Cellular Stress Markers Research Articles

Effect of Tricin on cardiomyocyte damage caused by diabetic cardiomyopathy (DCM)

ObjectivesFlavonoid compounds exhibit remarkable antioxidant and anti-inflammatory properties in DCM and various other diseases. However, the specific mechanisms by which Tricin, 4’,5,7-trihydroxy-3‘,5’-dimethoxyflavone, exerts its effects in the context of DCM remain to be elucidated.MethodsRat H9C2 cells were cultured and subjected to high glucose conditions to establish a DCM cell model. Tricin was administered in varying concentrations to evaluate its effects on cellular oxidative stress markers, including ROS, LDH, and SOD. Additionally, the levels of inflammatory cytokines TNF-α, IL-1β, and IL-6, as well as the expression of TLR4, MYD88, and p-NF-κB, were assessed through ELISA and Western blotting.ResultsTricin treatment significantly ameliorated high glucose-induced oxidative stress in H9C2 cells, evidenced by reduced ROS and LDH levels and increased SOD levels in a dose-dependent manner. Furthermore, Tricin effectively suppressed the elevation of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6. Tricin also inhibited the overactivation of the TLR4-MYD88-NF-κB signaling pathway, suggesting its role in modulating key inflammatory processes in DCM.ConclusionsTricin exhibits a protective role against high glucose-induced cardiac damage in a DCM cell model. By reducing oxidative stress and inflammation, and inhibiting the TLR4-MYD88-NF-κB pathway, Tricin shows significant therapeutic potential for DCM treatment. This study underscores the value of Tricin as a novel therapeutic approach for managing diabetic cardiomyopathy, warranting further research and clinical investigation.Clinical trial numberNot applicable.

Efficacy of anesthetics in an echinoderm based on multifaceted stress biomarkers

Animal care committees remain ambiguous on the need for anesthetics during experimental procedures on invertebrate taxa due to long-standing questioning of their sentience and pain perception. When used, anesthetizing procedures for invertebrates have commonly been adapted from those developed for vertebrates, under the largely unverified assumption that they afford the same benefits. The present study formally tested the efficacy of four common anesthetics of aquatic invertebrates (ethanol, MgCl2, clove oil, MS-222) using behavioural (reaction to physical contact and presence of a predator), physiological (respiration rate), cellular (coelomocytes), and hormonal (cortisol) biomarkers in the holothuroid Cucumaria frondosa (Echinodermata). While subjects recovered from exposures to all anesthetics tested, their responses differed markedly. Ethanol did not immobilize the individuals and concurrently increased their respiration rate, and cellular and hormonal stress markers. MgCl2 and clove oil reduced the behavioural and physiological responses, and decreased the cellular markers, but increased the cortisol levels. Only MS-222 fully immobilized the treated individuals and decreased their respiration rate, both during exposure and throughout ulterior interactions with a predator, while keeping coelomocyte counts and cortisol concentrations at baseline levels. MS-222 thus appears to induce the loss of sensation, representing a promising anesthetic and sedative in soft-bodied aquatic invertebrates.

Telomere length and mitochondrial DNA copy number in association with trauma-focused psychotherapy efficacy

Early life adversities (ELA) have been linked to a greater risk for major depressive disorder (MDD) and treatment-resistant depression (TRD). The molecular mechanisms underlying the link between ELA and MDD and/or TRD are yet unknown. It has been suggested that ELA induces an allostatic burden, which in turn promotes oxidative stress and an inflammatory response that are further intensified by the influence of maladaptive coping behaviour. In this study we explored the role of two markers of cellular aging and oxidative stress (leukocyte telomere length (LTL) and mitochondrial DNA copy number (mtDNAcn)) in TRD and in response to trauma-focused psychotherapies. The study comprised 30 TRD patients receiving trauma-focused psychotherapies and 65 healthy controls. LTL and mtDNAcn were measured at baseline and four weeks after the end of the psychotherapy sessions. Response was defined based on reduction in the Montgomery-Åsberg Depression Rating Scale (MADRS). In the case control analysis, the logistic regression model showed that mtDNAcn but not LTL was a significant predictor of diagnosis (chi-square 92.108, p = 7.72e-20; contribution of mtDNAcn, B = −9-297, p = 0.00009). In the TRD sample, LTL and mtDNAcn were inversely correlated with MADRS score at baseline (LTL, Pearson's r = −0.478, p = 0.008; mtDNAcn, Pearson's r = −0.656, p = 0.00008), but there was no difference in either LTL or mtDNAcn between responders and non-responders. In conclusion, our findings support an involvement of cellular aging in TRD, and suggest that LTL and mtDNAcn are not predictors or mediators of response to trauma-focused psychotherapies.

Patient-derived colon epithelial organoids reveal lipid-related metabolic dysfunction in pediatric ulcerative colitis.

Ulcerative colitis (UC) is associated with epithelial metabolic derangements which exacerbate gut inflammation. Patient-derived organoids recapitulate complexities of the parent tissue in health and disease; however, whether colon organoids (colonoids) model metabolic impairments in the pediatric UC epithelium is unclear. This study determined the functional metabolic differences in the colon epithelia using epithelial colonoids from pediatric patients. We developed biopsy-derived colonoids from pediatric patients with endoscopically active UC, inactive UC, and those without endoscopic or histologic evidence of colon inflammation (non-IBD controls). We extensively interrogated metabolic dysregulation through extracellular flux analyses and tested potential therapies that recapitulate or ameliorate such metabolic dysfunction. Epithelial colonoids from active UC patients exhibit elevated oxygen consumption and proton leak supported by enhanced glycolytic capacity and dysregulated lipid metabolism. The hypermetabolic features in active UC colonoids were associated with increased cellular stress and chemokine secretion, specifically during differentiation. Transcriptomic and pathway analyses indicated a role for PPAR-α in lipid-induced hypermetabolism in active UC colonoids, which was validated by PPAR-α activation in non-IBD colonoids. Accordingly, limiting neutral lipid accumulation in active UC colonoids through pharmacological inhibition of PPAR-α induced a metabolic shift towards glucose consumption, suppressed hypermetabolism and chemokine secretion, and improved cellular stress markers. Control and inactive UC colonoids had similar metabolic and transcriptomic profiles. Our pediatric colonoids revealed significant lipid-related metabolic dysregulation in the pediatric UC epithelium that may be alleviated by PPAR-α inhibition. This study supports the advancement of colonoids as a preclinical human model for testing epithelial-directed therapies against such metabolic dysfunction. Background and Context: Colon mucosa healing in pediatric UC requires reinstating normal epithelial function but a lack of human preclinical models of the diseased epithelium hinders the development of epithelial-directed interventions. Using colon biopsy-derived epithelial organoids, samples from pediatric patients with active UC show hyperactive metabolic function largely driven by enhanced lipid metabolism. Pharmacologic inhibition of lipid metabolism alleviates metabolic dysfunction, cellular stress, and chemokine production. Though our epithelial colon organoids from active UC patients show targetable metabolic and molecular features from non-IBD controls, they were cultured under sterile conditions, which may not fully capture any potential real-time contributions of the complex inflammatory milieu typically present in the disease. Current therapies for pediatric UC mainly target the immune system despite the need for epithelial healing to sustain remission. We identified a pharmacologic target that regulates epithelial metabolism and can be developed for epithelial-directed therapy in UC.Basic Research Relevance: Pediatric UC patient tissue adult stem cell-derived colon epithelial organoids retain disease-associated metabolic pathology and can serve as preclinical human models of disease. Excess reliance on lipids as an energy source leads to oxidative and inflammatory dysfunction in pediatric UC colon organoids. Preprint: This manuscript is currently on bioRxiv. doi: https://doi.org/10.1101/2024.08.22.609271 Lay Summary: Using patient tissue-derived colon epithelial organoids, the investigators identified epithelial metabolic dysfunction and inflammation in pediatric ulcerative colitis that can be alleviated by PPAR-a inhibition.

Mutations in fibronectin dysregulate chondrogenesis in skeletal dysplasia.

Fibronectin (FN) is an extracellular matrix glycoprotein essential for the development and function of major vertebrate organ systems. Mutations in FN result in an autosomal dominant skeletal dysplasia termed corner fracture-type spondylometaphyseal dysplasia (SMDCF). The precise pathomechanisms through which mutant FN induces impaired skeletal development remain elusive. Here, we have generated patient-derived induced pluripotent stem cells as a cell culture model for SMDCF to investigate the consequences of FN mutations on mesenchymal stem cells (MSCs) and their differentiation into cartilage-producing chondrocytes. In line with our previous data, FN mutations disrupted protein secretion from MSCs, causing a notable increase in intracellular FN and a significant decrease in extracellular FN levels. Analyses of plasma samples from SMDCF patients also showed reduced FN in circulation. FN and endoplasmic reticulum (ER) protein folding chaperones (BIP, HSP47) accumulated in MSCs within ribosome-covered cytosolic vesicles that emerged from the ER. Massive amounts of these vesicles were not cleared from the cytosol, and a smaller subset showed the presence of lysosomal markers. The accumulation of intracellular FN and ER proteins elevated cellular stress markers and altered mitochondrial structure. Bulk RNA sequencing revealed a specific transcriptomic dysregulation of the patient-derived cells relative to controls. Analysis of MSC differentiation into chondrocytes showed impaired mesenchymal condensation, reduced chondrogenic markers, and compromised cell proliferation in mutant cells. Moreover, FN mutant cells exhibited significantly lower transforming growth factor beta-1 (TGFβ1) expression, crucial for mesenchymal condensation. Exogenous FN or TGFβ1 supplementation effectively improved the MSC condensation and promoted chondrogenesis in FN mutant cells. These findings demonstrate the cellular consequences of FN mutations in SMDCF and explain the molecular pathways involved in the associated altered chondrogenesis.

T-Cell Senescence in Human Metabolic Diseases.

Immunosenescence denotes a state of dysregulated immune cell function characterized by a confluence of factors, including arrested cell cycle, telomere shortening, markers of cellular stress, mitochondrial dysfunction, loss of proteostasis, epigenetic reprogramming, and secretion of proinflammatory mediators. This state primarily manifests during the aging process but can also be induced in various pathological conditions, encompassing chronic viral infections, autoimmune diseases, and metabolic disorders. Age-associated immune system alterations extend to innate and adaptive immune cells, with T-cells exhibiting heightened susceptibility to immunosenescence. In particular, senescent T-cells have been identified in the context of metabolic disorders such as obesity, diabetes, and cardiovascular diseases. Recent investigations suggest a direct link between T-cell senescence, inflammation, and insulin resistance. The perturbation of biological homeostasis by senescent T-cells appears intricately linked to the initiation and progression of metabolic diseases, particularly through inflammation-mediated insulin resistance. Consequently, senescent T-cells are emerging as a noteworthy therapeutic target. This review aims to elucidate the intricate relationship between metabolic diseases and T-cell senescence, providing insights into the potential roles of senescent T-cells in the pathogenesis of metabolic disorders. Through a comprehensive examination of current research findings, this review seeks to contribute to a deeper understanding of the complex interplay between immunosenescence and metabolic health.

Tau-mediated coupling between Pol III synthesis and DnaB helicase unwinding helps maintain genomic stability

The τ-subunit of the clamp loader complex (CLC) physically interacts with both the DnaB helicase and the polymerase III (Pol III) core α-subunit through Domains IV and V, respectively. This interaction is proposed to help maintain rapid and efficient DNA synthesis rates with high genomic fidelity and plasticity, facilitating enzymatic coupling within the replisome. To test this hypothesis, CRISPR-Cas9 editing was used to create site-directed genomic mutations within the dnaX gene at the C-terminus of τ predicted to interact with the α-subunit of Pol III. Perturbation of the α-τ binding interaction in vivo resulted in cellular and genomic stress markers that included reduced growth rates, fitness, and viabilities. Specifically, dnaX:mut strains showed increased cell filamentation, mutagenesis frequencies, and activated SOS. In situ fluorescence flow cytometry and microscopy quantified large increases in the amount of single-stranded DNA (ssDNA) gaps present. Removal of the C-terminus of τ (I618X) still maintained its interactions with DnaB and stimulated unwinding but lost its interaction with Pol III, resulting in significantly reduced rolling circle DNA synthesis. Intriguingly, dnaX:L635P/D636G had the largest induction of SOS, high mutagenesis, and the most prominent ssDNA gaps, which can be explained by an impaired ability to regulate the unwinding speed of DnaB resulting in a faster rate of in vitro rolling circle DNA replication, inducing replisome decoupling. Therefore, τ stimulated DnaB unwinding and physical coupling with Pol III acts to enforce replisome plasticity to maintain an efficient rate of synthesis and prevent genomic instability.

Investigating the Hepatoprotective Properties of Mulberry Leaf Flavonoids against Oxidative Stress in HepG2 Cells.

Oxidative stress significantly contributes to ageing and disease, with antioxidants holding promise in mitigating its effects. Functional foods rich in flavonoids offer a potential strategy to mitigate oxidative damage by free radicals. We investigated the protective effects of mulberry leaf flavonoids (MLF) against H2O2-induced oxidative damage in HepG2 cells. It assessed the inhibitory effect of MLF (62.5-500 μg/mL) on H2O2-induced oxidative damage by analyzing cellular morphology and oxidative stress markers, including ROS production, mitochondrial membrane potential, antioxidant enzyme levels, MDA, and apoptosis-related proteins. The results demonstrated that MLF prevented spiny cell formation triggered by 750 μM H2O2 and significantly reduced ROS levels, restored mitochondrial membrane potential, decreased lactate dehydrogenase and alanine transaminase leakage, and reduced MDA content induced by H2O2. MLF also modulated antioxidant enzymes and attenuated oxidative damage to HepG2 cell DNA, as confirmed by staining techniques. These findings indicate the potential of MLF as a hepatoprotective agent against oxidative damage in HepG2 cells.

Volatile Organic Compounds in Cellular Headspace after Hyperbaric Oxygen Exposure: An In Vitro Pilot Study.

Volatile organic compounds (VOCs) might be associated with pulmonary oxygen toxicity (POT). This pilot study aims to identify VOCs linked to oxidative stress employing an in vitro model of alveolar basal epithelial cells exposed to hyperbaric and hyperoxic conditions. In addition, the feasibility of this in vitro model for POT biomarker research was evaluated. The hyperbaric exposure protocol, similar to the U.S. Navy Treatment Table 6, was conducted on human alveolar basal epithelial cells, and the headspace VOCs were analyzed using gas chromatography-mass spectrometry. Three compounds (nonane [p = 0.005], octanal [p = 0.009], and decane [p = 0.018]), of which nonane and decane were also identified in a previous in vivo study with similar hyperbaric exposure, varied significantly between the intervention group which was exposed to 100% oxygen and the control group which was exposed to compressed air. VOC signal intensities were lower in the intervention group, but cellular stress markers (IL8 and LDH) confirmed increased stress and injury in the intervention group. Despite the observed reductions in compound expression, the model holds promise for POT biomarker exploration, emphasizing the need for further investigation into the complex relationship between VOCs and oxidative stress.

Screening mitochondria-related biomarkers in skin and plasma of atopic dermatitis patients by bioinformatics analysis and machine learning.

There is a significant imbalance of mitochondrial activity and oxidative stress (OS) status in patients with atopic dermatitis (AD). This study aims to screen skin and peripheral mitochondria-related biomarkers, providing insights into the underlying mechanisms of mitochondrial dysfunction in AD. Public data were obtained from MitoCarta 3.0 and GEO database. We screened mitochondria-related differentially expressed genes (MitoDEGs) using R language and then performed GO and KEGG pathway analysis on MitoDEGs. PPI and machine learning algorithms were also used to select hub MitoDEGs. Meanwhile, the expression of hub MitoDEGs in clinical samples were verified. Using ROC curve analysis, the diagnostic performance of risk model constructed from these hub MitoDEGs was evaluated in the training and validation sets. Further computer-aided algorithm analyses included gene set enrichment analysis (GSEA), immune infiltration and mitochondrial metabolism, centered on these hub MitoDEGs. We also used real-time PCR and Spearman method to evaluate the relationship between plasma circulating cell-free mitochondrial DNA (ccf-mtDNA) levels and disease severity in AD patients. MitoDEGs in AD were significantly enriched in pathways involved in mitochondrial respiration, mitochondrial metabolism, and mitochondrial membrane transport. Four hub genes (BAX, IDH3A, MRPS6, and GPT2) were selected to take part in the creation of a novel mitochondrial-based risk model for AD prediction. The risk score demonstrated excellent diagnostic performance in both the training cohort (AUC = 1.000) and the validation cohort (AUC = 0.810). Four hub MitoDEGs were also clearly associated with the innate immune cells' infiltration and the molecular modifications of mitochondrial hypermetabolism in AD. We further discovered that AD patients had considerably greater plasma ccf-mtDNA levels than controls (U = 92.0, p< 0.001). Besides, there was a significant relationship between the up-regulation of plasma mtDNA and the severity of AD symptoms. The study highlights BAX, IDH3A, MRPS6 and GPT2 as crucial MitoDEGs and demonstrates their efficiency in identifying AD. Moderate to severe AD is associated with increased markers of mitochondrial damage and cellular stress (ccf=mtDNA). Our study provides data support for the variation in mitochondria-related functional characteristics of AD patients.

A human pluripotent stem cell-derived in vitro model of the blood–brain barrier in cerebral malaria

BackgroundBlood–brain barrier (BBB) disruption is a central feature of cerebral malaria (CM), a severe complication of Plasmodium falciparum (Pf) infections. In CM, sequestration of Pf-infected red blood cells (Pf-iRBCs) to brain endothelial cells combined with inflammation, hemolysis, microvasculature obstruction and endothelial dysfunction mediates BBB disruption, resulting in severe neurologic symptoms including coma and seizures, potentially leading to death or long-term sequelae. In vitro models have advanced our knowledge of CM-mediated BBB disruption, but their physiological relevance remains uncertain. Using human induced pluripotent stem cell-derived brain microvascular endothelial cells (hiPSC-BMECs), we aimed to develop a novel in vitro model of the BBB in CM, exhibiting enhanced barrier properties.MethodshiPSC-BMECs were co-cultured with HB3var03 strain Pf-iRBCs up to 9 h. Barrier integrity was measured using transendothelial electrical resistance (TEER) and sodium fluorescein permeability assays. Localization and expression of tight junction (TJ) proteins (occludin, zonula occludens-1, claudin-5), cellular adhesion molecules (ICAM-1, VCAM-1), and endothelial surface markers (EPCR) were determined using immunofluorescence imaging (IF) and western blotting (WB). Expression of angiogenic and cell stress markers were measured using multiplex proteome profiler arrays.ResultsAfter 6-h of co-culture with Pf-iRBCs, hiPSC-BMECs showed reduced TEER and increased sodium fluorescein permeability compared to co-culture with uninfected RBCs, indicative of a leaky barrier. We observed disruptions in localization of occludin, zonula occludens-1, and claudin-5 by IF, but no change in protein expression by WB in Pf-iRBC co-cultures. Expression of ICAM-1 and VCAM-1 but not EPCR was elevated in hiPSC-BMECs with Pf-iRBC co-culture compared to uninfected RBC co-culture. In addition, there was an increase in expression of angiogenin, platelet factor-4, and phospho-heat shock protein-27 in the Pf-iRBCs co-culture compared to uninfected RBC co-culture.ConclusionThese findings demonstrate the validity of our hiPSC-BMECs based model of the BBB, that displays enhanced barrier integrity and appropriate TJ protein localization. In the hiPSC-BMEC co-culture with Pf-iRBCs, reduced TEER, increased paracellular permeability, changes in TJ protein localization, increase in expression of adhesion molecules, and markers of angiogenesis and cellular stress all point towards a novel model with enhanced barrier properties, suitable for investigating pathogenic mechanisms underlying BBB disruption in CM.

Maternal and Umbilical Cord Heat-Shock Protein 70 Levels in Patients with Gestational Diabetes Mellitus

AIMS: The purpose of this study is to determine if heat shock protein 70 (Hsp-70), a marker of cellular stress, is elevated in maternal serum and umbilical cord in pregnancies complicated by gestational diabetes mellitus (GDM) and to determine whether altered serum Hsp-70 concentrations in umbilical cord are related to serve as an indicator of early term delivery (37 0/7–38 6/7 weeks of gestation) in women with GDM and control group. METHODS: The study included 62 patients with GDM (GDM group) and 22 non-diabetic, healthy women before caesarean section in this case-control study. We analyzed serum levels of Hsp-70 in pregnancies and umbilical cord sera and other biochemical and anthropometric markers, early term delivery in all subjects. RESULTS: Maternal Serum levels of Hsp-70 were significantly higher in patients with GDM than in healthy pregnant women. The umbilical cord levels of Hsp-70 in GDM patients were also increased as compared to healthy pregnant women but missed the commonly acceptable significance level. Cord Hsp-70 levels showed a negatively significant correlation with time of delivery, in women with GDM patients. Cord Hsp-70 levels showed a negatively significant correlation with time of delivery, also in the whole group. CONCLUSIONS: Maternal Hsp-70 was significantly higher in patients with GDM. The obtained results seem to indicate that elevated umbilical cord Hsp-70 values may potentially be used as indicators of risk factor for early term delivery in pregnancies.

Mycobacterium avium paratuberculosis Infection Suppresses Vitamin D Activation and Cathelicidin Production in Macrophages through Modulation of the TLR2-Dependent p38/MAPK-CYP27B1-VDR-CAMP Axis.

Vitamin D plays a vital role in modulating both innate and adaptive immune systems. Therefore, vitamin D deficiency has been associated with higher levels of autoimmune response and increased susceptibility to infections. CYP27B1 encodes a member of the cytochrome P450 superfamily of enzymes. It is instrumental in the conversion of circulating vitamin D (calcifediol) to active vitamin D (calcitriol). This is a crucial step for macrophages to express Cathelicidin Anti-microbial Peptide (CAMP), an anti-bacterial factor released during the immune response. Our recent study indicated that a Crohn's disease (CD)-associated pathogen known as Mycobacterium avium paratuberculosis (MAP) decreases vitamin D activation in macrophages, thereby impeding cathelicidin production and MAP infection clearance. The mechanism by which MAP infection exerts these effects on the vitamin D metabolic axis remains elusive. We used two cell culture models of THP-1 macrophages and Caco-2 monolayers to establish the effects of MAP infection on the vitamin D metabolic axis. We also tested the effects of Calcifediol, Calcitriol, and SB203580 treatments on the relative expression of the vitamin D metabolic genes, oxidative stress biomarkers, and inflammatory cytokines profile. In this study, we found that MAP infection interferes with vitamin D activation inside THP-1 macrophages by reducing levels of CYP27B1 and vitamin D receptor (VDR) gene expression via interaction with the TLR2-dependent p38/MAPK pathway. MAP infection exerts its effects in a time-dependent manner, with the maximal inhibition observed at 24 h post-infection. We also demonstrated the necessity to have toll-like receptor 2 (TLR2) for MAP infection to influence CYP27B1 and CAMP expression, as TLR2 gene knockdown resulted in an average increase of 7.78 ± 0.88 and 13.90 ± 3.5 folds in their expression, respectively. MAP infection also clearly decreased the levels of p38 phosphorylation and showed dependency on the p38/MAPK pathway to influence the expression of CYP27B1, VDR, and CAMP which was evident by the average fold increase of 1.93 ± 0.28, 1.86 ± 0.27, and 6.34 ± 0.51 in their expression, respectively, following p38 antagonism. Finally, we showed that calcitriol treatment and p38/MAPK blockade reduce cellular oxidative stress and inflammatory markers in Caco-2 monolayers following macrophage-mediated MAP infection. This study characterized the primary mechanism by which MAP infection leads to diminished levels of active vitamin D and cathelicidin in CD patients, which may explain the exacerbated vitamin D deficiency state in these cases.

Correlation of SNR Value on DPOAE Examination with HSP70 Levels in Blood and HSP70 Expression in Cochlea of Noise Model Rattus norvegicus as an Indicator of Inner Ear Damage

Background: Cellular stress caused by noise-induced hearing loss can be observed through the damage of cochlear hair cells, mechanically and metabolically. SNR value on the DPOAE examination assesses the sensory function of cochlear outer hair cells. HSP70 as marker of cellular stress can be identified from its levels in blood and its expression in the cochlea.Methods: Three groups of rats were used for the noise intervention: Group 1 was the control group, Group 2 had a noise exposure of 100 dB, and Group 3 received a noise exposure of 110 dB. DPOAE examination was then conducted, blood samples from rats’ tail were collected after a noise treatment, followed by the measurement of HSP70 levels by ELISA readings. Rats were terminated afterwards and immunohistochemical examination of the cochlear organ of Corti was performed to calculate the expression of HSP70. The data obtained were analyzed using SPSS.Results: A decrease occurred in the values of SNR and an increase occurred in HSP70 levels in blood along with its expression in the cochlea of noise model Rattus norvegicus, and there is a correlation between the three.Conclusion: The decrease in SNR values, increase in HSP70 levels in blood, and increase in HSP70 expression in the cochlear organ of Corti of Rattus norvegicus, proves that noise-induced hearing loss triggers the production of HSP70 as a cytoprotective agent in preventing inner ear damage.Keywords: DPOAE; Rattus norvegicus; NIHL; Heat Shock Protein 70

Cryopreservation of cerebrospinal fluid cells preserves the transcriptional landscape for single-cell analysis

Cerebrospinal fluid (CSF) matrix biomarkers have become increasingly valuable surrogate markers of neuropsychiatric diseases in research and clinical practice. In contrast, CSF cells have been rarely investigated due to their relative scarcity and fragility, and lack of common collection and cryopreservation protocols, with limited exceptions for neurooncology and primary immune-based diseases like multiple sclerosis. The advent of a microfluidics-based multi-omics approach to studying individual cells has allowed for the study of cellular phenotyping, intracellular dynamics, and intercellular relationships that provide multidimensionality unable to be obtained through acellular fluid-phase analyses. Challenges to cell-based research include site-to-site differences in handling, storage, and thawing methods, which can lead to inaccuracy and inter-assay variability. In the present study, we performed single-cell RNA sequencing (10x Genomics) on fresh or previously cryopreserved human CSF samples from three alternative cryopreservation methods: Fetal Bovine Serum with Dimethyl sulfoxide (FBS/DMSO), FBS/DMSO after a DNase step (a step often included in epigenetic studies), and cryopreservation using commercially available Recovery© media. In comparing relative differences between fresh and cryopreserved samples, we found little effect of the cryopreservation method on being able to resolve donor-linked cell type proportions, markers of cellular stress, and overall gene expression at the single-cell level, whereas donor-specific differences were readily discernable. We further demonstrate the compatibility of fresh and cryopreserved CSF immune cell sequencing using biologically relevant sexually dimorphic gene expression differences by donor. Our findings support the utility and interchangeability of FBS/DMSO and Recovery cryopreservation with fresh sample analysis, providing a methodological grounding that will enable researchers to further expand our understanding of the CSF immune cell contributions to neurological and psychiatric disease.

HDX–MS finds that partial unfolding with sequential domain activation controls condensation of a cellular stress marker

Eukaryotic cells form condensates to sense and adapt to their environment [S. F. Banani, H. O. Lee, A. A. Hyman, M. K. Rosen, Nat. Rev. Mol. Cell Biol. 18, 285-298 (2017), H. Yoo, C. Triandafillou, D. A. Drummond, J. Biol. Chem. 294, 7151-7159 (2019)]. Poly(A)-binding protein (Pab1), a canonical stress granule marker, condenses upon heat shock or starvation, promoting adaptation [J. A. Riback et al., Cell 168, 1028-1040.e19 (2017)]. The molecular basis of condensation has remained elusive due to a dearth of techniques to probe structure directly in condensates. We apply hydrogen-deuterium exchange/mass spectrometry to investigate the mechanism of Pab1's condensation. Pab1's four RNA recognition motifs (RRMs) undergo different levels of partial unfolding upon condensation, and the changes are similar for thermal and pH stresses. Although structural heterogeneity is observed, the ability of MS to describe populations allows us to identify which regions contribute to the condensate's interaction network. Our data yield a picture of Pab1's stress-triggered condensation, which we term sequential activation (Fig. 1A), wherein each RRM becomes activated at a temperature where it partially unfolds and associates with other likewise activated RRMs to form the condensate. Subsequent association is dictated more by the underlying free energy surface than specific interactions, an effect we refer to as thermodynamic specificity. Our study represents an advance for elucidating the interactions that drive condensation. Furthermore, our findings demonstrate how condensation can use thermodynamic specificity to perform an acute response to multiple stresses, a potentially general mechanism for stress-responsive proteins.

Environmental factors influence cross-talk between a heat shock protein and an oxidative stress protein modification in the lizard Gallotia galloti.

Better understanding how organisms respond to their abiotic environment, especially at the biochemical level, is critical in predicting population trajectories under climate change. In this study, we measured constitutive stress biomarkers and protein post-translational modifications associated with oxidative stress in Gallotia galloti, an insular lizard species inhabiting highly heterogeneous environments on Tenerife. Tenerife is a small volcanic island in a relatively isolated archipelago off the West coast of Africa. We found that expression of GRP94, a molecular chaperone protein, and levels of protein carbonylation, a marker of cellular stress, change across different environments, depending on solar radiation-related variables and topology. Here, we report in a wild animal population, cross-talk between the baseline levels of the heat shock protein-like GRP94 and oxidative damage (protein carbonylation), which are influenced by a range of available temperatures, quantified through modelled operative temperature. This suggests a dynamic trade-off between cellular homeostasis and oxidative damage in lizards adapted to this thermally and topologically heterogeneous environment.

Cannabidiol Disrupts Mitochondrial Respiration and Metabolism and Dysregulates Trophoblast Cell Differentiation.

Trophoblast differentiation is a crucial process in the formation of the placenta where cytotrophoblasts (CTs) differentiate and fuse to form the syncytiotrophoblast (ST). The bioactive components of cannabis, such as Δ9-THC, are known to disrupt trophoblast differentiation and fusion, as well as mitochondrial dynamics and respiration. However, less is known about the impact of cannabidiol (CBD) on trophoblast differentiation. Due to the central role of mitochondria in stem cell differentiation, we evaluated the impact of CBD on trophoblast mitochondrial function and differentiation. Using BeWo b30 cells, we observed decreased levels of mRNA for markers of syncytialization (GCM1, ERVW1, hCG) following 20 µM CBD treatment during differentiation. In CTs, CBD elevated transcript levels for the mitochondrial and cellular stress markers HSP60 and HSP70, respectively. Furthermore, CBD treatment also increased the lipid peroxidation and oxidative damage marker 4-hydroxynonenal. Mitochondrial membrane potential, basal respiration and ATP production were diminished with the 20 µM CBD treatment in both sub-lineages. mRNA levels for endocannabinoid system (ECS) components (FAAH, NAPEPLD, TRPV1, CB1, CB2, PPARγ) were altered differentially by CBD in CTs and STs. Overall, we demonstrate that CBD impairs trophoblast differentiation and fusion, as well as mitochondrial bioenergetics and redox homeostasis.

House sparrows are heavier on organic and integrated-production farms than on conventional farms

The negative impact of conventional farming on avian biodiversity has been increasingly documented. However, the potential effects of different farming practices on bird populations' health remain unclear. We aimed to investigate whether different farming practices (organic, integrated production, conventional/intensive) have differential effects on the body mass - as a proxy for body condition - and biomarkers of oxidative stress in house sparrows (Passer domesticus), a model species strongly associated with human activities and still abundant in Switzerland. We captured a total of 681 birds in 19 organic farms, 20 integrated-production farms (labelled “IP-Suisse”) and 18 conventional farms, and measured bird body mass and tarsus length, as well as levels of malondialdehydes (MDA, a marker of oxidative damage to lipids), superoxide dismutase (SOD, a first-line antioxidant enzyme) activity, and the ratio of oxidized over reduced glutathione (GSSG/GSH, a marker of cellular oxidative stress) in blood and sperm as biomarkers of the systemic oxidative stress endured by birds. Our findings show that house sparrows living in integrated and organic farms were 2.39 % and 4.33 % heavier than birds living in conventional farms, but we did not find any difference in tarsus length, suggesting that birds were of similar size. In addition, we did not find any difference in oxidative stress markers across farming practices. Our results highlight the potential benefits of sustainable farming practices, such as organic and integrated farming, for bird populations and emphasize the need for mitigating the negative impact of agricultural intensification on biodiversity through practices that may enhance the birds’ health and thus lead to positive population dynamics.

Abstract A054: Interleukin-16 is a novel target to prevent age-associated epigenetic changes leading to malignant transformation associated with ovarian high-grade serous carcinoma (HGSOC)

Abstract Low-grade chronic inflammation and persistent oxidative stress are hallmarks of malignant transformation. High-grade serous ovarian carcinoma (HGSOC) is a fatal malignancy of women, and the median age of its incidence is 60-65 years. Our earlier studies showed enhanced expression of interleukin 16 (IL-16, an inflammatory cytokine), its receptor CD9, and glucose-regulated protein (GRP78, a marker of cellular stress and inhibitor of DNA damage repair mechanism) in postmenopausal ovaries and patients with HGSOC as compared with premenopausal subjects. It is possible that these age-associated increases in IL-16, CD9, and GRP78 expression may contribute to HGSOC-related epigenetic modifications of gH2A histone family member X (gH2AX, a marker for double-stranded DNA breaks), and histone deacetylase 1 (HDAC1), involved in DNA repair. The goal of this study was to examine if age-associated such changes lead to HGSOC-associated malignant transformation and if so, to determine mechanisms involved in such transformation. Materials and Methods: Exploratory study: Archived tissue specimens were selected for immunohistochemical, immunoblotting, genomic studies, and immunoassays based on the review of their hematoxylin and eosin staining and final pathological reports. Specimens were grouped as normal premenopausal women (30-50 years old), normal postmenopausal women (55-85 years old), and ovarian high-grade serous carcinoma (HGSC). In vitro study: human ovarian surface epithelium (HOSE) cells were treated with or without recombinant human IL-16 (rhIL-16) and recombinant human GRP78 (rhGRP78), and small interfering RNA-GRP78 (siGRP78) for 24 hours or 48 hours. Nuclear fractionations from treated- or untreated HOSE cells or OVCAR3 (HGSOC cell line) cells were extracted. Results: Compared to premenopausal women, a subset of postmenopausal women exhibited significantly elevated expression (P&amp;lt;0.01) of inflammatory markers IL-16, and its receptor CD9, as well as a marker of oxidative stress (GRP78). Additionally, markers of epigenetic changes, including gH2AX and HDAC1, presented similar patterns of increase in their expression. These observations were also consistent in HGSOC patients. Enhanced expression of GRP78, gH2AX, HDAC1, and CD9 in rhIL-16 treated HOSE cells like OVCAR3 cells and their reduction in siGRP78 treated HOSE cells suggests that age-associated increase in IL-16 in postmenopausal women may be a risk factor for malignant transformation and GRP78 may be a mechanism for IL-16-induced HGSOC development. Thus, IL-16 and GRP78 represent novel targets that may be used to develop novel targeted therapies to prevent HGSOC. Expression of gH2AX and HDAC1 increased in rhGRP78-treated HOSE cells. Conclusion: The results of this study suggest that age-associated increases in IL-16 (a marker of chronic inflammation) and GRP78 (a marker of oxidative stress) may contribute to the predisposition for HGSOC-associated malignant transformation. IL-16 and GRP78 offer potential targets for the prevention of HGSOC in women. Support: The Portes Foundation Citation Format: Jessica Ramirez, Animesh Barua. Interleukin-16 is a novel target to prevent age-associated epigenetic changes leading to malignant transformation associated with ovarian high-grade serous carcinoma (HGSOC) [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A054.