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1.
Medicina (Kaunas) ; 59(11)2023 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-38004018

RESUMO

Background and Objectives: The prevalence of hypertrophic scarring after a burn is approximately 70%. Despite advances in burn management, there is currently no gold standard treatment to reduce or prevent its occurrence. Glucocorticoids are frequently given to patients early after burns for other therapeutic purposes and have been shown to induce scar regression. Therefore, the purpose of the present work is to determine the incidence of hypertrophic scar diagnosis in burn patients who were administered glucocorticoid treatment using TriNetX, a large patient database. Materials and Methods: Patients diagnosed with hypertrophic scarring, hypertrophic disorders of the skin, or scar conditions and fibrosis of the skin after burn injury were identified in the TriNetX database. The glucocorticoids investigated include hydrocortisone, methylprednisolone, dexamethasone, triamcinolone, and prednisone. Patients were stratified into three groups based on total body surface area (TBSA) burned: 0-19%, 20-39%, and 40-100%. The risk ratio was evaluated for burn patients who received varying glucocorticoids after injury based on TBSA burned. Additionally, treatment pathways, time of treatment, and treatment purity pathways were evaluated. Results: In patients with a 0-19% TBSA burn, methylprednisolone showed a decreased risk of developing hypertrophic scar diagnosis. In those with a 20-39% TBSA burn or 40-100% TBSA burn, dexamethasone showed an increased risk of developing hypertrophic scar diagnosis. Additionally, dexamethasone was the most commonly administered glucocorticoid for burn patients and was most likely to be administered earlier after burn injury, comparatively. Conclusions: Methylprednisolone was associated with reduced hypertrophic scar diagnosis in burn patients independent of TBSA burn. While glucocorticoids are one of the mainstay treatments for hypertrophic scarring, further studies are needed to determine early therapeutic interventions that will reduce the potential for hypertrophic scar development in burn patients.


Assuntos
Queimaduras , Cicatriz Hipertrófica , Humanos , Cicatriz Hipertrófica/tratamento farmacológico , Cicatriz Hipertrófica/etiologia , Cicatriz Hipertrófica/prevenção & controle , Glucocorticoides/efeitos adversos , Queimaduras/complicações , Queimaduras/terapia , Metilprednisolona/uso terapêutico , Dexametasona/uso terapêutico
2.
Int J Mol Sci ; 23(12)2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35743131

RESUMO

Dermal fibroblasts in pathological scars secrete constitutively elevated levels of TGF-ß, signaling the transcription of fibrotic genes via activin-like kinase 5 (ALK5). In the present study, we examine the antifibrotic effects of galunisertib, a small-molecule inhibitor of ALK5, on fibroproliferative dermal fibroblasts in an in vitro model of wound healing. We induced fibrosis in human dermal fibroblasts with exogenous TGF-ß and performed cellular proliferation assays after treatment with varying concentrations of galunisertib. Dermal fibroblast proliferation was diminished to homeostatic levels without cytotoxicity at concentrations as high as 10 µM. An in vitro scratch assay revealed that galunisertib significantly enhanced cellular migration and in vitro wound closure beginning 24 h post-injury. A gene expression analysis demonstrated a significant attenuation of fibrotic gene expression, including collagen-1a, alpha-smooth muscle actin, fibronectin, and connective tissue growth factor, with increased expression of the antifibrotic genes MMP1 and decorin. Protein synthesis assays confirmed drug activity and corroborated the transcription findings. In summary, galunisertib simultaneously exerts antifibrotic effects on dermal fibroblasts while enhancing rates of in vitro wound closure. Galunisertib has already completed phase II clinical trials for cancer therapy with minimal adverse effects and is a promising candidate for the treatment and prevention of pathological cutaneous scars.


Assuntos
Cicatriz , Fator de Crescimento Transformador beta , Proliferação de Células , Células Cultivadas , Cicatriz/patologia , Fibroblastos/metabolismo , Fibrose , Humanos , Pirazóis/metabolismo , Pirazóis/farmacologia , Quinolinas , Fator de Crescimento Transformador beta/metabolismo
3.
Medicina (Kaunas) ; 58(7)2022 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-35888643

RESUMO

Burn wound conversion refers to the phenomenon whereby superficial burns that appear to retain the ability to spontaneously heal, convert later into deeper wounds in need of excision. While no current treatment can definitively stop burn wound conversion, attempts to slow tissue damage remain unsatisfactory, justifying the need for new therapeutic interventions. To attenuate burn wound conversion, various studies have targeted at least one of the molecular mechanisms underlying burn wound conversion, including ischemia, inflammation, apoptosis, autophagy, generation of reactive oxygen species, hypothermia, and wound rehydration. However, therapeutic strategies that can target various mechanisms involved in burn wound conversion are still lacking. This review highlights the pathophysiology of burn wound conversion and focuses on recent studies that have turned to the novel use of biologics such as mesenchymal stem cells, biomaterials, and immune regulators to mitigate wound conversion. Future research should investigate mechanistic pathways, side effects, safety, and efficacy of these different treatments before translation into clinical studies.


Assuntos
Queimaduras , Autofagia , Queimaduras/terapia , Humanos , Inflamação , Isquemia , Cicatrização/fisiologia
4.
Am J Physiol Cell Physiol ; 319(2): C277-C287, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32432932

RESUMO

Severe burn injury induces a myriad of deleterious effects to skeletal muscle, resulting in impaired function and delayed recovery. Following burn, catabolic signaling and myofiber atrophy are key fiber-intrinsic determinants of weakness; less well understood are alterations in the interstitial environment surrounding myofibers. Muscle quality, specifically alterations in the extracellular matrix (ECM), modulates force transmission and strength. We sought to determine the impact of severe thermal injury on adaptation to the muscle ECM and quantify muscle fibrotic burden. After a 30% total body surface area dorsal burn, spinotrapezius muscle was harvested from mice at 7 (7d, n = 5), 14 (14d, n = 4), and 21 days (21d, n = 4), and a sham control group was also examined (Sham, n = 4). Expression of transforming growth factor-ß (TGFß), myostatin, and downstream effectors and proteases involved in fibrosis and collagen remodeling were measured by immunoblotting, and immunohistochemical and biochemical analyses assessed fibrogenic cell abundance and collagen deposition. Myostatin signaling increased progressively through 21 days postburn alongside fibrogenic/adipogenic progenitor cell expansion, with abundance peaking at 14 days postburn. Postburn, elevated expression of tissue inhibitor of matrix metalloproteinase 1 supported collagen remodeling resulting in a net accumulation of muscle collagen content. Collagen accumulation peaked at 14 days postburn but remained elevated through 21 days postburn, demonstrating minimal resolution of burn-induced fibrosis. These findings highlight a progressive upregulation of fibrogenic processes following burn injury, eliciting a fibrotic muscle phenotype that hinders regenerative capacity and is not resolved with 21 days of recovery.


Assuntos
Queimaduras/genética , Fibrose/genética , Músculo Esquelético/metabolismo , Miostatina/genética , Fator de Crescimento Transformador beta/genética , Animais , Queimaduras/metabolismo , Queimaduras/patologia , Proliferação de Células/genética , Colágeno/genética , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibrose/metabolismo , Fibrose/patologia , Regulação da Expressão Gênica/genética , Humanos , Camundongos , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/lesões , Músculo Esquelético/patologia , Transdução de Sinais/genética
5.
Int J Mol Sci ; 21(3)2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32046094

RESUMO

Cutaneous fibrosis results from suboptimal wound healing following significant tissue injury such as severe burns, trauma, and major surgeries. Pathologic skin fibrosis results in scars that are disfiguring, limit normal movement, and prevent patient recovery and reintegration into society. While various therapeutic strategies have been used to accelerate wound healing and decrease the incidence of scarring, recent studies have targeted the molecular regulators of each phase of wound healing, including the inflammatory, proliferative, and remodeling phases. Here, we reviewed the most recent literature elucidating molecular pathways that can be targeted to reduce fibrosis with a particular focus on post-burn scarring. Current research targeting inflammatory mediators, the epithelial to mesenchymal transition, and regulators of myofibroblast differentiation shows promising results. However, a multimodal approach addressing all three phases of wound healing may provide the best therapeutic outcome.


Assuntos
Anti-Inflamatórios/uso terapêutico , Cicatriz/metabolismo , Animais , Cicatriz/tratamento farmacológico , Cicatriz/patologia , Ensaios Clínicos como Assunto , Citocinas/genética , Citocinas/metabolismo , Transição Epitelial-Mesenquimal , Humanos
6.
Toxicol Appl Pharmacol ; 362: 9-19, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30248415

RESUMO

Hypertrophic scars (HS) limit movement, decrease quality of life, and remain a major impediment to rehabilitation from burns. However, no effective pharmacologic therapies for HS exist. Here we tested the in vitro anti-fibrotic effects of the novel chemical N-(2-aminoethyl) ethanolamine (AEEA) at non-toxic concentrations. Scanning electron microscopy showed that AEEA markedly altered the structure of the extracellular matrix (ECM) produced by primary dermal fibroblasts isolated from a HS of a burn patient (HTS). Compression atomic force microscopy revealed that AEEA stiffened the 3D nanostructure of ECM formed by HTS fibroblasts. Western blot analysis in three separate types of primary human dermal fibroblasts (including HTS) showed that AEEA exposure increased the extractability of type I collagen in a dose- and time-dependent fashion, while not increasing collagen synthesis. A comparison of the electrophoretic behavior of the same set of samples under native and denaturing conditions suggested that AEEA alters the 3D structure of type I collagen. The antagonization effect of AEEA to TGF-ß1 on ECM formation was also observed. Furthermore, analyses of the anti-fibrotic effects of analogs of AEEA (with modified pharmacophores) suggest the existence of a chemical structure-activity relationship. Thus, AEEA and its analogs may inhibit HS development; further study and optimization of analogs may be a promising strategy for the discovery for effective HS therapies.


Assuntos
Cicatriz Hipertrófica/tratamento farmacológico , Etanolaminas/farmacologia , Fibroblastos/efeitos dos fármacos , Linhagem Celular , Cicatriz Hipertrófica/metabolismo , Colágeno/metabolismo , Matriz Extracelular/efeitos dos fármacos , Fibroblastos/metabolismo , Fibrose , Humanos , Relação Estrutura-Atividade , Fator de Crescimento Transformador beta1/metabolismo
7.
Neurobiol Dis ; 115: 101-114, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29649621

RESUMO

DJ-1 is a redox-sensitive protein with several putative functions important in mitochondrial physiology, protein transcription, proteasome regulation, and chaperone activity. High levels of DJ-1 immunoreactivity are reported in astrocytes surrounding pathology associated with idiopathic Parkinson's disease, possibly reflecting the glial response to oxidative damage. Previous studies showed that astrocytic over-expression of DJ-1 in vitro prevented oxidative stress and mitochondrial dysfunction in primary neurons. Based on these observations, we developed a pseudotyped lentiviral gene transfer vector with specific tropism for CNS astrocytes in vivo to overexpress human DJ-1 protein in astroglial cells. Following vector delivery to the substantia nigra and striatum of adult Lewis rats, the DJ-1 transgene was expressed robustly and specifically within astrocytes. There was no observable transgene expression in neurons or other glial cell types. Three weeks after vector infusion, animals were exposed to rotenone to induce Parkinson's disease-like pathology, including loss of dopaminergic neurons, accumulation of endogenous α-synuclein, and neuroinflammation. Animals over-expressing hDJ-1 in astrocytes were protected from rotenone-induced neurodegeneration, and displayed a marked reduction in neuronal oxidative stress and microglial activation. In addition, α-synuclein accumulation and phosphorylation were decreased within substantia nigra dopaminergic neurons in DJ-1-transduced animals, and expression of LAMP-2A, a marker of chaperone mediated autophagy, was increased. Together, these data indicate that astrocyte-specific overexpression of hDJ-1 protects neighboring neurons against multiple pathologic features of Parkinson's disease and provides the first direct evidence in vivo of a cell non-autonomous neuroprotective function of astroglial DJ-1.


Assuntos
Astrócitos/metabolismo , Inseticidas/toxicidade , Transtornos Parkinsonianos/metabolismo , Transtornos Parkinsonianos/prevenção & controle , Proteína Desglicase DJ-1/biossíntese , Rotenona/toxicidade , Animais , Astrócitos/efeitos dos fármacos , Expressão Gênica , Humanos , Masculino , Transtornos Parkinsonianos/induzido quimicamente , Proteína Desglicase DJ-1/genética , Ratos , Ratos Endogâmicos Lew
8.
Ann Surg ; 268(3): 431-441, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30048322

RESUMO

BACKGROUND: Massive burns induce a hypermetabolic response that leads to total body wasting and impaired physical and psychosocial recovery. The administration of propranolol or oxandrolone positively affects postburn metabolism and growth. The combined administration of oxandrolone and propranolol (OxProp) for 1 year restores growth in children with large burns. Here, we investigated whether the combined administration of OxProp for 1 year would reduce scarring and improve quality of life compared with control. STUDY DESIGN: Children with large burns (n = 480) were enrolled into this institutional review board-approved study; patients were randomized to control (n = 226) or administration of OxProp (n = 126) for 1 year postburn. Assessments were conducted at discharge and 6, 12, and 24 months postburn. Scar biopsies were obtained for histology. Physical scar assessments and patient reported outcome measures of physical and psychosocial function were obtained. RESULTS: Reductions in cellularity, vascular structures, inflammation, and abnormal collagen (P < 0.05) occurred in OxProp-treated scars. With OxProp, scar severity was attenuated and pliability increased (both P < 0.05). Analyses of patient-reported outcomes showed improved general and emotional health within the OxProp-treated group (P < 0.05). CONCLUSIONS: Here, we have shown improvements in objective and subjective measures of scarring and an increase in overall patient-reported physical function. The combined administration of OxProp for up to a year after burn injury should be considered for the reduction of postburn scarring and improvement of long-term psychosocial outcomes in children with massive burns.


Assuntos
Anabolizantes/uso terapêutico , Queimaduras/complicações , Cicatriz Hipertrófica/etiologia , Cicatriz Hipertrófica/prevenção & controle , Oxandrolona/uso terapêutico , Propranolol/uso terapêutico , Vasodilatadores/uso terapêutico , Adolescente , Anabolizantes/administração & dosagem , Biomarcadores/metabolismo , Biópsia , Criança , Cicatriz Hipertrófica/metabolismo , Método Duplo-Cego , Esquema de Medicação , Combinação de Medicamentos , Feminino , Humanos , Técnicas Imunoenzimáticas , Masculino , Oxandrolona/administração & dosagem , Propranolol/administração & dosagem , Estudos Prospectivos , Qualidade de Vida , Recuperação de Função Fisiológica , Resultado do Tratamento , Vasodilatadores/administração & dosagem
9.
J Surg Res ; 232: 154-159, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30463712

RESUMO

BACKGROUND: It has been previously shown that anesthesia and analgesia can affect outcomes in the rat burn model and that buprenorphine alleviated pain without drastically altering the outcomes of interest. Recently, the use of a sustained release (SR) formulation of buprenorphine has been promoted over conventional buprenorphine. In this study, we assessed whether buprenorphine-SR altered hemodynamic parameters in our rat model of severe burn injury. MATERIALS AND METHODS: Adult male Sprague-Dawley rats were randomized to receive either conventional buprenorphine (0.05 mg/kg) or buprenorphine-SR (1 mg/kg). Buprenorphine-SR was administered 24 h before the experiment. Buprenorphine was administered on the day of experiment. These groups were further randomized to control or scald burn (60% of total body surface area). Systolic and diastolic blood pressure (SBP, DBP) and heart rate (HR) were measured using a noninvasive blood pressure system before receiving analgesia and after 72 h. RESULTS: As expected, HR was significantly higher after burn injury regardless of analgesic (P <0.0001). Both SBP and DBP were significantly decreased in burned animals receiving conventional buprenorphine (P < 0.0001), but neither was altered in the buprenorphine-SR-treated burned animals. However, SBP, DBP, and HR were significantly increased after 72 h in control animals receiving buprenorphine-SR (P < 0.0001). CONCLUSIONS: These data indicate that buprenorphine-SR alters the hemodynamic response to injury and may not be an appropriate choice for a model of severe burn injury. If this analgesic is used, investigators must cautiously form conclusions, especially in experimental conditions that would be expected to alter cardiac hemodynamics.


Assuntos
Analgésicos Opioides/farmacologia , Buprenorfina/farmacologia , Queimaduras/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Animais , Buprenorfina/administração & dosagem , Citocinas/sangue , Preparações de Ação Retardada , Modelos Animais de Doenças , Masculino , Ratos , Ratos Sprague-Dawley
10.
J Physiol ; 595(21): 6687-6701, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28833130

RESUMO

KEY POINTS: Severe burns result in significant skeletal muscle cachexia that impedes recovery. Activity of satellite cells, skeletal muscle stem cells, is altered following a burn injury and likely hinders regrowth of muscle. Severe burn injury induces satellite cell proliferation and fusion into myofibres with greater activity in muscles proximal to the injury site. Conditional depletion of satellite cells attenuates recovery of myofibre area and volume following a scald burn injury in mice. Skeletal muscle regrowth following a burn injury requires satellite cell activity, underscoring the therapeutic potential of satellite cells in the prevention of prolonged frailty in burn survivors. ABSTRACT: Severe burns result in profound skeletal muscle atrophy; persistent muscle atrophy and weakness are major complications that hamper recovery from burn injury. Many factors contribute to the erosion of muscle mass following burn trauma, and we have previously shown concurrent activation and apoptosis of muscle satellite cells following a burn injury in paediatric patients. To determine the necessity of satellite cells during muscle recovery following a burn injury, we utilized a genetically modified mouse model (Pax7CreER -DTA) that allows for the conditional depletion of satellite cells in skeletal muscle. Additionally, mice were provided 5-ethynyl-2'-deoxyuridine to determine satellite cell proliferation, activation and fusion. Juvenile satellite cell-wild-type (SC-WT) and satellite cell-depleted (SC-Dep) mice (8 weeks of age) were randomized to sham or burn injury consisting of a dorsal scald burn injury covering 30% of total body surface area. Both hindlimb and dorsal muscles were studied at 7, 14 and 21 days post-burn. SC-Dep mice had >93% depletion of satellite cells compared to SC-WT (P < 0.05). Burn injury induced robust atrophy in muscles located both proximal and distal to the injury site (∼30% decrease in fibre cross-sectional area, P < 0.05). Additionally, burn injury induced skeletal muscle regeneration, satellite cell proliferation and fusion. Depletion of satellite cells impaired post-burn recovery of both muscle fibre cross-sectional area and volume (P < 0.05). These findings support an integral role for satellite cells in the aetiology of lean tissue recovery following a severe burn injury.


Assuntos
Queimaduras/patologia , Células Satélites de Músculo Esquelético/patologia , Cicatrização , Animais , Proliferação de Células , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fibras Musculares Esqueléticas/patologia , Fibras Musculares Esqueléticas/fisiologia , Células Satélites de Músculo Esquelético/fisiologia
11.
Exp Brain Res ; 234(7): 1863-1873, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26894890

RESUMO

Insulin-like growth factor-1 (IGF-1) is an endogenous peptide transported across the blood brain barrier that is protective in several brain injury models, including an acute animal model of Parkinson's disease (PD). Motor deficits in PD are due largely to the progressive loss of nigrostriatal dopaminergic neurons. Thus, we examined the neuroprotective potential of IGF-1 in a progressive model of dopamine deficiency in which 6-hydroxydopamine (6-OHDA) is infused into the striatum. Rats received intrastriatal IGF-1 (5 or 50 µg) 6 h prior to infusion of 4 µg 6-OHDA into the same site and were euthanized 1 or 4 weeks later. Both concentrations of IGF-1 protected tyrosine hydroxylase (TH) immunoreactive terminals in striatum at 4 weeks but not at 1 week, indicating that IGF-induced restoration of the dopaminergic phenotype occurred over several weeks. TH-immunoreactive cell loss was only attenuated with 50 µg IGF-1. We then examined the effect of striatal IGF-1 on the Ras/ERK1/2 and PI3K/Akt pathways to ascertain whether their activation correlated with IGF-1-induced protection. Striatal and nigral levels of phospho-ERK1/2 were maximal 6 h after IGF-1 infusion and, with the exception of an increase in nigral pERK2 at 48 h, returned to basal levels by 7 days. Phospho-Akt (Ser473) was elevated 6-24 h post-IGF-1 infusion in both striatum and substantia nigra concomitant with inhibition of pro-death GSK-3ß, a downstream target of Akt. These results suggest that IGF-1 can protect the nigrostriatal pathway in a progressive PD model and that this protection is preceded by activation of key pro-survival signaling cascades.


Assuntos
Neurônios Dopaminérgicos/metabolismo , Fator de Crescimento Insulin-Like I/farmacologia , Neostriado/metabolismo , Fármacos Neuroprotetores/farmacologia , Transtornos Parkinsonianos/metabolismo , Substância Negra/metabolismo , Adrenérgicos/administração & dosagem , Adrenérgicos/farmacologia , Animais , Modelos Animais de Doenças , Glicogênio Sintase Quinase 3 beta/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta/metabolismo , Fator de Crescimento Insulin-Like I/administração & dosagem , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Neostriado/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Estresse Oxidativo , Oxidopamina/administração & dosagem , Oxidopamina/farmacologia , Transtornos Parkinsonianos/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Sprague-Dawley , Substância Negra/efeitos dos fármacos , Tirosina 3-Mono-Oxigenase/efeitos dos fármacos , Tirosina 3-Mono-Oxigenase/metabolismo
12.
Proc Natl Acad Sci U S A ; 109(33): 13416-21, 2012 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-22847417

RESUMO

The pathogenesis of Alzheimer's disease (AD) is associated with proteolytic processing of the amyloid precursor protein (APP) to an amyloidogenic peptide termed Aß. Although mutations in APP and the secretase enzymes that mediate its processing are known to result in familial forms of AD, the mechanisms underlying the more common sporadic forms of the disease are still unclear. Evidence suggests that the susceptibility of APP to amyloidogenic processing is related to its intracellular localization, and that secretase-independent degradation may prevent the formation of cytotoxic peptide fragments. Recently, single nucleotide polymorphisms in the UBQLN1 gene have been linked to late-onset AD, and its protein product, ubiquilin-1, may regulate the maturation of full-length APP. Here we show that ubiquilin-1 inhibits the maturation of APP by sequestering it in the early secretory pathway, primarily within the Golgi apparatus. This sequestration significantly delayed the proteolytic processing of APP by secretases and the proteasome. These effects were mediated by ubiquilin-1-stimulated K63-linked polyubiquitination of lysine 688 in the APP intracellular domain. Our results reveal the mechanistic basis by which ubiquilin-1 regulates APP maturation, with important consequences for the pathogenesis of late-onset AD.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Lisina/metabolismo , Chaperonas Moleculares/metabolismo , Poliubiquitina/metabolismo , Processamento de Proteína Pós-Traducional , Proteólise , Ubiquitinação , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Complexo de Golgi/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Lisossomos/metabolismo , Células PC12 , Transporte Proteico , Ratos , Proteínas Recombinantes de Fusão/metabolismo , Via Secretória
13.
J Biol Chem ; 288(3): 2040-8, 2013 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-23204517

RESUMO

PEP-19 is a small, intrinsically disordered protein that binds to the C-domain of calmodulin (CaM) via an IQ motif and tunes its Ca(2+) binding properties via an acidic sequence. We show here that the acidic sequence of PEP-19 has intrinsic Ca(2+) binding activity, which may modulate Ca(2+) binding to CaM by stabilizing an initial Ca(2+)-CaM complex or by electrostatically steering Ca(2+) to and from CaM. Because PEP-19 is expressed in cells that exhibit highly active Ca(2+) dynamics, we tested the hypothesis that it influences ligand-dependent Ca(2+) release. We show that PEP-19 increases the sensitivity of HeLa cells to ATP-induced Ca(2+) release to greatly increase the percentage of cells responding to sub-saturating doses of ATP and increases the frequency of Ca(2+) oscillations. Mutations in the acidic sequence of PEP-19 that inhibit or prevent it from modulating Ca(2+) binding to CaM greatly inhibit its effect on ATP-induced Ca(2+) release. Thus, this cellular effect of PEP-19 does not depend simply on binding to CaM via the IQ motif but requires its acidic metal binding domain. Tuning the activities of Ca(2+) mobilization pathways places PEP-19 at the top of CaM signaling cascades, with great potential to exert broad effects on downstream CaM targets, thus expanding the biological significance of this small regulator of CaM signaling.


Assuntos
Sinalização do Cálcio , Cálcio/metabolismo , Calmodulina/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Trifosfato de Adenosina/metabolismo , Motivos de Aminoácidos , Sítios de Ligação , Calmodulina/química , Células HeLa , Humanos , Cinética , Ligantes , Imagem Molecular , Dados de Sequência Molecular , Mutação , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Ressonância Magnética Nuclear Biomolecular , Ligação Proteica , Estrutura Terciária de Proteína , Eletricidade Estática , Transfecção
14.
J Burn Care Res ; 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38778576

RESUMO

Severely burned patients often developed cardiac dysfunction and heart failure. The purpose of this retrospective study is to evaluate the role of Cardiac Troponin I (cTI) and its association to patients with burns. Patients deidentified data were collected from a national database in May 2023. Adult burn patients who had cTnI lab counted were enrolled in this study. Patients were grouped by the cTnI mean level within 72 hours including patients with elevated cTnI levels at >0.3 ng/mL (n= 2188 patients), and patients with non-elevated cTnI level (< 0.04 ng/mL) (n= 3200). The cohorts were further stratified by less than 20% TBSA mild burn population and >20% TBSA severe burn population to replicate the severity of burns. The 30-days incidences of acute myocardial infarction (MI), sepsis, and mortality were investigated after the cohorts were propensity matching balanced. The odds ratios (ORs) with 95%CI for MI were (9.829/7.081-13.645), sepsis (1.527/1.269-1.959) and mortality (2.586/2.110- 3.170) respectively (p<0.05). The groups that were further stratified into mild burn and severe burn had the following results: The mild burn ORs and 95% CI for MI was (6.237/3.986-9.785), sepsis (1.603/1.132-2.270), and mortality was (2.298/1.629-3.242). The severe burn cohort had ORs and 95% CI for MI (3.145/1.469-6.732), sepsis (0.993/0.555-1.777), mortality (2.934/1.924-4.475). In conclusion, the patients with earlier elevated cTnI level had worse outcomes of MI and mortality in both severe and mild burns.

15.
Shock ; 61(4): 541-548, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38300832

RESUMO

ABSTRACT: Introduction: Hypertension is a prevalent condition in the United States and leads to an increased risk of developing various comorbidities. However, the impact of new-onset hypertension after severe burns on patient outcomes is not known. We posit that hypertension onset after severe burn is associated with increased risk of developing comorbidities and mortality. Methods: Using the TriNetX database, burned patients diagnosed with essential hypertension after injury were compared with those who did not develop hypertension; neither had prior hypertension. Each cohort was grouped by sex, percent total body surface area (TBSA) burned, and age, then propensity matched for sex, race, ethnicity, and laboratory values. Outcomes assessed were acute kidney injury (AKI), hyperglycemia, heart failure, myocardial infarction (MI), and death. Results: Those diagnosed with hypertension after severe burn were 4.9 times more likely to develop AKI, 3.6 times for hyperglycemia, 5.3 times for heart failure, 4.7 times for acute MI, and 1.5 times for mortality. Sex analysis shows that men were at greater risk for AKI (1.5 times), heart failure (1.1 times), and death (1.4 times). Women were 1.3 times more likely to develop hyperglycemia. Percent TBSA burned grouping showed increased risk for all outcomes with increasing severity. Age grouping indicated an elevated risk of developing AKI, heart failure, acute MI, and death. Conclusion: New-onset hypertension diagnosis in severely burned patients is associated with acute kidney injury, heart failure, acute MI, and death. Overall, males, older patients, and those with a higher % TBSA burned are at a higher risk of developing these comorbidities.


Assuntos
Injúria Renal Aguda , Queimaduras , Insuficiência Cardíaca , Hiperglicemia , Hipertensão , Feminino , Humanos , Masculino , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/etiologia , Hipertensão Essencial/complicações , Hiperglicemia/complicações , Hipertensão/complicações
16.
Burns ; 50(1): 75-86, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37734977

RESUMO

Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) exist on a spectrum of autoimmune conditions which cause epidermal detachment and keratinocyte necrosis. Due to the rare incidence of these conditions, a dramatic heterogeneity in treatment algorithms exists. To better appreciate pharmacologic immunosuppressive therapies' impact on survival, the authors queried a multi-institutional data network. Data for this study was extracted from TriNetX Research Network, a platform that contains ICD-9/ICD-10 coding data from a consortium of international healthcare organizations. Seventy-one institutions were queried to identify adult patients diagnosed with SJS, TEN or SJS-TEN Overlap. Cohorts were created based on the therapy received: systemic steroids (SS), diphenhydramine (DH), cyclosporine (CS), intravenous immunoglobulin (IVIG), tumor necrosis factor alpha inhibitors (TNFαi), or a combination of treatments. Cohorts were then propensity matched with patients who received supportive care. Patients who only received one of the above treatments showed no significant reduction in 90-day mortality. Patients who received CS or IVIG as part of their multitherapy showed a significantly increased risk of death when compared to supportive care (CS: RR = 1.583, 95% CI [1.119, 2.240]; IVIG: RR = 2.132, 95% CI [1.485, 3.059]). Despite their frequent utilization, this study's analysis suggests that none of these therapies confer significant 90-day mortality survival over supportive care alone. These results highlight the heterogeneity of therapies and emphasize the need for critical prospective appraisal of their outcomes in SJS and TEN.


Assuntos
Queimaduras , Síndrome de Stevens-Johnson , Adulto , Humanos , Síndrome de Stevens-Johnson/tratamento farmacológico , Síndrome de Stevens-Johnson/etiologia , Imunoglobulinas Intravenosas/uso terapêutico , Estudos Retrospectivos , Estudos Prospectivos , Queimaduras/complicações , Ciclosporina/uso terapêutico , Terapia de Imunossupressão/efeitos adversos
17.
Int J Pharm ; 649: 123658, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38042382

RESUMO

Graphene quantum dots (GQDs) are promising biomaterials with potential applicability in several areas due to their many useful and unique features. Among different applications, GQDs are photodynamic therapy agents that generate single oxygen and improve antimicrobial activity. In the present study, and for the first time, GQD were isolated from the Cannabis sativa L. seeds to generate C-GQDs as a new biomaterial for antibacterial and wound healing applications. Detailed characterization was performed using FTIR, UV-vis, Raman spectra, photoluminescence, TEM examination, HRTEM, ζ-potential, and XRD. Our results revealed in vitro and in vivo antibacterial activity of C-GQDs against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) with reduced minimal inhibitory concentration of 236 µg/mL for both strains. In addition, the C-GQDs confirmed the in vitro analysis and exhibited anti-inflammatory activity by reducing the level of neutrophils in blood and skin tissue. C-GQDs act by accelerating re-epithelization and granulation tissue formation. In addition, C-GQDs restored neurobehavioral alteration induced by incisional wounds by reducing oxidative stress, decreasing cortisol levels, increasing anxiolytic-like effect, and increasing vertical locomotor activity. The wound-healing effects of C-GQDs support its role as a potential therapeutic agent for diverse skin injuries.


Assuntos
Cannabis , Grafite , Pontos Quânticos , Animais , Camundongos , Grafite/farmacologia , Escherichia coli , Staphylococcus aureus , Cicatrização , Antibacterianos/farmacologia
18.
Burns ; 50(3): 561-568, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38233276

RESUMO

INTRODUCTION: Post-traumatic stress disorder (PTSD) afflicts a significant portion of burn patients. This study aims to analyze the morbidity, prevalence, and treatment of PTSD in the burn population. METHODS: Using the TriNetX database, we identified burned patients > 18 years of age without (A) or with (B) a PTSD diagnosis. Patients were then stratified by percent of total body surface area (TBSA) burned. Morbidity and mortality was analyzed in each cohort. Prevalence and pharmacologic treatments for PTSD were analyzed from 2002 to 2022. RESULTS: PTSD incidence increased from 2.4% (n = 2281) in patients with < 10% to 3.1% (n = 542) in 10-30%, 7.4% (n = 285) in 30-59%, and 5.3% (n = 90) in > 60% TBSA burned. In patients with < 60% TBSA burned, PTSD diagnosis increased the risk of depression (p = <0.0003) and anxiety (p = <0.0001). In those with < 30% TBSA burned, PTSD diagnosis also increased risk of insomnia (p = <0.0001) and pruritus (p = 0.0211 for TBSA <10% and 0.0059 for TBSA 10-29%). PTSD diagnosis was associated with a decreased risk of mortality in patients with > 30% TBSA burned (p = 0.0179 for TBSA 30-59% and p = 0.0089 for TBSA >60%). From 2002 to 2022, the prevalence of PTSD in all burn patients was relatively stable between 2.2% and 3.2%. We found an increase in the use of serotonergic agents and prazosin for the treatment of PTSD during this timeframe. CONCLUSION: PTSD is not uncommon in the burn population, and those with burns and concomitant PTSD have an increased risk of morbidity. Screening and preventative measures to reduce morbidity and early implementation of care in burned patients with PTSD are indicated.


Assuntos
Queimaduras , Transtornos de Estresse Pós-Traumáticos , Humanos , Queimaduras/complicações , Queimaduras/epidemiologia , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/etiologia , Incidência , Prevalência , Transtornos de Ansiedade , Estudos Retrospectivos
19.
PLoS One ; 19(2): e0278658, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38394094

RESUMO

Studies conflict on the significance of burn-induced coagulopathy. We posit that burn-induced coagulopathy is associated with injury severity in burns. Our purpose was to characterize coagulopathy profiles in burns and determine relationships between % total burn surface area (TBSA) burned and coagulopathy using the International Normalized Ratio (INR). Burned patients with INR values were identified in the TriNetX database and analyzed by %TBSA burned. Patients with history of transfusions, chronic hepatic failure, and those on anticoagulant medications were excluded. Interquartile ranges for INR in the burned study population were 1.2 (1.0-1.4). An INR of ≥ 1.5 was used to represent those with burn-induced coagulopathy as it fell outside the 3rd quartile. The population was stratified into subgroups using INR levels <1.5 or ≥1.5 on the day of injury. Data are average ± SD analyzed using chi-square; p < .05 was considered significant. There were 7,364 burned patients identified with INR <1.5, and 635 had INR ≥1.5. Comparing TBSA burned groups, burn-induced coagulopathy significantly increased in those with ≥20% TBSA; p = .048 at 20-29% TBSA, p = .0005 at 30-39% TBSA, and p < .0001 for 40% TBSA and above. Age played a significant factor with average age for those with burn-induced coagulopathy 59 ± 21.5 years and 46 ± 21.8 for those without (p < .0001). After matching for age, TBSA, and demographics, the risk of 28 day-mortality was higher in those with burn-induced coagulopathy compared to those without (risk difference 20.9%, p < .0001) and the odd ratio with 95% CI is 4.45 (3.399-5.825). Investigation of conditions associated with burn-induced coagulopathy showed the effect of heart diseases to be significant; 53% of patients with burn-induced coagulopathy had hypertension (p < .0001). Burn-induced coagulopathy increases with %TBSA burned. The information gained firmly reflects a link between %TBSA and burn-induced coagulopathy, which could be useful in prognosis and treatment decisions.


Assuntos
Transtornos da Coagulação Sanguínea , Queimaduras , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Coeficiente Internacional Normatizado , Prognóstico , Transfusão de Sangue , Transtornos da Coagulação Sanguínea/etiologia , Estudos Retrospectivos
20.
Burns ; 50(1): 52-58, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37777457

RESUMO

BACKGROUND: In the advent of increasing antibiotic resistance, several studies sought to determine antibiotic prescription trends; however, no pattern has been firmly identified particularly for the burned population. We performed a query of burned patients in a large established database to understand differences in antibiotic use related to patient-specific factors. METHODS: Burned patients with systemic antibiotics given within 7 days of injury were identified on the TriNetX database. The patient population was stratified by age, 1-year time intervals of antibiotic prescription from 2004 to 2019, time of antibiotic prescription in 1-day intervals after injury, and % TBSA burned in 10% intervals ranging from < 10% to > 90%. Data were analyzed using χ2 with p < 0.05 considered significant. Pearson coefficients (r2) values were used to correlate differences in antibiotic prescription between age groups and to changes over time. RESULTS: Stratification by age revealed higher use of antibiotics in older burned patients compared to younger patients. Surprisingly, 87.6% of burn patients of those who received antibiotic therapy was on the day of injury. Penicillins and beta-lactam antimicrobials were used most often at a frequency of 64%. No statistically significant differences in rates of antibiotic therapy were observed in burned patients when stratified by %TBSA burned. CONCLUSIONS: The study elucidates current patterns of antibiotic use in burn care in the United States, allowing for improved understanding of both past and present patterns of antibiotic prescription.


Assuntos
Queimaduras , Humanos , Estados Unidos , Idoso , Lactente , Queimaduras/tratamento farmacológico , Antibacterianos/uso terapêutico , Estudos Retrospectivos
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