Spider silk enhanced tissue engineering of cartilage tissue: Approach of a novel bioreactor model using adipose derived stromal cells.

Human cartilage tissue remains a challenge for the development of therapeutic options due to its poor vascularization and reduced regenerative capacities. There are a variety of research approaches dealing with cartilage tissue engineering. In addition to different biomaterials, numerous cell populations have been investigated in bioreactor-supported experimental setups to improve cartilage tissue engineering. The concept of the present study was to investigate spider silk cocoons as scaffold seeded with adipose-derived stromal cells (ASC) in a custom-made bioreactor model using cyclic axial compression to engineer cartilage-like tissue. For chemical induction of differentiation, BMP-7 and TGF-ß2 were added and changes in cell morphology and de-novo tissue formation were investigated using histological staining to verify chondrogenic differentiation. By seeding spider silk cocoons with ASC, a high colonization density and cell proliferation could be achieved. Mechanical induction of differentiation using a newly established bioreactor model led to a more roundish cell phenotype and new extracellular matrix formation, indicating a chondrogenic differentiation. The addition of BMP-7 and TGF-ß2 enhanced the expression of cartilage specific markers in immunohistochemical staining. Overall, the present study can be seen as pilot study and valuable complementation to the published literature.

Endothelial Progenitor Cells: A Brief Update.

An enormous amount of current data has suggested involvement of endothelial progenitor cells (EPCs) in neovasculogenesis in both human and animal models. EPC level is an indicator of possible cardiovascular risk such as Alzheimer disease. EPC therapeutics requires its identification, isolation, differentiation and thus expansion. We approach here the peculiar techniques through current and previous reports available to find the most plausible and fast way of their expansion to be used in therapeutics. We discuss here the techniques for EPCs isolation from different resources like bone marrow and peripheral blood circulation. EPCs have been isolated by methods which used fibronectin plating and addition of various growth factors to culture media. Particularly, the investigations which tried to enhance EPC differentiation while inducing with growth factors and endothelial nitric oxide synthase are shared. We also include the cryopreservation and other storage methods of EPCs for a longer time. Sufficient amount of EPCs are required in transplantation and other therapeutics which signifies their in vitro expansion. We highlight the role of EPCs in transplantation which improved neurogenesis in animal models of ischemic stroke and human with acute cerebral infarct in the brain. Accumulatively, these data suggest the exhilarating route for enhancing EPC number to make their use in the clinic. Finally, we identify the expression of specific biomarkers in EPCs under the influence of growth factors. This review provides a brief overview of factors involved in EPC expansion and transplantation and raises interesting questions at every stage with constructive suggestions.

Cardiac Pericytes Acquire a Fibrogenic Phenotype and Contribute to Vascular Maturation After Myocardial Infarction.

BACKGROUND: Pericytes have been implicated in tissue repair, remodeling, and fibrosis. Although the mammalian heart contains abundant pericytes, their fate and involvement in myocardial disease remains unknown. METHODS: We used NG2Dsred;PDGFRαEGFP pericyte:fibroblast dual reporter mice and inducible NG2CreER mice to study the fate and phenotypic modulation of pericytes in myocardial infarction. The transcriptomic profile of pericyte-derived cells was studied using polymerase chain reaction arrays and single-cell RNA sequencing. The role of transforming growth factor-ß (TGF-ß) signaling in regulation of pericyte phenotype was investigated in vivo using pericyte-specific TGF-ß receptor 2 knockout mice and in vitro using cultured human placental pericytes. RESULTS: In normal hearts, neuron/glial antigen 2 (NG2) and platelet-derived growth factor receptor α (PDGFRα) identified distinct nonoverlapping populations of pericytes and fibroblasts, respectively. After infarction, a population of cells expressing both pericyte and fibroblast markers emerged. Lineage tracing demonstrated that in the infarcted region, a subpopulation of pericytes exhibited transient expression of fibroblast markers. Pericyte-derived cells accounted for ~4% of PDGFRα+ infarct fibroblasts during the proliferative phase of repair. Pericyte-derived fibroblasts were overactive, expressing higher levels of extracellular matrix genes, integrins, matricellular proteins, and growth factors, when compared with fibroblasts from other cellular sources. Another subset of pericytes contributed to infarct angiogenesis by forming a mural cell coat, stabilizing infarct neovessels. Single-cell RNA sequencing showed that NG2 lineage cells diversify after infarction and exhibit increased expression of matrix genes, and a cluster with high expression of fibroblast identity markers emerges. Trajectory analysis suggested that diversification of infarct pericytes may be driven by proliferating cells. In vitro and in vivo studies identified TGF-ß as a potentially causative mediator in fibrogenic activation of infarct pericytes. However, pericyte-specific TGF-ß receptor 2 disruption had no significant effects on infarct myofibroblast infiltration and collagen deposition. Pericyte-specific TGF-ß signaling was involved in vascular maturation, mediating formation of a mural cell coat investing infarct neovessels and protecting from dilative remodeling. CONCLUSIONS: In the healing infarct, cardiac pericytes upregulate expression of fibrosis-associated genes, exhibiting matrix-synthetic and matrix-remodeling profiles. A fraction of infarct pericytes exhibits expression of fibroblast identity markers. Pericyte-specific TGF-ß signaling plays a central role in maturation of the infarct vasculature and protects from adverse dilative remodeling, but it does not modulate fibrotic remodeling.

Autologous Platelet and Extracellular Vesicle-Rich Plasma as Therapeutic Fluid: A Review.

The preparation of autologous platelet and extracellular vesicle-rich plasma (PVRP) has been explored in many medical fields with the aim to benefit from its healing potential. In parallel, efforts are being invested to understand the function and dynamics of PVRP that is complex in its composition and interactions. Some clinical evidence reveals beneficial effects of PVRP, while some report that there were no effects. To optimize the preparation methods, functions and mechanisms of PVRP, its constituents should be better understood. With the intention to promote further studies of autologous therapeutic PVRP, we performed a review on some topics regarding PVRP composition, harvesting, assessment and preservation, and also on clinical experience following PVRP application in humans and animals. Besides the acknowledged actions of platelets, leukocytes and different molecules, we focus on extracellular vesicles that were found abundant in PVRP.

Changes in serum pigment epithelium-derived factor levels after kidney transplantation in patients with end-stage renal disease.

BACKGROUND: Pigment epithelium-derived factor (PEDF) is a serin protease inhibitor and a potent inhibitor of angiogenesis. Its serum level has significant associations with metabolic parameters. However, little is known about the association between PEDF levels and lipid parameters in renal transplanted (TX) patients. Therefore, our aim was to investigate the relationship between PEDF level and lipid parameters in TX patients. METHODS: Seventy TX patients (47 males, 23 females, mean age 51.7 ± 12.4 years) and 34 healthy controls were enrolled. We examined the serum creatinine, C-reactive protein, fasting glucose and lipid parameters right before, then 1 and 6 months after TX. High-density lipoprotein (HDL)-associated paraoxonase-1 (PON1) activities were measured spectrophotometrically. Lipoprotein subfractions were determined by Lipoprint. PEDF and oxidized low-density liporotein (oxLDL) levels were measured by ELISA. RESULTS: Before transplantation, patients had had a significantly higher PEDF level compared to control subjects (p < 0.001). One month after transplantation, their PEDF level decreased significantly reaching the healthy controls' level, and this lower level was maintained during the 6 months follow-up period as well. The initial oxLDL level was significantly higher, while PON1 activities were significantly lower in the patient group compared to the control group. We found a significant positive correlation between PEDF and total cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride, oxLDL and small HDL subfraction; while negative correlations were found between PEDF and mean LDL size and large HDL subfraction during the entire follow-up period. CONCLUSION: PEDF may play an important role in the increased oxidative stress and enhanced atherogenesis in renal transplant patients.

The hypoxia-dependent angiogenic process in dental pulp.

BACKGROUND: In this review, we analyzed the existing literature to elucidate how the hypoxia-dependent angiogenic processes work in dental pulp. Angiogenesis is an essential biological process in the maturation and homeostasis of teeth. It involves multiple sequential steps such as endothelial cell proliferation and migration, cell-to-cell contact, and tube formation. HIGHLIGHT: Clinical implications of understanding the process of angiogenesis include how the mineralization processes of dental pulp occur and how dental pulp maintains its homeostasis, preventing irreversible inflammation or necrosis. CONCLUSION: The angiogenesis process in dental pulp regulates adequate concentrations of oxygen required for mineralization in root development and defense mechanisms against chronic stimuli.

Blockade of TGF-ß (Transforming Growth Factor Beta) Signaling by Deletion of Tgfbr2 in Smooth Muscle Cells of 11-Month-Old Mice Alters Aortic Structure and Causes Vasomotor Dysfunction-Brief Report.

BACKGROUND: To test the hypothesis that smooth muscle cell (SMC) TGF-ß (transforming growth factor beta) signaling contributes to maintenance of aortic structure and function beyond the early postnatal period. METHODS: We deleted the TBR2 (type 2 TGF-ß receptor) in SMC of 11-month-old mice (genotype Acta2-CreERT2+/0Tgfbr2f/f, termed TBR2SMΔ) and compared their ascending aorta structure and vasomotor function to controls (Acta2-CreERT20/0Tgfbr2f/f, termed TBR2f/f). RESULTS: We confirmed loss of aortic SMC TBR2 by immunoblotting. Four weeks after SMC TBR2 loss, TBR2SMΔ mice did not have aortic rupture, ulceration, dissection, dilation, or evidence of medial hemorrhage. However, aortic medial area of TBR2SMΔ mice was increased by 27% (0.14±0.01 versus 0.11±0.01 mm2; P=0.01) and medial thickness was increased by 23% (40±1.9 versus 33±1.3 µm; P=0.004) compared with littermate controls. Wire myography performed on ascending aortic rings showed hypercontractility of TBR2SMΔ aortas to phenylephrine (Emax, 15.9±1.2 versus 10.8±0.7 mN; P=0.0003) and reduced relaxation and sensitivity to acetylcholine (Emax, 64±14% versus 96±2%; P=0.001; -logEC50, 6.9±0.1 versus 7.7±0.1; P=0.0001). Neither maximal relaxation nor sensitivity to sodium nitroprusside differed (Emax, 102±0.3% versus 101±0.3%; -logEC50, 8.0±0.04 versus 7.9±0.08; P>0.4 for both). CONCLUSIONS: Loss of TGF-ß signaling in aortic SMC of 1-year-old mice does not cause early severe aortopathy or death; however, it causes mild structural and substantial physiological abnormalities. SMC TGF-ß signaling plays an important role in maintaining aortic homeostasis in older mice. This role should be considered in the design of clinical studies that aim to prevent aortopathy by blocking SMC TGF-ß signaling.

Macrophage-Specific IGF-1 Overexpression Reduces CXCL12 Chemokine Levels and Suppresses Atherosclerotic Burden in Apoe-Deficient Mice.

OBJECTIVE: IGF-1 (insulin-like growth factor 1) exerts pleiotropic effects including promotion of cellular growth, differentiation, survival, and anabolism. We have shown that systemic IGF-1 administration reduced atherosclerosis in Apoe-/- (apolipoprotein E deficient) mice, and this effect was associated with a reduction in lesional macrophages and a decreased number of foam cells in the plaque. Almost all cell types secrete IGF-1, but the effect of macrophage-derived IGF-1 on the pathogenesis of atherosclerosis is poorly understood. We hypothesized that macrophage-derived IGF-1 will reduce atherosclerosis. Approach and Results: We created macrophage-specific IGF-1 overexpressing mice on an Apoe-/- background. Macrophage-specific IGF-1 overexpression reduced plaque macrophages, foam cells, and atherosclerotic burden and promoted features of stable atherosclerotic plaque. Macrophage-specific IGF1 mice had a reduction in monocyte infiltration into plaque, decreased expression of CXCL12 (CXC chemokine ligand 12), and upregulation of ABCA1 (ATP-binding cassette transporter 1), a cholesterol efflux regulator, in atherosclerotic plaque and in peritoneal macrophages. IGF-1 prevented oxidized lipid-induced CXCL12 upregulation and foam cell formation in cultured THP-1 macrophages and increased lipid efflux. We also found an increase in cholesterol efflux in macrophage-specific IGF1-derived peritoneal macrophages. CONCLUSIONS: Macrophage IGF-1 overexpression reduced atherosclerotic burden and increased features of plaque stability, likely via a reduction in CXCL12-mediated monocyte recruitment and an increase in ABCA1-dependent macrophage lipid efflux.

A critical review on the potential role of adipose-derived stem cells for future treatment of hypertrophic scars.

INTRODUCTION: Adipose-derived stem cells (ASCs) have recently gained researchers' interest as a solution to various diseases and conditions, including hypertrophic scar. This literature review aims to elucidate ASCs as a potential solution to alleviate hypertrophic scar in human subjects. METHODS: Literature search was done in databases which includes PubMed, MEDLINE, and ProQuest using terms 'adipose derived stem cells', 'adipose cells', 'fat graft', 'fat grafting', 'autologous fat graft', 'fat injection', 'lipofilling', 'scar management', 'scar treatment', 'burn scar', and 'wound management'. The included articles which were published during year 2000-November 2020 must describe the use of ASCs or fat grafting or lipofilling as an attempt to alleviate hypertrophic scar. REMARKS: Clinically, ASCs improve hypertrophic scars in terms of scar color, elasticity, texture, thickness, and size. Histologically, ASCs promotes healthy tissue regeneration, reduction in fibroblasts, and reorganisation of collagen, resembling those of normal skin. In terms of molecular aspects, ASCs alleviates hypertrophic scars through direct differentiation and paracrine mechanisms. CONCLUSION: Adipose-derived stem cells, emerge to be a potential solution for alleviating hypertrophic scar, as demonstrated in various studies. However, there has been no studies conducted in human subjects to investigate the effect of ASCs on hypertrophic scar.

Myeloid-Derived Growth Factor Protects Against Pressure Overload-Induced Heart Failure by Preserving Sarco/Endoplasmic Reticulum Ca2+-ATPase Expression in Cardiomyocytes.

BACKGROUND: Inflammation contributes to the pathogenesis of heart failure, but there is limited understanding of inflammation's potential benefits. Inflammatory cells secrete MYDGF (myeloid-derived growth factor) to promote tissue repair after acute myocardial infarction. We hypothesized that MYDGF has a role in cardiac adaptation to persistent pressure overload. METHODS: We defined the cellular sources and function of MYDGF in wild-type (WT), Mydgf-deficient (Mydgf-/-), and Mydgf bone marrow-chimeric or bone marrow-conditional transgenic mice with pressure overload-induced heart failure after transverse aortic constriction surgery. We measured MYDGF plasma concentrations by targeted liquid chromatography-mass spectrometry. We identified MYDGF signaling targets by phosphoproteomics and substrate-based kinase activity inference. We recorded Ca2+ transients and sarcomere contractions in isolated cardiomyocytes. Additionally, we explored the therapeutic potential of recombinant MYDGF. RESULTS: MYDGF protein abundance increased in the left ventricular myocardium and in blood plasma of pressure-overloaded mice. Patients with severe aortic stenosis also had elevated MYDGF plasma concentrations, which declined after transcatheter aortic valve implantation. Monocytes and macrophages emerged as the main MYDGF sources in the pressure-overloaded murine heart. While Mydgf-/- mice had no apparent phenotype at baseline, they developed more severe left ventricular hypertrophy and contractile dysfunction during pressure overload than WT mice. Conversely, conditional transgenic overexpression of MYDGF in bone marrow-derived inflammatory cells attenuated pressure overload-induced hypertrophy and dysfunction. Mechanistically, MYDGF inhibited G protein-coupled receptor agonist-induced hypertrophy and augmented SERCA2a (sarco/endoplasmic reticulum Ca2+-ATPase 2a) expression in cultured neonatal rat ventricular cardiomyocytes by enhancing PIM1 (Pim-1 proto-oncogene, serine/threonine kinase) expression and activity. Along this line, cardiomyocytes from pressure-overloaded Mydgf-/- mice displayed reduced PIM1 and SERCA2a expression, greater hypertrophy, and impaired Ca2+ cycling and sarcomere function compared with cardiomyocytes from pressure-overloaded WT mice. Transplanting Mydgf-/- mice with WT bone marrow cells augmented cardiac PIM1 and SERCA2a levels and ameliorated pressure overload-induced hypertrophy and dysfunction. Pressure-overloaded Mydgf-/- mice were similarly rescued by adenoviral Serca2a gene transfer. Treating pressure-overloaded WT mice subcutaneously with recombinant MYDGF enhanced SERCA2a expression, attenuated left ventricular hypertrophy and dysfunction, and improved survival. CONCLUSIONS: These findings establish a MYDGF-based adaptive crosstalk between inflammatory cells and cardiomyocytes that protects against pressure overload-induced heart failure.

Utilidad del suero autólogo en lesiones de superficie ocular de evolución incierta. Evaluación clínica e imagenológica

Objetivo: Determinar la efectividad del suero autólogo rico en factores de crecimiento en la reparación de lesiones de la superficie ocular de evolución incierta con el tratamiento convencional. Materiales y métodos: Se trataron 46 unidades oculares con afecciones de la superficie ocular agrupadas en queratopatías por exposición, queratopatías por síndrome de ojo seco / neurotróficas, y traumas oculares. Las partes oculares afectadas fueron: conjuntiva, cornea (epitelio, estroma) y esclera. Se evaluaron de manera anatómica y funcional con la prueba de Schirmer, tinción con Fluoresceína y tomografía de coherencia óptica (TCO) entre marzo y diciembre del 2020. Resultados: Los síntomas mejoraron en el siguiente orden: dolor ocular, sensación de cuerpo extraño, blefaroespasmo, hiperemia y lagrimeo. Las lesiones evolucionaron favorablemente de la siguiente manera: en primer lugar las conjuntivales y del epitelio corneal, luego las del estroma corneal y finalmente las lesiones en la esclera. Se obtuvo una media de 15 días para recuperación inmediata de la superficie y de 21 días para recuperación tardía. Las lesiones con adelgazamiento parcial profundo de esclera tomaron alrededor de 2 meses. Conclusiones: Los hallazgos relacionados al umbral del dolor, tiempo de recuperación, remodelación cicatrizal del tejido afectado y recuperación de la agudeza visual son prometedores e importantes. La utilización de suero autólogo rico en factores de crecimiento puede ser una alternativa terapéutica para las lesiones de difícil resolución con el tratamiento convencional.

Objective: To determine the effectiveness of autologous serum rich in growth factors to repair ocular surface lesions which have uncertain progression with conventional treatment. Materials and methods: AForty-six (46) eyes with ocular surface disorders such as exposure keratopathy, keratopathy caused by dry eye syndrome, neurotrophic keratopathy and blunt eye injury were treated. The affected areas were the conjunctiva, cornea (epithelium, stroma) and sclera. Anatomical and functional evaluations were performed between March and December 2020 using Schirmer's test, fluorescein eye stain and optical coherence tomography (OCT). Results: The symptoms improved in the following order: eye pain, foreign body sensation, blepharospasm, hyperemia and epiphora. Additionally, the lesions progressed favorably as follows: first, those of the conjunctiva and corneal epithelium; then, those of the corneal stroma; and, finally, those of the sclera. An average of 15 days was required for immediate ocular surface recovery and 21 days for late recovery. The lesions with total scleral thinning healed in about two months. Conclusions: The findings related to pain threshold, recovery time, scar tissue remodeling of the affected tissue and visual acuity improvement are promising and important. Using autologous serum rich in growth factors may be a therapeutic alternative for those lesions that are difficult to resolve with conventional treatment.

Plasma Dickkopf-1 predicts early neurological deterioration and outcome in patients with acute ischemic stroke / 国际脑血管病杂志

Objective:To investigate the relationship between plasma Dickkopf-1 and early neurological deterioration (END) and outcome in patients with acute ischemic stroke.Methods:From January 2020 to December 2020, consecutive patients with first-ever ischemic stroke form the Department of Neurology, Nanjing Jiangbei Hospital were included. All patients were hospitalized within 24 h after onset. END was defined as the National Institutes of Health Stroke Scale (NIHSS) score within 7 d after admission increased by ≥2 or motor function score increased by ≥1 compared with the baseline. Poor outcome was defined as the modified Rankin Scale score >2 at 90 d after onset. Multivariate logistic regression analysis was used to determine the independent correlation between plasma Dickkopf-1 and END and outcome. Receiver operating characteristic (ROC) curve was used to evaluate the predictive value of plasma Dickkopf-1 for END and poor outcome. Results:A total of 176 patients were enrolled, including 92 males (52.3%), aged 66.7±9.6 years. The median Dickkopf-1 was 4.30 μg/L, 52 patients (29.5%) developed END, and 81 (46.0%) had poor outcome. Multivariate logistic regression analysis showed that the higher Dickkopf-1 was an independent predictor of END (odds ratio [ OR] 1.696, 95% confidence interval [ CI] 1.223-2.351; P=0.002) and poor outcome ( OR 1.566, 95% CI 1.156-2.121; P=0.004). ROC curve analysis showed that plasma Dickkopf-1 had good predictive value for END, and its area under the curve was 0.717 (95% CI 0.634-0.801); the optimal cut-off value was 4.40 μg/L, and the corresponding predictive sensitivity and specificity were 71.2% and 60.5%, respectively. Dickkopf-1 also had good predictive value for poor outcome, and its area under the curve was 0.701 (95% CI 0.624-0.778); the optimal cut-off value was 4.25 μg/L, and the corresponding predictive sensitivity and specificity were 65.4% and 61.1%, respectively. Conclusion:Plasma Dickkopf-1 has good predictive value for END and poor outcome in patients with acute ischemic stroke.

La aplicación de factores de crecimiento en el desarrollo de la Ingeniería de tejidos óseos / Application of growth factors in the development of bone tissue engineering

RESUMEN Introducción: los avances científico-técnicos en el campo de la Biología celular y molecular han permitido restaurar y mejorar la función de órganos y tejidos lesionados por ciertas enfermedades y traumatismos. La Ingeniería de tejido se define como el uso de los principios y métodos de la Ingeniería, la Biología y la Bioquímica, los cuales están orientados a la comprensión de la estructura y la función de los tejidos normales y patológicos, y al consecuente desarrollo de sustitutos biológicos para restaurar, mantener o mejorar su función. Objetivo: realizar un acercamiento a algunos aspectos de la Biología celular y molecular vinculada con la Ingeniería tisular ósea. Métodos: se realizó una búsqueda bibliográfica en SciELO Cuba y en Google académico durante el período de 1 de marzo al 28 de abril de 2018. Se evaluaron 134 artículos y el estudio se circunscribió a los 25 artículos que se enfocaban en estas temáticas de manera integral. Conclusiones: se ofreció una visión general de los avances que se han obtenido en la Biología celular y molecular, y en particular a: la aplicación de los factores de crecimiento en la Ingeniería del tejido óseo, así como sus futuras perspectivas. Se concluyó que es fundamental consolidar una base apropiada de conocimientos sobre la Biología celular y molecular y el desarrollo actual de la Ingeniería del tejido óseo.

ABSTRACT Introduction: scientific and technical advances in the field of cellular and molecular biology have allowed restoring and improving the function of organs and tissues injured by certain diseases and trauma. Tissue engineering is defined as the use of the principles and methods of Engineering, Biology and Biochemistry, which are aimed at understanding the structure and function of normal and pathological tissues, and the consequent development of biological substitutes to restore, maintain or improve their function. Objective: to carry out an approach to some aspects of cellular and molecular biology related to bone tissue engineering. Methods: a bibliographic review was carried out in SciELO Cuba and Google Scholar from March 1 to April 28, 2018. A number of 134 articles were evaluated and the study was limited to 25 articles that focused on these topics in an integral way. Conclusions: an overview of the advances that have been obtained in cellular and molecular biology was offered, particularly to the application of growth factors in bone tissue engineering, as well as its future perspectives. We concluded that it is essential to consolidate an appropriate knowledge base on cellular and molecular biology and the current development of bone tissue engineering.

HIF-1α Stabilization Enhances Angio-/Vasculogenic Properties of SHED.

The outcome of regenerative procedures could be augmented by enhancing the biological performances of stem cells prior to their transplantation. The current study aimed to investigate whether hypoxic preconditioning through stabilization of hypoxia-inducible factor 1α (HIF-1α) could enhance the angio-/vasculogenic properties of stem cells from human exfoliated deciduous teeth (SHED). HIF-1α expression in SHED under normoxia was stabilized by silencing the expression of prolyl hydroxylase domain-containing protein 2 (PHD2) via lentiviral small hairpin RNA. This in turn significantly increased the expression of an angiogenic factor: vascular endothelial growth factor. Conditioned medium of HIF-1α-stabilized SHED increased the migration and proliferation of human umbilical vein endothelial cells (HUVECs), indicating enhanced paracrine signaling of SHED following PHD2 knockdown (P < 0.05). Furthermore, the coculture of HIF-1α-stabilized SHED with HUVECs directly and in fibrin beads demonstrated significantly longer vascular sprouts through juxtacrine and paracrine effects (P < 0.05). When HIF-1α-stabilized SHED were added to a preformed HUVEC vascular tube network on Matrigel, it not only stabilized the vessels, as shown by the increased thickness (P < 0.05) and junctional area (P < 0.01) of tubes, but also gave rise to new sprouting (P < 0.01). This observation, with the morphologic changes and increased CD31 expression, suggested that HIF-1α stabilization enhanced the endothelial differentiation capacity of SHED through autocrine signaling. In vivo Matrigel plug assay demonstrated that HIF-1α-stabilized SHED alone could give rise to a vasculature that was significantly higher than that of control SHED ± HUVECs and similar to that of HIF-1α-stabilized SHED + HUVECs. In addition to vasculogenesis by endothelial differentiation, HIF-1α-stabilized SHED recruited host blood vessels into the implant by exerting a significant paracrine effect. Taken together, our results confirmed that HIF-1α-stabilized SHED could replace the function of HUVECs and act as the sole cell source of vascularization. Thus, targeting PHD2 to stabilize HIF-1α expression is an appealing strategy that enables the use of a single cell source for achieving vascularized tissue regeneration.

Treatment of venous ulcers with growth factors: systematic review and meta-analysis / Tratamiento de úlceras venosas confactores de crecimiento: revisión sistemática y metanálisis / Tratamento de úlceras venosas com fatores de crescimento: revisão sistemática e metanálise

ABSTRACT Objective: To identify evidence about the effects of growth factor application on venous ulcer healing. Method: Systematic review and meta-analysis, including Randomized Clinical Trials. Searches: Ovid MEDLINE, EMBASE, CINAHL, Cochrane CENTRAL, LILACS, Web of Science, Digital Library of Theses and Dissertations; Google Scholar and list of references. Results: 802 participants were recruited from the 10 included studies: 472 in the intervention group (growth factors) and 330 as control. The relative risk for the complete healing outcome was 1.06 [95% CI 0.92-1.22], p = 0.41. Participants who received Platelet-Rich Plasma and Epidermal Growth Factor showed a slight tendency to achieve complete healing, but without statistical relevance (p <0.05). Most of the studies were classified as moderate risk of bias. Conclusion: The effect of the application of growth factors for complete healing in venous ulcers is not clear, and clinical trials with methodological quality are required for more accurate recommendations.

RESUMEN Objetivo: Identificar evidencias acerca de los efectos de la aplicación de factores de crecimientoenlacicatrización de úlceras venosas. Método: Revisión sistemática y metanálisis, incluyendo Ensayos Clínicos aleatorizados. Búsquedas: Ovid MEDLINE, EMBASE, CINAHL, Cochrane CENTRAL, LILACS, Web of Science, Biblioteca Digital de Tesis y Disertaciones; Google Académico y lista de referencias Resultados: 802 participantes fueron reclutados por los 10 estudios incluidos: 472 en el grupo intervención (factores de crecimiento) y 330 como control. El riesgo relativo para el desenlace de cicatrización completa fue de 1,06 [IC95% 0,92-1,22], p = 0.41. Los participantes que recibieron Plasma Rico en Plaquetas y Factor de Crecimiento Epidérmico presentaron una ligera tendencia a alcanzar una cicatrización completa, pero sin relevancia estadística (p <0.05). La mayoría de los estudios se clasificaron como moderado riesgo de sesgo. Conclusión: El efecto de la aplicación de factores de crecimiento para cicatrización completa en úlceras venosas no está claro, siendo necesarios ensayos clínicos con calidad metodológica para recomendaciones más precisas.

RESUMO Objetivo: Identificar evidências acerca dos efeitos da aplicação de fatores de crescimento na cicatrização de úlceras venosas. Método: Revisão sistemática e metanálise, incluindo Ensaios Clínicos Randomizados. Buscas: Ovid MEDLINE, EMBASE, CINAHL, Cochrane CENTRAL, LILACS, Web of Science, Biblioteca Digital de Teses e Dissertações; Google Acadêmico e lista de referências. Resultados: 802 participantes foram recrutados pelos 10 estudos incluídos: 472 no grupo intervenção (fatores de crescimento) e 330 como controle. O risco relativo para o desfecho de cicatrização completa foi de 1,06 [IC95% 0,92-1,22], p=0.41. Os participantes que receberam Plasma Rico em Plaquetas e Fator de Crescimento Epidérmico apresentaram uma ligeira tendência a alcançar cicatrização completa, porém sem relevância estatística (p<0.05). A maioria dos estudos foi classificada como moderado risco de viés. Conclusão: O efeito da aplicação de fatores de crescimento para cicatrização completa em úlceras venosas não está claro, sendo necessários ensaios clínicos com qualidade metodológica para recomendações mais precisas.

Antiangiogenic VEGF165b Regulates Macrophage Polarization via S100A8/S100A9 in Peripheral Artery Disease.

BACKGROUND: Atherosclerotic occlusions decrease blood flow to the lower limbs, causing ischemia and tissue loss in patients with peripheral artery disease (PAD). No effective medical therapies are currently available to induce angiogenesis and promote perfusion recovery in patients with severe PAD. Clinical trials aimed at inducing vascular endothelial growth factor (VEGF)-A levels, a potent proangiogenic growth factor to induce angiogenesis, and perfusion recovery were not successful. Alternate splicing in the exon-8 of VEGF-A results in the formation of VEGFxxxa (VEGF165a) and VEGFxxxb (VEGF165b) isoforms with existing literature focusing on VEGF165b's role in inhibiting vascular endothelial growth factor receptor 2-dependent angiogenesis. However, we have recently shown that VEGF165b blocks VEGF-A-induced endothelial vascular endothelial growth factor receptor 1 (VEGFR1) activation in ischemic muscle to impair perfusion recovery. Because macrophage-secreted VEGF165b has been shown to decrease angiogenesis in peripheral artery disease, and macrophages were well known to play important roles in regulating ischemic muscle vascular remodeling, we examined the role of VEGF165b in regulating macrophage function in PAD. METHODS: Femoral artery ligation and resection were used as an in vivo preclinical PAD model, and hypoxia serum starvation was used as an in vitro model for PAD. Experiments including laser-Doppler perfusion imaging, adoptive cell transfer to ischemic muscle, immunoblot analysis, ELISAs, immunostainings, flow cytometry, quantitative polymerase chain reaction analysis, and RNA sequencing were performed to determine a role of VEGF165b in regulating macrophage phenotype and function in PAD. RESULTS: First, we found increased VEGF165b expression with increased M1-like macrophages in PAD versus non-PAD (controls) muscle biopsies. Next, using in vitro hypoxia serum starvation, in vivo pre clinical PAD models, and adoptive transfer of VEGF165b-expressing bone marrow-derived macrophages or VEGFR1+/- bone marrow-derived macrophages (M1-like phenotype), we demonstrate that VEGF165b inhibits VEGFR1 activation to induce an M1-like phenotype that impairs ischemic muscle neovascularization. Subsequently, we found S100A8/S100A9 as VEGFR1 downstream regulators of macrophage polarization by RNA-Seq analysis of hypoxia serum starvation-VEGFR1+/+ versus hypoxia serum starvation-VEGFR1+/- bone marrow-derived macrophages. CONCLUSIONS: In our current study, we demonstrate that increased VEGF165b expression in macrophages induces an antiangiogenic M1-like phenotype that directly impairs angiogenesis. VEGFR1 inhibition by VEGF165b results in S100A8/S100A9-mediated calcium influx to induce an M1-like phenotype that impairs ischemic muscle revascularization and perfusion recovery.

Function and mechanism of action of the PD-1/PD-L1 pathway in liver diseases / 临床肝胆病杂志

Programmed death-1 (PD-1) is an important immunosuppressive molecule which interacts with its ligand programmed death-ligand 1 (PD-L1) and plays an important role in central/peripheral immune tolerance, transplantation immunity, tumor immune escape, and autoimmune disease. At present, there is still no systematic understanding of the role of the PD-1/PD-L1 pathway in the development and progression of liver diseases. This article summarizes related studies on the role of the PD-1/PD-L1 pathway in the progression of liver diseases and reviews the immunoregulatory function of the PD-1/PD-L1 pathway and its role in liver diseases. It is pointed out that the PD-1/PD-L1 pathway is involved in immunoregulatory function of the liver and plays an important role in the development and progression of liver inflammation, autoimmune liver diseases, viral liver diseases, tumor immune escape, transplantation rejection reaction, induced immune response, and autoimmune tolerance. Intervention of the PD-1/PD-L1 pathway may provide new strategies and directions for the prevention and treatment of liver disease.

Function and mechanism of action of the PD-1/PD-L1 pathway in liver diseases / 临床肝胆病杂志

Programmed death-1 (PD-1) is an important immunosuppressive molecule which interacts with its ligand programmed death-ligand 1 (PD-L1) and plays an important role in central/peripheral immune tolerance, transplantation immunity, tumor immune escape, and autoimmune disease. At present, there is still no systematic understanding of the role of the PD-1/PD-L1 pathway in the development and progression of liver diseases. This article summarizes related studies on the role of the PD-1/PD-L1 pathway in the progression of liver diseases and reviews the immunoregulatory function of the PD-1/PD-L1 pathway and its role in liver diseases. It is pointed out that the PD-1/PD-L1 pathway is involved in immunoregulatory function of the liver and plays an important role in the development and progression of liver inflammation, autoimmune liver diseases, viral liver diseases, tumor immune escape, transplantation rejection reaction, induced immune response, and autoimmune tolerance. Intervention of the PD-1/PD-L1 pathway may provide new strategies and directions for the prevention and treatment of liver disease.

Expressions of transforming growth factor ß1 signaling cytokines in aortic dissection

Abstract Objective: To demonstrate the underlying mechanisms of aortic dissection compared to those of coronary artery disease in terms of the transforming growth factor-beta (TGF-β) signaling pathway. Methods: Twenty consecutive aortic dissection patients and 20 consecutive coronary artery disease patients undergoing a surgical treatment in this hospital were enrolled into this study. The aortic tissues were sampled and the TGF-β1 and its receptor TGF-β receptor I (TβRI) were detected by Western blotting assay. Results: TGF-β1 and TβRI were positively expressed in the aortic tissues in both groups by Western blotting assay. The expressions of the two proteins were significantly higher in the aortic tissue of patients with aortic dissection than in those with coronary artery disease. The quantitative analyses of the relative gray scales of the proteins disclosed close correlations between the expressions of TGF-β1 and TβRI in both the study and control group patients. Conclusions: The aortic remodeling of aortic dissection might differ from that of coronary artery atherosclerosis concerning the nature, mechanism, mode, and activities of TGF-β signaling pathway. The development of aortic dissection could be associated with a significantly enhanced function of TGF-β1/Smad signaling transduction as a result of aortic remodeling incorporating both vascular injury and repair.

Neurotrophin expression and histomorphometric evaluation in Wistar rats subjected to neural mobilization after compression of the median nerve.

OBJECTIVE: To evaluate the neurotrophin mRNA expression and axon count in the median nerve of Wistar rats submitted to neural mobilization (NM) after nerve compression. METHODS: Eighteen animals were randomly divided into G1 (nerve compression only), G2 (NM for 1 min), and G3 (NM for 3 min). For NM, the animals were anesthetized and the right scapula received the mobilization, adapted as indicated for humans, on alternate days, from the third to the 13th postoperative (PO) day, totaling six days of therapy. On the 14th PO day, animals were anesthetized and euthanized. Fragments of the median nerve, distal to the compression procedure, were removed for histomorphometric analysis and expression of neurotrophins, nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF) by RT-PCR. RESULTS: Histomorphometric analysis revealed differences in the number of axons in the injured side, which was significantly lower in the injured limb nerve compared to the control limb, whereas the RT-PCR analysis showed no significant differences in the expression of NGF or BDNF. CONCLUSION: NM treatment did not affect median nerve regeneration, which maintained normal recovery rates.

OBJETIVO: Avaliar a expressão de RNAm de neurotrofinas e a contagem de axônios no nervo mediano de ratos Wistar submetidos à mobilização neural (MN) após compressão nervosa. MÉTODOS: Foram divididos aleatoriamente 18 animais em G1 (apenas compressão nervosa), G2 (MN por 1 minuto) e G3 (MN por 3 minutos). Para a MN, os animais foram anestesiados e o membro escapular direito recebeu a mobilização, adaptada da forma indicada para humanos, em dias alternados, do terceiro ao 13° dia de pós-operatório (PO), em seis dias de terapia. No 14° dia PO, os animais foram anestesiados e eutanasiados. Fragmentos do nervo mediano, distais ao procedimento de compressão, foram retirados para análise histomorfométrica e de expressão das neutrotrofinas, fator de crescimento do nervo (NGF) e fator de crescimento derivado do cérebro (BNDF) por RT-PCR. RESULTADOS: A análise histomorfométrica evidenciou diferenças no número de axônios nos lados lesionados, que foi significativamente menor no nervo do membro lesado comparado com o membro controle; por sua vez, a análise por RT-PCR não apontou diferenças significativas na expressão de NGF e nem de BNDF. CONCLUSÃO: O tratamento de MN não afetou a regeneração do nervo mediano, que manteve índices normais de recuperação.