tau phosphorylations are mediated by DYRK1A. Moreover, DYRK1A can regulate the cytoskeletal architecture by phosphorylation of both tubulin subunits and microtubule-associated proteins. Therefore, we tested whether DYRK1A has a role in APP axonal transport regulation. We developed highly-polarized human-derived neurons in 2D cultures. At day 14 after terminal plating we inhibited DYRK1A for 48hs with harmine (7.5 M). DYRK1A overexpression was induced to perform live-cell imaging of APP-loaded vesicles in axons and analyzed transport dynamics. A custom-made MATLAB routine was developed to track and analyze single particle dynamics. Short-term harmine treatment reduced axonal APP vesicles density, due to a reduction in retrograde particles. Contrarily, DYRK1A overexpression enhanced axonal APP density, due to an increase in the retrograde and stationary component. Moreover, both harmine-mediated DYRK1A inhibition and DYRK1A overexpression revealed opposite phenotypes on single particle dynamics, affecting primarily dynein processivity. These results revealed an increased retrieval of distal APP vesicles in axons when DYRK1A is overexpressed and reinforce the suggestion that DYRK1A enhance APP endocytosis.. Taken together our results suggest that DYRK1A has a relevant role in the regulation of axonal transport and sub-cellular positioning of APP vesicles. Therefore, our work shed light on the role of DYRK1A in axonal transport regulation, and the putative use of harmine to restore axonal transport impairments.

neuroscience↗

bioRxiv2021

A cannabinoid receptor agonist shows anti-inflammatory and survival properties in human SARS-CoV-2-infected iPSC-derived cardiomyocytes

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which can infect several organs, especially impacting respiratory capacity. Among the extrapulmonary manifestations of COVID-19 is myocardial injury, which is associated with a high risk of mortality. Myocardial injury, caused directly or indirectly by SARS-CoV-2 infection, can be triggered by inflammatory processes that cause damage to the heart tissue. Since one of the hallmarks of severe COVID-19 is the "cytokine storm", strategies to control inflammation caused by SARS-CoV-2 infection have been considered. Cannabinoids are known to have anti-inflammatory properties by negatively modulating the release of pro-inflammatory cytokines. Herein, we investigated the effects of the cannabinoid agonist WIN 55,212-2 (WIN) in human iPSC-derived cardiomyocytes (hiPSC-CMs) infected with SARS-CoV-2. WIN did not modify angiotensin-converting enzyme II protein levels, nor reduced viral infection and replication in hiPSC-CMs. On the other hand, WIN reduced the levels of interleukins 6, 8, 18 and tumor necrosis factor-alpha (TNF-) released by infected cells, and attenuated cytotoxic damage measured by the release of lactate dehydrogenase (LDH). Our findings suggest that cannabinoids should be further explored as a complementary therapeutic tool for reducing inflammation in COVID-19 patients.

cell biology↗

bioRxiv2021

Inhibition of SARS-CoV-2 infection in human cardiomyocytes by targeting the Sigma-1 receptor disrupts cytoskeleton architecture and contractility

Heart dysfunction, represented by conditions such as myocarditis and arrhythmia, has been reported in COVID-19 patients. Therapeutic strategies focused on the cardiovascular system, however, remain scarce. The Sigma-1 receptor (S1R) has been recently proposed as a therapeutic target because its inhibition reduces SARS-CoV-2 replication. To investigate the role of S1R in SARS-CoV-2 infection in the heart, we used human cardiomyocytes derived from induced pluripotent stem cells (hiPSC-CM) as an experimental model. Here we show that the S1R antagonist NE-100 decreases SARS-CoV-2 infection and viral replication in hiPSC-CMs. Also, NE-100 reduces cytokine release and cell death associated with infection. Because S1R is involved in cardiac physiology, we investigated the effects of NE-100 in cardiomyocyte morphology and function. We show that NE-100 compromises cytoskeleton integrity and reduces beating frequency, causing contractile impairment. These results show that targeting S1R to challenge SARS-CoV-2 infection may be a useful therapeutic strategy but its detrimental effects in vivo on cardiac function should not be ignored.

cell biology↗

bioRxiv2020

Non-permissive SARS-CoV-2 infection of neural cells in the developing human brain and neurospheres

Coronavirus disease 2019 (COVID-19) was initially described as a viral infection of the respiratory tract. It is now known, however, that several other organs are affected, including the brain. Neurological manifestations such as stroke, encephalitis, and psychiatric conditions have been reported in COVID-19 patients, but the neurotropic potential of the virus is still debated. Herein, we sought to investigate SARS-CoV-2 infection in human neural cells. We demonstrated that SARS-CoV-2 infection of neural tissue is non-permissive, however, it can elicit inflammatory response and cell damage. These findings add to the hypothesis that most of the neural damage caused by SARS-CoV-2 infection is due to a systemic inflammation leading to indirect harmful effects on the central nervous system despite the absence of local viral replication.

neuroscience↗

bioRxiv2019

d-Lysergic acid diethylamide has major potential as a cognitive enhancer

Psychedelic agonists of serotonin receptors induce neural plasticity and synaptogenesis, but their potential to enhance learning remains uncharted. Here we show that a single dose of d-LSD, a potent serotonergic agonist, increased novel object preference in young and adult rats several days after treatment. d-LSD alone did not increase preference in old animals, but could rescue it to young levels when followed by a 6-day exposure to enriched environment (EE). Mass spectrometry-based proteomics in human brain organoids treated with d-LSD showed upregulation of proteins from the presynaptic active zone. A computational model of synaptic connectivity in the hippocampus and prefrontal cortex suggests that d-LSD enhances novelty preference by combining local synaptic changes in mnemonic and executive regions, with alterations of long-range synapses. Better pattern separation within EE explained its synergy with d-LSD in rescuing novelty preference in old animals. These results advance the use of d-LSD in cognitive enhancement.

neuroscience↗

bioRxiv2019

The cyanobacterial saxitoxin exacerbates neural cell death and brain malformations induced by Zika virus

The northeast (NE) region of Brazil commonly goes through drought periods, which favor cyanobacterial blooms, capable of producing neurotoxins with implications for human and animal health. The most severe dry spell in the history of Brazil occurred between 2012 and 2016. Coincidently, the highest incidence of microcephaly associated with the Zika virus (ZIKV) outbreak was described in the NE region of Brazil during the same years. In this work, we tested the hypothesis that saxitoxin (STX), a neurotoxin produced in South America by the freshwater cyanobacteria Raphidiopsis raciborskii, could have contributed to the most severe Congenital Zika Syndrome (CZS) profile described worldwide. Quality surveillance showed higher cyanobacteria amounts and STX occurrence in human drinking water supplies of NE compared to other regions of Brazil. Experimentally, we described that STX doubled the amount of ZIKV-induced neural cell death in progenitor areas of human brain organoids, while the chronic ingestion of water contaminated with STX before and during gestation caused brain abnormalities in offspring of ZIKV-infected immunocompetent C57BL/6J mice. Our data indicate that saxitoxin-producing cyanobacteria is overspread in water reservoirs of the NE and might have acted as a co-insult to ZIKV infection in Brazil. These results raise a public health concern regarding the consequences of arbovirus outbreaks happening in areas with droughts and/or frequent freshwater cyanobacterial blooms.\n\nAuthor summaryThe uncontrolled spreading of cyanobacteria in drinking water reservoirs has been the cause of serious public health problems worldwide. Toxin-producing cyanobacterial blooms commonly occur during drought periods in the northeast (NE) region of Brazil. During Zika Virus (ZIKV) outbreak in 2015-16, Brazilian NE showed disproportionately higher microcephaly incidence. Here, we test the hypothesis that the cyanotoxin saxitoxin (STX) may act as a co-insult for ZIKV. Water quality surveillance data showed increased cyanobacteria population and higher STX amount in NE region during 2014-2018. In vitro, we observed that neural progenitor cell death was doubled after STX exposure to ZIKV-infected brain organoids. In vivo, chronic ingestion of STX during gestational period potentiated ZIKV-derived brain abnormalities in newborn mice. Our study provides new insights that may explain the discrepancies among Brazilian regions regarding CZS severity. Moreover, the data highlight the importance of cyanobacteria and cyanotoxin freshwater monitoring for future arbovirus outbreaks.

neuroscience↗