RESUMO
Acute respiratory distress syndrome (ARDS) has high mortality (~40 %) and requires the lifesaving intervention of mechanical ventilation. A variety of systemic inflammatory insults can progress to ARDS, and the inflamed and injured lung is susceptible to ventilator-induced lung injury (VILI). Strategies to mitigate the inflammatory response while restoring pulmonary function are limited, thus we sought to determine if treatment with CNP-miR146a, a conjugate of novel free radical scavenging cerium oxide nanoparticles (CNP) to the anti-inflammatory microRNA (miR)-146a, would protect murine lungs from acute lung injury (ALI) induced with intratracheal endotoxin and subsequent VILI. Lung injury severity and treatment efficacy were evaluated via lung mechanical function, relative gene expression of inflammatory biomarkers, and lung morphometry (stereology). CNP-miR146a reduced the severity of ALI and slowed the progression of VILI, evidenced by improvements in inflammatory biomarkers, atelectasis, gas volumes in the parenchymal airspaces, and the stiffness of the pulmonary system.
Assuntos
Lesão Pulmonar Aguda , Síndrome do Desconforto Respiratório , Lesão Pulmonar Induzida por Ventilação Mecânica , Humanos , Camundongos , Animais , Pulmão/metabolismo , Lesão Pulmonar Induzida por Ventilação Mecânica/tratamento farmacológico , Lesão Pulmonar Induzida por Ventilação Mecânica/genética , Lesão Pulmonar Induzida por Ventilação Mecânica/metabolismo , Síndrome do Desconforto Respiratório/metabolismo , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/genéticaRESUMO
Acute respiratory distress syndrome (ARDS) is a highly morbid pulmonary disease characterized by hypoxic respiratory failure. Its pathogenesis is characterized by unrestrained oxidative stress and inflammation, with long-term sequelae of pulmonary fibrosis and diminished lung function. Unfortunately, prior therapeutic ARDS trials have failed and therapy is limited to supportive measures. Free radical scavenging cerium oxide nanoparticles (CNP) conjugated to the anti-inflammatory microRNA-146a (miR146a), termed CNP-miR146a, have been shown to prevent acute lung injury in a pre-clinical model. In this study, we evaluated the potential of delayed treatment with CNP-miR146a at three or seven days after injury to rescue the lung from acute injury. We found that intratracheal CNP-miR146a administered three days after injury lowers pulmonary leukocyte infiltration, reduce inflammation and oxidative stress, lower pro-fibrotic gene expression and collagen deposition in the lung, and ultimately improve pulmonary function.
Assuntos
Lesão Pulmonar Aguda , Lesão Pulmonar , Nanopartículas , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/patologia , Cério , Humanos , Pulmão/patologia , Lesão Pulmonar/patologia , Tempo para o TratamentoRESUMO
Diabetic wounds represent a significant healthcare burden and are characterized by impaired wound healing due to increased oxidative stress and persistent inflammation. We have shown that CNP-miR146a synthesized by the conjugation of cerium oxide nanoparticles (CNP) to microRNA (miR)-146a improves diabetic wound healing. CNP are divalent metal oxides that act as free radical scavenger, while miR146a inhibits the pro-inflammatory NFκB pathway, so CNP-miR146a has a synergistic role in modulating both oxidative stress and inflammation. In this study, we define the mechanism(s) by which CNP-miR146a improves diabetic wound healing by examining immunohistochemical and gene expression analysis of markers of inflammation, oxidative stress, fibrosis, and angiogenesis. We have found that intradermal injection of CNP-miR146a increases wound collagen, enhances angiogenesis, and lowers inflammation and oxidative stress, ultimately promoting faster closure of diabetic wounds.
Assuntos
Cério , Diabetes Mellitus , MicroRNAs , Nanopartículas , Cério/química , Cério/farmacologia , Humanos , MicroRNAs/metabolismo , Nanopartículas/química , CicatrizaçãoRESUMO
Diabetes produces a chronic inflammatory state that contributes to the development of vascular disease and impaired wound healing. Despite the known individual and societal impacts of diabetic ulcers, there are limited therapies effective at improving healing. Stromal cell-derived factor 1α (SDF-1α) is a CXC chemokine that functions via activation of the CXC chemokine receptor type 4 (CXCR4) receptor to recruit hematopoietic cells to locations of tissue injury and promote tissue repair. The expression of SDF-1α is reduced in diabetic wounds, suggesting a potential contribution to wound healing impairment and presenting the CXCR4 receptor as a target for therapeutic investigations. We developed a high-throughput ß-arrestin recruitment assay and conducted structure-activity relationship (SAR) studies to screen compounds for utility as CXCR4 agonists. We identified CXCR4 agonist UCUF-728 from our studies and further validated its activity in vitro in diabetic fibroblasts. UCUF-728 reduced overexpression of miRNA-15b and miRNA-29a, negative regulators of angiogenesis and type I collagen production, respectively, in diabetic fibroblasts. In vivo, UCUF-728 reduced the wound closure time by 36% and increased the evidence of angiogenesis in diabetic mice. Together, this work demonstrates the clinical potential of small molecule CXCR4 agonists as novel therapies for pathologic wound healing in diabetes.
Assuntos
Diabetes Mellitus Experimental , Receptores CXCR4 , Cicatrização , Animais , Quimiocina CXCL12/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Camundongos , MicroRNAs , Neovascularização Fisiológica , Receptores CXCR4/agonistas , Receptores CXCR4/metabolismoRESUMO
Acute respiratory distress syndrome (ARDS) is a devastating pulmonary disease with significant in-hospital mortality and is the leading cause of death in COVID-19 patients. Excessive leukocyte recruitment, unregulated inflammation, and resultant fibrosis contribute to poor ARDS outcomes. Nanoparticle technology with cerium oxide nanoparticles (CNP) offers a mechanism by which unstable therapeutics such as the anti-inflammatory microRNA-146a can be locally delivered to the injured lung without systemic uptake. In this study, we evaluated the potential of the radical scavenging CNP conjugated to microRNA-146a (termed CNP-miR146a) in preventing acute lung injury (ALI) following exposure to bleomycin. We have found that intratracheal delivery of CNP-miR146a increases pulmonary levels of miR146a without systemic increases, and prevents ALI by altering leukocyte recruitment, reducing inflammation and oxidative stress, and decreasing collagen deposition, ultimately improving pulmonary biomechanics.
Assuntos
Bleomicina/efeitos adversos , Cério , Sistemas de Liberação de Medicamentos , MicroRNAs , Síndrome do Desconforto Respiratório/tratamento farmacológico , Animais , Bleomicina/farmacologia , COVID-19/genética , COVID-19/metabolismo , Cério/química , Cério/farmacologia , Modelos Animais de Doenças , Masculino , Camundongos , MicroRNAs/química , MicroRNAs/farmacologia , Síndrome do Desconforto Respiratório/induzido quimicamente , Síndrome do Desconforto Respiratório/genética , Síndrome do Desconforto Respiratório/metabolismo , SARS-CoV-2/metabolismo , Tratamento Farmacológico da COVID-19RESUMO
BACKGROUND: Biliary atresia (BA) is an inflammatory pediatric cholangiopathy with only surgical means for treatment. Many contributors to bile acid synthesis and transport have previously been reported to be downregulated in patients with BA; yet, the driving factors of the abnormal bile acid synthesis and transport in regard to BA have not been previously studied. MATERIALS AND METHODS: Wild type or Ig-α-/- mice were injected with salt solution (control) or rotavirus on day of life 0, and analyses were performed on day of life 14. The mRNA levels of bile acid transporters/nuclear receptors and liver microRNAs (miRNAs) were compared between groups. A mouse hepatocyte cell line was used to examine the effects of innate cytokines on miRNA levels and bile acid transporter/nuclear receptor expression and miRNAs on bile acid transporter/nuclear receptor expression. RESULTS: BA mice had significantly increased mRNA expression of innate cytokines and miRNAs known to bind bile acid transporters/nuclear receptors (miRNAs -22-5p, -34a-5p, and -222-3p) and decreased mRNA expression of bile acid transporters and nuclear receptors. In vitro, TNF-α and IL-1ß decreased BSEP and CYP7A1 while increasing miRNA-34a-5p and miRNA 222-3p. LXR, SHP, CYP7A1, NTCP, and MRP2 were decreased by miRNA-34a-5p, whereas miRNA-222-3p decreased NTCP and MRP4. TNF-α and IL-1ß increased expression of miRNAs 34a-5p and 222-3p and these miRNAs then decrease expression of multiple bile acid transporters and nuclear receptors. CONCLUSIONS: Loss of bile acid transporters increases hepatotoxicity via bile acid retention. Therapeutic agents that increase bile acid transport or nuclear receptor functioning should be investigated in BA.
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Ácidos e Sais Biliares/metabolismo , Atresia Biliar/imunologia , Colestase/imunologia , Inflamação/genética , MicroRNAs/metabolismo , Animais , Ductos Biliares/imunologia , Ductos Biliares/patologia , Atresia Biliar/patologia , Antígenos CD79/genética , Antígenos CD79/imunologia , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Linhagem Celular , Colestase/patologia , Modelos Animais de Doenças , Regulação da Expressão Gênica/imunologia , Hepatócitos/metabolismo , Humanos , Inflamação/complicações , Inflamação/imunologia , Fígado/citologia , Fígado/imunologia , Fígado/patologia , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismoRESUMO
Pressure ulcers are preventable, yet highly prevalent, chronic wounds that have significant patient morbidity and high healthcare costs. Like other chronic wounds, they are characterized by impaired wound healing due to dysregulated immune processes. This review will highlight key biochemical pathways in the pathogenesis of pressure injury and how this signaling leads to impaired wound healing. This review is the first to comprehensively describe the current literature on microRNA (miRNA, miR) regulation of pressure ulcer pathophysiology.
Assuntos
Regulação da Expressão Gênica , Imunidade , MicroRNAs/genética , Úlcera por Pressão/etiologia , Úlcera por Pressão/terapia , Animais , Apoptose , Gerenciamento Clínico , Suscetibilidade a Doenças , Matriz Extracelular , Redes Reguladoras de Genes , Humanos , Imunidade/genética , Estresse Oxidativo , Úlcera por Pressão/metabolismo , Úlcera por Pressão/patologia , Interferência de RNA , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais , Cicatrização/genéticaRESUMO
Impaired diabetic wound healing is associated with a dermal extracellular matrix protein profile favoring proteolysis; within the healing diabetic wound, this is represented by an increase in activated matrix metalloproteinase (MMPs). Treatment of diabetic wounds with mesenchymal stem cells (MSCs) has been shown to improve wound healing; however, there has not yet been an assessment of their ability to correct dysregulation of MMPs in diabetic wounds. Furthermore, there has been no prior assessment of the role of microRNA29b (miR-29b), an inhibitory regulatory molecule that targets MMP-9 mRNA. Using in vitro models of fibroblast coculture with MSCs and in vivo murine wound healing models, we tested the hypothesis that MSCs correct dysregulation of MMPs in a microRNA-29b-dependent mechanism. In this study, we first demonstrated that collagen I and III protein content is significantly reduced in diabetic wounds, and treatment with MSCs significantly improves collagen I content in both nondiabetic and diabetic wounds. We then found that MMP-9 gene expression and protein content were significantly upregulated in diabetic wounds, indicating elevated proteolysis. Treatment with MSCs resulted in a decrease in MMP-9 gene expression and protein content level in diabetic wounds 3 and 7 days after wounding. Zymographic analysis indicated that MSC treatment also decreased the amount of activated MMP-9 present in diabetic wounds. Furthermore, miR-29b expression was inversely associated with MMP-9 gene expression; miR-29b expression was decreased in diabetic wounds and diabetic fibroblast. Following treatment of diabetic wounds with MSCs, as well as in diabetic fibroblasts cocultured with MSCs, miR-29b was significantly increased. These findings suggest a potential mechanism through which MSCs enhance diabetic wound healing by improving collagen I content in diabetic wounds through decreasing MMP-9 expression and increasing miR-29b expression.
Assuntos
Diabetes Mellitus Experimental/fisiopatologia , Proteínas da Matriz Extracelular/metabolismo , Transplante de Células-Tronco Mesenquimais/métodos , Cicatrização/fisiologia , Animais , Técnicas de Cocultura , Colágeno Tipo I/metabolismo , Colágeno Tipo III/metabolismo , Feminino , Fibroblastos/citologia , Regulação da Expressão Gênica , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Células-Tronco Mesenquimais/citologia , Camundongos Transgênicos , MicroRNAs/genética , ProteóliseRESUMO
Diabetic skin has impaired wound healing properties following injury. We have further shown that diabetic skin has weakened biomechanical properties at baseline. We hypothesize that the biomechanical properties of diabetic skin decline during the progression of the diabetic phenotype, and that this decline is due to the dysregulation of miR-29a, resulting in decreased collagen content. We further hypothesize that treatment with mesenchymal stem cells (MSCs) may improve diabetic wound healing by correction of the dysregulated miR-29a expression. We analyzed the biomechanical properties, collagen gene expression, collagen protein production, and miR-29a levels in skin harvested from 6 to 18 week old mice during the development of the diabetic phenotype. We also examined the correction of these impairments by both MSC treatment and the inhibition of miR-29a. Diabetic skin demonstrated a progressive impairment of biomechanical properties, decreased collagen content, and increased miR-29a levels during the development of the diabetic phenotype. MSC treatment decreased miR-29a levels, increased collagen content, and corrected the impaired biomechanical properties of diabetic skin. Additionally, direct inhibition of miR-29a also increased collagen content in diabetic skin. This decline in the biomechanical properties of diabetic skin during the progression of diabetes may increase the susceptibility of diabetic skin to injury and miR-29a appears to play a key role in this process.
Assuntos
Diabetes Mellitus/patologia , Células-Tronco Mesenquimais/fisiologia , MicroRNAs/genética , Pele/patologia , Cicatrização/genética , Ferimentos e Lesões/patologia , Animais , Western Blotting , Colágeno Tipo I/metabolismo , Colágeno Tipo III/metabolismo , Diabetes Mellitus/genética , Modelos Animais de Doenças , Feminino , Humanos , Transplante de Células-Tronco Mesenquimais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Transdução de Sinais , Pele/lesões , Regulação para Cima , Ferimentos e Lesões/genética , Ferimentos e Lesões/terapiaRESUMO
Diabetic skin wounds lack the ability to heal properly and constitute a major and significant complication of diabetes. Nontraumatic lower extremity amputations are the number one complication of diabetic skin wounds. The complexity of their pathophysiology requires an intervention at many levels to enhance healing and wound closure. Stem cells are a promising treatment for diabetic skin wounds as they have the ability to correct abnormal healing. Stem cell factor (SCF), a chemokine expressed in the skin, can induce stem cells migration, however the role of SCF in diabetic skin wound healing is still unknown. We hypothesize that SCF would correct the impairment and promote the healing of diabetic skin wounds. Our results show that SCF improved wound closure in diabetic mice and increased HIF-1α and vascular endothelial growth factor (VEGF) expression levels in these wounds. SCF treatment also enhanced the migration of red fluorescent protein (RFP)-labeled skin stem cells via in utero intra-amniotic injection of lenti-RFP at E8. Interestingly these RFP+ cells are present in the epidermis, stain negative for K15, and appear to be distinct from the already known hair follicle stem cells. These results demonstrate that SCF improves diabetic wound healing in part by increasing the recruitment of a unique stem cell population present in the skin.
Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Prenhez , Pele/lesões , Fator de Células-Tronco/genética , Células-Tronco/patologia , Cicatrização/genética , Ferimentos e Lesões/genética , Animais , Animais Recém-Nascidos , Movimento Celular/fisiologia , Diabetes Mellitus Experimental , Feminino , Imuno-Histoquímica , Queratina-15/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Fisiológica , Gravidez , RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Pele/embriologia , Pele/metabolismo , Fator de Células-Tronco/biossíntese , Células-Tronco/metabolismo , Ferimentos e Lesões/metabolismo , Ferimentos e Lesões/patologiaRESUMO
The impairment in diabetic wound healing represents a significant clinical problem. Decreased angiogenesis is thought to play a central role in the pathogenesis of this impairment. We have previously shown that treatment of diabetic murine wounds with mesenchymal stem cells can improve healing, but the mechanisms are not completely defined. MicroRNA-15b (miR-15b) has been implicated in the regulation of the angiogenic response. We hypothesized that abnormal miR-15b expression may contribute to the impaired angiogenesis observed in impaired diabetic wound healing. To test this hypothesis, we examined the expression of miR-15b and its target genes in diabetic and nondiabetic mice before and after injury. MiR-15b expression was significantly up-regulated in diabetic mouse wounds during the wound healing response. Increased miR-15b levels also closely correlated with decreased gene expression of its proangiogenic target genes. Furthermore, the correction of the diabetic wound healing impairment with mesenchymal stem cell treatment was associated with a significant decrease in miR-15b expression level and increased gene expression of its proangiogenic target genes. These results provide the first evidence that increased expression of miR-15b in diabetic wounds in response to injury may, in part, be responsible for the abnormal angiogenic response seen in diabetic wounds and may contribute to the observed wound healing impairment.
Assuntos
Diabetes Mellitus , MicroRNAs/fisiologia , Neovascularização Fisiológica/genética , RNA Mensageiro/metabolismo , Cicatrização/genética , Ferimentos e Lesões/genética , Animais , Modelos Animais de Doenças , Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Ferimentos e Lesões/complicações , Ferimentos e Lesões/metabolismoRESUMO
Wound size impacts the threshold between scarless regeneration and reparative healing in the fetus with increased inflammation showed in fetal scar formation. We hypothesized that increased fetal wound size increases pro-inflammatory and fibrotic genes with resultant inflammation and fibroplasia and that transition to scar formation could be reversed by overexpression of interleukin-10 (IL-10). To test this hypothesis, 2-mm and 8-mm dermal wounds were created in mid-gestation fetal sheep. A subset of 8-mm wounds were injected with a lentiviral vector containing the IL-10 transgene (n = 4) or vehicle (n = 4). Wounds were harvested at 3 or 30 days for histology, immunohistochemistry, analysis of gene expression by microarray, and validation with real-time polymerase chain reaction. In contrast to the scarless 2-mm wounds, 8-mm wounds showed scar formation with a differential gene expression profile, increased inflammatory cytokines, decreased CD45+ cells, and subsequent inflammation. Lentiviral-mediated overexpression of the IL-10 gene resulted in conversion to a regenerative phenotype with decreased inflammatory cytokines and regeneration of dermal architecture. In conclusion, increased fetal wounds size leads to a unique gene expression profile that promotes inflammation and leads to scar formation and furthermore, these results show the significance of attenuated inflammation and IL-10 in the transition from fibroplasia to fetal regenerative healing.
Assuntos
Cicatriz/patologia , Inflamação/patologia , Interleucina-10/metabolismo , Pele/patologia , Cicatrização , Ferimentos e Lesões/patologia , Animais , Cicatriz/embriologia , Feminino , Feto , Fibroblastos , Expressão Gênica , Imuno-Histoquímica , Inflamação/embriologia , Fenótipo , Gravidez , Regeneração , Ovinos , Pele/embriologia , Ferimentos e Lesões/embriologiaRESUMO
Recurrent injury has been implicated in the development of chronic diabetic wounds. We have developed a chronic diabetic wound model based upon recurrent injury in diabetic mice. We hypothesized that dysregulation of collagen production at both the mRNA and microRNA levels contributes to the development of chronic diabetic wounds. To test this, both diabetic and nondiabetic mice were made to undergo recurrent injury. Real-time PCR for TGF-ß1, SMAD-3, Col1α1, Col3α1, microRNA-25, and microRNA-29a and Western blot for collagen I and III were performed 7 days following each injury. Diabetic wounds displayed decreased collagen at all time points. This was associated with dysregulated collagen production at both the gene and microRNA levels at all time points. Following the final injury, however, diabetic collagen production significantly improved. This appeared to be due to a substantial decrease in both microRNAs as well as an increase in the expression of collagen pathway genes. That dysregulated collagen production progressed throughout the course of wounding suggests that this is one factor contributing to the development of chronic diabetic wounds. Future studies using this model will allow for the determination of other factors that may also contribute to the development and/or persistence of chronic diabetic wounds.
Assuntos
Colágeno/metabolismo , Complicações do Diabetes/metabolismo , Úlcera Cutânea/metabolismo , Pele/lesões , Pele/metabolismo , Cicatrização , Animais , Fenômenos Biomecânicos , Western Blotting , Doença Crônica , Colágeno/genética , Colágeno Tipo I/metabolismo , Colágeno Tipo III/metabolismo , Diabetes Mellitus Experimental/metabolismo , Elasticidade , Camundongos , Camundongos Endogâmicos NOD , MicroRNAs/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Úlcera Cutânea/etiologia , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta1/metabolismoRESUMO
Inflammation and oxidative stress are implicated in the pathogenesis of Crohn's disease. Cerium oxide nanoparticle (CNP) conjugated to microRNA 146a (miR146a) (CNP-miR146a) is a novel compound with anti-inflammatory and antioxidative properties. We hypothesized that local administration of CNP-miR146a would improve colitis in a 2,4,6-Trinitrobenzenesulfonic acid (TNBS) mouse model for Crohn's disease by decreasing colonic inflammation. Balb/c mice were instilled with TNBS enemas to induce colitis. Two days later, the mice received cellulose gel enema, cellulose gel with CNP-miR146a enema, or no treatment. Control mice received initial enemas of 50% ethanol and PBS enemas on day two. The mice were monitored daily for weight loss and clinical disease activity. The mice were euthanized on days two or five to evaluate their miR146a expression, inflammation on histology, and colonic IL-6 and TNF gene expressions and protein concentrations. CNP-miR146a enema successfully increased colonic miR146a expression at 12 h following delivery. At the end of five days from TNBS instillation, the mice treated with CNP-miR146a demonstrated reduced weight loss, improved inflammation scores on histology, and reduced gene expressions and protein concentrations of IL-6 and TNF. The local delivery of CNP-miR146a in a TNBS mouse model of acute Crohn's colitis dramatically decreased inflammatory signaling, resulting in improved clinical disease.
RESUMO
Normal wound healing occurs through a careful orchestration of cytokine and chemokine signaling in response to injury. Chemokines are a small family of chemotactic cytokines that are secreted by immune cells in response to injury and are primarily responsible for recruiting appropriate immune cell types to injured tissue at the appropriate time. Dysregulation of chemokine signaling is suspected to contribute to delayed wound healing and chronic wounds in diseased states. Various biomaterials are being used in the development of new therapeutics for wound healing and our understanding of their effects on chemokine signaling is limited. It has been shown that modifications to the physiochemical properties of biomaterials can affect the body's immune reaction. Studying these effects on chemokine expression by various tissues and cell type can help us develop novel biomaterial therapies. In this review, we summarize the current research available on both natural and synthetic biomaterials and their effects on chemokine signaling in wound healing. In our investigation, we conclude that our knowledge of chemokines is still limited and that many in fact share both pro-inflammatory and anti-inflammatory properties. The predominance of either a pro-inflammatory or anti-inflammatory profile is mostly likely dependent on timing after injury and exposure to the biomaterial. More research is needed to better understand the interaction and contribution of biomaterials to chemokine activity in wound healing and their immunomodulatory effects.
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Diabetes mellitus is a morbid condition affecting a growing number of the world population, and approximately one third of diabetic patients are afflicted with diabetic foot ulcers (DFU), which are chronic non-healing wounds that frequently progress to require amputation. The treatments currently used for DFU focus on reducing pressure on the wound, staving off infection, and maintaining a moist environment, but the impaired wound healing that occurs in diabetes is a constant obstacle that must be faced. Aberrant angiogenesis is a major contributor to poor wound healing in diabetes and surgical intervention is often necessary to establish peripheral blood flow necessary for healing wounds. Over recent years, microRNAs (miRNAs) have been implicated in the dysregulation of angiogenesis in multiple pathologies including diabetes. This review explores the pathways of angiogenesis that become dysregulated in diabetes, focusing on miRNAs that have been identified and the mechanisms by which they affect angiogenesis.
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Acute respiratory distress syndrome (ARDS) has approximately 40% in-hospital mortality, and treatment is limited to supportive care. Pneumonia is the underlying etiology in many cases with unrestrained inflammation central to the pathophysiology. We have previously shown that CNP-miR146a, a radical scavenging cerium oxide nanoparticle (CNP) conjugated to the anti-inflammatory microRNA(miR)-146a, reduces bleomycin- and endotoxin-induced acute lung injury (ALI) by decreasing inflammation. We therefore hypothesized that CNP-miR146a would decrease inflammation in murine infectious ALI. Mice were injured with intratracheal (IT) MRSA or saline followed by treatment with IT CNP-miR146a or saline control. Twenty-four hours post-infection, bronchoalveolar lavage fluid (BALF) and whole lungs were analyzed for various markers of inflammation. Compared to controls, MRSA infection significantly increased proinflammatory gene expression (IL-6, IL-8, TNFα, IL-1ß; p < 0.05), BALF proinflammatory cytokines (IL-6, IL-8, TNFα, IL-1ß; p < 0.01), and inflammatory cell infiltrate (p = 0.03). CNP-miR146a treatment significantly decreased proinflammatory gene expression (IL-6, IL-8, TNFα, IL-1ß; p < 0.05), bronchoalveolar proinflammatory protein leak (IL-6, IL-8, TNFα; p < 0.05), and inflammatory infiltrate (p = 0.01). CNP-miR146a decreases inflammation and improves alveolar-capillary barrier integrity in the MRSA-infected lung and has significant promise as a potential therapeutic for ARDS.
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Development of specific therapies that target and accelerate diabetic wound repair is an urgent need to alleviate pain and suffering and the huge socioeconomic burden of this debilitating disease. C-X-C Motif Chemokine Ligand 12 (CXCL12) also know an stromal cell-derived factor 1α (SDF-1α) is a chemokine that binds the CXC chemokine receptor type 4 (CXCR4) and activates downstream signaling resulting in recruitment of hematopoietic cells to locations of tissue injury and promotes tissue repair. In diabetes, low expression of CXCL12 correlates with impaired wound healing. Activation of CXCR4 receptor signaling with agonists or positive allosteric modulators (PAMs) provides a potential for small molecule therapeutic discovery and development. We recently reported high throughput screening and identification of the CXCR4 partial agonist UCUF-728, characterization of in vitro activity and reduced wound closure time in diabetic mice at 100 µM as a proof-of-concept study. We report here, the discovery of a second chemical scaffold demonstrating increased agonist potency and represented by thiadiazine derivative, UCUF-965. UCUF-965 is a potent partial agonist of ß-arrestin recruitment in CXCR4 receptor overexpressing cell line. Furthermore, UCUF-965 potentiates the CXCL12 maximal response in cAMP signaling pathway, activates CXCL12 stimulated migration in lymphoblast cells and modulates the levels of specific microRNA involved in the complex wound repair process, specifically in mouse fibroblasts. Our results indicate that UCUF-965 acts as a PAM agonist of the CXCR4 receptor. Furthermore, UCUF-965 enhanced angiogenesis markers and reduced wound healing time by 36% at 10.0 µM in diabetic mice models compared to untreated control.
Assuntos
Diabetes Mellitus Experimental , Receptores CXCR4 , Cicatrização , Animais , Camundongos , Movimento Celular/fisiologia , Quimiocina CXCL12/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/imunologia , Células-Tronco Hematopoéticas , Receptores CXCR4/agonistas , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , Transdução de Sinais , Cicatrização/efeitos dos fármacos , Cicatrização/genética , Cicatrização/fisiologiaRESUMO
Diabetic foot ulcers (DFUs) are a devastating ailment for many diabetic patients with increasing prevalence and morbidity. The complex pathophysiology of DFU wound environments has made finding effective treatments difficult. Standard wound care treatments have limited efficacy in healing these types of chronic wounds. Topical biomaterial gels have been developed to implement novel treatment approaches to improve therapeutic effects and are advantageous due to their ease of application, tunability, and ability to improve therapeutic release characteristics. Here, we provide an updated, comprehensive review of novel topical biomaterial gels developed for treating chronic DFUs. This review will examine preclinical data for topical gel treatments in diabetic animal models and clinical applications, focusing on gels with protein/peptides, drug, cellular, herbal/antioxidant, and nano/microparticle approaches. STATEMENT OF SIGNIFICANCE: By 2050, 1 in 3 Americans will develop diabetes, and up to 34% of diabetic patients will develop a diabetic foot ulcer (DFU) in their lifetime. Current treatments for DFUs include debridement, infection control, maintaining a moist wound environment, and pressure offloading. Despite these interventions, a large number of DFUs fail to heal and are associated with a cost that exceeds $31 billion annually. Topical biomaterials have been developed to help target specific impairments associated with DFU with the goal to improve healing. A summary of these approaches is needed to help better understand the current state of the research. This review summarizes recent research and advances in topical biomaterials treatments for DFUs.
Assuntos
Diabetes Mellitus , Pé Diabético , Administração Tópica , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/uso terapêutico , Pé Diabético/tratamento farmacológico , Géis/uso terapêutico , Humanos , CicatrizaçãoRESUMO
In general, wound healing is a highly ordered process, with distinct phases of inflammation, proliferation, and remodeling. However, among diabetic patients, the progression through these phases is often impeded by increased level of oxidative stress and persistent inflammation. Our previous studies demonstrated that cerium oxide nanoparticles (CNPs) conjugated with therapeutic microRNA146a (miR146a) could effectively enhance wound healing by targeting the NFκB pathway, reducing oxidative stress and inflammation. In the present study, we consider the potential effects of nanomaterial surface-faceting and morphology on the efficacy of miRNA delivery. Compared with octahedral-CNPs and cubic-CNPs, rod-CNPs exhibited higher loading capacity. In addition, in comparing the influence of particle morphology on wound healing efficacy, several markers for bioactivity were evaluated and ascribed to the combined effects of the gene delivery and reactive oxygen species (ROS) scavenging properties. In the cellular treatment study, rod-CNP-miR146a displayed the greatest miR146a delivery into cells. However, the reduction of IL-6 was only observed in the octahedral-CNP-miR146a, suggesting that the efficacy of the miRNA delivery is a result of the combination of various factors. Overall, our results give enlightenments into the relative delivery efficiency of the CNPs with different morphology enhancing miRNA delivery efficacy.