Chain Protein Research Articles

Endothelium-independent vasorelaxant effects of Curcuma phaeocaulis essential oil and its representative compound isocurcumenol.

The rhizomes of Curcuma phaeocaulis Val. are a Rhizoma curcumae source in Chinese pharmacopoeia, and this traditional Chinese medicine has been extensively used in China to promote blood circulation and remove blood stasis. However, little is known regarding the vasodilatory effects and underlying mechanisms. This study investigated the vasorelaxant effects and mechanisms of C. phaeocaulis essential oil (CPEO) and its representative compound, isocurcumenol. The effects of CPEO and isocurcumenol on the contractile tension of isolated rat thoracic aortic rings in a resting state and a KCl or phenylephrine (PHE) preincubation state in the tissue organ bath system were studied. The potential vasodilatory mechanisms of CPEO and isocurcumenol were investigated using a series of experiments that included endothelium removal, CPEO and isocurcumenol preincubation, extracellular Ca2+-induced contraction and intracellular Ca2+ release, and incubation with various blockers. Laser confocal microscopy was used to evaluate the effect of isocurcumenol on the intracellular Ca2+ fluorescence intensity in A7r5 cells. The influence of isocurcumenol on the myosin light chain (MLC) protein expression and phosphorylation was determined using a Western blot assay. Furthermore, the whole-cell patch clamp technique was used to investigate the effect of isocurcumenol on voltage-dependent K⁺channel (Kv) current cells. CPEO (0.25-25mg/L) and isocurcumenol (0.25-25μM) exhibited concentration-dependent vasodilatory effects on endothelial intact vascular rings that were pre-contracted using KCl or PHE. These vasodilatory effects did not significantly change after the endothelium was removed. Notably, the vasodilatory effects of the CPEO and isocurcumenol were attenuated when preincubation was performed using with 4-aminopyridine (4-AP, a Kv channel blocker) or verapamil hydrochloride (an L-type calcium channel blocker). In the cell experiments, isocurcumenol suppressed an increase in the Ca2+ fluorescence intensity and inhibited the phosphorylation of the MLC protein in A7r5 cells. The results of the whole-cell patch clamp assay indicated that 25μM of isocurcumenol enhanced Kv channel currents. In this study, we confirmed that CPEO and isocurcumenol had significant endothelium-independent vasorelaxant effects. The underlying mechanism was attributed to the activation Kv channels and the suppression of L-type calcium channels. This resulted in a Ca2+ influx decrease in vascular smooth muscle cells and subsequent vascular contraction inhibition.

Serine phosphorylation facilitates protein degradation by the human mitochondrial ClpXP protease

ClpXP is a two-component mitochondrial matrix protease. The caseinolytic mitochondrial matrix peptidase chaperone subunit X (ClpX) recognizes and translocates protein substrates into the degradation chamber of the caseinolytic protease P (ClpP) for proteolysis. ClpXP degrades damaged respiratory chain proteins and is necessary for cancer cell survival. Despite the critical role of ClpXP in mitochondrial protein quality control, the specific degrons, or modifications that tag substrate proteins for degradation by human ClpXP, are still unknown. We demonstrated that phosphorylated serine (pSer) targets substrates to ClpX and facilitates their degradation by ClpXP in biochemical assays. In contrast, ClpP hyperactivated by the small-molecule drug ONC201 lost the preference for phosphorylated substrates. Hydrogen deuterium exchange mass spectrometry combined with biochemical assays showed that pSer binds the RKL loop of ClpX. ClpX variants with substitutions in the RKL loop failed to recognize phosphorylated substrates. In intact cells, ClpXP also preferentially degraded substrates with pSer. Moreover, ClpX substrates with the pSer were selectively found in aggregated mitochondrial proteins. Our work uncovers a mechanism for substrate recognition by ClpXP, with implications for targeting acute myeloid leukemia and other disorders involving ClpXP dysfunction.

Effects of Physical Exercise on Neurofilament Light Chain and Glial Fibrillary Acidic Protein Level in Patients with Multiple Sclerosis: A Systematic Review and Bayesian Network Meta-Analysis

Background: The prognosis of people with multiple sclerosis (MS) has improved substantially in recent decades due to advances in diagnosis and treatment. Due to the unpredictable course and heterogenous treatment response in MS, there is a clear need for biomarkers that reflect disease activity in the clinical follow-up of these patients. We conducted a systematic review with Bayesian network meta-analysis with the aim of analyzing the effects of physical exercise on neurofilaments (NfL) and glial fibrillary acidic protein (GFAP) levels in patients with MS. Methods: A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, starting with a PICO (patient/population, intervention, comparison, and outcome) question: what are the clinical effects of physical exercise (with independence of the type) on NfL and/or GFAP levels in patients with MS compared with other interventions or no intervention whatsoever? A systematically comprehensive literature search was conducted from January to March 2024 to identify original studies that answered the PICO question, using the main data sources. The quality of the studies included was assessed using the Quality Index of Downs & Black. For studies included in the systematic review that followed a randomized controlled trial (RCT) design, the methodological quality of each paper was assessed using the Physiotherapy Evidence Database (PEDro) Scale. Risk of bias was also explored by two independent reviewers. Finally, all articles were classified according to the levels of evidence and grades of recommendation for diagnosis studies established by the Oxford Center for Evidence-Based Medicine. For continuous outcome measures with enough comparisons and a methodological quality greater than or equal to good according to the PEDro scale, a Bayesian network meta-analysis (NMA) was applied. The statistical analyses were performed in R (version 4.1.3, R Core Team 2023) using the “BUGSnet” and “gemtc” packages. Bayesian NMA can be used to obtain a posterior probability distribution of all the relative treatment effects, which allows us to quantify the uncertainty of parameter estimates and to rank all the treatments in the network. Results: Eight studies were included in this systematic review and six articles in the NMA, and they were appraised for quality. The characteristics of the included studies, types of training and described protocols, methodological quality, risk of bias, and clinical effects on the studied biomarkers were outlined. Qualitative synthesis, effects of different exercise modalities in NfL with the Bayesian NMA, selection of the final model and model assessment, and ranking of interventions are also shown. Conclusions: Our findings indicated that moderate-intensity exercise is more likely to reduce NfL concentration compared to high-intensity exercise, and, in turn, high-intensity exercise is more likely to reduce NfL concentration than low-intensity exercise. However, the effects of high-intensity exercise on GFAP levels were inconclusive.

Development of an in vitro model to study muscle maladaptation to overtraining

Introduction Physical training stimulates skeletal muscle mitochondrial biogenesis and protein synthesis, inducing beneficial adaptations and promoting performance. However, in some cases when the training load is higher than required, the outcome may lead to non-functional overreaching – a state in which performance may be transiently reduced. This condition is relatively common especially among endurance athletes, and if protracted would result in the development of the overtraining syndrome (OTS), whose impact on skeletal muscle metabolism and function is still unknown. Muscle soreness, increased inflammation and reduced muscle mass are often reported. It has been reported that regeneration of skeletal muscle fibres is impaired, probably through a change in energy metabolism (Grobler et al., 2004). For instance, altered mitochondrial structure and function have been suggested (Grobler et al., 2004). The aim of the present project is to determine the molecular mechanisms underlying skeletal muscle maladaptation’s in response to simulated exercise in vitro. Methods Using a model developed in our laboratory (Zanou et al., 2021), we electrically stimulated C2C12 myotubes (a mouse skeletal muscle cell line) to simulate endurance exercise (Zanou et al., 2021). For simulated training (s-T) the stimulation was applied once daily, for three consecutive days. For simulated overtraining (s-OT), the stimulation was applied three times per day for three consecutive days. Mitochondrial biogenesis biomarkers have been measured, alongside proteomics analysis and mitochondrial respiration. Results In the in vitro s-T model, we observed the expected beneficial adaptations to training, which include myotube hypertrophy, increased fast and slow-twitch myosin heavy chain protein content, and increased mitochondrial respiration. Our proteomics data highlighted many positive adaptations, including upregulation of the muscle contractile and mitochondrial proteins. Immunofluorescence staining of F-actin and of the mitochondrial outer membrane protein Tom20, clearly showed robust F-actin structure and regular mitochondrial distribution in response to s-T. Interestingly, s-OT model presented myotube atrophy, and a decrease in fast and slow-twitch myosin heavy chain protein content. Mitochondrial respiration was increased in s-T and showed a clear trend versus reduction in s-OT. Our proteomics data revealed many downregulated proteins pathways in s-OT including muscle contractile and mitochondrial pathways. Immunofluorescence staining also revealed disrupted F-actin structure and aberrant mitochondrial aggregation in response to s-OT. Conclusions s-T recapitulates training positive adaptations, whereas s-OT recapitulates many of the muscle maladaptation observed in overtraining. Our next studies in human OTS muscle will validate key findings from our in vitro s-OT model and guide our mechanistic investigations into the molecular mechanisms of OTS.

Advances in Huntington’s Disease Biomarkers: A 10-Year Bibliometric Analysis and a Comprehensive Review

Neurodegenerative disorders (NDs) cause progressive neuronal loss and are a significant public health concern, with NDs projected to become the second leading global cause of death within two decades. Huntington’s disease (HD) is a rare, progressive ND caused by an autosomal-dominant mutation in the huntingtin (HTT) gene, leading to severe neuronal loss in the brain and resulting in debilitating motor, cognitive, and psychiatric symptoms. Given the complex pathology of HD, biomarkers are essential for performing early diagnosis, monitoring disease progression, and evaluating treatment efficacy. However, the identification of consistent HD biomarkers is challenging due to the prolonged premanifest HD stage, HD’s heterogeneous presentation, and its multiple underlying biological pathways. This study involves a 10-year bibliometric analysis of HD biomarker research, revealing key research trends and gaps. The study also features a comprehensive literature review of emerging HD biomarkers, concluding the need for better stratification of HD patients and well-designed longitudinal studies to validate HD biomarkers. Promising candidate wet HD biomarkers— including neurofilament light chain protein (NfL), microRNAs, the mutant HTT protein, and specific metabolic and inflammatory markers— are discussed, with emphasis on their potential utility in the premanifest HD stage. Additionally, biomarkers reflecting brain structural deficits and motor or behavioral impairments, such as neurophysiological (e.g., motor tapping, speech, EEG, and event-related potentials) and imaging (e.g., MRI, PET, and diffusion tensor imaging) biomarkers, are evaluated. The findings underscore that the discovery and validation of reliable HD biomarkers urgently require improved patient stratification and well-designed longitudinal studies. Reliable biomarkers, particularly in the premanifest HD stage, are crucial for optimizing HD clinical management strategies, enabling personalized treatment approaches, and advancing clinical trials of HD-modifying therapies.

Sagittaria sagittifolia polysaccharide extract regulates Nrf2 to improve endoplasmic reticulum stress-mediated apoptosis in rat cataracts and HLEB3 cells.

Age-related cataract (ARC) remains the leading cause of blindness worldwide. Sagittaria sagittifolia polysaccharide (SSP) extract, a key component of Sagittaria sagittifolia L., exhibits anti-oxidant and anti-apoptotic effects with potential applications in ARC. This study aimed to explore the therapeutic potential of SSP in ARC and the underlying mechanisms. In sodium selenite-induced cataracts in rats and hydrogen peroxide (H2O2)-induced human lens epithelial B3 (HLEB3) cells, SSP significantly improved lens opacity and pathological changes and alleviated apoptosis and endoplasmic reticulum stress (ERS)-related injury indicators (by inhibiting the intracellular Ca2+ and protein expression of Bcl-2-associated X, cleaved caspase-3, binding immunoglobulin heavy chain protein, protein kinase RNA-like kinase), inositol-requiring enzyme 1α, activating transcription factor 6, C/EBP homology protein, c-Jun N terminal kinase, caspase-12, and calpain-2). In addition, SSP increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1, sarco/endoplasmic reticulum-type calcium transport ATPase 2, and B-cell lymphoma-2. After applying Nrf2 knockdown technology by transferring short interfering RNA in HLEB3 cells, SSP demonstrated its protective role by activating Nrf2 and inhibiting ERS-mediated apoptosis. These findings indicate that SSP may protect against ARC by regulating Nrf2/ERS-mediated apoptosis, providing potential evidence for its use in preventing or delaying ARC.

Increased serum NfL and GFAP levels indicate different subtypes of neurologic immune-related adverse events during treatment with immune checkpoint inhibitors.

Neurologic immune-related adverse events (nirAEs) represent rare, yet severe side effects associated with immune checkpoint inhibitor (ICI) therapy. Given the absence of established diagnostic biomarkers for nirAEs, we aimed to evaluate the diagnostic utility of serum Neurofilament Light Chain (NfL) and Glial Fibrillary Acidic Protein (GFAP). Fifty-three patients were included at three comprehensive cancer centers, of these 20 patients with manifest nirAEs and 11 patients with irHypophysitis. Controls included patients without any irAE (n = 8) and other irAEs (n = 14). Using a single-molecule enzyme-linked immunosorbent assay (Simoa), serum levels were measured prior to, during and after the manifestation of (n)irAEs in 80 samples. Symptom severity of the (n)irAEs was graded according to the Common Criteria for Adverse Events (CTCAE) version 5.0. Serum NfL levels were significantly higher in the nirAE group (n = 20) compared to irHypophysitis (n = 11; p = .0025) and controls (n = 22; p = .0384). Subgroup analysis demonstrated a significant elevation of NfL in nirAEs of the peripheral nerves (PNirAE) in contrast to neuromuscular syndromes (NMirAE) (p = .0260). GFAP levels were highest in patients with nirAE affecting the central nervous system (CNSirAE) compared to PNirAE and NMirAE (p = .0064). Symptom severity of nirAEs was associated with increased levels of NfL and GFAP (p = .0069, .0092). Individuals with elevated NfL levels exhibited less favorable outcomes of the (n)irAEs (p = .0199). Measurement of NfL and GFAP may be helpful for the differentiation of the broad spectrum of nirAEs and may serve as an indicator of symptom severity. Further investigation is needed to evaluate their potential as diagnostic and prognostic biomarkers.

The total extract of Abelmoschus manihot (L.) medic flowers (TEA) mediated Nrf2-TFAM signalling to regulate mitochondrial antioxidant mechanism

Skin, as the first line of defence of the human body, is exposed to dangers such as overheating substances, ultraviolet rays, and environmental pollutants, and the incidence of skin diseases is increasing annually. Oxidative stress plays a dominant role in most skin diseases. Abelmoschus manihot (L.) medic flower (TEA) is a traditional Chinese medicine widely used to treat injuries to the skin such as water and fire scalds. It has been reported that TEA has excellent antioxidant effects. In this study, we aimed to explore the antioxidant and mitochondrial protection effects of TEA in H2O2-mediated HaCaT cell damage. HaCaT cells were incubated with H2O2 to simulate oxidative stress in the skin. The effect of TEA on HaCaT cells was also evaluated. Cell morphology was observed via inverted microscopy, and cell viability was measured via the MTT reagent. The cells were stained with Hoechst 33,324 solution. Reactive oxygen species (ROS), superoxide dismutase (SOD), malondialdehyde (MDA) and ATP detection kits were used to detect the corresponding indicators. The mitochondrial membrane potential was detected by JC-1. RT-PCR was used to detect mRNA and mtDNA expression. The expression of the target protein was detected by Western blotting and immunofluorescence. H2O2 triggered oxidative damage in HaCaT cells, which manifested as apoptosis, increased ROS and MDA contents, and decreased SOD activity. H2O2 activates the KEAP1/Nrf2/NQO1 signalling pathway, which decreases the expression of the intracellular KEAP1 protein and slightly increases the expression of the Nrf2 and NQO1 proteins, further causing mitochondrial oxidative stress, resulting in changes in the mitochondrial membrane potential, a reduction in the mtDNA copy number, and decreased expression of the PGC-1α and TFAM proteins. In addition the expression of mitochondrial respiratory chain genes and proteins decreased. TEA promoted the expression of Nrf2 in HaCaT cells, activated the downstream antioxidant response, and alleviated the oxidative stress and mitochondrial damage caused by H2O2. ML385 is an Nrf2 inhibitor, under which the antioxidant and mitochondrial protective effects of TEA are inhibited. When TFAM was knocked down, the protective effect of TEA on mitochondria was also inhibited. TEA protects HaCaT cells from H2O2-induced oxidative damage and mitochondrial oxidative damage through the KEAP1/Nrf2/NQO1/PGC-1α/TFAM pathway.

Nerve repair with polylactic acid and inosine treatment enhance regeneration and improve functional recovery after sciatic nerve transection.

Following transection, nerve repair using the polylactic acid (PLA) conduit is an effective option. In addition, inosine treatment has shown potential to promote nerve regeneration. Therefore, this study aimed to investigate the regenerative potential of inosine after nerve transection and polylactic acid conduit repair. C57/Black6 mice were subjected to sciatic nerve transection, repair with PLA conduit, and intraperitoneal injection of saline or inosine 1 h after injury and daily for 1 week. To assess motor and sensory recovery, functional tests were performed before and weekly up to 8 weeks after injury. Following, to evaluate the promotion of regeneration and myelination, electroneuromyography, morphometric analysis and immunohistochemistry were then performed. Our results showed that the inosine group had a greater number of myelinated nerve fibers (1,293 ± 85.49 vs. 817 ± 89.2), an increase in neurofilament high chain (NFH) and myelin basic protein (MBP) immunolabeling and a greater number of fibers within the ideal g-ratio (453.8 ± 45.24 vs. 336.6 ± 37.01). In addition, the inosine group presented a greater adenosine A2 receptor (A2AR) immunolabeling area. This resulted in greater compound muscle action potential amplitude and nerve conduction velocity, leading to preservation of muscle and neuromuscular junction integrity, and consequently, the recovery of motor and sensory function. Our findings suggest that inosine may enhance regeneration and improve both motor and sensory function recovery after nerve transection when repaired with a poly-lactic acid conduit. This advances the understanding of biomaterials and molecular treatments.

TGFβ1 Restores Energy Homeostasis of Human Trophoblast Cells Under Hyperglycemia In Vitro by Inducing PPARγ Expression, AMPK Activation, and HIF1α Degradation.

Elevated glucose levels at the fetal-maternal interface are associated with placental trophoblast dysfunction and increased incidence of pregnancy complications. Trophoblast cells predominantly utilize glucose as an energy source, metabolizing it through glycolysis in the cytoplasm and oxidative respiration in the mitochondria to produce ATP. The TGFβ1/SMAD2 signaling pathway and the transcription factors PPARγ, HIF1α, and AMPK are key regulators of cell metabolism and are known to play critical roles in extravillous trophoblast cell differentiation and function. While HIF1α promotes glycolysis over mitochondrial respiration, PPARγ and AMPK encourage the opposite. However, the interplay between TGFβ1 and these energy-sensing regulators in trophoblast cell glucose metabolism remains unclear. This study aimed to investigate whether and how TGFβ1 regulates energy metabolism in trophoblast cells exposed to normal and high glucose conditions. The trophoblast JEG-3 cells were incubated in normal (5 mM) and high (25 mM) glucose conditions for 24 h in the absence and the presence of TGFβ1. The protein expression levels of phosphor (p)-SMAD2, GLUT1/3, HIF1α, PPARγ, p-AMPK, and specific OXPHOS protein subunits were determined by western blotting, and ATP and lactate production by bioluminescent assay kits. JEG-3 cells exposed to 25 mM glucose decreased ATP production but did not affect lactate production. These changes led to a reduction in the expression levels of GLUT1/3, mitochondrial respiratory chain proteins, and PPARγ, coinciding with an increase in HIF1α expression. Conversely, TGFβ1 treatment at 25 mM glucose reduced HIF1α expression while enhancing the expression levels of GLUT1/3, PPARγ, p-AMPK, and mitochondrial respiratory chain proteins, thereby rejuvenating ATP production. Our findings reveal that high glucose conditions disrupt cellular glucose metabolism in trophoblast cells by perturbing mitochondrial oxidative respiration and decreasing ATP production. Treatment with TGFβ1 appears to counteract this trend, probably by enhancing both glycolytic and mitochondrial metabolism, suggesting a potential regulatory role of TGFβ1 in placental trophoblast cell glucose metabolism.

Neurofilament Light Chain as a Discriminator of Disease Activity Status in MOG Antibody-Associated Disease.

In patients with myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD), acute disease activity is generally identified through medical history, neurologic examination, and imaging. However, these may be insufficient for detecting disease activity in specific conditions. This study aimed to investigate the dynamics of serum neurofilament light chain (sNfL) and serum glial fibrillary acidic protein (sGFAP) after clinical attacks and to assess their utility in discriminating attacks from remission in patients with MOGAD. We conducted a multicenter, retrospective, longitudinal study including 239 sera from 62 MOGAD patients assessed from 1995 to 2023 in a discovery and validation setup. Sera were measured for sNfL and sGFAP with a single-molecule array assay and for MOG-IgG with a live cell-based assay. sNfL and sGFAP Z scores and percentiles adjusted for age, body mass index, and sex (sGFAP) were calculated from a healthy control normative database. Mixed-effects regression models were used to characterize biomarkers' dynamics and to investigate associations between serum biomarkers, clinical variables, and disease activity status. Among the 62 study participants, 29 (46.8%) were female, with a median age at baseline of 40.0 years (interquartile range [IQR] 29.5-49.8) and a median duration of follow-up of 20.0 months (IQR 3.0-62.8). sNfL and sGFAP Z scores were nonlinearly associated with time from attack onset (p < 0.001 and = 0.002, respectively). During attacks, both biomarkers presented higher median values (sNfL Z score 2.9 [IQR 1.4-3.5], 99.8th; sGFAP Z score 0.4 [IQR -0.5 to 1.5], 65.5th) compared with remission (sNfL Z score 0.9 [IQR -0.1 to 1.6], 81.6th, p < 0.001; sGFAP Z score -0.2 [IQR -0.8 to 0.5], 42.1th; p < 0.001) across all clinical phenotypes. sNfL values consistently discriminated disease activity status in the discovery and validation cohorts, showing a 3.5-fold increase in the odds of attacks per Z score unit (odds ratio 3.5, 95% confidence interval 2.3-5.1; p < 0.001). Logistic models incorporating sNfL Z scores demonstrated favorable performance in discriminating disease activity status across both cohorts. sNfL Z scores may serve as a biomarker for monitoring disease activity in MOGAD.

Riboflavin-mediated ultraviolet photosensitive oxidation of beef myofibrillar proteins with different storage times.

The study was designed to investigate the mechanism of Riboflavin (RF)-mediated UVA photosensitive oxidation on beef myofibrillar proteins (MP) oxidized at different storage times. To elucidate the direct relationship between RF and protein oxidation, the mechanism of action was analyzed in terms of amino acid and side chain residues, protein structure, and protein oxidative metabolism. Oxidation of MP resulted in significant changes in the levels of carbonyls, sulfhydryls, Lysine, Arginine, Threonin, and Histidine. The oxidized MP secondary structure was changed, fluorescence intensity decreased, and surface hydrophobicity increased. Metabolomics results revealed that RF-mediated UVA photosensitized oxidation is primarily mediated by Riboflavin metabolism and co-regulated with Phenylalanine metabolism. Moreover, with the increase of frozen storage time, Arginine and proline metabolism was inhibited, and the contents of creatine were significantly reduced, which exacerbated MP oxidative damage. The results provide a theoretical basis for unraveling the mechanism of RF-mediated UVA photosensitive oxidation of MP.

Prognostic serum biomarkers of synaptic, neuronal and glial injury in patients with acute ischemic stroke of the anterior circulation.

We aimed to investigate the prognostic role of β-synuclein in comparison to that of neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) for predicting functional outcome after acute ischemic stroke (AIS). We measured serum concentrations of β-synuclein, NfL and GFAP 24 h after hospital admission in 213 consecutive patients with moderate-to-severe AIS. We investigated the association between serum biomarkers and radiological/clinical characteristics, 3-months mortality and functional outcome on the modified Rankin Scale (mRS). In 213 patients with AIS [mean age: 76.1 (±12.5) years, 53.1% males, median NIHSS score on admission: 13 (IQR: 9-17)], higher levels of β-synuclein, NfL and GFAP were associated with higher NIHSS scores and with lower Alberta Stroke Program CT Score (ASPECTS) points on admission. Serum β-synuclein levels was significantly correlated with NfL (rho = 0.715, p < 0.001) and GFAP concentrations (rho = 0.684, p < 0.001). The inclusion of serum β-synuclein significantly improved the accuracy of prediction models without biomarkers for overall mortality (AUC: 0.836 vs. 0.752, p < 0.001) and mRS 3-6 vs. 0-2 (AUC: 0.812 vs. 0.624, p < 0.001). Combination models with NfL and/or GFAP showed a similar accuracy. Serum β-synuclein may be used to assess synaptic damage/dysfunction and to predict 3-months clinical outcomes in patients with AIS.

3-(4-Hydroxy-3-methoxyphenyl) propionic acid mitigates dexamethasone-induced muscle atrophy by attenuating Atrogin-1 and MuRF-1 expression in mouse C2C12 skeletal myotubes

3-(4-Hydroxy-3-methoxyphenyl) propionic acid is an in vivo metabolite of 4-hydroxy-3-methoxycinnamic acid which is abundantly found in coffee bean, rice bran, fruits, and vegetables. Previous studies reported that polyphenols and their metabolites exhibit positive effects on muscle health. Thus, the effect of 3-(4-hydroxy-3-methoxyphenyl) propionic acid on muscle atrophy induced by dexamethasone was investigated using mouse C2C12 skeletal myotubes. Dexamethasone treatment (10 ‍μM) reduced the diameter and myosin heavy chain protein expression in C2C12 myotubes; it also increased muscle atrophy-associated ubiquitin ligases, such as muscle atrophy F-box protein 1/Atrogin-1 and muscle ring finger protein-1, along with their upstream regulator Krüppel-like factor 15. Dexamethasone dephosphorylated FoxO3a transcription factor and increased total FoxO3a expression. Interestingly, 10 ‍μM 3-(4-hydroxy-3-methoxyphenyl) propionic acid treatment significantly attenuated dexamethasone-induced reduction in myotube thickness and muscle protein degradation and suppressed muscle atrophy-associated ubiquitin ligases. 3-(4-Hydroxy-3-methoxyphenyl) propionic acid also prevented dexamethasone-induced Krüppel-like factor 15 and FoxO3a expression. In conclusion, these results suggest that in vivo metabolite of polyphenols per se could be the real origin of the anti-muscular atrophy activity, as 3-(4-hydroxy-3-methoxyphenyl) propionic acid ameliorated glucocorticoid-induced muscle atrophy by suppressing Atrogin-1 and MuRF-1.

Plastic harmful ingredients reduce the level of neurofilament light chain protein.

Population exposure to plastics is increasing, and plasticizers are frequently detected in humans as important ingredients of plastic products. However, patterns of exposure to harmful ingredients of plastics and their effects on neurofilament light chain (NFL), a marker of active brain pathology, are currently inconclusive. Herein, we employed a range of statistical methods to thoroughly investigate the impact of 24 plastic hazardous ingredients and their varying exposure patterns on NFL concentrations in the blood of the general population in 533 participants. Generalized linear model revealed a positive correlation between Mono-isononyl phthalate and Mono (2-Ethyl- 5-Hydroxyhexyl) Phthalate (MEHHP) with NFL. Furthermore, a significant dose-response relationship was observed between MEHHP and NFL, while Butyl paraben and Mono (Hydroxy-Isononyl) Ester exhibited a distinct "inverted U-shaped" nonlinear pattern with NFL. Additionally, Weighted Quantile Sum model allowed us to identify the mixed effects of all 24 plastic hazardous ingredients, with Mono(2-Ethyl-5-Oxohexyl) Phthalate, Mono-isobutyl phthalate, Mon butyl Phthalate, Propyl paraben and Triclosan occupying prominent positions. Finally, the latent profile analysis categorized exposures into high, medium, and low patterns, confirming that higher exposure to plastic hazardous ingredients posed a significant risk factor for elevated NFL levels in the blood. Exposure to plastic hazardous ingredients significantly increases the risk of NFL, the present contributes to early detection and intervention to reduce the incidence of neurodevelopmental disorder.

Plasma Neurofilament Light Chain and Glial Fibrillary Acidic Protein as Biomarkers of Cognitive Decline in People Living with HIV.

This study examined the relationship between neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) and cognition in people living with HIV (PLWH) at baseline and over time. Plasma and clinical data were available from PLWH aged ≥45 years with HIV RNA <200 copies/mL enrolled in the AIDS Clinical Trials Group HAILO cohort study. We measured plasma NfL and GFAP using a single molecule array platform. Four neuropsychological assessments, standardized to z-scores and averaged (NPZ-4), were used as a marker of cognitive function. Date of plasma collection marked study baseline; longitudinal changes in NPZ-4 were summarized by slope. Linear regressions between biomarkers and baseline NPZ-4 were adjusted for demographic factors. Regressions of longitudinal data were adjusted for baseline NPZ-4 and weighted by number of visits. The study included 503 participants with a median [IQR] age of 52 [48, 57] years, observation of 6 [5, 7] years, and 26% had baseline cognitive impairment defined by HAILO. Cross-sectionally, higher NfL (β=-0.76, p<0.01) and GFAP (β=-0.44, p=0.02) were associated with worse baseline NPZ-4. Longitudinally, the median [IQR] NPZ-4 slope was 0.003 [-0.06, 0.06] units/year with 48% demonstrating cognitive decline (slope<0). Higher NfL (β=-0.08, p<0.01), but not GFAP (β=-0.03, p=0.08), was associated with cognitive decline. NfL and GFAP were associated with worse cognition cross-sectionally; only NfL was associated with longitudinal cognitive decline. However, the clinical utility of NfL and GFAP is uncertain given small effect sizes and should be studied in populations with more rapid decline (e.g., aged ≥60).

Inhibition of phosphodiesterases 1 and 4 prevents myofibroblast transformation in Peyronie's disease

ObjectivesTo investigate which phosphodiesterase (PDE) isoforms are expressed in fibroblasts isolated from the tunica albuginea (TA) of patients with Peyronie's disease (PD), and to measure the potency of PDE inhibitors in preventing transformation of these fibroblasts to profibrotic myofibroblasts.Materials and MethodsFibroblasts isolated from the TA of men undergoing surgery for correction of PD curvature were transformed to myofibroblasts using transforming growth factor beta‐1. The expression of 21 PDE isoforms was investigated using quantitative reverse transcriptase‐polymerase chain reaction and protein analysis, as were the effects of various PDE inhibitors on prevention of myofibroblast transformation. Intracellular cAMP and cGMP in the presence of PDE inhibitors were quantified using cGMP/cAMP enzyme‐linked immunosorbant assay assays.ResultsWe found that PDE1A, 1C, 4, 5A, 7B and 8B were expressed at mRNA and protein levels. Selective inhibitors of these enzymes prevented myofibroblast transformation in a concentration‐dependent manner, with PDE1 inhibitor ITI‐214 and PDE4 inhibitors roflumilast and roflumilast N‐oxide showing greatest potency. ITI‐214 and roflumilast N‐oxide increased intracellular cAMP, but not cGMP, in a concentration‐dependent manner.ConclusionsThis is the first demonstration of the expression of PDE1, 7 and 8 isoforms, and the function of PDE1 and PDE4 in human TA fibroblasts. The ability of inhibitors of these enzymes to prevent myofibroblast transformation suggests that such inhibitors can be developed to treat acute PD.

Vitamin C Ameliorates Potassium Dichromate-Induced Oxidative Stress and Mitochondrial Dysfunction via PGC-1α/Nrf-2/TFAM Pathway.

Exposure to potassium dichromate (K2Cr2O7) is well known for its nephrotoxic effects on humans and animals. This study investigated the protective effects of vitamin C against K2Cr2O7-induced nephrotoxicity, focusing on its impact on altered carbohydrate metabolism, mitochondrial dysfunction, and associated molecular mechanisms in the cortical and medullary kidney segments. Male Wistar rats (n = 8) were divided into four groups: Group I received saline, Group II received a single 250 mg/kg body weight (bwt) intraperitoneal (i.p.) injection of vitamin C, Group III received K2Cr2O7 (15 mg/kg bwt, i.p.), and Group IV received vitamin C 6 h before K2Cr2O7 administration. Vitamin C significantly mitigated K2Cr2O7-induced nephrotoxic effects, restoring normal renal function and histological architecture. It preserved the activities of glycolytic and gluconeogenic enzymes altered by K2Cr2O7. Additionally, vitamin C mitigated K2Cr2O7-induced mitochondrial dysfunction by maintaining tricarboxylic acid (TCA) cycle enzymes, electron transport chain proteins, mitochondrial DNA copy number, and ATP content. It also reduced oxidative stress markers and enhanced antioxidant enzyme activity. The protective mechanism of vitamin C against K2Cr2O7-induced renal damage involved upregulation of the protein expression of peroxisome proliferation-activated receptor-γ coactivator-1α (PGC-1α), which further elevated the protein expression of nuclear factor erythroid 2-related factor-2 (Nrf-2) and transcription factor A, mitochondrial (TFAM), crucial for protecting cells from oxidative stress, enhancing mitochondrial function, and promoting cellular health. Overall, this study highlights the significant protective role of vitamin C against K2Cr2O7-induced renal damage by preserving carbohydrate metabolism and mitigating mitochondrial dysfunction through the PGC-1α/Nrf-2/TFAM pathway, offering valuable insights into its protective mechanisms in nephrotoxicity.

Effect of Natalizumab on sNfL and sGFAP Levels in Multiple Sclerosis Patients.

Natalizumab is a highly effective therapy for multiple sclerosis (MS). The aim of this study was to evaluate serum neurofilament light chain (sNfL) and serum glial fibrillary acidic protein (sGFAP) in patients with relapsing-remitting MS treated with Natalizumab. sNfL and sGFAP were analyzed at baseline, 6 and 12 months post treatment using the single-molecule array (SiMoA) technique. We recruited matched healthy controls for comparison. The study included 54 patients, with a median age of 33 years (Interquartile range (IQR), 29-41), with 32 women (60%) and 76 healthy controls. A decrease in sNfL was observed at 6 (67%, p = 0.005) and 12 (72%, p < 0.0001) months compared to baseline. After two years, six patients experienced evidence of disease activity (EDA-3). The remaining ones had no evidence of disease activity (NEDA-3). NEDA-3 presented a remarkable reduction in sNfL (p < 0.0001) and sGFAP (p = 0.01) after 6 months of treatment that continued to be observed after 12 months compared to baseline. EDA-3 only reached a significant decrease in sNfL after 12 months; there were no significant changes in sGFAP values. Natalizumab leads to a decrease in sNfL, which is higher and occurs earlier in NEDA-3 patients. Patients also showed a significant reduction in sGFAP levels, which was not observed in the EDA-3 group.

Structural Analysis of Variants of the Ferritin Light Chain Protein and Its Relationship with Neuroferritinopathy.

Ferritin is a highly conserved spherical protein that stores iron and possesses triple and quadruple symmetry input ports. Additionally, it is composed of light chains that can be affected by post-translational mutations, reducing the iron storage capacity in the brain and leading to neuroferritinopathy, which is a rare disease with limited bioinformatics data. In this study, we analyzed the biochemical mechanism of different ferritin mutations reported in the literature, through the characterization and determination of the in silico structural model by searching databases, implementing bioinformatics programs such as Jalview, NetNGlyc 1.0, NetOGlyc 3.1, and three-dimensional structure predictors with machine learning such as Alphafold, demonstrating the generation of hairpin and steric hindrances that hinder the aggregation of subunits and changes in the size and arrangement of quadruple and triple entry holes of the A96T mutation compared to the wild-type protein, since in the quadruple entry hole, a decrease in area is observed compared to the wild-type protein and the triple entry hole has a decrease in distance measurements of 6.504 Å. This possibly affects the functionality of the protein, thus releasing high concentrations of iron in the brain and causing neurodegeneration.