Amyloid-like Aggregation Propensities of Metabolites - Homogentisic acid, N-Acetyl aspartic acid and Isovaleric acid.

The transformation of metabolites into amyloidogenic aggregates represent an intriguing dimension in the pathophysiology of metabolic disorders, including alkaptonuria, canavan disease, and isovaleric acidemia. Central to this phenomenon are the metabolites homogentisic acid (HA), N-acetyl aspartic acid (NAA), and isovaleric acid (IVA), which we found, weave an intricate network of self-assembled structures. Leveraging an array of microscopy techniques, we traced the morphological behavior of these assemblies that exhibit concentration and time-dependent morphological transitions from isolated globules to clustered aggregates. MD simulation studies suggest significant role of hydrogen bonding interactions in the aggregation process. While displaying strong amyloidogenic propensity in solution, these aged aggregates were significantly cytotoxic to mouse neural N2a cell lines.  In vivo effect in Caenorhabditis elegans (C. elegans) nematode further validated cytotoxicity of aggregates. Our findings provide fresh insights to amyloidogenic nature of HA, NAA, and IVA aggregates and their possible role in associated metabolic disorders such as alkaptonuria, canavan disease and isovaleric acidemia.

Ageing, proteostasis, and the gut: Insights into neurological health and disease.

Recent research has illuminated the profound bidirectional communication between the gastrointestinal tract and the brain, furthering our understanding of neurological ailments facilitating possible therapeutic strategies. Technological advancements in high-throughput sequencing and multi-omics have unveiled significant alterations in gut microbiota and their metabolites in various neurological disorders. This review provides a thorough analysis of the role of microbiome-gut-brain axis in neurodegenerative disease pathology, linking it to reduced age-associated proteostasis. We discuss evidences that substantiate the existence of a gut-brain cross talk ranging from early clinical accounts of James Parkinson to Braak's hypothesis. In addition to understanding of microbes, the review particularly entails specific metabolites which are altered in neurodegenerative diseases. The regulatory effects of microbial metabolites on protein clearance mechanisms, proposing their potential therapeutic implications, are also discussed. By integrating this information, we advocate for a combinatory therapeutic strategy that targets early intervention, aiming to restore proteostasis and ameliorate disease progression. This approach not only provides a new perspective on the pathogenesis of neurodegenerative diseases but also highlights innovative strategies to combat the increasing burden of these age-related disorders.

Microglia and gut microbiota: A double-edged sword in Alzheimer's disease.

The strong association between gut microbiota (GM) and brain functions such as mood, behaviour, and cognition has been well documented. Gut-brain axis is a unique bidirectional communication system between the gut and brain, in which gut microbes play essential role in maintaining various molecular and cellular processes. GM interacts with the brain through various pathways and processes including, metabolites, vagus nerve, HPA axis, endocrine system, and immune system to maintain brain homeostasis. GM dysbiosis, or an imbalance in GM, is associated with several neurological disorders, including anxiety, depression, and Alzheimer's disease (AD). Conversely, AD is sustained by microglia-mediated neuroinflammation and neurodegeneration. Further, GM and their products also affect microglia-mediated neuroinflammation and neurodegeneration. Despite the evidence connecting GM dysbiosis and AD progression, the involvement of GM in modulating microglia-mediated neuroinflammation in AD remains elusive. Importantly, deciphering the mechanism/s by which GM regulates microglia-dependent neuroinflammation may be helpful in devising potential therapeutic strategies to mitigate AD. Herein, we review the current evidence regarding the involvement of GM dysbiosis in microglia activation and neuroinflammation in AD. We also discuss the possible mechanisms through which GM influences the functioning of microglia and its implications for therapeutic intervention. Further, we explore the potential of microbiota-targeted interventions, such as prebiotics, probiotics, faecal microbiota transplantation, etc., as a novel therapeutic strategy to mitigate neuroinflammation and AD progression. By understanding and exploring the gut-brain axis, we aspire to revolutionize the treatment of neurodegenerative disorders, many of which share a common theme of microglia-mediated neuroinflammation and neurodegeneration.

Oral Administration of a Specific p300/CBP Lysine Acetyltransferase Activator Induces Synaptic Plasticity and Repairs Spinal Cord Injury.

TTK21 is a small-molecule activator of p300/creb binding protein (CBP) acetyltransferase activity, which, upon conjugation with a glucose-derived carbon nanosphere (CSP), can efficiently cross the blood-brain barrier and activate histone acetylation in the brain. Its role in adult neurogenesis and retention of long-term spatial memory following intraperitoneal (IP) administration is well established. In this study, we successfully demonstrate that CSP-TTK21 can be effectively administered via oral gavage. Using a combination of molecular biology, microscopy, and electrophysiological techniques, we systematically investigate the comparative efficacy of oral administration of CSP and CSP-TTK21 in wild-type mice and evaluate their functional effects in comparison to intraperitoneal (IP) administration. Our findings indicate that CSP-TTK21, when administered orally, induces long-term potentiation in the hippocampus without significantly altering basal synaptic transmission, a response comparable to that achieved through IP injection. Remarkably, in a spinal cord injury model, oral administration of CSP-TTK21 exhibits efficacy equivalent to that of IP administration. Furthermore, our research demonstrates that oral delivery of CSP-TTK21 leads to improvements in motor function, histone acetylation dynamics, and increased expression of regeneration-associated genes (RAGs) in a spinal injury rat model, mirroring the effectiveness of IP administration. Importantly, no toxic and mutagenic effects of CSP-TTK21 are observed at a maximum tolerated dose of 1 g/kg in Sprague-Dawley (SD) rats via the oral route. Collectively, these results underscore the potential utility of CSP as an oral drug delivery system, particularly for targeting the neural system.

Amyloid Mimicking Assemblies Formed by Glutamine, Glutamic Acid, and Aspartic Acid.

The aggregation of amino acids into amyloid-like structures is a critical phenomenon for understanding the pathophysiology of various diseases, including inborn errors of metabolism (IEMs) associated with amino acid imbalances. Previous studies have primarily focused on self-assembly of aromatic amino acids, leading to a limited understanding of nonaromatic, polar amino acids in this context. To bridge this gap, our study investigates the self-assembly and aggregation behavior of specific nonaromatic charged and uncharged polar amino acids l-glutamine (Gln), l-aspartic acid (Asp), and l-glutamic acid (Glu), which have not been reported widely in the context of amyloid aggregation. Upon aging these amino acids under controlled conditions, we observed the formation of uniform, distinct aggregates, with Gln forming fibrillar gel-like structures and Glu exhibiting fibrous globular morphologies. Computational simulations validated these findings, identifying Gln as the most potent in forming stable aggregates, followed by Glu and Asp. These simulations elucidated the driving forces behind the distinct morphologies and stabilities of the aggregates. Thioflavin T assays were employed to confirm the amyloid-like nature of these aggregates, suggesting their potential cytotoxic impact. To assess toxicity, we performed in vitro studies on neural cell lines and in vivo experiments in Caenorhabditis elegans (C. elegans), which demonstrated measurable cytotoxic effects, corroborated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and heat shock survival assays. Importantly, this study fills a critical gap in our understanding on the role of nonaromatic amino acids in amyloidogenesis and its implications for IEMs. Our findings provide a foundation for future investigations into the mechanisms of diseases associated with amino acid accumulation and offer potential avenues for the development of targeted therapeutic strategies.

Green synthesized silver nanoparticles from Phoenix dactylifera synergistically interact with bioactive extract of Punica granatum against bacterial virulence and biofilm development.

The global rise of antibiotic resistance poses a substantial risk to mankind, underscoring the necessity for alternative antimicrobial options. Developing novel drugs has become challenging in matching the pace at which microbial resistance is evolving. Recently, nanotechnology, coupled with natural compounds, has emerged as a promising solution to combat multidrug-resistant bacteria. In the present study, silver nanoparticles were green-synthesized using aqueous extract of Phoenix dactylifera (variety Ajwa) fruits and characterized by UV-vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) coupled with Energy dispersive X-ray analysis (EDX), Transmission electron microscopy (TEM) and Thermogravimetric-differential thermal analysis (TGA-DTA). The in-vitro synergy of green synthesized P. dactylifera silver nanoparticle (PD-AgNPs) with selected antibiotics and bioactive extract of Punica granatum, i.e., ethyl acetate fraction (PGEF), was investigated using checkerboard assays. The most effective synergistic combination was evaluated against the QS-regulated virulence factors production and biofilm of Pseudomonas aeruginosa PAO1 by spectroscopic assays and electron microscopy. In-vivo anti-infective efficacy was examined in Caenorhabditis elegans N2 worms. PD-AgNPs were characterized as spherical in shape with an average diameter of 28.9 nm. FTIR analysis revealed the presence of functional groups responsible for the decrease and stabilization of PD-AgNPs. The signals produced by TGA-DTA analysis indicated the generation of thermally stable and pure crystallite AgNPs. Key phytocompounds detected in bioactive fractions include gulonic acid, dihydrocaffeic acid 3-O-glucuronide, and various fatty acids. The MIC of PD-AgNPs and PGEF ranged from 32 to 128 µg/mL and 250-500 µg/mL, respectively, against test bacterial strains. In-vitro, PD-AgNPs showed additive interaction with selected antibiotics (FICI 0.625-0.75) and synergy with PGEF (FICI 0.25-0.375). This combination inhibited virulence factors by up to 75 % and biofilm formation by 84.87 % in P. aeruginosa PAO1. Infected C. elegans worms with P. aeruginosa PAO1 had a 92.55 % survival rate when treated with PD-AgNPs and PGEF. The combination also reduced the reactive oxygen species (ROS) level in C. elegans N2 compared to the untreated control. Overall, these findings highlight that biosynthesized PD-AgNPs and bioactive P. granatum extract may be used as a potential therapeutic formulation against MDR bacteria.

Functional implications of NHR-210 enrichment in C. elegans cephalic sheath glia: insights into metabolic and mitochondrial disruptions in Parkinson's disease models.

Glial cells constitute nearly half of the mammalian nervous system's cellular composition. The glia in C. elegans perform majority of tasks comparable to those conducted by their mammalian equivalents. The cephalic sheath (CEPsh) glia, which are known to be the counterparts of mammalian astrocytes, are enriched with two nuclear hormone receptors (NHRs)-NHR-210 and NHR-231. This unique enrichment makes the CEPsh glia and these NHRs intriguing subjects of study concerning neuronal health. We endeavored to assess the role of these NHRs in neurodegenerative diseases and related functional processes, using transgenic C. elegans expressing human alpha-synuclein. We employed RNAi-mediated silencing, followed by behavioural, functional, and metabolic profiling in relation to suppression of NHR-210 and 231. Our findings revealed that depleting nhr-210 changes dopamine-associated behaviour and mitochondrial function in human alpha synuclein-expressing strains NL5901 and UA44, through a putative target, pgp-9, a transmembrane transporter. Considering the alteration in mitochondrial function and the involvement of a transmembrane transporter, we performed metabolomics study via HR-MAS NMR spectroscopy. Remarkably, substantial modifications in ATP, betaine, lactate, and glycine levels were seen upon the absence of nhr-210. We also detected considerable changes in metabolic pathways such as phenylalanine, tyrosine, and tryptophan biosynthesis metabolism; glycine, serine, and threonine metabolism; as well as glyoxalate and dicarboxylate metabolism. In conclusion, the deficiency of the nuclear hormone receptor nhr-210 in alpha-synuclein expressing strain of C. elegans, results in altered mitochondrial function, coupled with alterations in vital metabolite levels. These findings underline the functional and physiological importance of nhr-210 enrichment in CEPsh glia.

Amyloidogenic Propensity of Metabolites in the Uric Acid Pathway and Urea Cycle Critically Impacts the Etiology of Metabolic Disorders.

Novel insights into the etiology of metabolic disorders have recently been uncovered through the study of metabolite amyloids. In particular, inborn errors of metabolism (IEMs), including gout, Lesch-Nyhan syndrome (LNS), xanthinuria, citrullinemia, and hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome, are attributed to the dysfunction of the urea cycle and uric acid pathway. In this study, we endeavored to understand and mechanistically characterize the aggregative property exhibited by the principal metabolites of the urea cycle and uric acid pathway, specifically hypoxanthine, xanthine, citrulline, and ornithine. Employing scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM), we studied the aggregation profiles of the metabolites. Insights obtained through molecular dynamics (MD) simulation underscore the vital roles of π-π stacking and hydrogen bonding interactions in the self-assembly process, and thioflavin T (ThT) assays further corroborate the amyloid nature of these metabolites. The in vitro MTT assay revealed the cytotoxic trait of these assemblies, a finding that was substantiated by in vivo assays employing the Caenorhabditis elegans (C. elegans) model, which revealed that the toxic effects were more pronounced and dose-specific in the case of metabolites that had aged via longer preincubation. We hence report a compelling phenomenon wherein these metabolites not only aggregate but transform into a soft, ordered assembly over time, eventually crystallizing upon extended incubation, leading to pathological implications. Our study suggests that the amyloidogenic nature of the involved metabolites could be a common etiological link in IEMs, potentially providing a unified perspective to study their pathophysiology, thus offering exciting insights into the development of targeted interventions for these metabolic disorders.

Strategies for gaseous neuromodulator release in chemical neuroscience: Experimental approaches and translational validation.

Gasotransmitters are a group of short-lived gaseous signaling molecules displaying diverse biological functions depending upon their localized concentration. Nitric oxide (NO), hydrogen sulfide (H2S), and carbon monoxide (CO) are three important examples of endogenously produced gasotransmitters that play a crucial role in human neurophysiology and pathogenesis. Alterations in their optimal physiological concentrations can lead to various severe pathophysiological consequences, including neurological disorders. Exogenous administration of gasotransmitters has emerged as a prominent therapeutic approach for treating such neurological diseases. However, their gaseous nature and short half-life limit their therapeutic delivery. Therefore, developing synthetic gasotransmitter-releasing strategies having control over the release and duration of these gaseous molecules has become imperative. However, the complex chemistry of synthesis and the challenges of specific quantified delivery of these gases, make their therapeutic application a challenging task. This review article provides a focused overview of emerging strategies for delivering gasotransmitters in a controlled and sustained manner to re-establish neurophysiological homeostasis.

Efflux Pump Inhibition-Based Screening and Anti-Infective Evaluation of Punica granatum Against Bacterial Pathogens.

Drug efflux pumps contribute to bacterial multidrug resistance (MDR), reducing antibiotic effectiveness and causing treatment failures. Besides their role in MDR, efflux pumps also assist in the transportation of quorum sensing (QS) signal molecules and increased the tolerance of biofilms. Recently, the search for efflux pump inhibitors from natural sources, including anti-infective plants, has gained attention as a potential therapy against drug-resistant bacteria. In this study, 19 traditional Indian medicinal plants were screened for their efflux pump inhibitory activity against Escherichia coli TGI. The promising extract, i.e., Punica granatum was subsequently fractioned in the solvents of increasing polarity. Among them, at sub-MIC active EPI fraction was PGEF (P. granatum ethyl acetate fraction), further investigated for anti-infective potential against Chromobacterium violaceum 12,472, Pseudomonas aeruginosa PAO1, and Serratia marcescens MTCC 97. PGEF was also evaluated for in vivo efficacy in Caenorhabditis elegans model. Major phytocompounds were analyzed by mass spectroscopic techniques. At respective Sub-MIC, PGEF reduced violacein production by 71.14% in C. violaceum 12,472. Moreover, PGEF inhibited pyocyanin (64.72%), pyoverdine (48.17%), protease (51.35%), and swarming motility (44.82%) of P. aeruginosa PAO1. Furthermore, PGEF reduced the production of prodigiosin and exoprotease by 64.73% and 61.80%, respectively. Similarly, at sub-MIC, PGEF inhibited (≥ 50%) biofilm development in all test pathogens. The key phytocompounds detected in active fraction include 5-hydroxymethylfurfural, trans-p-coumaric acid 4- glucoside, (-)-Epicatechin 3'-O-glucuronide, and ellagic acid. Interestingly, PGEF also demonstrated anti-infective efficacy against the PAO1-infected C. elegans test model and highlighting its therapeutic potential as an anti-infective agent to combat drug-resistant problems.

Modulation of Neurotransmitter Pathways and Associated Metabolites by Systemic Silencing of Gut Genes in C. elegans.

The gut is now recognized as the "second brain" of the human body due to its integral role in neuronal health and functioning. Although we know that the gut communicates with the brain via immunological factors, microbial metabolites, and neurotransmitters, the interplay of these systems remains poorly understood. To investigate this interplay, we silenced 48 genes that are exclusively or primarily expressed in the C. elegans intestine. We studied the associated effects on various aspects of neurodegeneration, including proteotoxicity induced by α-Syn expression. We also assayed behaviours, such as mobility and cognition, that are governed by various neurotransmitters. We identified nine gut genes that significantly modulated these events. We further performed HR-MAS NMR-based metabolomics to recognize the metabolic variability induced by the respective RNAi conditions of R07E3.1, C14A6.1, K09D9.2, ZK593.2, F41H10.8, M02D8.4, M88.1, C03G6.15 and T01D3.6. We found that key metabolites such as phenylalanine, tyrosine, inosine, and glutamine showed significant variation among the groups. Gut genes that demonstrated neuroprotective effects (R07E3.1, C14A6.1, K09D9.2, and ZK593.2) showed elevated levels of inosine, phenylalanine, and tyrosine; whereas, genes that aggravated neurotransmitter levels demonstrated decreased levels of the same metabolites. Our results shed light on the intricate roles of gut genes in the context of neurodegeneration and suggest a new perspective on the reciprocal interrelation of gut genes, neurotransmitters, and associated metabolites. Further studies are needed to decipher the intricate roles of these genes in context of neurodegeneration in greater detail.

CLUH functions as a negative regulator of inflammation in human macrophages and determines ulcerative colitis pathogenesis.

Altered mitochondrial function without a well-defined cause has been documented in patients with ulcerative colitis (UC). In our efforts to understand UC pathogenesis, we observed reduced expression of clustered mitochondrial homolog (CLUH) only in the active UC tissues compared with the unaffected areas from the same patient and healthy controls. Stimulation with bacterial Toll-like receptor (TLR) ligands similarly reduced CLUH expression in human primary macrophages. Further, CLUH negatively regulated secretion of proinflammatory cytokines IL-6 and TNF-α and rendered a proinflammatory niche in TLR ligand-stimulated macrophages. CLUH was further found to bind to mitochondrial fission protein dynamin related protein 1 (DRP1) and regulated DRP1 transcription in human macrophages. In the TLR ligand-stimulated macrophages, absence of CLUH led to enhanced DRP1 availability for mitochondrial fission, and a smaller dysfunctional mitochondrial pool was observed. Mechanistically, this fissioned mitochondrial pool in turn enhanced mitochondrial ROS production and reduced mitophagy and lysosomal function in CLUH-knockout macrophages. Remarkably, our studies in the mouse model of colitis with CLUH knockdown displayed exacerbated disease pathology. Taken together, this is the first report to our knowledge explaining the role of CLUH in UC pathogenesis, by means of regulating inflammation via maintaining mitochondrial-lysosomal functions in the human macrophages and intestinal mucosa.

The Emerging Landscape of Natural Small-molecule Therapeutics for Huntington's Disease.

Huntington's disease (HD) is a rare and fatal neurodegenerative disorder with no diseasemodifying therapeutics. HD is characterized by extensive neuronal loss and is caused by the inherited expansion of the huntingtin (HTT) gene that encodes a toxic mutant HTT (mHTT) protein having expanded polyglutamine (polyQ) residues. Current HD therapeutics only offer symptomatic relief. In fact, Food and Drug Administration (FDA) approved two synthetic small-molecule VMAT2 inhibitors, tetrabenazine (1) and deutetrabenazine (2), for managing HD chorea and various other diseases in clinical trials. Therefore, the landscape of drug discovery programs for HD is evolving to discover disease- modifying HD therapeutics. Likewise, numerous natural products are being evaluated at different stages of clinical development and have shown the potential to ameliorate HD pathology. The inherent anti-inflammatory and antioxidant properties of natural products mitigate the mHTT-induced oxidative stress and neuroinflammation, improve mitochondrial functions, and augment the anti-apoptotic and pro-autophagic mechanisms for increased survival of neurons in HD. In this review, we have discussed HD pathogenesis and summarized the anti-HD clinical and pre-clinical natural products, focusing on their therapeutic effects and neuroprotective mechanism/s.

Delineating the Spectrum of Genetic Variants Associated with Bardet-Biedl Syndrome in Consanguineous Pakistani Pedigrees.

This study aimed to find the molecular basis of Bardet-Biedl syndrome (BBS) in Pakistani consanguineous families. A total of 12 affected families were enrolled. Clinical investigations were performed to access the BBS-associated phenotypes. Whole exome sequencing was conducted on one affected individual from each family. The computational functional analysis predicted the variants' pathogenic effects and modeled the mutated proteins. Whole-exome sequencing revealed 9 pathogenic variants in six genes associated with BBS in 12 families. The BBS6/MKS was the most common BBS causative gene identified in five families (5/12, 41.6%), with one novel (c.1226G>A, p.Gly409Glu) and two reported variants. c.774G>A, Thr259LeuTer21 was the most frequent BBS6/MMKS allele in three families 3/5 (60%). Two variants, c.223C>T, p.Arg75Ter and a novel, c. 252delA, p.Lys85STer39 were detected in the BBS9 gene. A novel 8bp deletion c.387_394delAAATAAAA, p. Asn130GlyfsTer3 was found in BBS3 gene. Three known variants were detected in the BBS1, BBS2, and BBS7 genes. Identification of novel likely pathogenic variants in three genes reaffirms the allelic and genetic heterogeneity of BBS in Pakistani patients. The clinical differences among patients carrying the same pathogenic variant may be due to other factors influencing the phenotype, including variants in other modifier genes.

Multiple Actions of H2S-Releasing Peptides in Human ß-Amyloid Expressing C. elegans.

Alzheimer's disease (AD) is a debilitating progressive neurodegenerative disorder characterized by the loss of cognitive function. A major challenge in treating this ailment fully is its multifactorial nature, as it is associated with effects like deposition of Aß plaques, oxidative distress, inflammation of neuronal cells, and low levels of the neurotransmitter acetylcholine (ACh). In the present work, we demonstrate the design, synthesis, and biological activity of peptide conjugates by coupling a H2S-releasing moiety to the peptides known for their Aß antiaggregating properties. These conjugates release H2S in a slow and sustained manner, due to the formation of self-assembled structures and delivered a significant amount of H2S within Caenorhabditis elegans. These conjugates are shown to target multiple factors responsible for the progression of AD: notably, we observed reduction in oxidative distress, inhibition of Aß aggregation, and significantly increased ACh levels in the C. elegans model expressing human Aß.

Butyrylation Meets Adipogenesis-Probed by a p300-Catalyzed Acylation-Specific Small Molecule Inhibitor: Implication in Anti-obesity Therapy.

The enzyme p300, besides having acetyltransferase activity, can also catalyze other acylation modifications, whose physiological implications are still being investigated. Here, we report that the level of histone butyrylation increases globally as well as locally in the promoters of pro-adipogenic genes during adipogenesis. To delineate the role of p300-catalyzed butyrylation from acetylation in adipogenesis, we identified a semisynthetic derivative (LTK-14A) of garcinol, which specifically inhibited histone butyrylation without affecting acetylation. Treatment of 3T3L1 cells with LTK-14A abolished adipogenesis with downregulation of pro-adipogenic genes along with inhibition of H4K5 butyrylation. Administering LTK-14A to high-fat diet-fed and genetically obese db/db mice led to attenuation/decrease in their weight gain. The reduced obesity could be partially attributed to the inhibition of H4K5 butyrylation in adipocytes and liver. This report therefore not only, for the first time, causally links histone butyrylation with adipogenesis but also presents a probable candidate for anti-obesity therapeutics.

Multiple checkpoints of protein clearance machinery are modulated by a common microRNA, miR-4813-3p, through its putative target genes: Studies employing transgenic C. elegans model.

In order to maintain cellular homeostasis and a healthy state, aberrant and aggregated proteins are to be recognized and rapidly cleared from cells. Parkinson's disease, known to be associated with multiple factors; presents with impaired clearance of aggregated alpha synuclein as a key factor. We endeavored to study microRNA molecules with potential role on regulating multiple checkpoints of protein quality control within cells. Carrying out global miRNA profiling in a transgenic C. elegans model that expresses human alpha synuclein, we identified novel miRNA, miR-4813-3p, as a significantly downregulated molecule. Further studying its putative downstream target genes, we were able to mechanistically characterize six genes gbf-1, vha-5, cup-5, cpd-2, acs-1 and C27A12.7, which relate to endpoints associated with alpha synuclein expression, oxidative stress, locomotory behavior, autophagy and apoptotic pathways. Our study reveals the novel role of miR-4813-3p and provides potential functional characterization of its putative target genes, in regulating the various pathways associated with PQC network. miR-4813-3p modulates ERUPR, MTUPR, autophagosome-lysosomal-pathway and the ubiquitin-proteasomal-system, making this molecule an interesting target for further studies towards therapeutically addressing multifactorial aspect of Parkinson's disease.

Food-Grade Quercetin-Loaded Nanoemulsion Ameliorates Effects Associated with Parkinson's Disease and Cancer: Studies Employing a Transgenic C. elegans Model and Human Cancer Cell Lines.

A nanosized food-grade quercetin-loaded nanoemulsion (QNE) system comprising capmul MCM NF (oil) and cremophor RH 40 (surfactant) was developed using a high-speed homogenization technique. The developed QNE was studied for its significant neuroprotective (anti-Parkinsonism) and cytotoxicity (anticancer) effects against Caenorhabditis elegans (C. elegans) strains and human cancer cells, respectively. HR-TEM studies revealed that the QNE was spherical with a mean globule size of ~50 nm. Selected area electron diffraction (SAED) studies results demonstrated that QNE was amorphous. In vivo results show that QNE potentially reduced the α-Syn aggregation, increased mitochondrial and fat content, and improved the lifespan in transgenic C. elegans strain NL5901. QNE significantly downregulated the reactive oxygen species (ROS) levels in wild-type C. elegans strain N2. In vitro results of the MTT assay show that QNE significantly exhibited chemotherapeutic effects in all treated human cancer cells in an order of cytotoxicity: HeLa cells > A549 cells > MIA PaCa-2 cells, based on the IC50 values at 24 h. Conclusively, the QNE showed improved solubility, targetability, and neuroprotective effects against the PD-induced C. elegans model, and also cytotoxicity against human cancer cells and could be potentially used as an anti-Parkinson's or anticancer agent.

Crosstalk Between ROS and Autophagy in Tumorigenesis: Understanding the Multifaceted Paradox.

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.

Genetic modulators associated with regulatory surveillance of mitochondrial quality control, play a key role in regulating stress pathways and longevity in C. elegans.

The multi-factorial Parkinson's disease (PD) is known to be associated with mitochondrial dysfunction, endoplasmic reticulum stress, alpha synuclein aggregation and dopaminergic neuronal death, with oxidative stress being a common denominator to these underlying processes. The perception of mitochondria being 'just ATP producing compartments' have been counterpoised as studies, particularly related to PD, have underlined their strong role in cause and progression of the disease. During PD pathogenesis, neurons encounter chronic stress conditions mainly due to failure of Mitochondrial Quality Control (MQC) machinery. To dissect the regulatory understanding of mitochondrial dysfunction during neurological disease progression, we endeavored to identify key regulatory endpoints that control multiple facets of MQC machinery. Our studies, employing transgenic C. elegans strain expressing human α-synuclein, led us to identification of mitochondrial genes nuo-5 (involved in oxidative phosphorylation), F25B4.7 (exhibits ATP transmembrane transporter activity) and C05D11.9 (having ribonuclease activity), which form predicted downstream targets of most elevated and down-regulated mi-RNA molecules. RNAi mediated silencing, gene ontology and functional genomics analysis studies demonstrated their role in modulating major MQC pathways. The attenuated MQC pathways mainly affected clearance of misfolded and aggregated proteins, redox homeostasis and longevity with compromised dopaminergic functions. Overexpression of the mitochondrial genes by 3 beta-hydroxyl steroid, Tomatidine, was found to curtail the redox imbalance thus leading to amelioration of effects associated with PD and an increase in the lifespan of treated nematodes. Therefore, this study unveils the regulatory role of mitochondrial genes as critical modulators of stress control involved in effects associated with PD pathogenesis.