Cellular homeostasis is maintained by rapid and systematic cleansing of aberrant and aggregated proteins within cells. Neurodegenerative diseases (NDs) especially Parkinson’s and Alzheimer’s disease ...are known to be associated with multiple factors, most important being impaired clearance of aggregates, resulting in the accumulation of specific aggregated protein in the brain. Protein quality control (PQC) of proteostasis network comprises proteolytic machineries and chaperones along with their regulators to ensure precise operation and maintenance of proteostasis. Such regulatory factors coordinate among each other multiple functional aspects related to proteins, including their synthesis, folding, transport, and degradation. During aging due to inevitable endogenous and external stresses, sustaining a proteome balance is a challenging task. Such stresses decline the capacity of the proteostasis network compromising the proteome integrity, affecting the fundamental physiological processes including reproductive fitness of the organism. This review focuses on highlighting proteome-wide changes during aging and the strategies for proteostasis improvements. The possibility of augmenting the proteostasis network either via genetic or pharmacological interventions may be a promising strategy towards delaying age-associated pathological consequences due to proteome disbalance, thus promoting healthy aging and prolonged longevity.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Neurodegenerative Parkinson's disease (PD) is a multi-factorial disorder lacking complete cure. Understanding the complete mechanism of initiation and progression of this disease has been quite ...challenging; however, progress has been made toward deciphering certain genetic aspects related to the disease condition. Genetics studies have provided clues toward the role of microRNAs (miRNAs) in various disease conditions. One of the crucial miRNA molecules, let-7, is highly conserved miRNA and is known to regulate important functions of development and viability; its altered expression has been reported in
model of PD. We carried out studies with let-7, employing transgenic
model expressing 'human' alpha-synuclein and developed a let-7 loss-of-function model toward studying the downstream effects related to PD. We observed that let-7 miRNA was upregulated in
model of PD and figured that loss of let-7 miRNA leads to decreased alpha-synuclein expression, increased autophagy, increased Daf-16 expression, increased oxidative stress and increased lipid content with no effect on dopaminergic/acetylcholinergic neurons. Our findings indicate that let-7 miRNA regulates PD-associated pathways. Our study provides insight toward the role of let-7 in regulating expression of genes associated with these pathways which might have implications on the multi-factorial nature of PD. Potential pharmacological agents modulating the expression of let-7 could be studied toward targeting the multi-factorial aspect of PD.
Hsp90 is regarded as an important therapeutic target in cancer treatment. Client proteins of Hsp90 like Beclin-1, PI3K, and AKT, are associated with tumor development, poor prognosis, and resistance ...to cancer therapies. This study aims to analyze the role of Gedunin, an Hsp-90 inhibitor, in mediation of crosstalk between apoptosis and autophagy by targeting Beclin-1:Bcl-2 interaction, and ER stress.
A549 cells were treated with different concentrations of gedunin, and inhibitory rate was evaluated by MTT assay. Effect of gedunin on generation of reactive oxygen species, mitochondrial membrane potential, and chromatin condensation was studied by staining methods like DCFH-DA, MitoTracker, and DAPI. Expression of EGFR, PIK3CA, AKT, marker genes for apoptosis and autophagy were studied using semi-quantitative RT-PCR. Interaction study of Hsp90:Beclin-1:Bcl-2 was done by immunoprecipitation analysis. Protein expression of autophagy and apoptosis markers along with Grp78, Hsp70, and Hsp90 was analyzed by immunoblotting.
Gedunin exerts cytotoxic effects, causes increase in ROS generation, downregulates mitochondrial membrane potential and induces loss in DNA integrity. mRNA expression analysis revealed that gedunin sensitized A549 cells towards apoptosis by downregulating EGFR, PIK3CA, AKT, and autophagy. Gedunin also inhibited interaction between Hsp90:Beclin-1:Bcl-2, leading to downregulation of autophagy (Beclin-1, Atg5-12 complex, and LC3) and antiapoptotic protein Bcl-2, which may result in ER stress-induced apoptosis. Moreover, Hsp90 inhibition by gedunin did not cause upregulation of Hsp70 expression.
Gedunin induces apoptosis in lung cancer cells by disrupting Hsp90:Beclin-1:Bcl-2 interaction and autophagy downregulation, thus making gedunin a good drug lead for targeting lung cancer.
•Hsp90 is an essential and highly abundant protein overexpressed in lung cancer.•Hsp90 client proteins help in cancer progression.•Hsp90 inhibitors targeting client proteins can help develop anti-cancer therapy.•Hsp90 inhibition caused autophagy inhibition by breaking Hsp90:Beclin-1:Bcl-2.•Lung cancer cells were chemo-sensitized towards ER-mediated apoptosis.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background
The aim of this study was to describe the clinical characteristics and outcome of patients with coronavirus disease-2019 (COVID-19) pneumonia admitted to an intensive care unit (ICU) of a ...tertiary care center in the United Arab Emirates (UAE) and to identify early risk factors for in-hospital mortality in these patients.
Methods
A total of 371 adult patients (>18 years) admitted to the ICU of Al Ain Hospital between March 16 and July 19, 2020 with SARS-CoV-2 infection confirmed using real-time reverse transcription polymerase chain reaction (rt-PCR) on nasopharyngeal swabs were included.
Results
The mean patient age was 53 years (standard deviation = 13). Patients were mostly male (n = 314 84.6%) and of South Asian origin (n = 231 62.3%). Invasive mechanical ventilation was required in 182 (49.1%) patients for a median of 11 days (25–75% interquartile range: 6–17). During the ICU stay, renal replacement therapy was required in 87 (23.5%) and vasopressor therapy in 190 (51.2%) patients. ICU and hospital lengths of stay were 9 (IQ: 5–17) and 18 (IQ: 13–29) days, respectively and ICU and hospital mortality rates were both 20.2%. In a multivariable analysis with in-hospital mortality as the dependent variable, greater Acute Physiology and Chronic Health Evaluation II score on ICU admission, diarrhea prior to hospital admission, greater, admission from hospital ward, and higher lactate dehydrogenase levels and neutrophil:lymphocyte ratio on admission to the ICU were independently associated with higher risk of in-hospital mortality.
Conclusion
In this cohort of patients admitted to the ICU of a tertiary hospital in the UAE, COVID-19 pneumonia was associated with high morbidity and mortality rates. Identifying patients at high risk of death may help detect future therapeutic targets.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Age-associated neurodegenerative diseases are known to have "impaired protein clearance" as one of the key features causing their onset and progression. Hence, homeostasis is the key to maintaining ...balance throughout the cellular system as an organism ages. Any imbalance in the protein clearance machinery is responsible for accumulation of unwanted proteins, leading to pathological consequences-manifesting in neurodegeneration and associated debilitating outcomes. Multiple processes are involved in regulating this phenomenon; however, failure to regulate the autophagic machinery is a critical process that hampers the protein clearing pathway, leading to neurodegeneration. Another important and widely known component that plays a role in modulating neurodegeneration is a class of proteins called sirtuins. These are class III histone deacetylases (HDACs) that are known to regulate various vital processes such as longevity, genomic stability, transcription and DNA repair. These enzymes are also known to modulate neurodegeneration in an autophagy-dependent manner. Considering its genetic relevance and ease of studying disease-related endpoints in neurodegeneration, the model system
has been successfully employed in deciphering various functional outcomes related to critical protein molecules, cell death pathways and their association with ageing. This review summarizes the vital role of sirtuins and autophagy in ageing and neurodegeneration, in particular highlighting the knowledge obtained using the
model system.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Cancer formation is a highly regulated and complex process, largely dependent on its microenvironment. This complexity highlights the need for developing novel target-based therapies depending on ...cancer phenotype and genotype. Autophagy, a catabolic process, removes damaged and defective cellular materials through lysosomes. It is activated in response to stress conditions such as nutrient deprivation, hypoxia, and oxidative stress. Oxidative stress is induced by excess reactive oxygen species (ROS) that are multifaceted molecules that drive several pathophysiological conditions, including cancer. Moreover, autophagy also plays a dual role, initially inhibiting tumor formation but promoting tumor progression during advanced stages. Mounting evidence has suggested an intricate crosstalk between autophagy and ROS where they can either suppress cancer formation or promote disease etiology. This review highlights the regulatory roles of autophagy and ROS from tumor induction to metastasis. We also discuss the therapeutic strategies that have been devised so far to combat cancer. Based on the review, we finally present some gap areas that could be targeted and may provide a basis for cancer suppression.
A new class of live cell permeant, nontoxic fluoranthene-based fluorescent probe (FLUN-550) having a high Stokes shift in aqueous medium has been discovered. It showed selective staining of lipid ...droplets (LDs, dynamic cytoplasmic organelles) at a low concentration without background noise in in vitro live cell imaging of 3T3-L1 preadipocytes, J774 macrophages, MCF7 breast cancer cells, and single-celled, parasitic protozoa Leishmania donovani promastigotes and in vivo nonparasitic soil nematode C. elegans.
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IJS, KILJ, NUK, PNG, UL, UM
Various human diseases are known to occur as a result of gene-environment interactions. Amongst such diseases, neurodegenerative Parkinson's disease (PD) is a complex disorder in which genetics and ...exposure to toxins constitute the main determinants in the onset of the disease. Many studies have reported on a link between pesticide exposure and increased risk of PD, however the role of different classes of pesticides vis-à-vis Parkinsonism has not been well elucidated. We carried out the present study to explore the role of six groups of pesticides viz botanicals, herbicides, fungicides, organophosphates, carbamates and pyrethroids on PD and and associated neurotoxic effects. These pesticides were studied using transgenic Caenorhabditis elegans model expressing human alpha synuclein protein tagged with yellow fluorescent protein NL5901; (Punc-54::alphasynuclein::YFP+unc-119) in the body wall muscle. Amongst all the classes of pesticides examined, botanical rotenone showed severe effects on PD pathogenesis. It significantly increased alpha synuclein aggregation and oxidative stress. Furthermore, it reduced mitochondrial and lipid content in the worms. Pesticides from other classes were observed to exert marginal effects as compared to rotenone thus suggesting that there is a class or structure specific effect of environmental chemicals vis-à-vis Parkinsonism. Hence it may be deduced that all classes of toxicants do not induce similar effects on neurodegeneration and associated events.
The discovery of an iron(III)-selective ratiometric fluorescent probe to detect and visualize endogenous labile iron pools in living organisms at the molecular level has been long awaited. Herein we ...report the first dual colorimetric and ratiometric fluorescent probe naphtho2,1-b1,10phenanthroline for selective and 'direct' visualization of labile iron(III) pools in a multicellular organism, Caenorhabditis elegans.
The approach of RNAi mediated gene knockdown, employing exogenous dsRNA, is being beneficially exploited in various fields of functional genomics. The immense utility of the approach came to fore ...from studies with model system C. elegans, but quickly became applicable with varied research models ranging from in vitro to various in vivo systems. Previously, there have been reports on the refractoriness of the neuronal cells to RNAi mediated gene silencing following which several modulators like eri-1 and lin-15 were described in C. elegans which, when present, would negatively impact the gene knockdown.
Taking a clue from these findings, we went on to screen hypothesis-driven- methodologies towards exploring the efficiency in the process of RNAi under various experimental conditions, wherein these genes would be knocked down preceding to, or concurrently with, the knocking down of a gene of interest. For determining the efficiency of gene knockdown, we chose to study visually stark phenotypes of uncoordinated movement, dumpy body morphology and blistered cuticle obtained by knocking down of genes unc-73, dpy-9 and bli-3 respectively, employing the RNAi-by-feeding protocol in model system C. elegans.
Our studies led to a very interesting outcome as the results reveal that amongst various methods tested, pre-incubation with eri-1 dsRNA synthesizing bacteria followed by co-incubation with eri-1 and gene-of-interest dsRNA synthesizing bacteria leads to the most efficient gene silencing as observed by the analysis of marker phenotypes. This provides an approach for effectively employing RNAi induced gene silencing while working with different genetic backgrounds including transgenic and mutant strains.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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