RESUMEN
Although blood-heart-barrier (BHB) leakage is the hallmark of congestive (cardio-pulmonary) heart failure (CHF), the primary cause of death in elderly, and during viral myocarditis resulting from the novel coronavirus variants such as the severe acute respiratory syndrome novel corona virus 2 (SARS-CoV-2) known as COVID-19, the mechanism is unclear. The goal of this project is to determine the mechanism of the BHB in CHF. Endocardial endothelium (EE) is the BHB against leakage of blood from endocardium to the interstitium; however, this BHB is broken during CHF. Previous studies from our laboratory, and others have shown a robust activation of matrix metalloproteinase-9 (MMP-9) during CHF. MMP-9 degrades the connexins leading to EE dysfunction. We demonstrated juxtacrine coupling of EE with myocyte and mitochondria (Mito) but how it works still remains at large. To test whether activation of MMP-9 causes EE barrier dysfunction, we hypothesized that if that were the case then treatment with hydroxychloroquine (HCQ) could, in fact, inhibit MMP-9, and thus preserve the EE barrier/juxtacrine signaling, and synchronous endothelial-myocyte coupling. To determine this, CHF was created by aorta-vena cava fistula (AVF) employing the mouse as a model system. The sham, and AVF mice were treated with HCQ. Cardiac hypertrophy, tissue remodeling-induced mitochondrial-myocyte, and endothelial-myocyte contractions were measured. Microvascular leakage was measured using FITC-albumin conjugate. The cardiac function was measured by echocardiography (Echo). Results suggest that MMP-9 activation, endocardial endothelial leakage, endothelial-myocyte (E-M) uncoupling, dyssynchronous mitochondrial fusion-fission (Mfn2/Drp1 ratio), and mito-myocyte uncoupling in the AVF heart failure were found to be rampant; however, treatment with HCQ successfully mitigated some of the deleterious cardiac alterations during CHF. The findings have direct relevance to the gamut of cardiac manifestations, and the resultant phenotypes arising from the ongoing complications of COVID-19 in human subjects.
Asunto(s)
COVID-19/complicaciones , Insuficiencia Cardíaca/metabolismo , Corazón/virología , Animales , Sangre/virología , Fenómenos Fisiológicos Sanguíneos/inmunología , COVID-19/fisiopatología , Cardiomegalia/metabolismo , Enfermedades Cardiovasculares/metabolismo , Fenómenos Fisiológicos Cardiovasculares/inmunología , Modelos Animales de Enfermedad , Endotelio/metabolismo , Corazón/fisiopatología , Insuficiencia Cardíaca/virología , Hidroxicloroquina/farmacología , Masculino , Metaloproteinasa 9 de la Matriz/efectos de los fármacos , Metaloproteinasa 9 de la Matriz/metabolismo , Ratones , Ratones Endogámicos C57BL , Células Musculares/metabolismo , Miocardio/metabolismo , SARS-CoV-2/metabolismo , SARS-CoV-2/patogenicidad , Remodelación Ventricular/fisiologíaRESUMEN
Traumatic brain injury (TBI) is a damage to the brain from an external force that results in temporary or permanent impairment in brain functions. Unfortunately, not many treatment options are available to TBI patients. Therefore, knowledge of the complex interplay between gut microbiome (GM) and brain health may shed novel insights as it is a rapidly expanding field of research around the world. Recent studies show that GM plays important roles in shaping neurogenerative processes such as blood-brain-barrier (BBB), myelination, neurogenesis, and microglial maturation. In addition, GM is also known to modulate many aspects of neurological behavior and cognition; however, not much is known about the role of GM in brain injuries. Since GM has been shown to improve cellular and molecular functions via mitigating TBI-induced pathologies such as BBB permeability, neuroinflammation, astroglia activation, and mitochondrial dysfunction, herein we discuss how a dysbiotic gut environment, which in fact, contributes to central nervous system (CNS) disorders during brain injury and how to potentially ward off these harmful effects. We further opine that a better understanding of GM-brain (GMB) axis could help assist in designing better treatment and management strategies in future for the patients who are faced with limited options.
Asunto(s)
Lesiones Traumáticas del Encéfalo/metabolismo , Eje Cerebro-Intestino/fisiología , Encéfalo/metabolismo , Disbiosis/metabolismo , Microbioma Gastrointestinal/fisiología , Animales , Encéfalo/inmunología , Lesiones Traumáticas del Encéfalo/inmunología , Lesiones Traumáticas del Encéfalo/terapia , Disbiosis/inmunología , Disbiosis/terapia , Humanos , Mediadores de Inflamación/inmunología , Mediadores de Inflamación/metabolismoRESUMEN
This study investigated the effects of long-term NF-κB inhibition in mitigating retinal vasculopathy in a type 1 diabetic mouse model (Akita, Ins2Akita). Akita and wild-type (C57BL/6J) male mice, 24 to 26 weeks old, were treated with or without a selective inhibitor of NF-κB, 4-methyl-N1-(3-phenyl-propyl) benzene-1,2-diamine (JSH-23), for 4 weeks. Treatment was given when the mice were at least 24 weeks old. Metabolic parameters, key inflammatory mediators, blood-retinal barrier junction molecules, retinal structure, and function were measured. JSH-23 significantly lowered basal glucose levels and intraocular pressure in Akita. It also mitigated vascular remodeling and microaneurysms significantly. Optical coherence tomography of untreated Akita showed thinning of retinal layers; however, treatment with JSH-23 could prevent it. Electroretinogram demonstrated that A- and B-waves in Akita were significantly smaller than in wild type mice, indicating that JSH-23 intervention prevented loss of retinal function. Protein levels and gene expression of key inflammatory mediators, such as NOD-like receptor family pyrin domain-containing 3, intercellular adhesion molecule-1, inducible nitric oxide synthase, and cyclooxygenase-2, were decreased after JSH-23 treatment. At the same time, connexin-43 and occludin were maintained. Vision-guided behavior also improved significantly. The results show that reducing inflammation could protect the diabetic retina and its vasculature. Findings appear to have broader implications in treating not only ocular conditions but also other vasculopathies.
Asunto(s)
Diabetes Mellitus Experimental/complicaciones , Inflamación/patología , FN-kappa B/antagonistas & inhibidores , Fenilendiaminas/farmacología , Enfermedades de la Retina/prevención & control , Enfermedades Vasculares/prevención & control , Animales , Apoptosis , Glucemia/análisis , Modelos Animales de Enfermedad , Electrorretinografía , Humanos , Hiperglucemia/patología , Leucocitos/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Mutación , FN-kappa B/metabolismo , Retina/diagnóstico por imagen , Retina/patología , Enfermedades de la Retina/diagnóstico por imagen , Enfermedades de la Retina/etiología , Enfermedades de la Retina/patología , Vasos Retinianos/diagnóstico por imagen , Vasos Retinianos/patología , Tomografía de Coherencia Óptica , Enfermedades Vasculares/diagnóstico por imagen , Enfermedades Vasculares/etiología , Enfermedades Vasculares/patologíaRESUMEN
Epigenetic memory plays crucial roles in gene regulation. It not only modulates the expression of specific genes but also has ripple effects on transcription as well as translation of other genes. Very often an alteration in expression occurs either via methylation or demethylation. In this context, "1-carbon metabolism" assumes a special significance since its dysregulation by higher levels of homocysteine; Hcy (known as hyperhomocysteinemia; HHcy), a byproduct of "1-Carbon Metabolism" during methionine biosynthesis leads to serious implications in cardiovascular, renal, cerebrovascular systems, and a host of other conditions. Currently, the circular RNAs (circRNAs) generated via non-canonical back-splicing events from the pre-mRNA molecules are at the center stage for their essential roles in diseases via their epigenetic manifestations. We recently identified a circular RNA transcript (circGRM4) that is significantly upregulated in the eye of cystathionine ß-synthase-deficient mice. We also discovered a concurrent over-expression of the mGLUR4 receptor in the eyes of these mice. In brief, circGRM4 is selectively transcribed from its parental mGLUR4 receptor gene (GRM4) functions as a "molecular-sponge" for the miRNAs and results into excessive turnover of the mGLUR4 receptor in the eye in response to extremely high circulating glutamate concentration. We opine that this epigenetic manifestation potentially predisposes HHcy people to retinovascular malfunctioning.
Asunto(s)
Cistationina betasintasa/genética , Ojo/irrigación sanguínea , Ojo/metabolismo , Ácido Glutámico/metabolismo , MicroARNs/metabolismo , ARN Circular/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Animales , Cistationina betasintasa/metabolismo , Células Endoteliales/metabolismo , Epigénesis Genética , Oftalmopatías/inducido químicamente , Oftalmopatías/genética , Oftalmopatías/metabolismo , Oftalmopatías/patología , Homocisteína/metabolismo , Humanos , Hiperhomocisteinemia/genética , MicroARNs/genética , ARN Circular/genética , Receptores de Glutamato Metabotrópico/genética , Enfermedades Vasculares/inducido químicamente , Enfermedades Vasculares/genética , Enfermedades Vasculares/metabolismo , Enfermedades Vasculares/patologíaRESUMEN
Epigenetic DNA methylation (1-carbon metabolism) is crucial for gene imprinting/off-printing that ensures epigenetic memory but also generates a copious amount of homocysteine (Hcy), unequivocally. That is why during pregnancy, expectant mothers are recommended "folic acid" preemptively to avoid birth defects in the young ones because of elevated Hcy levels (i.e., hyperhomocysteinemia (HHcy)). As we know, children born with HHcy have several musculoskeletal abnormalities, including growth retardation. Here, we focus on the gut-dysbiotic microbiome implication(s) that we believe instigates the "1-carbon metabolism" and HHcy causing growth retardation along with skeletal muscle abnormalities. We test our hypothesis whether high-methionine diet (HMD) (an amino acid that is high in red meat), a substrate for Hcy, can cause skeletal muscle and growth retardation, and treatment with probiotics (PB) to mitigate skeletal muscle dysfunction. To test this, we employed cystathionine ß-synthase, CBS deficient mouse (CBS+/-) fed with/without HMD and with/without a probiotic (Lactobacillus rhamnosus) in drinking water for 16 weeks. Matrix metalloproteinase (MMP) activity, a hallmark of remodeling, was measured by zymography. Muscle functions were scored via electric stimulation. Our results suggest that compared to the wild-type, CBS+/- mice exhibited reduced growth phenotype. MMP-2 activity was robust in CBS+/- and HMD effects were successfully attenuated by PB intervention. Electrical stimulation magnitude was decreased in CBS+/- and CBS+/- treated with HMD. Interestingly; PB mitigated skeletal muscle growth retardation and atrophy. Collectively, results imply that individuals with mild/moderate HHcy seem more prone to skeletal muscle injury and its dysfunction.
Asunto(s)
Disbiosis/complicaciones , Trastornos del Crecimiento/prevención & control , Hiperhomocisteinemia/complicaciones , Músculo Esquelético/patología , Probióticos/administración & dosificación , Animales , Cistationina betasintasa/deficiencia , Cistationina betasintasa/genética , Metilación de ADN , Modelos Animales de Enfermedad , Disbiosis/metabolismo , Disbiosis/microbiología , Disbiosis/terapia , Epigénesis Genética , Femenino , Microbioma Gastrointestinal/fisiología , Trastornos del Crecimiento/sangre , Trastornos del Crecimiento/metabolismo , Trastornos del Crecimiento/patología , Homocisteína/sangre , Homocisteína/metabolismo , Humanos , Hiperhomocisteinemia/sangre , Hiperhomocisteinemia/genética , Hiperhomocisteinemia/metabolismo , Lacticaseibacillus rhamnosus , Masculino , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 2 de la Matriz/metabolismo , Metionina/administración & dosificación , Metionina/metabolismo , Ratones , Ratones Transgénicos , Músculo Esquelético/metabolismoRESUMEN
Hyperhomocysteinemia (HHcy) affects bone remodeling, since a destructive process in cortical alveolar bone has been linked to it; however, the mechanism remains at large. HHcy increases proinflammatory cytokines viz. TNF-α, IL-1b, IL-6, and IL-8 that leads to a cascade that negatively impacts methionine metabolism and homocysteine cycling. Further, chronic inflammation decreases vitamins B12, B6, and folic acid that are required for methionine homocysteine homeostasis. This study aims to investigate a HHcy mouse model (cystathionine ß-synthase deficient, CBS+/-) for studying the potential pathophysiological changes, if any, in the periodontium (gingiva, periodontal ligament, cement, and alveolar bone). We compared the periodontium side-by-side in the CBS+/- model with that of the wild-type (C57BL/6J) mice. Histology and histomorphometry of the mandibular bone along with gene expression analyses were carried out. Also, proangiogenic proteins and metalloproteinases were studied. To our knowledge, this research shows, for the first time, a direct connection between periodontal disease during CBS deficiency, thereby suggesting the existence of disease drivers during the hyperhomocysteinemic condition. Our findings offer opportunities to develop diagnostics/therapeutics for people who suffer from chronic metabolic disorders like HHcy.
Asunto(s)
Cistationina betasintasa/deficiencia , Hiperhomocisteinemia/complicaciones , Periodontitis/inmunología , Periodoncio/patología , Animales , Cistationina betasintasa/genética , Modelos Animales de Enfermedad , Ácido Fólico , Homocisteína/sangre , Homocisteína/metabolismo , Humanos , Hiperhomocisteinemia/sangre , Hiperhomocisteinemia/inmunología , Hiperhomocisteinemia/metabolismo , Masculino , Ratones , Ratones Transgénicos , Estrés Oxidativo/inmunología , Periodontitis/patología , Periodoncio/inmunologíaRESUMEN
Research demonstrates that senescence is associated with tissue and organ dysfunction, and the eye is no exception. Sequelae arising from aging have been well defined as distinct clinical entities and vision impairment has significant psychosocial consequences. Retina and adjacent tissues like retinal pigmented epithelium and choroid are the key structures that are required for visual perception. Any structural and functional changes in retinal layers and blood retinal barrier could lead to age-related macular degeneration, diabetic retinopathy, and glaucoma. Further, there are significant oxygen gradients in the eye that can lead to excessive reactive oxygen species, resulting in endoplasmic reticulum and mitochondrial stress response. These radicals are source of functional and morphological impairment in retinal pigmented epithelium and retinal ganglion cells. Therefore, ocular diseases could be summarized as disturbance in the redox homeostasis. Hyperhomocysteinemia is a risk factor and causes vascular occlusive disease of the retina. Interestingly, hydrogen sulfide (H2S) has been proven to be an effective antioxidant agent, and it can help treat diseases by alleviating stress and inflammation. Concurrent glutamate excitotoxicity, endoplasmic reticulum stress, and microglia activation are also linked to stress; thus, H2S may offer additional interventional strategy. A refined understanding of the aging eye along with H2S biology and pharmacology may help guide newer therapies for the eye.
Asunto(s)
Envejecimiento/fisiología , Ojo/efectos de los fármacos , Sulfuro de Hidrógeno/farmacología , Envejecimiento/efectos de los fármacos , Animales , HumanosRESUMEN
Periodontal disease is one of the most common conditions resulting from poor oral hygiene and is characterized by a destructive process in the periodontium that essentially includes gingiva, alveolar mucosa, cementum, periodontal ligament, and alveolar bone. Notably, the destructive event in the alveolar bone has been linked to homocysteine (Hcy) metabolism; however, it has not been fully investigated. Therefore; the implication of Hcy towards initiation, progression, and maintenance of the periodontal disease remains incompletely understood. Higher levels of Hcy (also known as hyperhomocysteinemia (HHcy)) exerts deleterious effects on gum health and teeth in distinct ways. Firstly, increased production of proinflammatory cytokines such as TNF-α, IL-1ß, IL-6, and IL-8 leads to an inflammatory cascade of events that affect methionine (Met) and Hcy metabolism (i.e., 1-carbon metabolism) leading to HHcy. Secondly, metabolic dysregulation during chronic medical conditions increases systemic inflammation leading to a decrease in vitamins, more specifically B6, B12, and folic acid, that play important roles as cofactors in Hcy metabolism. Also, given the folate level in the HHcy state that is important during dysbiosis, these two conditions appear to be intimately related, and in this context, HHcy-induced dysbiosis may be one of the potential causes of periodontal disease. This paper sums up the link between periodontitis and HHcy, with a special emphasis on the "oral-gut microbiome axis" and the potential probiotic intervention towards warding off some of the serious periodontal disease conditions.
Asunto(s)
Disbiosis/complicaciones , Microbioma Gastrointestinal/fisiología , Homocisteína/metabolismo , Hiperhomocisteinemia/inmunología , Periodontitis/inmunología , Disbiosis/sangre , Disbiosis/inmunología , Disbiosis/microbiología , Ácido Fólico/sangre , Ácido Fólico/metabolismo , Homocisteína/sangre , Homocisteína/inmunología , Humanos , Hiperhomocisteinemia/sangre , Hiperhomocisteinemia/metabolismo , Metionina/metabolismo , Periodontitis/sangre , Periodontitis/metabolismo , ProbióticosRESUMEN
Hidradenitis suppurativa (HS) is a chronic, inflammatory skin condition characterized by painful nodules which suppurate and later develop into scar tissues followed by the development of hypodermal tracts. Although the mechanisms behind HS are not fully understood, it is known that dietary factors play important roles in flare frequency and severity. We hypothesize that the high fat diet (HFD) causes dysbiosis, systemic inflammation, and hyperhomocysteinemia (HHcy) in susceptible individuals, which subsequently elevate inflammatory cytokines such as IL-1ß, IL-6, IL-17, and tumor necrosis factor alpha (TNF-α). This increase in dysbiosis-led inflammation coupled with a dysregulation of the 1-carbon metabolism results in an increase in matrix metalloproteinases MMP-2, MMP-8, and MMP-9 along with tissue matrix remodeling in the development and maintenance of the lesions and tracts. This manuscript weaves together the potential roles played by the gut microbiome, HHcy, MMPs, and the 1-carbon metabolism toward HS disease causation in susceptible individuals.
Asunto(s)
Bacterias/metabolismo , Dieta Alta en Grasa/efectos adversos , Microbioma Gastrointestinal , Hidradenitis Supurativa/etiología , Homocisteína/sangre , Hiperhomocisteinemia/complicaciones , Metaloproteinasas de la Matriz/metabolismo , Piel/enzimología , Animales , Biomarcadores/sangre , Disbiosis , Hidradenitis Supurativa/enzimología , Hidradenitis Supurativa/microbiología , Hidradenitis Supurativa/patología , Humanos , Hiperhomocisteinemia/sangre , Medición de Riesgo , Factores de Riesgo , Piel/patologíaRESUMEN
Although a high-fat diet (HFD) induces gut dysbiosis and cardiovascular system remodeling, the precise mechanism is unclear. We hypothesize that HFD instigates dysbiosis and cardiac muscle remodeling by inducing matrix metalloproteinases (MMPs), which leads to an increase in white adipose tissue, and treatment with lactobacillus (a ketone body donor from lactate; the substrate for the mitochondria) reverses dysbiosis-induced cardiac injury, in part, by increasing lipolysis (PGC-1α, and UCP1) and adipose tissue browning and decreasing lipogenesis. To test this hypothesis, we used wild type (WT) mice fed with HFD for 16 weeks with/without a probiotic (PB) in water. Cardiac injury was measured by CKMB activity which was found to be robust in HFD-fed mice. Interestingly, CKMB activity was normalized post PB treatment. Levels of free fatty acids (FFAs) and methylation were increased but butyrate was decreased in HFD mice, suggesting an epigenetically governed 1-carbon metabolism along with dysbiosis. Levels of PGC-1α and UCP1 were measured by Western blot analysis, and MMP activity was scored via zymography. Collagen histology was also performed. Contraction of the isolated myocytes was measured employing the ion-optic system, and functions of the heart were estimated by echocardiography. Our results suggest that mice on HFD gained weight and exhibited an increase in blood pressure. These effects were normalized by PB. Levels of fibrosis and MMP-2 activity were robust in HFD mice, and treatment with PB mitigated the fibrosis. Myocyte calcium-dependent contraction was disrupted by HFD, and treatment with PB could restore its function. We conclude that HFD induces dysbiosis, and treatment with PB creates eubiosis and browning of the adipose tissue.
RESUMEN
Homocysteine (Hcy), a sulfur-containing nonproteinogenic amino acid, is generated as a metabolic intermediate. Hcy constitutes an important part of the "1-carbon metabolism" during methionine turnover. Elevated levels of Hcy known as hyperhomocysteinemia (HHcy) results from vitamin B deficiency, lack of exercise, smoking, excessive alcohol intake, high-fat and methionine-rich diet, and the underlying genetic defects. These factors directly affect the "1-carbon metabolism (methionine-Hcy-folate)" of a given cell. In fact, the Hcy levels are determined primarily by dietary intake, vitamin status, and the genetic blueprint of the susceptible individual. Although Hcy performs an important role in cellular functions, genetic alterations in any of the key enzymes responsible for the "1-carbon metabolism" could potentially upset the metabolic cycle, thus causing HHcy environment in susceptible people. As such, HHcy relates to several clinical conditions like atherosclerosis, myocardial infarction, stroke, cognitive impairment, dementia, Parkinson's disease, multiple sclerosis, epilepsy, and ocular disorders, among others. This article summarizes the findings from our laboratory and public database regarding genetics of HHcy and its effects on ocular disorders, their respective management during dysregulation of the 1-carbon metabolism.
Asunto(s)
Carbono/metabolismo , Hiperhomocisteinemia/genética , Hiperhomocisteinemia/metabolismo , Retina/patología , Retina/fisiopatología , Animales , Humanos , Hiperhomocisteinemia/patología , Hiperhomocisteinemia/fisiopatologíaRESUMEN
Unless there is a genetic defect/mutation/deletion in a gene, the causation of a given disease is chronic dysregulation of gut metabolism. Most of the time, if not always, starts within the gut; that is what we eat. Recent research shows that the imbalance between good versus bad microbial population, especially in the gut, causes systemic diseases. Thus, an appropriate balance of the gut microbiota (eubiosis over dysbiosis) needs to be maintained for normal health (Veeranki and Tyagi, 2017, Journal of Cellular Physiology, 232, 2929-2930). However, during various diseases such as metabolic syndrome, inflammatory bowel disease, diabetes, obesity, and hypertension the dysbiotic gut environment tends to prevail. Our research focuses on homocysteine (Hcy) metabolism that occupies a center-stage in many biochemically relevant epigenetic mechanisms. For example, dysbiotic bacteria methylate promoters to inhibit gene activities. Interestingly, the product of the 1-carbon metabolism is Hcy, unequivocally. Emerging studies show that host resistance to various antibiotics occurs due to inverton promoter inhibition, presumably because of promoter methylation. This results from modification of host promoters by bacterial products leading to loss of host's ability to drug compatibility and system sensitivity. In this study, we focus on the role of high methionine diet (HMD), an ingredient rich in red meat and measure the effects of a probiotic on cardiac muscle remodeling and its functions. We employed wild type (WT) and cystathionine beta-synthase heterozygote knockout (CBS+/- ) mice with and without HMD and with and without a probiotic; PB (Lactobacillus) in drinking water for 16 weeks. Results indicate that matrix metalloproteinase-2 (MMP-2) activity was robust in CBS+/- fed with HMD and that it was successfully attenuated by the PB treatment. Cardiomyocyte contractility and ECHO data revealed mitigation of the cardiac dysfunction in CBS+/- + HMD mice treated with PB. In conclusion, our data suggest that probiotics can potentially reverse the Hcy-meditated cardiac dysfunction.
Asunto(s)
Cistationina betasintasa/genética , Disbiosis/metabolismo , Microbioma Gastrointestinal/genética , Homocisteína/metabolismo , Animales , Carbono/metabolismo , Modelos Animales de Enfermedad , Disbiosis/genética , Disbiosis/microbiología , Epigénesis Genética/genética , Homocisteína/genética , Humanos , Lactobacillus/efectos de los fármacos , Lactobacillus/metabolismo , Metaloproteinasa 2 de la Matriz/genética , Ratones , Ratones Noqueados , Miocardio/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Probióticos/farmacologíaRESUMEN
Retinal degeneration from inherited gene mutation(s) is a common cause of blindness because of structural and functional alterations in photoreceptors. Accordingly, various approaches are being tested to ameliorate or even cure neuroretinal blinding conditions in susceptible patients by employing neuroprotective agents, gene therapeutics, optogenetics, regenerative therapies, and retinal prostheses. The FVB/NJ mouse strain inherently has a common Pde6b rd1 homozygous allele that renders its progeny blind by the time pups reach weaning age. To study the role matrix metalloproteinase-9 (MMP-9) in retinal structure and function, we examined a global MMP-9 knockout (KO) mouse model that has been engineered on the same FVB/NJ background to test the hypothesis whether lack of MMP-9 activity diminishes neuroretinal degenerative changes and thus helps improve the vision. We compared side-by-side various aspects of the ocular physiology in the wild-type (WT) C57BL/6J, FVB/NJ, and MMP-9 KO strains of mice. The results suggest that MMP-9 KO mice display subdued changes in their retinae as reflected by both structural and functional enhancement in the overall ocular neurophysiological parameters. Altogether, the findings appear to have clinical relevance for targeting conditions wherein MMPs and their overactivities are suspected to play dominant pathophysiological roles in advancing neurodegenerative retinal diseases.
Asunto(s)
Metaloproteinasa 9 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/metabolismo , Retina/patología , Degeneración Retiniana/genética , Degeneración Retiniana/fisiopatología , Remodelación Vascular/genética , Animales , Modelos Animales de Enfermedad , Femenino , Técnicas de Inactivación de Genes , Homeostasis/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Visión Ocular/genéticaRESUMEN
Recent studies have shown that the integrity of the gastrointestinal tract and its microbiome impact the functioning of various body systems by regulating immunological responses, extracting energy, remodeling intestinal epithelia, and strengthening the gut itself. The gastrointestinal tract microbiota includes bacteria, fungi, protozoa, viruses, and archaea which collectively comprise a dynamic community prone to alterations via influences such as the environment, illness, and metabolic processes. The idea that the host's diet possesses characteristics that could potentially alter microbiota composition is a novel notion. We hypothesize that a high fat diet leads to the alteration of the gastrointestinal microbiota composition and that metabolic transformation of the compound trimethylamine into trimethylamine-N-oxide promotes vasculopathy such as atherosclerosis and affects cardiovascular functionality. Furthermore, we hypothesize that treatment with probiotics will restore the homeostatic environment (eubiosis) of the gastrointestinal tract.
Asunto(s)
Aterosclerosis/metabolismo , Bacterias/metabolismo , Dieta Alta en Grasa/efectos adversos , Endotelio Vascular/metabolismo , Microbioma Gastrointestinal , Metilaminas/metabolismo , Animales , Aterosclerosis/microbiología , Aterosclerosis/fisiopatología , Aterosclerosis/terapia , Bacterias/crecimiento & desarrollo , Disbiosis , Endotelio Vascular/fisiopatología , Interacciones Huésped-Patógeno , Humanos , Lípidos/sangre , Placa Aterosclerótica , Probióticos/uso terapéutico , Factores de RiesgoRESUMEN
Homocysteine, a non-proteinogenic amino acid but an important metabolic intermediate is generated as an integral component for the "1-carbon metabolism" during normal physiology. It is catabolized to cysteine via the transulfuration pathway resulting in the generation of hydrogen sulfide, a naturally endogenous byproduct. Genetics or metabolic derangement can alter homocysteine concentration leading to hyperhomocysteinemia (HHcy), a physiologically unfavorable condition that causes serious medical conditions including muscle wasting. HHcy environment can derail physiological processes by targeting biomolecules such as Akt; however, not much is known regarding the effects of HHcy on regulation of transcription factors such as forkhead box O (FOXO) proteins. Recently, hydrogen sulfide has been shown to be highly effective in alleviating the effects of HHcy by serving as an antiapoptotic factor, but role of FOXO and its interaction with hydrogen sulfide are yet to be established. In this review, we discuss role(s) of HHcy in skeletal muscle atrophy and how HHcy interact with FOXO and peroxisome proliferator-activated receptor gamma coactivator 1-alpha expressions that are relevant in musculoskeletal atrophy. Further, therapeutic intervention with hydrogen sulfide for harnessing its beneficial effects might help mitigate the dysregulated 1-carbon metabolism that happens to be the hallmark of HHcy-induced pathologies such as muscle atrophy.
Asunto(s)
Carbono/metabolismo , Factores de Transcripción Forkhead/metabolismo , Atrofia Muscular/metabolismo , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo , Animales , Humanos , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Atrofia Muscular/patologíaRESUMEN
AIM: To investigate the applications of hydrogen sulï¬de (H2S) in eye-specific ailments in mice. METHODS: Heterozygous cystathionine-ß-synthase (CBS+/-) and wild-type C57BL/6J (WT) mice fed with or without high methionine diet (HMD) were administered either phosphate buffered saline (PBS) or the slow-release H2S donor: GYY4137. Several analyses were performed to study GYY4137 effects by examining retinal lysates for key protein expressions along with plasma glutamate and glutathione estimations. Intraocular pressure (IOP) was monitored during GYY4137 treatment; barium sulfate and bovine serum albumin conjugated fluorescein isothiocyanate (BSA-FITC) angiographies were performed for examining vasculature and its permeability post-treatment. Vision-guided behavior was also tested employing novel object recognition test (NORT) and light-dark box test (LDBT) recordings. RESULTS: CBS deficiency (CBS+/-) coupled with HMD led disruption of methionine/homocysteine (Hcy) metabolism leading to hyperhomocysteinemia (HHcy) in CBS+/- mice as reflected by increased Hcy, and s-adenosylhomocysteine hydrolase (SAHH) levels. Unlike CBS, cystathionine-γ lyase (CSE), methylenetetrahydrofolate reductase (MTHFR) levels which were reduced but compensated by GYY4137 intervention. Heightened oxidative and endoplasmic reticulum (ER) stress responses were mitigated by GYY4137 effects along with enhanced glutathione (GSH) levels. Increased glutamate levels in CBS+/- strain were prominent than WT mice and these mice also exhibited higher IOP that was lowered by GYY4137 treatment. CBS deficiency also resulted in vision-guided behavioral impairment as revealed by NORT and LDBT findings. Interestingly, GYY4137 was able to improve CBS+/- mice behavior together with lowering their glutamate levels. Blood-retinal barrier (BRB) appeared compromised in CBS+/- with vessels' leakage that was mitigated in GYY4137 treated group. This corroborated the results for occludin (an integral plasma membrane protein of the cellular tight junctions) stabilization. CONCLUSION: Findings reveal that HHcy-induced glutamate excitotoxicity, oxidative damage, ER-stress and vascular permeability alone or together can compromise ocular health and that GYY4137 could serve as a potential therapeutic agent for treating HHcy induced ocular disorders.
RESUMEN
The objectives of this study are to identify the mechanism of mitochondrial dysfunction during cerebral ischemic/reperfusion (I/R) injury and the therapeutic potential of tetrahydrocurcumin (THC) to mitigate mitochondrial dysfunction in experimental stroke model. In our study, 8-10 weeks old male C57BL/6 wild-type mice were subjected to middle cerebral artery occlusion (MCAO) for 40 min, followed by reperfusion for 72 h. THC (25mg/kg-BW/day) was injected intraperitoneally once daily for 3 days after 4 h of ischemia. The experimental groups were: (i) sham, (ii) I/R and (iii) I/R + THC. We noticed that THC treatment in ischemic mice significantly improved the functional capacity and motor co-ordination along with reduced neuroscore, infarct volume, brain edema and microvascular leakage in brain parenchyma. The study revealed that level of total homocysteine (tHcy), homocysteine metabolizing enzymes, mitochondrial oxidative stress were significantly altered in I/R mice compared to sham. We also observed alteration in mitochondrial transition pore, ATP production and O2 consumption in the ischemic brain as compared to sham. Further, elevated matrix metalloproteinases-9 (MMP-9) activity and reduced tight junction protein expressions intensified the brain vascular impairment in I/R mice compared to sham. Interestingly, we found that levels of mitophagy markers, fusion and fission proteins were significantly altered. However THC treatment in I/R mice almost normalized the above functional and molecular changes. Mechanistic study demonstrated that DNA Methyltransferase 1 (DNMT1) expression was higher and was associated with reduced mitochondrial tissue inhibitor of metalloproteinases 2 (TIMP-2) expression through hyper-methylation of CpG island of TIMP-2 promoter in I/R mice compared to sham. However, administration of epigenetic inhibitor, 5-Azacytidine (5-Aza) abrogated I/R induced hyper-methylation of TIMP-2 promoter and maintaining the extracellular matrix (ECM) integrity. In conclusion, this study suggests that THC epigenetically ameliorates mitochondrial dysfunction in brain vasculature during Ischemic Stroke.
Asunto(s)
Isquemia Encefálica/tratamiento farmacológico , Encéfalo/efectos de los fármacos , Curcumina/análogos & derivados , Mitocondrias/efectos de los fármacos , Animales , Barrera Hematoencefálica/efectos de los fármacos , Barrera Hematoencefálica/metabolismo , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Curcumina/farmacología , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/metabolismo , Masculino , Ratones Endogámicos C57BL , Mitocondrias/metabolismo , Daño por Reperfusión/tratamiento farmacológico , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/metabolismoRESUMEN
PURPOSE: To characterize the global profile of circular RNAs (circRNAs) and their differential expression levels in homocysteine (Hcy)-treated ARPE-19 cells, a line of human retinal pigment epithelial (RPE) cells. MATERIALS AND METHODS: We treated ARPE-19 cells with and without Hcy to investigate the influence of Hcy on circRNA expression levels using dedicated human circRNA microarrays. RESULTS: A total of 12,233 circRNAs were identified out of them 54 were differentially expressed (17 were down-regulated, and 37 were up-regulated) with a fold change >2.0 (p < 0.05) in Hcy-treated versus untreated cells. CONCLUSIONS: To our knowledge, this is the first report profiling circRNAs in human RPE cells post-Hcy treatment mimicking hyperhomocysteinemic (HHcy) conditions that negatively affect retinal biology and vision. These findings are of potential clinical significance as they will help understand Hcy metabolism and HHcy-mediated diseases and identify potential diagnostic and therapeutic targets for eye diseases that are caused by elevated Hcy concentrations.
Asunto(s)
Regulación de la Expresión Génica/fisiología , Homocisteína/farmacología , ARN Circular/genética , Epitelio Pigmentado de la Retina/efectos de los fármacos , Línea Celular , Epigenómica , Perfilación de la Expresión Génica , Humanos , MicroARNs/genética , Epitelio Pigmentado de la Retina/metabolismo , Regulación hacia ArribaRESUMEN
Elevated homocysteine (Hcy), i.e., hyperhomocysteinemia (HHcy), causes skeletal muscle myopathy. Among many cellular and metabolic alterations caused by HHcy, oxidative and endoplasmic reticulum (ER) stress are considered the major ones; however, the precise molecular mechanism(s) in this process is unclear. Nevertheless, there is no treatment option available to treat HHcy-mediated muscle injury. Hydrogen sulfide (H2S) is increasingly recognized as a potent anti-oxidant, anti-apoptotic/necrotic/pyroptotic, and anti-inflammatory compound and also has been shown to improve angiogenesis during ischemic injury. Patients with CBS mutation produce less H2S, making them vulnerable to Hcy-mediated cellular damage. Many studies have reported bidirectional regulation of ER stress in apoptosis through JNK activation and concomitant attenuation of cell proliferation and protein synthesis via PI3K/AKT axis. Whether H2S mitigates these detrimental effects of HHcy on muscle remains unexplored. In this review, we discuss molecular mechanisms of HHcy-mediated oxidative/ER stress responses, apoptosis, angiogenesis, and atrophic changes in skeletal muscle and how H2S can restore skeletal muscle homeostasis during HHcy condition. This review also highlights the molecular mechanisms on how H2S could be developed as a clinically relevant therapeutic option for chronic conditions that are aggravated by HHcy.
Asunto(s)
Estrés del Retículo Endoplásmico , Homeostasis , Sulfuro de Hidrógeno/metabolismo , Hiperhomocisteinemia/metabolismo , Músculo Esquelético/metabolismo , Estrés Oxidativo , Animales , Humanos , Hiperhomocisteinemia/patología , Músculo Esquelético/patologíaRESUMEN
Circular RNAs (circRNAs) are being hailed as a newly rediscovered class of covalently closed transcripts that are produced via alternative, noncanonical pre-mRNA back-splicing events. These single-stranded RNA molecules have been identified in organisms ranging from the worm (Cortés-López et al. 2018. BMC Genomics, 19: 8; Ivanov et al. 2015. Cell Rep. 10: 170-177) to higher eukaryotes (Yang et al. 2017. Cell Res. 27: 626-641) to plants (Li et al. 2017. Biochem. Biophys. Res. Commun. 488: 382-386). At present, research on circRNAs is an active area because of their diverse roles in development, health, and diseases. Partly because their circularity makes them resistant to degradation, they hold great promise as unique biomarkers for ocular and central nervous system (CNS) disorders. We believe that further work on their applications could help in developing them as "first-in-class" diagnostics, therapeutics, and prognostic targets for numerous eye conditions. Interestingly, many circRNAs play key roles in transcriptional regulation by acting as miRNAs sponges, meaning that they serve as master regulators of RNA and protein expression. Since the retina is an extension of the brain and is part of the CNS, we highlight the current state of circRNA biogenesis, properties, and function and we review the crucial roles that they play in the eye and the brain. We also discuss their regulatory roles as miRNA sponges, regulation of their parental genes or linear mRNAs, translation into micropeptides or proteins, and responses to cellular stress. We posit that future advances will provide newer insights into the fields of RNA metabolism in general and diseases of the aging eye and brain in particular. Furthermore, in keeping pace with the rapidly evolving discipline of RNA"omics"-centered metabolism and to achieve uniformity among researchers, we recently introduced the term "cromics" (circular ribonucleic acids based omics) (Singh et al. 2018. Exp. Eye Res. 174: 80-92).