Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 430
Filtrar
1.
J Ethnopharmacol ; 336: 118742, 2025 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-39197806

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: In traditional Persian medicine (TPM), people often use herbal infusions as a dosage form to treat diseases related to hyperglycemia, known as 'dam-kardeh'. Traditionally, herbal preparations of Eryngium bungei Boiss. (E. b), Tragopogon buphthalmoides (DC.) Boiss. (T. b), Salvia hydrangea DC. ex Benth. (S. h), and Juniperus polycarpos K. Koch. (J. p) are used to manage diabetes in Iran. However, there is no evidence of their effectiveness in controlling glucose levels and their mechanisms remain unclear. AIM OF THE STUDY: This study aimed to investigate whether traditional doses of plant infusions can have hypoglycemic and/or anti-hyperglycemic effects during fasting and/or postprandial states and establish the basis for future research on their potential mechanisms of action. MATERIALS AND METHODS: The effects of traditional doses of herbal extracts on blood glucose levels in STZ-NA-induced hyperglycemic rats were investigated in 2-h acute tests during fasting and postprandial states (with a glucose load). In addition, the potential inhibitory effect in vitro of enzymes involved in relevant pathways, such as gluconeogenesis (fructose-1,6-bisphosphatase, FBPase and glucose-6-phosphatase, G6Pase), carbohydrate breakdown (intestinal α-glucosidases), and insulin sensitivity (protein tyrosine phosphatase 1B, PTP-1B) was evaluated. Acute toxicity tests were carried out and HPLC-SQ-TOF was used to analyze the chemical profiles of the plant extracts. RESULTS: In the fasting state, T. b, S. h, and E. b were as effective as glibenclamide in lowering blood glucose levels in hyperglycemic rats. Moreover, all three suppressed G6Pase and FBPase enzymatic activity by 90-97% and 80-91%, respectively. On the other hand, significant postprandial hypoglycemic efficacy was observed for E. b, S. h, and T. b. Based on the AUC values, T. b caused a reduction comparable to the therapeutic efficacy of repaglinide. When investigating the possible mechanisms of action involved in this activity, E. b, S. h, and T. b showed significant inhibition of PTP-1B in vitro (>70%). Finally, all plant extracts showed no signs of acute toxicity. Several compounds that may contribute to biological activities were identified, including phenolic acids and flavonoid glycosides. CONCLUSIONS: The present study supports the traditional use of T. b, E. b and S. h for the control of diabetes in the fasting and postprandial state. Moreover, these plants were found to be rich in bioactive compounds with hypoglycemic and antihyperglycemic activities. On the other hand, J. p, showed a modest effect only in the fasting state and after 90 min. Further studies are needed to expand these results by analyzing the chemical composition and using complementary experimental models.


Asunto(s)
Glucemia , Diabetes Mellitus Experimental , Ayuno , Hipoglucemiantes , Extractos Vegetales , Periodo Posprandial , Animales , Hipoglucemiantes/farmacología , Extractos Vegetales/farmacología , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/sangre , Masculino , Irán , Ratas , Medicina Persa , Ratas Wistar , Hiperglucemia/tratamiento farmacológico , Plantas Medicinales/química , Estreptozocina , Juniperus/química
2.
Biol Res ; 57(1): 69, 2024 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-39342392

RESUMEN

BACKGROUND: The LYP tyrosine phosphatase presents a SNP (1858C > T) that increases the risk of developing autoimmune diseases such as type I diabetes and arthritis. It remains unclear how this SNP affects LYP function and promotes the development of these diseases. The scarce information about LYP substrates is in part responsible for the poor understanding of LYP function. RESULTS: In this study, we identify in T lymphocytes several adaptor proteins as potential substrates targeted by LYP, including FYB, SLP-76, HS-1, Vav, SKAP1 and SKAP2. We also show that LYP co-localizes with SLP76 in microclusters, upon TCR engagement. CONCLUSIONS: These data indicate that LYP may modulate T cell activation by dephosphorylating several adaptor proteins, such as FYB, SLP-76, HS-1, Vav, SKAP1 and SKAP2 upon TCR engagement.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Fosfoproteínas , Proteína Asociada a la Molécula de Señalización de la Activación Linfocitaria , Linfocitos T , Humanos , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Células Jurkat , Activación de Linfocitos , Fosfoproteínas/metabolismo , Fosforilación , Proteínas Tirosina Fosfatasas/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Linfocitos T/metabolismo , Proteína Asociada a la Molécula de Señalización de la Activación Linfocitaria/genética , Proteína Asociada a la Molécula de Señalización de la Activación Linfocitaria/metabolismo
3.
J Fungi (Basel) ; 10(8)2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39194857

RESUMEN

Stress management is an adaptive advantage for survival in adverse environments. Pathogens face this challenge during host colonization, requiring an appropriate stress response to establish infection. The fungal pathogen Cryptococcus neoformans undergoes thermal, oxidative, and osmotic stresses in the environment and animal host. Signaling systems controlled by Ras1, Hog1, and calcineurin respond to high temperatures and osmotic stress. Cationic stress caused by Na+, K+, and Li+ can be overcome with glycerol, the preferred osmolyte. Deleting the glycerol phosphate phosphatase gene (GPP2) prevents cells from accumulating glycerol due to a block in the last step of its biosynthetic pathway. Gpp2 accumulates in a phosphorylated form in a cna1Δ strain, and a physical interaction between Gpp2 and Cna1 was found; moreover, the gpp2Δ strain undergoes slow growth and has attenuated virulence in animal models of infection. We provide biochemical evidence that growth in 1 M NaCl increases glycerol content in the wild type, whereas gpp2Δ, cna1Δ, and cnb1Δ mutants fail to accumulate it. The deletion of cnb1Δ or cna1Δ renders yeast cells sensitive to cationic stress, and the Gfp-Gpp2 protein assumes an abnormal localization. We suggest a mechanism in which calcineurin controls Gpp2 at the post-translational level, affecting its localization and activity, leading to glycerol biosynthesis. Also, we showed the transcriptional profile of glycerol-deficient mutants and established the cationic stress response mediated by calcineurin; among the biological processes differentially expressed are carbon utilization, translation, transmembrane transport, glutathione metabolism, oxidative stress response, and transcription regulation. To our knowledge, this is the first time that this transcriptional profile has been described. These results have implications for pathogen stress adaptability.

4.
Braz J Microbiol ; 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39044105

RESUMEN

Fonsecaea pedrosoi is a melanized fungus that causes chromoblastomycosis (CBM), a tropical neglected disease responsible for chronic and disability-related subcutaneous mycosis. Given the challenging nature of CBM treatment, the study of new targets and novel bioactive drugs capable of improving patient life quality is urgent. In the present work, we detected a calcineurin activity in F. pedrosoi conidial form, employing primarily colorimetric, immunoblotting and flow cytometry assays. Our findings reveal that the calcineurin activity of F. pedrosoi was stimulated by Ca2+/calmodulin, inhibited by EGTA and specific inhibitors, such as tacrolimus (FK506) and cyclosporine A (CsA), and proved to be insensitive to okadaic acid. In addition, FK506 and CsA were able to affect the cellular viability and the fungal proliferation. This effect was corroborated by transmission electron microscopy that showed both calcineurin inhibitors promoted profound changes in the ultrastructure of conidia, causing mainly cytoplasm condensation and intense vacuolization that are clear indication of cell death. Our data indicated that FK506 exhibited the highest effectiveness, with a minimum inhibitory concentration (MIC) of 3.12 mg/L, whereas CsA required 15.6 mg/L to inhibit 100% of conidial growth. Interestingly, when both were combined with itraconazole, they demonstrated anti-F. pedrosoi activity, exhibiting a synergistic effect. Moreover, the fungal filamentation was affected after treatment with both calcineurin inhibitors. These data corroborate with other calcineurin studies in fungal cells and open up further discussions aiming to establish the role of this enzyme as a potential target for antifungal therapy against CBM infections.

5.
Biol Res ; 57(1): 40, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38890753

RESUMEN

BACKGROUND: The brain cortex is responsible for many higher-level cognitive functions. Disruptions during cortical development have long-lasting consequences on brain function and are associated with the etiology of brain disorders. We previously found that the protein tyrosine phosphatase receptor delta Ptprd, which is genetically associated with several human neurodevelopmental disorders, is essential to cortical brain development. Loss of Ptprd expression induced an aberrant increase of excitatory neurons in embryonic and neonatal mice by hyper-activating the pro-neurogenic receptors TrkB and PDGFRß in neural precursor cells. However, whether these alterations have long-lasting consequences in adulthood remains unknown. RESULTS: Here, we found that in Ptprd+/- or Ptprd-/- mice, the developmental increase of excitatory neurons persists through adulthood, affecting excitatory synaptic function in the medial prefrontal cortex. Likewise, heterozygosity or homozygosity for Ptprd also induced an increase of inhibitory cortical GABAergic neurons and impaired inhibitory synaptic transmission. Lastly, Ptprd+/- or Ptprd-/- mice displayed autistic-like behaviors and no learning and memory impairments or anxiety. CONCLUSIONS: These results indicate that loss of Ptprd has long-lasting effects on cortical neuron number and synaptic function that may aberrantly impact ASD-like behaviors.


Asunto(s)
Trastorno Autístico , Neuronas , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores , Animales , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores/metabolismo , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores/genética , Ratones , Trastorno Autístico/genética , Trastorno Autístico/fisiopatología , Modelos Animales de Enfermedad , Masculino , Corteza Cerebral/metabolismo , Ratones Noqueados , Transmisión Sináptica/fisiología , Ratones Endogámicos C57BL , Femenino
6.
Pharmaceuticals (Basel) ; 17(6)2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38931411

RESUMEN

Rarely has a chemical elicited as much controversy as dichloroacetate (DCA). DCA was initially considered a dangerous toxic industrial waste product, then a potential treatment for lactic acidosis. However, the main controversies started in 2008 when DCA was found to have anti-cancer effects on experimental animals. These publications showed contradictory results in vivo and in vitro such that a thorough consideration of this compound's in cancer is merited. Despite 50 years of experimentation, DCA's future in therapeutics is uncertain. Without adequate clinical trials and health authorities' approval, DCA has been introduced in off-label cancer treatments in alternative medicine clinics in Canada, Germany, and other European countries. The lack of well-planned clinical trials and its use by people without medical training has discouraged consideration by the scientific community. There are few thorough clinical studies of DCA, and many publications are individual case reports. Case reports of DCA's benefits against cancer have been increasing recently. Furthermore, it has been shown that DCA synergizes with conventional treatments and other repurposable drugs. Beyond the classic DCA target, pyruvate dehydrogenase kinase, new target molecules have also been recently discovered. These findings have renewed interest in DCA. This paper explores whether existing evidence justifies further research on DCA for cancer treatment and it explores the role DCA may play in it.

7.
J Periodontal Res ; 59(5): 982-992, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38742802

RESUMEN

AIMS: This study aimed to investigate the effects of Umbelliferone (UMB) on the inflammation underlying alveolar bone resorption in mouse periodontitis. METHODS: Male Swiss mice subjected to a ligature of molars were grouped as non-treated (NT), received UMB (15, 45, or 135 mg/kg) or saline daily for 7 days, respectively, and were compared with naïve mice as control. Gingival tissues were evaluated by myeloperoxidase (MPO) activity and interleukin-1ß level by ELISA. The bone resorption was directly assessed on the region between the cement-enamel junction and the alveolar bone crest. Microscopically, histomorphometry of the furcation region, immunofluorescence for nuclear factor-kappa B (NF-ĸB), and immunohistochemistry for tartrate-resistant acid phosphatase (TRAP), and cathepsin K (CTSK) were performed. Systemically, body mass variation and leukogram were analyzed. RESULTS: Periodontitis significantly increased MPO activity, interleukin-1ß level, and NF-ĸB+ immunofluorescence, and induced severe alveolar bone and furcation resorptions, besides increased TRAP+ and CTSK+ cells compared with naïve. UMB significantly prevented the inflammation by reducing MPO activity, interleukin-1ß level, and NF-ĸB+ intensity, besides reduction of resorption of alveolar bone and furcation area, and TRAP+ and CTSK+ cells compared with the NT group. Periodontitis or UMB treatment did not affect the animals systemically. CONCLUSION: UMB improved periodontitis by reducing inflammation and bone markers.


Asunto(s)
Pérdida de Hueso Alveolar , Interleucina-1beta , Periodontitis , Umbeliferonas , Animales , Masculino , Ratones , Pérdida de Hueso Alveolar/prevención & control , Pérdida de Hueso Alveolar/patología , Pérdida de Hueso Alveolar/tratamiento farmacológico , Periodontitis/tratamiento farmacológico , Periodontitis/patología , Umbeliferonas/uso terapéutico , Umbeliferonas/farmacología , Osteoclastos/efectos de los fármacos , Osteoclastos/patología , FN-kappa B/metabolismo , Fosfatasa Ácida Tartratorresistente/metabolismo , Peroxidasa , Inflamación , Catepsina K , Ligadura , Encía/patología , Encía/efectos de los fármacos
8.
New Phytol ; 243(1): 132-144, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38742309

RESUMEN

Nutrient limitation may constrain the ability of recovering and mature tropical forests to serve as a carbon sink. However, it is unclear to what extent trees can utilize nutrient acquisition strategies - especially root phosphatase enzymes and mycorrhizal symbioses - to overcome low nutrient availability across secondary succession. Using a large-scale, full factorial nitrogen and phosphorus fertilization experiment of 76 plots along a secondary successional gradient in lowland wet tropical forests of Panama, we tested the extent to which root phosphatase enzyme activity and mycorrhizal colonization are flexible, and if investment shifts over succession, reflective of changing nutrient limitation. We also conducted a meta-analysis to test how tropical trees adjust these strategies in response to nutrient additions and across succession. We find that tropical trees are dynamic, adjusting investment in strategies - particularly root phosphatase - in response to changing nutrient conditions through succession. These changes reflect a shift from strong nitrogen to weak phosphorus limitation over succession. Our meta-analysis findings were consistent with our field study; we found more predictable responses of root phosphatase than mycorrhizal colonization to nutrient availability. Our findings suggest that nutrient acquisition strategies respond to nutrient availability and demand in tropical forests, likely critical for alleviating nutrient limitation.


Asunto(s)
Bosques , Micorrizas , Nitrógeno , Nutrientes , Fósforo , Árboles , Clima Tropical , Fósforo/metabolismo , Nitrógeno/metabolismo , Micorrizas/fisiología , Nutrientes/metabolismo , Raíces de Plantas/metabolismo , Raíces de Plantas/microbiología , Monoéster Fosfórico Hidrolasas/metabolismo , Panamá
9.
J Endocrinol ; 261(3)2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38579817

RESUMEN

Exposure to glyphosate-based herbicides (GBH) and consumption of cafeteria (CAF) diet, which are widespread in Western society, seem to be associated with endometrial hyperplasia (EH). Here, we aimed to evaluate the effects of a subchronic low dose of GBH added to the CAF diet on the rat uterus. Female Wistar rats were fed from postnatal day (PND)21 until PND240 with chow (control) or CAF diet. Since PND140, rats also received GBH (2 mg of glyphosate/kg/day) or water through food, yielding four experimental groups: control, CAF, GBH, and CAF+GBH. On PND240, CAF and CAF+GBH animals showed an increased adiposity index. With respect to the control group, no changes in the serum levels of 17ß-estradiol and progesterone were found. However, progesterone levels were higher in the CAF+GBH group than in the CAF and GBH groups. In the uterus, both studied factors alone and in combination induced morphological and molecular changes associated with EH. Furthermore, the addition of GBH provoked an increased thickness of subepithelial stroma in rats fed with the CAF diet. As a consequence of GBH exposure, CAF+GBH rats exhibited an increased density of abnormal gland area, considered preneoplastic lesions, as well as a reduced PTEN and p27 expression, both tumor suppressor molecules that inhibit cell proliferation, with respect to control rats. These results indicate that the addition of GBH exacerbates the CAF effects on uterine lesions and that the PTEN/p27 signaling pathway seems to be involved. Further studies focusing on the interaction between unhealthy diets and environmental chemicals should be encouraged to better understand uterine pathologies.


Asunto(s)
Glicina , Glifosato , Herbicidas , Ratas Wistar , Útero , Animales , Femenino , Útero/efectos de los fármacos , Útero/patología , Útero/metabolismo , Herbicidas/toxicidad , Glicina/análogos & derivados , Ratas , Hiperplasia Endometrial/inducido químicamente , Hiperplasia Endometrial/patología , Hiperplasia Endometrial/metabolismo , Progesterona/sangre , Dieta , Estradiol/sangre , Fosfohidrolasa PTEN/metabolismo , Fosfohidrolasa PTEN/genética
10.
Biomedica ; 44(1): 35-44, 2024 03 31.
Artículo en Inglés, Español | MEDLINE | ID: mdl-38648348

RESUMEN

INTRODUCTION: Metabolic bone disease of premature infants is a rare complication characterized by a lower mineral content in bone tissue. OBJECTIVE: To establish the incidence of metabolic bone disease in premature infants and to determine associated risk factors. MATERIALS AND METHOD: We conducted a descriptive prospective cohort study for one year in all newborns under 32 gestational weeks, or 1,500 g, at the Hospital Universitario de Santander to determine the incidence of metabolic bone disease. We collected demographic data and prenatal histories of the selected patients, and later, we measured serum alkaline phosphatase and serum phosphorus at the third week of birth, having as reference values for diagnosis less than 5.6 mg/dl for the first one and more than 500 UI/L for the second one. We applied statistical tools for data analysis, such as average proportions, dispersion, distribution and association measures, and binomial regression. RESULTS: From a total of 58 patients, 7 had a diagnosis of metabolic bone disease, with an incidence of 12%. The weight was reported as an independent variable for the development of the disease, being significant in children under 1,160 g, as well as prolonged parenteral nutrition for more than 24 days. When performing the multivariate analysis, low weight and short time of parenteral nutrition appeared as risk factors; in the same way, maternal age below 22 years is associated with a higher relative risk, even more than a newborn weight inferior to 1,160 g. CONCLUSION: Establishing an early intervention in patients with metabolic bone disease enhancing risk factors, such as low weight and prolonged parenteral nutrition, is critical to prevent severe complications.


Introducción. La enfermedad metabólica ósea de neonatos prematuros es una complicación poco común que se caracteriza por una disminución del contenido mineral en el hueso. Objetivo. Establecer la incidencia de la enfermedad metabólica ósea en neonatos prematuros y los factores de riesgo asociados. Materiales y métodos. Durante un año, se realizó un estudio prospectivo de cohorte, descriptivo, con todos los neonatos nacidos con menos de 32 semanas de gestación o un peso menor de 1.500 g en el Hospital Universitario de Santander. Se recolectaron datos demográficos y antecedentes prenatales de los pacientes seleccionados. A la tercera semana de nacimiento, se midieron la fosfatasa alcalina y el fósforo sérico, tomando como valores de referencia diagnóstica aquellos inferiores a 5,6 mg/dl para el primero y aquellos mayores de 500 UI/L para la segunda. Para el análisis de la información, se emplearon herramientas estadísticas, como proporciones de promedios, medidas de dispersión, distribución y asociación, y regresión binomial. Resultados. De un total de 58 pacientes, 7 tuvieron diagnóstico de enfermedad metabólica ósea, con una incidencia del 12 %. De las variables estudiadas, el peso se reportó como una variable independiente para el desarrollo de la enfermedad, significativa en aquellos neonatos con peso menor de 1.160 g, al igual que la nutrición parenteral prolongada por más de 24 días. Al hacer el análisis multivariado, La edad materna menor de 22 años representó un riesgo relativo mayor, en comparación con un peso inferior a 1.160 g. Conclusión. Se estableció la importancia de una intervención temprana en pacientes con factores de riesgo para enfermedad metabólica ósea, como bajo peso (menor de 1.160 g) y nutrición parenteral prolongada (mayor de 24 días), con el fin de prevenir complicaciones graves.


Asunto(s)
Enfermedades Óseas Metabólicas , Humanos , Colombia/epidemiología , Recién Nacido , Incidencia , Enfermedades Óseas Metabólicas/epidemiología , Estudios Prospectivos , Femenino , Masculino , Factores de Riesgo , Edad Gestacional , Nutrición Parenteral , Recien Nacido Prematuro , Fosfatasa Alcalina/sangre , Enfermedades del Prematuro/epidemiología , Enfermedades del Prematuro/sangre , Hospitales Universitarios , Fósforo/sangre
11.
Curr Issues Mol Biol ; 46(4): 3424-3437, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38666945

RESUMEN

Escherichia coli phytase (AppA) is widely used as an exogenous enzyme in monogastric animal feed mainly because of its ability to degrade phytic acid or its salt (phytate), a natural source of phosphorus. Currently, successful recombinant production of soluble AppA has been achieved by gene overexpression using both bacterial and yeast systems. However, some methods for the biomembrane immobilization of phytases (including AppA), such as surface display on yeast cells and bacterial spores, have been investigated to avoid expensive enzyme purification processes. This study explored a homologous protein production approach for displaying AppA on the cell surface of E. coli by engineering its outer membrane (OM) for extracellular expression. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of total bacterial lysates and immunofluorescence microscopy of non-permeabilized cells revealed protein expression, whereas activity assays using whole cells or OM fractions indicated functional enzyme display, as evidenced by consistent hydrolytic rates on typical substrates (i.e., p-nitrophenyl phosphate and phytic acid). Furthermore, the in vitro results obtained using a simple method to simulate the gastrointestinal tract of poultry suggest that the whole-cell biocatalyst has potential as a feed additive. Overall, our findings support the notion that biomembrane-immobilized enzymes are reliable for the hydrolysis of poorly digestible substrates relevant to animal nutrition.

12.
Plants (Basel) ; 13(5)2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38475490

RESUMEN

In the pursuit of identifying the novel resin glycoside modulators glucose-6-phosphatase and α-glucosidase enzymes, associated with blood sugar regulation, methanol-soluble extracts from the flowers of Ipomoea murucoides (cazahuate, Nahuatl), renowned for its abundance of glycolipids, were employed. The methanol-soluble extracts were fractionated by applying the affinity-directed method with glucose-6-phosphatase enzymes from a rat's liver and α-glucosidase enzymes from its intestines. Mass spectrometry and nuclear magnetic resonance were employed to identify the high-affinity compound as a free ligand following the release from the enzymatic complex. Gel permeation through a spin size-exclusion column allowed the separated high-affinity molecules to bind to glucose-6-phosphatase and α-glucosidase enzymes in solution, which led to the identification of some previously reported resin glycosides in the flowers of cazahuate, where a glycolipid mainly structurally related to murucoidin XIV was observed. In vitro studies demonstrated the modulating properties of resin glycosides on the glucose-6-phosphatase enzyme. Dynamic light scattering revealed conformational variations induced by resin glycosides on α-glucosidase enzyme, causing them to become more compact, akin to observations with the positive control, acarbose. These findings suggest that resin glycosides may serve as a potential source for phytotherapeutic agents with antihyperglycemic properties.

13.
J Endocrinol ; 261(2)2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38470178

RESUMEN

For many years, research in the field of steroid synthesis has aimed to understand the regulation of the rate-limiting step of steroid synthesis, i.e. the transport of cholesterol from the outer to the inner mitochondrial membrane, and identify the protein involved in the conversion of cholesterol into pregnenolone. The extraordinary work by B Clark, J Wells, S R King, and D M Stocco eventually identified this protein and named it steroidogenic acute regulatory protein (StAR). The group's finding was also one of the milestones in understanding the mechanism of nonvesicular lipid transport between organelles. A notable feature of StAR is its high degree of phosphorylation. In fact, StAR phosphorylation in the acute phase is required for full steroid biosynthesis. As a contribution to this subject, our work has led to the characterization of StAR as a substrate of kinases and phosphatases and as an integral part of a mitochondrion-associated multiprotein complex, essential for StAR function and cholesterol binding and mitochondrial transport to yield maximum steroid production. Results allow us to postulate the existence of a specific cellular microenvironment where StAR protein synthesis and activation, along with steroid synthesis and secretion, are performed in a compartmentalized manner, at the site of hormone receptor stimulation, and involving the compartmentalized formation of the steroid molecule-synthesizing complex.


Asunto(s)
Fosfoproteínas , Esteroides , Fosfoproteínas/metabolismo , Colesterol/metabolismo , Microambiente Celular
14.
Int J Phytoremediation ; 26(8): 1305-1320, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38391288

RESUMEN

The rupture of the Fundão dam (Brazil) spread tailings contaminated with sodium and ether-amine into the Doce River Basin. Aiming at rehabilitating a contaminated riparian site, phytoremediation with native species of the Atlantic Forest was performed under four treatments: ES-1: physical remediation (sediment scraping) + chemical remediation (organic matter) + bioremediation (double inoculation with the arbuscular mycorrhizal fungus (AMF) Rhizophagus irregularis and the plant growth-promoting bacteria Bacillus subtilis); ES-2: chemical remediation + bioremediation; ES-3: physical remediation + chemical remediation; ES-4: chemical remediation. Ether-amine and sodium contents, plant growth and, soil quality parameters were compared among treatments and relative to preserved and degraded sites. Two years after planting, the outstanding plant growth was attributed to the phytoremediation of ether-amine and ammonium, followed by a significant increase in soil microbial biomass (Phospholipid fatty acids-PLFAs), particularly the Gram+ bacteria and total fungi but not AMF, whose response was independent of the inoculation. While sodium and ether-amine declined, soil K, P, NO3- contents, dehydrogenase and acid phosphatase activities, cation exchange capacity (CEC) and soil aggregation increased, especially in ES-1. Thus, such remediation procedures are recommended for the restoration of riparian areas affected by the Fundão tailings, ultimately improving sediment fertility, aggregation and stabilization.


To the best of our knowledge, this is the only successful example of fragment of riparian Atlantic Forest successfully rehabilitated using native trees from the Atlantic Forest in the riparian zone affected by the contaminated Fundão dam tailings. For that, phytoremediation and bioremediation procedures were adopted to alleviate etheramine and sodium toxicity, resulting in the amelioration of soil fertility and particularly the stabilization of such highly disaggregated sediments, ultimately protecting the Doce river basin against these contaminants.


Asunto(s)
Biodegradación Ambiental , Contaminantes del Suelo , Contaminantes del Suelo/metabolismo , Brasil , Micorrizas/fisiología , Microbiología del Suelo
15.
Environ Pollut ; 346: 123589, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38373626

RESUMEN

In recent years, the concern derived from the presence of emerging contaminants in the environment and the possible effects on the One Health trilogy has increased. This study determined the concentration of pharmaceutical contaminants of emerging concern and their relationship with the extracellular enzymatic activity of microbial communities from two rivers in western Cuba. Two sampling stations were analyzed; one in the Almendares River (urban) and the other in the San Juan River (rural), taking into account the pollution sources that arrive at these stations and previous physicochemical characterizations. Extracellular protease, acid phosphatase, alkaline phosphatase, lipase, and catalase activities in water and sediments were determined and correlated with contaminants of emerging concern determined by liquid chromatography with mass spectrometry. This study evidenced the presence of different pharmaceutical contaminants found in the categories of antihypertensives, stimulants, anti-inflammatories, and antibiotics in both rivers. Concentrations of contaminants of emerging concern were greater in the Almendares River compared to the San Juan River. In addition, through the canonical redundancy analysis, the influence of these contaminants on the extracellular enzymatic activities of microbial communities was documented, where in most cases they inhibit protease, phosphatase, and lipase activities and enhance catalase activity in response to oxidative stress. The present investigation constitutes the first report in Cuba of the presence of pharmaceutical contaminants of emerging concern and one of the few works that exist in the Latin American region.


Asunto(s)
Microbiota , Contaminantes Químicos del Agua , Ríos/química , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/análisis , Cuba , Catalasa , Péptido Hidrolasas , Lipasa , Preparaciones Farmacéuticas , Monitoreo del Ambiente/métodos
16.
Braz. j. med. biol. res ; 57: e13253, fev.2024. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1574233

RESUMEN

Jun N-terminal kinase pathway-associated phosphatase (JKAP) regulates CD4+ T-cell differentiation and immunity, which are linked to mental disorders. This study aimed to explore the relationships between JKAP and T helper 17 (Th17)/regulatory T (Treg) ratio, as well as their associations with anxiety and depression in postpartum women. Serum JKAP were measured by enzyme-linked immunosorbent assay and blood Th17 and Treg cells were measured by flow cytometry in 250 postpartum women. Anxiety and depression were evaluated by the 6-item State-Trait Anxiety Inventory (STAI6) and Edinburgh Postnatal Depression Scale (EPDS). Anxiety and depression rates were 22.0 and 28.4%, respectively, among postpartum women. Notably, JKAP was negatively associated with the STAI6 (P=0.002) and EPDS scores (P<0.001) in postpartum women and was lower in postpartum women with anxiety (P=0.023) or depression (P=0.002) than in those without. Moreover, JKAP was inversely related to Th17 cells and Th17/Treg ratio but positively correlated with Treg cells in postpartum women (all P<0.001). Interestingly, Th17 cells and Th17/Treg ratio were both positively associated with STAI6 and EPDS scores in postpartum women (all P<0.001). Furthermore, Th17 cells and Th17/Treg ratio were lower in postpartum women with anxiety or depression than in those without (all P<0.01). Nevertheless, Treg cells were not linked to anxiety or depression in postpartum women. JKAP was negatively associated with Th17 cells and Th17/Treg ratio; moreover, they all related to anxiety and depression in postpartum women, indicating that JKAP may be involved in postpartum anxiety and depression via interactions with Th17 cells.

17.
Bioengineering (Basel) ; 11(1)2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-38247960

RESUMEN

To examined alkaline phosphatase enzyme (ALP) activity and the effects of incorporating it in the thickener solution of a hydrogen-peroxide-based bleaching gel containing calcium-polyphosphate (CaPP) on the orthophosphate (PO43-) levels, bleaching effectiveness, and enamel microhardness. ALP activity was assessed at different pH levels and H2O2 concentrations, and in H2O- and Tris-based thickeners. Circular dichroism (CD) was used to examine the ALP secondary structure in water-, Tris-, or H2O2-based mediums. The PO43- levels were evaluated in thickeners with and without ALP. Enamel/dentin specimens were allocated into the following groups: control (without bleaching); commercial (Whiteness-HP-Maxx); Exp-H (H2O-based); CaPP-H; ALP-H (CaPP+ALP); Exp-T (Tris-based); CaPP-T; and ALP-T (CaPP+ALP). Color changes (ΔE/ΔE00) and the bleaching index (ΔWID) were calculated, and surface (SMH) and cross-sectional microhardness (CSMH) were assessed. The two-way ANOVA and Tukey's post-hoc tests were used to compare ALP and PO43- levels; generalized linear models were used to examine: ΔE/ΔE00/SMH/CSMH; and Kruskal-Wallis and Dunn's tests were used for ΔWID (α = 5%). The ALP activity was higher at pH 9, lower in H2O2-based mediums, and similar in both thickeners. The CD-spectra indicated denaturation of the enzyme upon contact with H2O2. The PO43- levels were higher after incorporating ALP, and the ΔE/ΔE00/ΔWID were comparable among bleached groups. SMH was lower after bleaching in Exp-H, while CSMH was highest in ALP-T.

18.
Cell Biol Int ; 48(2): 162-173, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37818706

RESUMEN

For cells to obtain inorganic phosphate, ectoenzymes in the plasma membrane, which contain a catalytic site facing the extracellular environment, hydrolyze phosphorylated molecules. In this study, we show that increased Pi levels in the extracellular environment promote a decrease in ecto-phosphatase activity, which is associated with Pi-induced oxidative stress. High levels of Pi inhibit ecto-phosphatase because Pi generates H2 O2 . Ecto-phosphatase activity is inhibited by H2 O2 , and this inhibition is selective for phospho-tyrosine hydrolysis. Additionally, it is shown that the mechanism of inhibition of ecto-phosphatase activity involves lipid peroxidation. In addition, the inhibition of ecto-phosphatase activity by H2 O2 is irreversible. These findings have new implications for understanding ecto-phosphatase regulation in the tumor microenvironment. H2 O2 stimulated by high Pi inhibits ecto-phosphatase activity to prevent excessive accumulation of extracellular Pi, functioning as a regulatory mechanism of Pi variations in the tumor microenvironment.


Asunto(s)
Neoplasias de la Mama , Peróxido de Hidrógeno , Humanos , Femenino , Peróxido de Hidrógeno/farmacología , Fosfatos/farmacología , Fosfatos/metabolismo , Monoéster Fosfórico Hidrolasas , Hidrólisis , Microambiente Tumoral
19.
Am J Physiol Renal Physiol ; 326(2): F285-F299, 2024 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-38096266

RESUMEN

Vasopressin regulates water homeostasis via the V2 receptor in the kidney at least in part through protein kinase A (PKA) activation. Vasopressin, through an unknown pathway, upregulates the activity and phosphorylation of Na+-Cl- cotransporter (NCC) and Na+-K+-2Cl- cotransporter 2 (NKCC2) by Ste20-related proline/alanine-rich kinase (SPAK) and oxidative stress-responsive kinase 1 (OSR1), which are regulated by the with-no-lysine kinase (WNK) family. Phosphorylation of WNK4 at PKA consensus motifs may be involved. Inhibitor 1 (I1), a protein phosphatase 1 (PP1) inhibitor, may also play a role. In human embryonic kidney (HEK)-293 cells, we assessed the phosphorylation of WNK4, SPAK, NCC, or NKCC2 in response to forskolin or desmopressin. WNK4 and cotransporter phosphorylation were studied in desmopressin-infused WNK4-/- mice and in tubule suspensions. In HEK-293 cells, only wild-type WNK4 but not WNK1, WNK3, or a WNK4 mutant lacking PKA phosphorylation motifs could upregulate SPAK or cotransporter phosphorylation in response to forskolin or desmopressin. I1 transfection maximized SPAK phosphorylation in response to forskolin in the presence of WNK4 but not of mutant WNK4 lacking PP1 regulation. We observed direct PP1 regulation of NKCC2 dephosphorylation but not of NCC or SPAK in the absence of WNK4. WNK4-/- mice with desmopressin treatment did not increase SPAK/OSR1, NCC, or NKCC2 phosphorylation. In stimulated tubule suspensions from WNK4-/- mice, upregulation of pNKCC2 was reduced, whereas upregulation of SPAK phosphorylation was absent. These findings suggest that WNK4 is a central node in which kinase and phosphatase signaling converge to connect cAMP signaling to the SPAK/OSR1-NCC/NKCC2 pathway.NEW & NOTEWORTHY With-no-lysine kinases regulate the phosphorylation and activity of the Na+-Cl- and Na+-K+-2Cl- cotransporters. This pathway is modulated by arginine vasopressin (AVP). However, the link between AVP and WNK signaling remains unknown. Here, we show that AVP activates WNK4 through increased phosphorylation at putative protein kinase A-regulated sites and decreases its dephosphorylation by protein phosphatase 1. This work increases our understanding of the signaling pathways mediating AVP actions in the kidney.


Asunto(s)
Arginina Vasopresina , Proteínas Serina-Treonina Quinasas , Ratones , Humanos , Animales , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo , Células HEK293 , Arginina Vasopresina/metabolismo , Cotransportadores de K Cl , Desamino Arginina Vasopresina , Colforsina , Proteína Fosfatasa 1/metabolismo , Riñón/metabolismo , Miembro 3 de la Familia de Transportadores de Soluto 12/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo
20.
Biomédica (Bogotá) ; Biomédica (Bogotá);44(1): 35-44, 2024. tab, graf
Artículo en Inglés | LILACS, COLNAL | ID: biblio-1574069

RESUMEN

Introduction. Metabolic bone disease of premature infants is a rare complication characterized by a lower mineral content in bone tissue. Objective. To establish the incidence of metabolic bone disease in premature infants and to determine associated risk factors. Materials and methods. We conducted a descriptive prospective cohort study for one year in all newborns under 32 gestational weeks, or 1,500 g, at the Hospital Universitario de Santander to determine the incidence of metabolic bone disease. We collected demographic data and prenatal histories of the selected patients, and later, we measured serum alkaline phosphatase and serum phosphorus at the third week of birth, having as reference values for diagnosis less than 5.6 mg/dl for the first one and more than 500 UI/L for the second one. We applied statistical tools for data analysis, such as average proportions, dispersion, distribution and association measures, and binomial regression. Results. From a total of 58 patients, 7 had a diagnosis of metabolic bone disease, with an incidence of 12%. The weight was reported as an independent variable for the development of the disease, being significant in children under 1,160 g, as well as prolonged parenteral nutrition for more than 24 days. When performing the multivariate analysis, low weight and short time of parenteral nutrition appeared as risk factors; in the same way, maternal age below 22 years is associated with a higher relative risk, even more than a newborn weight inferior to 1,160 g. Conclusion. Establishing an early intervention in patients with metabolic bone disease enhancing risk factors, such as low weight and prolonged parenteral nutrition, is critical to prevent severe complications.


Introducción. La enfermedad metabólica ósea de neonatos prematuros es una complicación poco común que se caracteriza por una disminución del contenido mineral en el hueso. Objetivo. Establecer la incidencia de la enfermedad metabólica ósea en neonatos prematuros y los factores de riesgo asociados. Materiales y métodos. Durante un año, se realizó un estudio prospectivo de cohorte, descriptivo, con todos los neonatos nacidos con menos de 32 semanas de gestación o un peso menor de 1.500 g en el Hospital Universitario de Santander. Se recolectaron datos demográficos y antecedentes prenatales de los pacientes seleccionados. A la tercera semana de nacimiento, se midieron la fosfatasa alcalina y el fósforo sérico, tomando como valores de referencia diagnóstica aquellos inferiores a 5,6 mg/dl para el primero y aquellos mayores de 500 UI/L para la segunda. Para el análisis de la información, se emplearon herramientas estadísticas, como proporciones de promedios, medidas de dispersión, distribución y asociación, y regresión binomial. Resultados. De un total de 58 pacientes, 7 tuvieron diagnóstico de enfermedad metabólica ósea, con una incidencia del 12 %. De las variables estudiadas, el peso se reportó como una variable independiente para el desarrollo de la enfermedad, significativa en aquellos neonatos con peso menor de 1.160 g, al igual que la nutrición parenteral prolongada por más de 24 días. Al hacer el análisis multivariado, La edad materna menor de 22 años representó un riesgo relativo mayor, en comparación con un peso inferior a 1.160 g. Conclusión. Se estableció la importancia de una intervención temprana en pacientes con factores de riesgo para enfermedad metabólica ósea, como bajo peso (menor de 1.160 g) y nutrición parenteral prolongada (mayor de 24 días), con el fin de prevenir complicaciones graves.


Asunto(s)
Humanos , Enfermedades Óseas Metabólicas , Recien Nacido Prematuro , Fósforo , Vitamina D , Fosfatasa Alcalina
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA