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Investigative Ophthalmology & Visual... Jul 2024Glucocorticoid-induced glaucoma (GIG) is a prevalent complication associated with glucocorticoids (GCs), resulting in irreversible blindness. GIG is characterized by the...
PURPOSE
Glucocorticoid-induced glaucoma (GIG) is a prevalent complication associated with glucocorticoids (GCs), resulting in irreversible blindness. GIG is characterized by the abnormal deposition of extracellular matrix (ECM) in the trabecular meshwork (TM), elevation of intraocular pressure (IOP), and loss of retinal ganglion cells (RGCs). The objective of this study is to investigate the effects of nicotinamide riboside (NR) on TM in GIG.
METHODS
Primary human TM cells (pHTMs) and C57BL/6J mice responsive to GCs were utilized to establish in vitro and in vivo GIG models, respectively. The study assessed the expression of ECM-related proteins in TM and the functions of pHTMs to reflect the effects of NR. Mitochondrial morphology and function were also examined in the GIG cell model. GIG progression was monitored through IOP, RGCs, and mitochondrial morphology. Intracellular nicotinamide adenine dinucleotide (NAD+) levels of pHTMs were enzymatically assayed.
RESULTS
NR significantly prevented the expression of ECM-related proteins and alleviated dysfunction in pHTMs after dexamethasone treatment. Importantly, NR protected damaged ATP synthesis, preventing overexpression of mitochondrial reactive oxygen species (ROS), and also protect against decreased mitochondrial membrane potential induced by GCs in vitro. In the GIG mouse model, NR partially prevented the elevation of IOP and the loss of RGCs. Furthermore, NR effectively suppressed the excessive expression of ECM-associated proteins and mitigated mitochondrial damage in vivo.
CONCLUSIONS
Based on the results, NR effectively enhances intracellular levels of NAD+, thereby mitigating abnormal ECM deposition and TM dysfunction in GIG by attenuating mitochondrial damage induced by GCs. Thus, NR has promising potential as a therapeutic candidate for GIG treatment.
Topics: Animals; Niacinamide; Pyridinium Compounds; Glucocorticoids; Mice, Inbred C57BL; Mitochondria; Mice; Glaucoma; Extracellular Matrix; Intraocular Pressure; Humans; Disease Models, Animal; Trabecular Meshwork; Cells, Cultured; Retinal Ganglion Cells; Reactive Oxygen Species; Dexamethasone; Male
PubMed: 38949632
DOI: 10.1167/iovs.65.8.1 -
Physiological Genomics Jul 2024Type 2 diabetes (T2D) is a common metabolic disease due to insufficient insulin secretion by pancreatic beta cells in the context of insulin resistance. Islet molecular...
Type 2 diabetes (T2D) is a common metabolic disease due to insufficient insulin secretion by pancreatic beta cells in the context of insulin resistance. Islet molecular pathology reveals a role for protein misfolding in beta cell dysfunction and loss with islet amyloid derived from islet amyloid polypeptide (IAPP), a protein co-expressed and co-secreted with insulin. The most toxic form of misfolded IAPP is intracellular membrane disruptive toxic oligomers present in beta cells in T2D and in beta cells of mice transgenic for human IAPP (hIAPP). Prior work revealed a high degree of overlap of transcriptional changes in islets from T2D and pre-diabetic 9-10-week-old mice transgenic for hIAPP with most changes being pro-survival adaptations and therefore of limited therapeutic guidance. Here we investigated islets from hIAPP transgenic mice at an earlier age (6 weeks) to screen for potential mediators of hIAPP toxicity that precede predominance of pro-survival signaling. We identified early suppression of cholesterol synthesis and trafficking along with aberrant intra-beta cell cholesterol and lipid deposits, and impaired cholesterol trafficking to cell membranes. These findings align with comparable lipid deposits present in beta cells in T2D and increased vulnerability to develop T2D in individuals taking medications that suppress cholesterol synthesis.
PubMed: 38949617
DOI: 10.1152/physiolgenomics.00029.2024 -
Hepatology Research : the Official... Jul 2024Acute liver failure (ALF) induces increased energy expenditure and disrupts the metabolism of essential nutrients. Hepatic encephalopathy is a complication of ALF with a... (Review)
Review
Acute liver failure (ALF) induces increased energy expenditure and disrupts the metabolism of essential nutrients. Hepatic encephalopathy is a complication of ALF with a poor prognosis and mainly involves the metabolic disturbance of amino acids in its pathogenesis. In this review, we discuss the nutritional management for ALF in consideration of the pathophysiology of ALF with respect to the impairment of hepatocyte function. It is known that enteral nutrition is recommended for patients with ALF, while parenteral nutrition is recommended for patients who cannot tolerate enteral nutrition. As ALF leads to a hypermetabolic state, the energy intake is recommended to cover 1.3 times the resting energy expenditure. Because of the high risk of hypoglycemia associated with disturbances in glucose metabolism, substantial glucose intake is recommended. Along with the deterioration of glucose metabolism, protein metabolism is also disrupted. As patients with ALF have increased systemic protein catabolism together with decreased protein synthesis, appropriate amounts of amino acids or protein under monitoring serum ammonia levels are recommended. In conclusion, nutritional management based on the understanding of nutritional pathophysiology is a pivotal therapeutic approach for patients with ALF. The approach should be individualized in the acute phase, the recovery phase, and the pretransplant phase.
PubMed: 38949571
DOI: 10.1111/hepr.14090 -
Microbial Biotechnology Jul 2024Rhodopsins, a diverse class of light-sensitive proteins found in various life domains, have attracted considerable interest for their potential applications in... (Review)
Review
Rhodopsins, a diverse class of light-sensitive proteins found in various life domains, have attracted considerable interest for their potential applications in sustainable synthetic biology. These proteins exhibit remarkable photochemical properties, undergoing conformational changes upon light absorption that drive a variety of biological processes. Exploiting rhodopsin's natural properties could pave the way for creating sustainable and energy-efficient technologies. Rhodopsin-based light-harvesting systems offer innovative solutions to a few key challenges in sustainable engineering, from bioproduction to renewable energy conversion. In this opinion article, we explore the recent advancements and future possibilities of employing rhodopsins for sustainable engineering, underscoring the transformative potential of these biomolecules.
Topics: Synthetic Biology; Rhodopsin; Light-Harvesting Protein Complexes; Light
PubMed: 38949508
DOI: 10.1111/1751-7915.14521 -
European Journal of Clinical... Jul 2024The glomerular filtration rate (GFR) is estimated by the serum or plasma concentration of creatinine and/or cystatin C using equations that include demographic data. The... (Review)
Review
BACKGROUND
The glomerular filtration rate (GFR) is estimated by the serum or plasma concentration of creatinine and/or cystatin C using equations that include demographic data. The equations worldwide most widely used are those of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) consortium and updated in 2021 to remove the Afro-American racial correction factor. In 2021 and then in 2023, the European Kidney Function Consortium also developed equations based on creatinine and cystatin C, usable across the full age spectrum, and constructed by including the Q value (i.e. the median creatinine or cystatin C in healthy men and women, which is customizable for specific populations).
METHODS
The aim of this narrative review is to examine the strengths and weaknesses of each biomarker.
RESULTS
Both biomarkers have non-GFR determinants, namely muscle mass, protein intake and tubular secretion for creatinine; dysthyroidism and systemic corticosteroids for cystatin C, as well as other more debated determinants (diabetes, obesity, proteinuria, inflammatory syndrome). These non-GFR determinants are the reason why no equation based on a single endogenous biomarker has an accuracy within 30% greater than 90% over the entire age spectrum (in at least one patient in 10, estimated GFR is at least 30% higher or at least 30% lower than the measured GFR).
CONCLUSION
Equations combining the two biomarkers provide a better estimate of GFR, particularly in the subgroup of patients whose estimates based on each of the biomarkers are highly discordant. These patients must also be identified as being at increased risk of morbidity, particularly cardiovascular, and mortality.
PubMed: 38949475
DOI: 10.1111/eci.14278 -
The Onderstepoort Journal of Veterinary... Jun 2024Wild animals, sharing pathogens with domestic animals, play a crucial role in the epidemiology of infectious diseases. Sampling from wild animals poses significant...
Wild animals, sharing pathogens with domestic animals, play a crucial role in the epidemiology of infectious diseases. Sampling from wild animals poses significant challenges, yet it is vital for inclusion in disease surveillance and monitoring programmes. Often, mass surveillance involves serological screenings using enzyme-linked immunosorbent assay (ELISA) tests, typically validated only for domestic animals. This study assessed the diagnostic specificity of commercially available ELISA tests on 342 wild ruminant serum samples and 100 from wild boars. We evaluated three tests for foot-and-mouth disease: two for Peste des petits ruminants, two for Rift Valley fever and one for Capripox virus. Diagnostic specificity was calculated using the formula True Negative/(False Positive + True Negative). Cohen's kappa coefficient measured agreement between tests. Results showed high specificity and agreement across all tests. Specificity for foot-and-mouth disease (FMD) ranged from 93.89% for Prionics to 100% for IDEXX, with IDvet showing 99.6%. The highest agreement was between FMD IDvet and IDEXX at 97.1%. Rift Valley fever (RVF) tests, Ingezim and IDvet, achieved specificities of 100% and 98.83%, respectively. The optimal specificity was attained by retesting single reactors and inactivating the complement.Contribution: Commercially available ELISA kits are specific for foot-and-mouth disease and similar transboundary animal diseases and can be used for highly specific wild animal testing.
Topics: Animals; Enzyme-Linked Immunosorbent Assay; Animals, Wild; Sensitivity and Specificity; Foot-and-Mouth Disease; Rift Valley Fever; Sus scrofa; Ruminants; Antibodies, Viral
PubMed: 38949427
DOI: 10.4102/ojvr.v91i1.2164 -
Paths of least resistance: Unconventional effector secretion by fungal and oomycete plant pathogens.Molecular Plant-microbe Interactions :... Jul 2024Effector secretion by different routes mediates the molecular interplay between host plant and pathogen, but mechanistic details in eukaryotes are sparse. This may limit...
Effector secretion by different routes mediates the molecular interplay between host plant and pathogen, but mechanistic details in eukaryotes are sparse. This may limit the discovery of new effectors that could be utilized for improving host plant disease resistance. In fungi and oomycetes, apoplastic effectors are secreted via the conventional ER-Golgi pathway while cytoplasmic effectors are packaged into vesicles that bypass Golgi in an unconventional protein secretion (UPS) pathway. In , the Golgi bypass UPS pathway incorporates components of the exocyst complex and a t-SNARE, presumably to fuse Golgi bypass vesicles to the fungal plasma membrane. Upstream, cytoplasmic effector mRNA translation in requires the efficient decoding of AA-ending codons. This involves the modification of wobble uridines in the anticodon loop of cognate tRNAs and fine-tunes cytoplasmic effector translation and secretion rates to maintain biotrophic interfacial complex integrity and permit host infection. Thus, plant-fungal interface integrity is intimately tied to effector codon usage, a surprising constraint on pathogenicity. Here, we discuss these findings within the context of fungal and oomycete effector discovery, delivery, and function in host cells. We show how cracking the codon code for unconventional cytoplasmic effector secretion in has revealed AA-ending codon usage bias in cytoplasmic effector mRNAs across kingdoms, including within the RxLR-dEER motif-encoding sequence of a bona fide cytoplasmic effector, suggesting its subjection to translational speed control. By focusing on recent developments in understanding unconventional effector secretion, we draw attention to this important but understudied area of host-pathogen interactions.
PubMed: 38949402
DOI: 10.1094/MPMI-12-23-0212-CR -
Journal of Diabetes Investigation Jul 2024Diabetes is an epidemic caused by a multitude of factors. Despite the studies attempting to unravel its mechanism, there is still more to discover about glucose-insulin...
Diabetes is an epidemic caused by a multitude of factors. Despite the studies attempting to unravel its mechanism, there is still more to discover about glucose-insulin dynamics. In a recent issue of the Journal of Clinical Investigation, Cheruiyot et al. uncovered a translational regulatory circuit during β-cell glucose toxicity that inherently affects the translational makeup and protein expression in functioning β-cells.Journal of Clinical Investigation, Cheruiyot et al. uncovered a translational regulatory circuit during β-cell glucose toxicity that inherently affects the translational makeup and protein expression in functioning β-cells. Their multiomics approach might provide a deeper understanding of high glucose and translational regulation of genes involved in β-cell insulin impairment caused by prolonged high-glucose exposure.
PubMed: 38949390
DOI: 10.1111/jdi.14258 -
Journal of Visualized Experiments : JoVE Jun 2024The repair of DNA double strand breaks (DSBs) is crucial for the maintenance of genome stability and cell viability. DSB repair (DSBR) in cells is mediated through...
The repair of DNA double strand breaks (DSBs) is crucial for the maintenance of genome stability and cell viability. DSB repair (DSBR) in cells is mediated through several mechanisms: homologous recombination (HR), non-homologous end joining (NHEJ), microhomology-mediated end joining (MMEJ), and single strand annealing (SSA). Cellular assays are essential to measure the proficiency and modulation of these pathways in response to various stimuli. Here, we present a suite of extrachromosomal reporter assays that each measure the reconstitution of a nanoluciferase reporter gene by one of the four major DSBR pathways in cells. Upon transient transfection into cells of interest, repair of pathway-specific reporter substrates can be measured in under 24 h by the detection of Nanoluciferase (NanoLuc) luminescence. These robust assays are quantitative, sensitive, titratable, and amenable to a high-throughput screening format. These properties provide broad applications in DNA repair research and drug discovery, complementing the currently available toolkit of cellular DSBR assays.
Topics: DNA Breaks, Double-Stranded; DNA Repair; Humans; High-Throughput Screening Assays; Luminescent Measurements; Genes, Reporter; Luciferases
PubMed: 38949387
DOI: 10.3791/66969 -
Journal of Visualized Experiments : JoVE Jun 2024Lung transplantation is hampered by the lack of suitable donors. Previously, donors that were thought to be marginal or inadequate were discarded. However, new and...
Lung transplantation is hampered by the lack of suitable donors. Previously, donors that were thought to be marginal or inadequate were discarded. However, new and exciting technology, such as ex vivo lung perfusion (EVLP), offers lung transplant providers extended assessment for marginal donor allografts. This dynamic assessment platform has led to an increase in lung transplantation and has allowed providers to use donors that were previously discarded, thus expanding the donor pool. Current perfusion techniques use cellular or acellular perfusates, and both have distinct advantages and disadvantages. Perfusion composition is critical to maintaining a homeostatic environment, providing adequate metabolic support, decreasing inflammation and cellular death, and ultimately improving organ function. Perfusion solutions must contain sufficient protein concentration to maintain appropriate oncotic pressure. However, current perfusion solutions often lead to fluid extravasation through the pulmonary endothelium, resulting in inadvertent pulmonary edema and damage. Thus, it is necessary to develop novel perfusion solutions that prevent excessive damage while maintaining proper cellular homeostasis. Here, we describe the application of a polymerized human hemoglobin (PolyhHb)-based oxygen carrier as a perfusate and the protocol in which this perfusion solution can be tested in a model of rat EVLP. The goal of this study is to provide the lung transplant community with key information in designing and developing novel perfusion solutions, as well as the proper protocols to test them in clinically relevant translational transplant models.
Topics: Animals; Rats; Lung Transplantation; Hemoglobins; Perfusion; Lung; Humans; Oxygen; Blood Substitutes; Male; Organ Preservation Solutions
PubMed: 38949382
DOI: 10.3791/66702