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1.
Front Endocrinol (Lausanne) ; 15: 1387272, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38686205

RESUMEN

Objective: Obesity, hypertension and diabetes are high prevalent that are often associated with poor outcomes. They have become major global health concern. Little research has been done on the impact of lymphocyte-to-monocyte ratio (LMR) on outcomes in these patients. Thus, we aimed to explore the association between LMR and all-cause mortality in obese hypertensive patients with diabetes and without diabetes. Methods: The researchers analyzed data from the National Health and Nutrition Examination Survey (2001-2018), which included 4,706 participants. Kaplan-Meier analysis was employed to compare survival rate between different groups. Multivariate Cox proportional hazards regression models with trend tests and restricted cubic splines (RCS) analysis and were used to investigate the relationship between the LMR and all-cause mortality. Subgroup analysis was performed to assess whether there was an interaction between the variables. Results: The study included a total of 4706 participants with obese hypertension (48.78% male), of whom 960 cases (20.40%) died during follow-up (median follow-up of 90 months). Kaplan-Meier curves suggested a remarkable decrease in all-cause mortality with increasing LMR value in patients with diabetes and non-diabetes (P for log-rank test < 0.001). Moreover, multivariable Cox models demonstrated that the risk of mortality was considerably higher in the lowest quartile of the LMR and no linear trend was observed (P > 0.05). Furthermore, the RCS analysis indicated a non-linear decline in the risk of death as LMR values increased (P for nonlinearity < 0.001). Conclusions: Increased LMR is independently related with reduced all-cause mortality in patients with obese hypertension, regardless of whether they have combined diabetes.


Asunto(s)
Diabetes Mellitus , Hipertensión , Linfocitos , Monocitos , Encuestas Nutricionales , Obesidad , Humanos , Masculino , Femenino , Hipertensión/complicaciones , Hipertensión/mortalidad , Hipertensión/epidemiología , Obesidad/complicaciones , Obesidad/mortalidad , Obesidad/sangre , Persona de Mediana Edad , Diabetes Mellitus/mortalidad , Diabetes Mellitus/epidemiología , Adulto , Estudios de Cohortes , Anciano , Estudios de Seguimiento
2.
Cell Rep ; 43(4): 114111, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38615319

RESUMEN

The efficacy of immunotherapy against colorectal cancer (CRC) is impaired by insufficient immune cell recruitment into the tumor microenvironment. Our study shows that targeting circDNA2v, a circular RNA commonly overexpressed in CRC, can be exploited to elicit cytotoxic T cell recruitment. circDNA2v functions through binding to IGF2BP3, preventing its ubiquitination, and prolonging the IGF2BP3 half-life, which in turn sustains mRNA levels of the protooncogene c-Myc. Targeting circDNA2v by gene silencing downregulates c-Myc to concordantly induce tumor cell senescence and the release of proinflammatory mediators. Production of CXCL10 and interleukin-9 by CRC cells is elicited through JAK-STAT1 signaling, in turn promoting the chemotactic and cytolytic activities of CD8+ T cells. Clinical evidence associates increased circDNA2v expression in CRC tissues with reductions in CD8+ T cell infiltration and worse outcomes. The regulatory relationship between circDNA2v, cellular senescence, and tumor-infiltrating lymphocytes thus provides a rational approach for improving immunotherapy in CRC.


Asunto(s)
Senescencia Celular , Neoplasias Colorrectales , Humanos , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/inmunología , ARN Circular/genética , ARN Circular/metabolismo , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Línea Celular Tumoral , Animales , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Ratones , Transducción de Señal , Regulación Neoplásica de la Expresión Génica , Microambiente Tumoral/inmunología , Proteínas Proto-Oncogénicas c-myc/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Factor de Transcripción STAT1/metabolismo
3.
J Cosmet Dermatol ; 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38497418

RESUMEN

BACKGROUND: Intense pulsed light (IPL) is used for the treatment and improvement of various skin issues. However, patients often experience local skin burning and pain after IPL treatment. Cooling and analgesic measures are indispensable. AIMS: To investigate the clinical effect of thermal shock therapy on pain relief and reduction of adverse reactions during IPL therapy. PATIENTS/METHODS: A total of 60 female patients with facial photoaging who received IPL therapy were enrolled in the study. As a comparative split-face study, one side of the face was randomly selected as the control side. The other side was given thermal shock therapy before and after the IPL treatment immediately as analgesic side. The visual analog scale (VAS) was used to evaluate the pain degree of the patients. The telephone follow-ups regarding the occurrence of adverse reactions were conducted respectively on the 2nd day, 7th day, and 1 month after treatment. RESULTS: The VAS score and skin temperature of analgesia side was lower than that of control side at different stages of treatment. In terms of adverse reactions, the incidence of transient facial redness on the analgesic side was lower than that on the control side. Two patients showed slight secondary pigmentation on the control side, and the other patients showed no other adverse reactions on both sides. CONCLUSIONS: Thermal shock therapy assisted IPL therapy can reduce skin temperature during treatment, effectively relieve patients' pain, reduce the occurrence of adverse reactions caused by heat injury, and improve patients' comfort level.

4.
Neoplasia ; 49: 100971, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38301392

RESUMEN

More than half of all cancers demonstrate aberrant c-Myc expression, making this arguably the most important human oncogene. Deregulated long non-coding RNAs (lncRNAs) are also commonly implicated in tumorigenesis, and some limited examples have been established where lncRNAs act as biological tuners of c-Myc expression and activity. Here, we demonstrate that the lncRNA denoted c-Myc Enhancing Factor (MEF) enjoys a cooperative relationship with c-Myc, both as a transcriptional target and driver of c-Myc expression. Mechanistically, MEF functions by binding to and stabilizing the expression of hnRNPK in colorectal cancer cells. The MEF-hnRNPK interaction serves to disrupt binding between hnRNPK and the E3 ubiquitin ligase TRIM25, which attenuates TRIM25-dependent hnRNPK ubiquitination and proteasomal destruction. In turn, the stabilization of hnRNPK through MEF enhances c-Myc expression by augmenting the translation c-Myc. Moreover, modulating the expression of MEF in shRNA-mediated knockdown and overexpression studies revealed that MEF expression is essential for colorectal cancer cell proliferation and survival, both in vitro and in vivo. From the clinical perspective, we show that MEF expression is differentially increased in colorectal cancer tissues compared to normal adjacent tissues. Further, correlations exist between MEF, c-Myc, and hnRNPK suggesting the MEF-c-Myc positive feedback loop is active in patients. Together these data demonstrate that MEF is a pivotal partner of the c-Myc network and propose MEF as a valuable therapeutic target for colorectal cancer.


Asunto(s)
Neoplasias Colorrectales , ARN Largo no Codificante , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Regulación Neoplásica de la Expresión Génica , Transformación Celular Neoplásica/genética , Carcinogénesis/genética , Neoplasias Colorrectales/metabolismo , Proliferación Celular/genética , Línea Celular Tumoral
5.
BMC Gastroenterol ; 23(1): 335, 2023 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-37770848

RESUMEN

INTRODUCE: The purpose of this study was to establish a comprehensive prognosis nomogram for patients with liver cirrhosis complicated with hepatic encephalopathy (HE) in the intensive care unit (ICU) and to evaluate the predictive value of the nomogram. METHOD: This study analyzed 620 patients with liver cirrhosis complicated with HE from the Medical Information Mart for Intensive Care III(MIMIC-III) database. The patients were randomly divided into two groups in a 7-to-3 ratio to form a training cohort (n = 434) and a validation cohort (n = 176). Cox regression analyses were used to identify associated risk variables. Based on the multivariate Cox regression model results, a nomogram was established using associated risk predictor variables to predict the 90-day survival rate of patients with cirrhosis complicated with HE. The new model was compared with the Sequential organ failure assessment (SOFA) scoring model in terms of the concordance index (C-index), the area under the curve (AUC) of receiver operating characteristic (ROC) analysis, the net reclassification improvement (NRI), the integrated discrimination improvement (IDI), calibration curve, and decision curve analysis (DCA). RESULTS: This study showed that older age, higher mean heart rate, lower mean arterial pressure, lower mean temperature, higher SOFA score, higher RDW, and the use of albumin were risk factors for the prognosis of patients with liver cirrhosis complicated with HE. The use of proton pump inhibitors (PPI) was a protective factor. The performance of the nomogram was evaluated using the C-index, AUC, IDI value, NRI value, and DCA curve, showing that the nomogram was superior to that of the SOFA model alone. Calibration curve results showed that the nomogram had excellent calibration capability. The decision curve analysis confirmed the good clinical application ability of the nomogram. CONCLUSION: This study is the first study of the 90-day survival rate prediction of cirrhotic patients with HE in ICU through the data of the MIMIC-III database. It is confirmed that the eight-factor nomogram has good efficiency in predicting the 90-day survival rate of patients.


Asunto(s)
Encefalopatía Hepática , Nomogramas , Humanos , Encefalopatía Hepática/diagnóstico , Encefalopatía Hepática/etiología , Pronóstico , Cirrosis Hepática/complicaciones , Factores de Riesgo
6.
Mediators Inflamm ; 2022: 8007078, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35497095

RESUMEN

Ischemic stroke is a major condition that remains extremely problematic to treat. A cerebral reperfusion injury becomes apparent after an ischemic accident when reoxygenation of the afflicted area produces pathological side effects that are different than those induced by the initial oxygen and nutrient deprivation insult. Pyroptosis is a form of lytic programmed cell death that is distinct from apoptosis, which is initiated by inflammasomes and depends on the activation of Caspase-1. Then, Caspase-1 mobilizes the N-domain of gasdermin D (GSDMD), resulting in the release of cytokines, such as interleukin-1ß (IL-1ß) and interleukin-18 (IL-18). X-box binding protein l (XBP-1) is activated under endoplasmic reticulum (ER) stress to form an important transcription factor XBP-1 splicing (XBP-1s). The cerebral ischemia/reperfusion (CI/R) causes cytotoxicity, which correlates with the activation of splicing XBP-1 mRNA and NLRP3 (NOD-, LRR-, and pyrin domain-containing 3) inflammasomes, along with increases in the expression and secretion of proinflammatory cytokines and upregulation of pyroptosis-related genes in HT22 cells and in the middle cerebral artery occlusion (MCAO) rat model. However, whether XBP-1 plays a role in regulating pyroptosis involved in CI/R is still unknown. Our present study showed that behavior deficits, cerebral ischemic lesions, and neuronal death resulted from CI/R. CI/R increased the mRNA level of XBP-1s, NLRP3, IL-1ß, and IL-18 and the expressions of XBP-1s, NLRP3, Caspase-1, GSDMD-N, IL-1ß, and IL-18. We further repeated this process in HT22 cells and C8-B4 cells and found that OGD/R decreased cell viability and increased LDH release, XBP-1s, NLRP3, Caspase-1, GSDMD-N, IL-1ß, IL-18, and especially the ratio of pyroptosis, which were reversed by Z-YVAD-FMK and downregulated XBP-1. Our results suggest that downregulated XBP-1 inhibited pyroptosis through the classical NLRP3/Caspase-1/GSDMD pathway to protect the neurons.


Asunto(s)
Isquemia Encefálica , Daño por Reperfusión , Animales , Caspasa 1 , Inflamasomas , Interleucina-18 , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Piroptosis , ARN Mensajero , Ratas , Proteína 1 de Unión a la X-Box
7.
Front Cell Neurosci ; 15: 653881, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33935653

RESUMEN

Alzheimer's disease (AD) is a common neurodegenerative disorder that places a heavy burden on patients and society. Hippocampal neuronal loss is a hallmark of AD progression. Therefore, understanding the mechanism underlying hippocampal neuronal death would be of great importance for the diagnosis and treatment of AD. This study aimed to explore the molecular mechanism via which nuclear factor kappa ß (NF-κB) promotes hippocampal neuronal oxidative stress and pyroptosis in AD. We collected serum samples from 101 healthy elderly people and 112 patients with AD at the Affiliated Hospital of Kunming University of Science and Technology between January 2017 and January 2020. Commercially available human hippocampal neurons (HHNs) were used to establish an AD model (AD-HHN) following Aß25-35 treatment. The mRNA expression levels of NF-κB and pyroptosis markers [NLR family pyrin domain-containing 3, caspase-1, interleukin (IL)-1ß, and interleukin-18] mRNA and the expression level of miR-146a-5p in the serum samples of patients with AD and AD-HHNs were determined by quantitative reverse transcription polymerase chain reaction. Oxidative stress indices (reactive oxygen species, malondialdehyde, nicotinamide adenine dinucleotide phosphate, superoxide dismutase, glutathione, and catalase) were measured by Enzyme-Linked Immunosorbent Assay (ELISA). The expression of proteins [NF-κB, TP53-induced glycolysis and apoptosis regulator (TIGAR), and pyroptosis markers] was tested by western blotting. The relationship between miR-146a-5p and TIGAR was investigated using a dual luciferase reporter gene assay. We found that NF-κB and miR-146a-5p were highly expressed, while TIGAR was low expressed in patients with AD and AD-HHNs. In addition, there was a significant positive correlation between the expression levels of NF-κB and miR-146a-5p, but a negative correlation between NF-κB mRNA and TIGAR mRNA in patients with AD, as well as miR-146a-5p and TIGAR mRNA in patients with AD. In AD-HNNs, miR-146a-5p targeted and downregulated the expression of TIGAR. Knockdown of NF-κB or overexpression of TIGAR markedly attenuated oxidative stress and pyroptosis in AD-HHNs, while concurrent overexpression of miR-146a-5p inhibited these effects. In conclusion, NF-κB-induced upregulation of miR-146a-5p promoted oxidative stress and pyroptosis in AD-HNNs by targeting TIGAR.

8.
Front Cell Neurosci ; 15: 654340, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33859553

RESUMEN

The protective effect of Cannabidiol on Parkinson's disease (PD) has been found in recent study. However, the specific mechanism of the protective effect of Cannabidiol on PD nerve damage require further exploration. This study aims to investigate effect of Cannabidiol on MMP-induced Neural Cells (SH-SY5Y) mitochondrial dysfunction. MMP+ and Cannabidiol were used to treat SH-SY5Y cells, the cells viability was measured by MTT assay. The expression of Tyrosine hydroxylase (TH) in cells was measured by western blotting and Immunofluorescence staining. The relationship among Cannabidiol, Silent mating type information regulation 2 homolog-1 (SIRT1) and NOTCH signaling, NF-κB signaling was examined by western blotting. The effect of Cannabidiol on MMP+-induced mitochondrial dysfunction of SH-SY5Y cells was measured by western blotting. Cannabidiol alleviated loss of TH expression and cytotoxicity in the MPP+-induced SH-SY5Y cells. Further mechanistic investigation showed that Cannabidiol induced SH-SY5Y cells autophagy to protects cells from mitochondrial dysfunction by upregulating SIRT1 to Inhibits NF-κB and NOTCH Pathways. Taken together, Cannabidiol acts as a protector in PD.

9.
Food Funct ; 11(4): 3393-3409, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32232300

RESUMEN

Vascular calcification (VC) is a common pathological manifestation in patients with cardiovascular diseases, leading to high mortality in patients with chronic kidney diseases. The deposition of hydroxyapatite (HAP) crystals on vascular smooth muscle cells leads to cell damage, which promotes osteogenic transformation. In this study, four different molecular weights (MWs ) of Porphyra yezoensis polysaccharides (PYP1, PYP2, PYP3, and PYP4 with MWs of 576, 49.5, 12.6, and 4.02 kDa, respectively) were used to coat HAP, and the differences in toxicity and calcification of HAP on A7R5 cells before and after coating were studied. The results showed that PYPs could effectively reduce HAP damage to the A7R5 cells. Under the protection of PYPs, cell viability increased and lactate dehydrogenase release, active oxygen level, and cell necrosis rate decreased; also, the amount of the HAP crystals adhering to cell surfaces and entering cells decreased. PYPs with low molecular weights presented better protective effects than high-molecular-weight PYPs. PYPs also inhibited the osteogenic transformation of the A7R5 cells induced by HAP and decreased alkaline phosphatase (ALP) activity and expressions of bone/chondrocyte phenotype genes (runt-related factor 2, ALP, osteopontin, and osteocalcin). In the adenine-induced chronic renal failure (CRF) mouse VC model, PYP4 was found to obviously inhibit the aortic calcium level, and it also inhibited the serum creatinine, serum phosphorus and serum BUN levels. PYP4 (least molecular weight) showed the best inhibitory effect on calcification and may be considered as a candidate drug with therapeutic potential for inhibiting cellular damage and osteoblast differentiation induced by the HAP crystals.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Durapatita/toxicidad , Osteogénesis/efectos de los fármacos , Polisacáridos/farmacología , Porphyra/química , Algas Marinas/química , Fosfatasa Alcalina/metabolismo , Animales , Aorta/efectos de los fármacos , Aorta/metabolismo , Nitrógeno de la Urea Sanguínea , Calcio/metabolismo , Línea Celular , Supervivencia Celular/efectos de los fármacos , Creatinina/sangre , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica de Transmisión , Peso Molecular , Miocitos del Músculo Liso/efectos de los fármacos , Miocitos del Músculo Liso/metabolismo , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Osteopontina/metabolismo , Fósforo/sangre , Polisacáridos/análisis , Ratas , Especies Reactivas de Oxígeno/metabolismo , Calcificación Vascular/inducido químicamente , Calcificación Vascular/tratamiento farmacológico
10.
Transl Stroke Res ; 11(1): 122-134, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31055735

RESUMEN

Brain microbleeds are increased in chronic kidney disease (CKD) and their presence increases risk of cognitive decline and stroke. We examined the interaction between CKD and brain microhemorrhages (the neuropathological substrate of microbleeds) in mouse and cell culture models and studied progression of microbleed burden on serial brain imaging from humans. Mouse studies: Two CKD models were investigated: adenine-induced tubulointerstitial nephritis and surgical 5/6 nephrectomy. Cell culture studies: bEnd.3 mouse brain endothelial cells were grown to confluence, and monolayer integrity was measured after exposure to 5-15% human uremic serum or increasing concentrations of urea. Human studies: Progression of brain microbleeds was evaluated on serial MRI from control, pre-dialysis CKD, and dialysis patients. Microhemorrhages were increased 2-2.5-fold in mice with CKD independent of higher blood pressure in the 5/6 nephrectomy model. IgG staining was increased in CKD animals, consistent with increased blood-brain barrier permeability. Incubation of bEnd.3 cells with uremic serum or elevated urea produced a dose-dependent drop in trans-endothelial electrical resistance. Elevated urea induced actin cytoskeleton derangements and decreased claudin-5 expression. In human subjects, prevalence of microbleeds was 50% in both CKD cohorts compared with 10% in age-matched controls. More patients in the dialysis cohort had increased microbleeds on follow-up MRI after 1.5 years. CKD disrupts the blood-brain barrier and increases brain microhemorrhages in mice and microbleeds in humans. Elevated urea alters the actin cytoskeleton and tight junction proteins in cultured endothelial cells, suggesting that these mechanisms explain (at least in part) the microhemorrhages and microbleeds observed in the animal and human studies.


Asunto(s)
Hemorragia Cerebral/patología , Hemorragia Cerebral/fisiopatología , Insuficiencia Renal Crónica/patología , Insuficiencia Renal Crónica/fisiopatología , Citoesqueleto de Actina/patología , Animales , Células Cultivadas , Hemorragia Cerebral/complicaciones , Modelos Animales de Enfermedad , Células Endoteliales/patología , Femenino , Humanos , Masculino , Ratones Endogámicos C57BL , Persona de Mediana Edad , Insuficiencia Renal Crónica/complicaciones , Uniones Estrechas/patología
11.
Nano Lett ; 20(1): 410-417, 2020 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-31860318

RESUMEN

Photoluminescence (PL) from single-wall carbon nanotubes (SWCNTs) enables structural identification, but to derive the content rate of the specific chirality species it is necessary to know the quantum yield of each chirality. However, in the PL of SWCNTs, because the Stokes shift is small, the photon reabsorption effect is dominant and the apparent PL spectral shape and emission intensity are greatly modified depending on the concentration. This problem makes quantitative identification of SWCNTs by PL difficult. In this study, the concentration dependence of the PL of SWCNTs separated into a few chiralities was analyzed in detail, including the effect of reabsorption. It is clear that all changes in the PL spectrum occurring in the high concentration range can be explained simply by the reabsorption effect, and additional effects such as Coulomb interactions between SWCNTs can be negligible. Furthermore, a reliable quantum yield was derived from the emission intensity corrected for the reabsorption effect. The PL quantum yield varied with SWCNT chirality and exhibited a clear "family pattern". This is consistent with the theoretical report showing that the chirality-dependent PL quantum yield is dominated mainly by relaxation by optical phonons from E22 to E11.

12.
Arch Biochem Biophys ; 677: 108154, 2019 11 30.
Artículo en Inglés | MEDLINE | ID: mdl-31672498

RESUMEN

The proliferation and migration of vascular smooth muscle cells (VSMCs) play important roles in the development and progression of diabetes-related vascular complications. Recently, microRNAs (miRNAs) have been suggested to be involved in the pathogenesis of vascular diseases. This study was designed to investigate the influences of tanshinone IIA, an active compound extracted from Chinese herb Salvia miltiorrhiza, on the proliferation and migration of human aortic VSMCs (HASMCs). cultured in a high glucose medium and the underlying mechanisms related miRNAs. Using a miRNA microarray method, we profiled the miRNA expression signature in human aortic VSMCs (HASMCs) exposed to normal glucose, high glucose with and without Tanshinone IIA. Cell proliferation was measured with 5-bromo-2'-deoxyuridine (BrdU) incorporation assay. Cell migration was evaluated using transwell migration assay and wound scratch assay. Western blot was used to examine the expression of tropomyosin 1 (TPM1) and miRNA level was quantified by real-time PCR. The results showed that several miRNAs that were highly expressed in the high glucose group were significantly decreased in the high glucose with Tanshinone IIA group compared with the normal glucose group (P < 0.05). Among these miRNAs, miR-21-5p was significantly upregulated in the high glucose group and downregulated after Tanshinone IIA treatment (P < 0.05). The depletion of miR-21-5p in HASMCs resulted in decreased cell proliferation and migration (P < 0.05). Moreover, we found that Tanshinone IIA inhibited proliferation and migration partly through miR-21-5p-mediated TPM1 downregulation (P < 0.05). In conclusion, the present study demonstrates that Tanshinone IIA is able to protect HASMCs from high glucose-induced proliferation and migration through regulating expression of miRNAs.


Asunto(s)
Abietanos/farmacología , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , MicroARNs/metabolismo , Miocitos del Músculo Liso/metabolismo , Tropomiosina/metabolismo , Abietanos/toxicidad , Aorta/citología , Cardiotónicos/farmacología , Cardiotónicos/toxicidad , Células Cultivadas , Regulación hacia Abajo/efectos de los fármacos , Glucosa/metabolismo , Humanos
13.
J Am Chem Soc ; 141(19): 7660-7664, 2019 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-31045358

RESUMEN

Phenol-soluble modulin α3 (PSMα3) is a cytotoxic peptide secreted by virulent strains of Staphylococcus aureus. We used a stereochemical strategy to examine the mechanism of PSMα3-mediated toxicity. One hypothesis is that PSMα3 toxicity requires fibril formation; an alternative is that toxicity is caused by soluble forms of PSMα3, possibly oligomeric. We find that the unnatural enantiomer (D residues) displays cytotoxicity comparable to that of L-PSMα3. Racemic PSMα3 is similarly toxic to enantiopure PSMα3 (L or D) under some conditions, but the toxicity is lost under conditions that cause racemic PSMα3 to aggregate. A crystal structure of racemic PSMα3-NH2 displays an α-helical secondary structure and a packing pattern that is reminiscent of the cross-α arrangement recently discovered in crystals of L-PSMα3. Our data suggest that the cytotoxicity of PSMα3 does not depend on stereospecific engagement of a target protein or other chiral macromolecule, an observation that supports a mechanism based on membrane disruption. In addition, our data support the hypothesis that toxicity is exerted by a soluble form rather than an insoluble fibrillar form.


Asunto(s)
Toxinas Bacterianas/química , Toxinas Bacterianas/toxicidad , Células HEK293 , Humanos , Modelos Moleculares , Conformación Proteica , Estereoisomerismo , Relación Estructura-Actividad
14.
J Am Chem Soc ; 141(4): 1583-1592, 2019 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-30645104

RESUMEN

The structural principles that govern interactions between l- and d-peptides are not well understood. Among natural proteins, coiled-coil assemblies formed between or among α-helices are the most regular feature of tertiary and quaternary structures. We recently reported the first high-resolution structures for heterochiral coiled-coil dimers, which represent a starting point for understanding associations of l- and d-polypeptides. These structures were an unexpected outcome from crystallization of a racemic peptide corresponding to the transmembrane domain of the influenza A M2 protein (M2-TM). The reported structures raised the possibility that heterochiral coiled-coil dimers prefer an 11-residue (hendecad) sequence repeat, in contrast to the 7-residue (heptad) sequence repeat that is dominant among natural coiled coils. To gain insight on sequence repeat preferences of heterochiral coiled-coils, we have examined three M2-TM variants containing substitutions intended to minimize steric clashes between side chains at the coiled-coil interface. In each of the three new crystal structures, we observed heterochiral coiled-coil associations that closely match a hendecad sequence motif, which strengthens the conclusion that this motif is intrinsic to the pairing of α-helices with opposite handedness. In each case, the presence of a hendecad motif was established by comparing the observed helical frequency to that of an ideal hendecad. This comparison revealed that decreasing the size of the amino acid side chain at positions that project toward the superhelical axis produces tighter packing, as determined by the size of the coiled-coil radius. These results provide a basis for future design of heterochiral coiled-coil pairings.


Asunto(s)
Proteínas de la Matriz Viral/química , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Cristalografía por Rayos X , Modelos Moleculares , Estereoisomerismo
15.
J Cardiovasc Pharmacol ; 72(6): 270-276, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-29738375

RESUMEN

BACKGROUND: Hypomagnesemia was identified as a strong risk factor for cardiovascular disease in patients with chronic renal failure (CRF). However, the effects of magnesium (Mg) on vascular calcification (VC) have not been fully elucidated. Thus, we aim to determine the effects of Mg citrate (MgCit) on VC in CRF rats. METHODS: Rats were divided into 5 groups: group 1 (normal diet), group 2 (normal diet with MgCit), group 3 (the VC model of CRF induced by 0.75% adenine and 0.9% phosphorus diet from day 1 to day 28), group 4 (group 3 treated with low-dose MgCit from day 1 to day 42), and group 5 (same as group 3 except the high-dose MgCit). All rats were killed at day 43 with collection of blood and aortas. Then, serum biochemical parameters, VC-related staining, calcium and P contents, alkaline phosphatase contents and activity, expression of alpha smooth muscle actin, and runt-related transcription factor 2 (RUNX2) in aortas were assessed. RESULTS: Group 3 had extensive VC. The VC degree decreased in groups 4 and 5 in a dose-depended manner with reduced calcium content, P levels, alkaline phosphatase content and activity, and protein levels of RUNX2 and increased protein levels of alpha smooth muscle actin in aortas. CONCLUSIONS: MgCit exerted a protective role in VC in adenine-induced CRF rats; thus, it may be a potential drug for the prevention of VC in patients with CRF.


Asunto(s)
Adenina , Aorta/efectos de los fármacos , Enfermedades de la Aorta/prevención & control , Fármacos Cardiovasculares/farmacología , Ácido Cítrico/farmacología , Fallo Renal Crónico/tratamiento farmacológico , Compuestos Organometálicos/farmacología , Fósforo Dietético , Calcificación Vascular/prevención & control , Actinas/metabolismo , Fosfatasa Alcalina/metabolismo , Animales , Aorta/metabolismo , Aorta/patología , Enfermedades de la Aorta/inducido químicamente , Enfermedades de la Aorta/metabolismo , Enfermedades de la Aorta/patología , Calcio/metabolismo , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Modelos Animales de Enfermedad , Fallo Renal Crónico/inducido químicamente , Masculino , Ratas Sprague-Dawley , Calcificación Vascular/inducido químicamente , Calcificación Vascular/metabolismo , Calcificación Vascular/patología
16.
Life Sci ; 197: 130-139, 2018 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-29428600

RESUMEN

AIMS: Thrombin is a serine proteinase that is not only involved in coagulation cascade, but also mediates a number of biological responses relevant to tissues repair, and induces bronchoconstriction. TGF-ß plays a pivotal role in airway remodeling due to its effects on airway smooth muscle proliferation and extracellular matrix (ECM) deposition. Recently, bronchoconstriction itself is found to constitute a form of strain and is highly relevant to asthmatic airway remodeling. However, the underlying mechanisms remain unknown. Here, we investigated the role of contraction- dependent TGF-ß activation in thrombin-induced remodeling in human airway smooth muscle (HASM) cells. MATERIALS AND METHODS: Primary HASM cells were treated with or without thrombin in the absence or presence of anti-TGF-ß antibody, cytochalasin D and formoterol. CFSE labeling index or CCK-8 assay were performed to test cell proliferation. RT-PCR and Western blotting were used to examined ECM mRNA level and collagen Iα1, α-actin protein expression, respectively. Immunofluorescence was also used to confirm contraction induced by thrombin in HASM cells. KEY FINDING: Thrombin stimulation enhanced HASM cells proliferation and activated TGF-ß signaling. Thrombin induced ECM mRNA and collagen Iα1 protein expression, and these effects are mediated by TGF-ß. Abrogation of TGF-ß activation by contraction inhibitors cytochalasin D and formoterol prevents the thrombin-induced effects. SIGNIFICANCE: These findings suggest that contraction-dependent TGF-ß activation could be a mechanism by which thrombin leads to the development of asthmatic airway remodeling. Blocking physical forces with bronchodilator would be an intriguing way in reducing airway remodeling in asthma.


Asunto(s)
Remodelación de las Vías Aéreas (Respiratorias)/efectos de los fármacos , Bronquios/metabolismo , Proliferación Celular/efectos de los fármacos , Miocitos del Músculo Liso/metabolismo , Transducción de Señal/efectos de los fármacos , Trombina/farmacología , Factor de Crecimiento Transformador beta1/metabolismo , Bronquios/patología , Células Cultivadas , Humanos , Miocitos del Músculo Liso/patología
17.
J Tissue Eng Regen Med ; 12(2): e905-e917, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28097806

RESUMEN

A porous structure is critically important for wound dressing or tissue engineering scaffolds. However, the influence of the pore sizes on cell proliferation, tissue regeneration and the underlying mechanism remains unclear. In this study, silicone rubber membranes with different pore sizes were prepared using certain constituents of liquid silicone rubber precursor/liquid paraffin/hexane based on our previous studies. It was found that pore size had a significant impact on cell proliferation and wound healing. The CCK8 analysis revealed that the membrane with a certain pore size (110.47 µm, middle pore membrane, MPM) was suitable for cell proliferation compared with the membranes with other pore sizes (218.03 µm, large pore membrane, LPM; 5.27 µm, small pore membrane, SPM; non-porous membrane, NPM). Further studies demonstrated that the MPM promoted cell proliferation via activating the Wnt/ß-catenin signalling pathway. More importantly, wound healing experiments showed that 7 days post-wounding, the rate of wound healing was 89.25% with the MPM, which was significantly higher than with LPM, SPM or NPM. The in vivo data indicated that wound healing was accelerated by treatment with a silicone rubber membrane with a pore size of 110.47 µm. Our results strongly suggest that different pore structures might affect cell proliferation and wound healing and that a silicone rubber membrane with a specific pore size could potentially be used as a promising wound dressing. Copyright © 2017 John Wiley & Sons, Ltd.


Asunto(s)
Membranas Artificiales , Regeneración/efectos de los fármacos , Elastómeros de Silicona/farmacología , Cicatrización de Heridas/efectos de los fármacos , Animales , Adhesión Celular/efectos de los fármacos , Adhesión Celular/genética , Proliferación Celular/efectos de los fármacos , Proliferación Celular/genética , Ratones Endogámicos BALB C , Porosidad , Antígeno Nuclear de Célula en Proliferación/metabolismo , Repitelización/efectos de los fármacos , Repitelización/genética , Vía de Señalización Wnt/efectos de los fármacos , Vía de Señalización Wnt/genética , beta Catenina/metabolismo
18.
Int Urol Nephrol ; 49(11): 2061-2069, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28936714

RESUMEN

PURPOSE: To systematically determine the prevalence of abdominal artery calcification (AAC) in dialysis patients with end-stage renal disease (ESRD) and identify reasons for heterogeneity. METHODS: We searched PubMed, EMBASE, and Web of Science from database inception to March 2017. Cross-sectional or cohort (only used baseline data) studies reporting estimates of AAC prevalence in dialysis adult patients with ESRD were included. We performed a random-effects meta-analysis to generate pooled prevalence estimates. Subgroup analyses were used to compare differences within categorical variables (geographic region, AAC detection instruments, dialysis methods, study design, and sample size), and meta-regression analyses to assess the impact of continuous variables (participants' age, duration of dialysis, and male proportion). RESULTS: A total of 44 studies with 9883 dialysis patients were included. The pooled prevalence for AAC was 68.5% (95% CI 63-73.9%). Subgroup analyses suggested that AAC prevalence varied significantly by geographical region and AAC detection instruments, not by dialysis methods, study design and sample size. Meta-regression analysis suggested that positive correlations were found between AAC prevalence and the age of participants as well as the male proportion (r = 1.01477, P = 0.002 and r = 2.034413, P = 0.01, respectively), but not with the duration of dialysis (P = 0.576). CONCLUSION: The pooled and nearest estimate of AAC prevalence among dialysis patients was as high as 65%. Geographical region, AAC detection instruments, age of participants, and male proportion potentially lead to the high variance of the reported prevalence. Considering the high AAC prevalence, effective treatment for preventing vascular calcification in these patients is badly needed.


Asunto(s)
Aorta Abdominal , Enfermedades de la Aorta/epidemiología , Fallo Renal Crónico/terapia , Calcificación Vascular/epidemiología , África/epidemiología , Australia/epidemiología , Europa (Continente)/epidemiología , Humanos , América del Norte/epidemiología , Prevalencia , Diálisis Renal
19.
Sci Rep ; 7: 46066, 2017 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-28383066

RESUMEN

Burns are a major cause of injury worldwide. We investigated the epidemiology and outcomes of burn patients in a major burn center in southwest China between 2011 and 2015 to provide guidance for burn prevention. Of the 6,325 included burn patients, 66.8% were male and 34.7% were 0 ~ 6 years old. The incidence of burns peaked in autumn. Scald was the most common cause of burns, which was predominant in patients aged 0 ~ 6 years. The mean total body surface area (TBSA) of burns was 13.4%, and patients with burns ≤10% TBSA comprised 64.1% of all cases. Patients with full-thickness burns accounted for 40.1% of all patients and 81.0% of operated patients; these burns were primarily caused by flame (34.8%), scald (21.0%), and electricity (20.4%). Fifty-six deaths occurred (mortality 0.9%), and risk factors included full-thickness burns, larger TBSA and older age. The median length of stay was 17 days, and major risk factors included more operations, better outcomes and larger TBSA. Our data showed that closer attention should be paid to children under 6 years old, males, incidents in autumn and scald burns to prevent burn injuries. Furthermore, individualized burn prevention and treatment measures based on related risk factors should be adopted.


Asunto(s)
Unidades de Quemados/estadística & datos numéricos , Quemaduras/epidemiología , Evaluación de Resultado en la Atención de Salud , Adolescente , Anciano , Anciano de 80 o más Años , Quemaduras/etiología , Quemaduras/mortalidad , Niño , Preescolar , China/epidemiología , Femenino , Humanos , Lactante , Recién Nacido , Tiempo de Internación , Modelos Lineales , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de Tiempo
20.
Stem Cells Dev ; 26(6): 451-460, 2017 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-27927130

RESUMEN

P311 is a newly discovered functional gene, and it has been proved to play a key role in blood pressure homeostasis, glioblastoma invasion, renal fibrosis, hypertrophic scar formation, and others. In this study, for the first time, we found that P311 could enhance reepithelialization during wound healing via promoting epidermal stem cell (EpSC) migration through Rho GTPases. P311 expression was highly increased in neo-epidermal cells during human and mouse skin wound healing, and P311was co-localized with 5-bromo-2'-deoxyuridine positive label-retaining cells in a mouse superficial second-degree burn wound model. Furthermore, transfection of human EpSCs with adenovirus encoding P311 significantly accelerated the cell migration in vitro. Moreover, highly expressed P311 could enhance the activities of the Rho GTPases (RhoA, Rac1, and Cdc42) in cultured human EpSCs. P311-knockout mouse EpSCs showed dramatically decreased cell migration and activities of Rho GTPases (RhoA, Rac1, and Cdc42). Besides, both the RhoA-specific inhibitor and the Rac1 inhibitor, not the Cdc42 inhibitor, could significantly suppress P311-induced human EpSC migration. In vivo, the reepithelialization was markedly impaired during wound healing after P311 was knocked out. Together, our results suggested that P311 could accelerate skin wound reepithelialization by promoting the migration of EpSCs through RhoA and Rac1 activation. P311 could serve as a novel target for regulation of EpSC migration during cutaneous wound healing.


Asunto(s)
Movimiento Celular , Epidermis/patología , Proteínas del Tejido Nervioso/metabolismo , Proteínas Oncogénicas/metabolismo , Repitelización , Células Madre/patología , Proteína de Unión al GTP rac1/metabolismo , Proteína de Unión al GTP rhoA/metabolismo , Animales , Animales Recién Nacidos , Movimiento Celular/efectos de los fármacos , Niño , Activación Enzimática/efectos de los fármacos , Humanos , Masculino , Ratones Endogámicos C57BL , Proteínas del Tejido Nervioso/deficiencia , Compuestos Orgánicos/farmacología , Repitelización/efectos de los fármacos , Células Madre/efectos de los fármacos , Células Madre/metabolismo
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