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BACKGROUND: Parkinson's disease (PD) is one of the most prevalent neurodegenerative diseases, following Alzheimer's disease. The onset of PD is characterized by the loss of dopaminergic neurons in the substantia nigra. Stem cell therapy has great potential for the treatment of neurodegenerative diseases, and human nasal turbinate-derived stem cells (hNTSCs) have been found to share some characteristics with mesenchymal stem cells. Although the Hippo signaling pathway was originally thought to regulate cell size in organs, recent studies have shown that it can also control inflammation in neural cells. METHODS: Dopaminergic neuron-like cells were differentiated from SH-SY5Y cells (DA-Like cells) and treated with 1-Methyl-4-phenylpyridinium iodide to stimulate Reactive oxidative species (ROS) production. A transwell assay was conducted to validate the effect of hNTSCs on the Hippo pathway. We generated an MPTP-induced PD mouse model and transplanted hNTSCs into the substantia nigra of PD mice via stereotaxic surgery. After five weeks of behavioral testing, the brain samples were validated by immunoblotting and immunostaining to confirm the niche control of hNTSCs. RESULTS: In-vitro experiments showed that hNTSCs significantly increased cell survival and exerted anti-inflammatory effects by controlling ROS-mediated ER stress and hippocampal signaling pathway factors. Similarly, the in-vivo experiments demonstrated an increase in anti-inflammatory effects and cell survival rate. After transplantation of hNTSCs, the PD mouse model showed improved mobility and relief from PD symptoms. CONCLUSION: hNTSCs improved the survival rate of dopaminergic neurons by manipulating the hippocampal pathway through Yes-associated protein (YAP)/transcriptional coactivator with a PDZ-binding motif (TAZ) by reducing inflammatory cytokines. In this study, we found that controlling the niche of hNTSCs had a therapeutic effect on PD lesions.
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Modelos Animais de Doenças , Via de Sinalização Hippo , Células-Tronco Neurais , Doença de Parkinson , Proteínas Serina-Treonina Quinases , Transdução de Sinais , Conchas Nasais , Humanos , Animais , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Proteínas Serina-Treonina Quinases/metabolismo , Doença de Parkinson/terapia , Doença de Parkinson/metabolismo , Camundongos , Conchas Nasais/metabolismo , Neurônios Dopaminérgicos/metabolismo , Parte Compacta da Substância Negra/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Substância Negra/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Diferenciação CelularRESUMO
[This corrects the article DOI: 10.3389/fonc.2022.945057.].
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A lack of the T cell-inflamed tumor microenvironment limits the efficacy of immune checkpoint inhibitors (ICIs). Activation of stimulator of interferon genes (STING)-mediated innate immunity has emerged as a novel therapeutic approach in cancer therapy. 2',3'-Cyclic GMP-AMP (cGAMP) is a natural STING agonist; however, cGAMP is subjected to endogenous degradation by ecto-nucleotide pyrophosphatase phosphodiesterase 1 (ENPP1). To improve the ICI response rate, we developed 29f, a novel ENPP1 inhibitor with phthalazin-1(2H)-one as the core scaffold. 29f inhibited the cGAMP hydrolysis by ENPP1 in vitro (IC50 = 68 nM) and enhanced the STING-mediated type I interferon response in both immune and tumor cells. 29f demonstrated excellent metabolic stability and bioavailability (F = 65%). Orally administered 29f promoted tumor growth inhibition in a CT26 syngeneic model and increased the anti-PD-L1 response. Furthermore, 29f-induced immunological memory prevented the tumor relapse against tumor rechallenge, suggesting the promising therapeutic potential of 29f.
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Neoplasias , Diester Fosfórico Hidrolases , Humanos , Diester Fosfórico Hidrolases/metabolismo , Neoplasias/terapia , Pirofosfatases , Imunoterapia , Microambiente TumoralRESUMO
BACKGROUND: The substance P-neurokinin 1 receptor pathway has been proposed as a therapeutic target for tendinopathy. However, there is a lack of evidence regarding its practical applications. PURPOSE: To investigate the therapeutic effects of substance P inhibitor (SPI) on inflamed tenocytes in vitro and in a collagenase-induced rat model of tendinopathy in vivo. STUDY DESIGN: Controlled laboratory study. METHODS: We analyzed the mRNA levels of inflammatory (cyclooxygenase [COX]-2 and interleukin [IL]-6) and tenogenic (Mohawk and scleraxis [SCX]) markers using reverse transcription quantitative polymerase chain reaction to demonstrate the effects of SPI on lipopolysaccharide-treated (inflamed) tenocytes. A collagenase-induced rat model of tendinopathy was created by injecting 20 µL of collagenase into the Achilles tendon. A behavior test using an incapacitance apparatus was performed to detect changes in postural equilibrium. The tendon specimens were obtained, and their gross findings were examined. The tensile strength was measured, and histopathological evaluation was performed (hematoxylin and eosin, alcian blue, and immunohistochemical staining). RESULTS: The mRNA levels of COX-2, IL-6, Mohawk, and SCX differed significantly between inflamed tenocytes and those treated with SPI. SPI improved the weight burden in a rat model of tendinopathy in a behavioral test. The specimens of the SPI group showed a normal tendon-like appearance. In the biomechanical test, the tensile strength of the SPI group was significantly greater than that of the tendinopathy group. In the histopathological evaluation, the degree of collagen matrix breakdown was mild in the SPI group. In alcian blue staining, only small focal depositions of proteoglycans and glycosaminoglycans were observed in the SPI group. The SPI group showed decreased expression of IL-6 and neurokinin 1 receptor. CONCLUSION: This study suggests that SPI has therapeutic effects on tendon healing and restoration in a collagenase-induced rat model of tendinopathy. CLINICAL RELEVANCE: SPI is a promising agent for tendinopathy in humans.
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Tendão do Calcâneo , Tendinopatia , Animais , Humanos , Ratos , Tendão do Calcâneo/patologia , Azul Alciano , Colagenases , Interleucina-6 , Receptores da Neurocinina-1 , RNA Mensageiro , Substância P , Tendinopatia/terapiaRESUMO
Background: Colchicine is a traditional medication that is currently approved to treat gout and familial Mediterranean fever (FMF). However, colchicine has a wide range of anti-inflammatory activities, and several studies have indicated that it may be useful in a variety of other conditions, such as rheumatic disease, cardiac disease, and cancer. Osteosarcoma, the most common type of bone sarcoma, is derived from primitive bone-forming mesenchymal cells. In this study, we investigated whether colchicine could be used to treat osteosarcoma through the regulation of cell cycle signaling. Methods: Two human osteosarcoma cell lines, U2OS and Saos-2, were used. A clonogenic assay was used to determine the antiproliferative effects of colchicine on osteosarcoma cells. Reactive oxygen species (ROS) production and apoptosis were measured by flow cytometry. Migration and invasion assays were performed to investigate the inhibitory effects of colchicine. The signaling pathways related to colchicine treatment were verified by GO biological process (GOBP) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Results: Colchicine was selected as the lead compound based on the results of initial screening and cell viability assays conducted in Saos-2 and U2Os cells. Colchicine reduced the viability of Saos-2 and U2OS cells in a concentration-dependent manner. It also significantly inhibited colony-forming ability and induced ROS production and apoptosis. It also inhibited the migration and invasion of both Saos-2 and U2OS cells. GOBP and KEGG enrichment analyses indicated the involvement of microtubule-based processes and cancer-related pathways. Conclusions: These findings suggest that colchicine has therapeutic potential in osteosarcoma.
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MicroRNAs are key regulators of gene expression in tumorigenesis. In this study, we investigated the tumor-suppressive function of miR-31-3p. Analysis of the Gene Expression Omnibus database revealed that the expression of miR-31-3p in prostate cancer tissues is lower than that in adjacent normal tissues from patients with prostate cancer. Moreover, miR-31-3p induces apoptosis in DU145, PC-3, and LNCap prostate cancer cells, while those transfected with miR-31-3p exhibit significantly decreased cell proliferation, migration, invasiveness, and tumor sphere-forming ability, as determined using the cell counting kit-8, transwell, and sphere-forming assays. Further analysis revealed that GABBR2 is a direct target of miR-31-3p. Within a DU145 xenograft murine model, intratumoral injection of a miR-31-3p mimic suppresses tumor growth. Taken together, the findings of this study suggest that miR-31-3p performs a novel tumor-suppressive function in prostate cancer and may represent a novel target for anti-prostate cancer miRNA therapeutics.
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BACKGROUND AND AIMS: Cardiovascular diseases (CVD), including coronary heart disease, are the leading cause of death worldwide. Several studies investigating the relationship between fish intake, methylmercury exposure, and CVDs in adults have reported inconsistent results. This study aimed to determine the association between hair methylmercury levels and arterial stiffness using brachial-ankle pulse wave velocity (baPWV). METHODS: This cross-sectional study included 891 seemingly healthy Korean adults (418 men and 473 women). The anthropometric and biochemical profiles, including methylmercury levels in the hair, were measured. Arterial stiffness was measured using baPWV, wherein high baPWV was defined as >1375 cm/s (>75th percentile). The odds ratios for high baPWVs were examined using multivariable logistic regression analysis after adjusting for potential confounders across the quintiles of hair methylmercury levels (Q1 = ≤0.6, Q2 = 0.6-0.8, Q3 = 0.8-1.1, Q4 = 1.1-1.5, and Q5=>1.5 µg/g). RESULTS: After adjusting for multiple confounders-age, sex, height, body weight, smoking status, weekly alcohol consumption, total metabolic equivalent of task, mean arterial blood pressure, resting heart rate, triglycerides, low density lipoprotein cholesterol, fasting plasma glucose, uric acid and white blood cell count-the odds ratios (95% confidence intervals) for high baPWVs in each quintile of hair methylmercury levels were 1.00, 0.36 (0.17-0.76), 0.38 (0.20-0.76), 0.28 (0.13-0.61), and 0.49 (0.24-0.99), respectively. CONCLUSIONS: Within non-toxic low levels, higher hair methylmercury levels are independently associated with lower arterial stiffness in seemingly healthy Korean adults regardless of classical cardiovascular risk factors.
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Doenças Cardiovasculares , Compostos de Metilmercúrio , Rigidez Vascular , Índice Tornozelo-Braço , Estudos Transversais , Feminino , Cabelo , Humanos , Análise de Onda de Pulso , Fatores de Risco , Rigidez Vascular/fisiologiaRESUMO
Metabolic oligosaccharide engineering (MOE) has fundamentally contributed to our understanding of protein glycosylation. Efficient MOE reagents are activated into nucleotide-sugars by cellular biosynthetic machineries, introduced into glycoproteins and traceable by bioorthogonal chemistry. Despite their widespread use, the metabolic fate of many MOE reagents is only beginning to be mapped. While metabolic interconnectivity can affect probe specificity, poor uptake by biosynthetic salvage pathways may impact probe sensitivity and trigger side reactions. Here, we use metabolic engineering to turn the weak alkyne-tagged MOE reagents Ac4GalNAlk and Ac4GlcNAlk into efficient chemical tools to probe protein glycosylation. We find that bypassing a metabolic bottleneck with an engineered version of the pyrophosphorylase AGX1 boosts nucleotide-sugar biosynthesis and increases bioorthogonal cell surface labeling by up to two orders of magnitude. A comparison with known azide-tagged MOE reagents reveals major differences in glycoprotein labeling, substantially expanding the toolbox of chemical glycobiology.
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Galactosamina/análogos & derivados , Galactosamina/metabolismo , Galactosiltransferases/metabolismo , Glucosamina/análogos & derivados , Glucosamina/metabolismo , Alcinos/química , Sequência de Aminoácidos , Animais , Azidas/química , Linhagem Celular Tumoral , Química Click , Corantes Fluorescentes/química , Glicoproteínas/química , Glicoproteínas/metabolismo , Glicosilação , Humanos , Engenharia Metabólica/métodos , Camundongos , Sondas Moleculares/química , Oligossacarídeos/biossíntese , Polissacarídeos/biossíntese , Açúcares de Uridina Difosfato/biossíntese , Açúcares de Uridina Difosfato/metabolismoRESUMO
Protein glycosylation events that happen early in the secretory pathway are often dysregulated during tumorigenesis. These events can be probed, in principle, by monosaccharides with bioorthogonal tags that would ideally be specific for distinct glycan subtypes. However, metabolic interconversion into other monosaccharides drastically reduces such specificity in the living cell. Here, we use a structure-based design process to develop the monosaccharide probe N-(S)-azidopropionylgalactosamine (GalNAzMe) that is specific for cancer-relevant Ser/Thr(O)-linked N-acetylgalactosamine (GalNAc) glycosylation. By virtue of a branched N-acylamide side chain, GalNAzMe is not interconverted by epimerization to the corresponding N-acetylglucosamine analog by the epimerase N-acetylgalactosamine-4-epimerase (GALE) like conventional GalNAc-based probes. GalNAzMe enters O-GalNAc glycosylation but does not enter other major cell surface glycan types including Asn(N)-linked glycans. We transfect cells with the engineered pyrophosphorylase mut-AGX1 to biosynthesize the nucleotide-sugar donor uridine diphosphate (UDP)-GalNAzMe from a sugar-1-phosphate precursor. Tagged with a bioorthogonal azide group, GalNAzMe serves as an O-glycan-specific reporter in superresolution microscopy, chemical glycoproteomics, a genome-wide CRISPR-knockout (CRISPR-KO) screen, and imaging of intestinal organoids. Additional ectopic expression of an engineered glycosyltransferase, "bump-and-hole" (BH)-GalNAc-T2, boosts labeling in a programmable fashion by increasing incorporation of GalNAzMe into the cell surface glycoproteome. Alleviating the need for GALE-KO cells in metabolic labeling experiments, GalNAzMe is a precision tool that allows a detailed view into the biology of a major type of cancer-relevant protein glycosylation.
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Acetilgalactosamina/metabolismo , Glicoproteínas/metabolismo , Acetilgalactosamina/química , Regulação Enzimológica da Expressão Gênica , Glicosilação , Humanos , Racemases e Epimerases/genética , Racemases e Epimerases/metabolismo , Especificidade por Substrato , Uridina Difosfato N-Acetilgalactosamina/químicaRESUMO
Rosacea is a skin inflammatory condition accompanied by cutaneous signs such as oedema, flushing, erythema, telangiectasia and pustules. Generally, rosacea is triggered by ultraviolet B (UVB) exposure. When exposed to UVB, skin epidermis thickens and produces elevated levels of pro-inflammatory cytokines, especially keratinocyte-related VEGF, a potent angiogenic factor. The upregulations of VEGF expression and its secretion promote the formation of new blood vessels and exacerbates rosacea. In this study, radiofrequency (RF) irradiation reduced keratinocyte proliferation in the epidermal layer, the expressions of pro-inflammatory cytokines, angiogenesis-related inflammatory factors and VEGF in our UVB-induced model of rosacea in vitro and in vivo. RF irradiation attenuated VEGF-induced angiogenesis-associated processes such as tube formation, cell migration and endothelial cell proliferation. Notably, blood vessel densities in the skins of UVB-treated mice and rosacea patients were significantly decreased by RF irradiation. These results provide experimental and molecular evidence regarding the effectiveness of RF irradiation for the treatment of rosacea.
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Proliferação de Células/efeitos da radiação , Neovascularização Patológica/radioterapia , Terapia por Radiofrequência , Rosácea/metabolismo , Rosácea/radioterapia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Movimento Celular/efeitos da radiação , Modelos Animais de Doenças , Células Endoteliais , Epiderme , Expressão Gênica/efeitos da radiação , Humanos , Interleucina-1beta/genética , Queratinócitos , Masculino , Camundongos , Neovascularização Patológica/metabolismo , RNA Mensageiro/metabolismo , Ondas de Rádio , Transdução de Sinais/efeitos da radiação , Raios Ultravioleta , Fator A de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genéticaRESUMO
Studying posttranslational modifications classically relies on experimental strategies that oversimplify the complex biosynthetic machineries of living cells. Protein glycosylation contributes to essential biological processes, but correlating glycan structure, underlying protein, and disease-relevant biosynthetic regulation is currently elusive. Here, we engineer living cells to tag glycans with editable chemical functionalities while providing information on biosynthesis, physiological context, and glycan fine structure. We introduce a non-natural substrate biosynthetic pathway and use engineered glycosyltransferases to incorporate chemically tagged sugars into the cell surface glycome of the living cell. We apply the strategy to a particularly redundant yet disease-relevant human glycosyltransferase family, the polypeptide N-acetylgalactosaminyl transferases. This approach bestows a gain-of-chemical-functionality modification on cells, where the products of individual glycosyltransferases can be selectively characterized or manipulated to understand glycan contribution to major physiological processes.
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Glicosiltransferases/metabolismo , Polissacarídeos/metabolismo , Engenharia de Proteínas/métodos , Vias Biossintéticas , Membrana Celular/metabolismo , Glicosilação , Glicosiltransferases/química , Glicosiltransferases/fisiologia , Células HEK293 , Células Hep G2 , Humanos , Células K562 , N-Acetilgalactosaminiltransferases/química , N-Acetilgalactosaminiltransferases/metabolismo , N-Acetilgalactosaminiltransferases/fisiologia , Polissacarídeos/química , Proteínas/metabolismo , Polipeptídeo N-AcetilgalactosaminiltransferaseRESUMO
Carbon nanotube fibers (CNTFs) are directly spun from a floating-catalyst chemical vapor deposition apparatus using gas-phase carbon and an iron nanocatalyst. The essential synthesis and post-treatment factors that affect the strength of CNTFs are investigated to obtain CNTFs with greater strength than those of any previously reported high-performance fibers. The key factors optimized included the degree of rotational flow inside the reactor, the ratio of the starting materials, and the postsynthesis treatment conditions. The formation of rotational gas flow inside the reactor was confirmed by computational fluid dynamics simulations, and the feed ratio of the starting materials was optimized through response surface methodology. In addition, a reproducible and highly efficient postsynthesis treatment method was established. Pristine CNTFs with a high specific strength (SS) (average 2.2 N/tex, max. 2.3 N/tex) were synthesized through decreased rotational flow and optimization of the CNTF synthesis conditions. To improve the SS of the CNTFs further, we adopted an acid wet-stretching method that included washing and heat treatment. This drastically increased the SS of the CNTFs (average 5.5 N/tex, max. 6.4 N/tex) because of the decrease in the volume of the pores between the CNT bundles.
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Obesity induces inflammation both in the adipose tissue and the brain. Activated macrophage infiltration, polarization of macrophages to a more inflammatory type (M1), and increased levels of pro-inflammatory cytokines are related to brain inflammation, which induces leptin resistance in the brain. Pyrogallol-phloroglucinol-6,6-bieckol (PPB), a compound from Ecklonia cava, has anti-inflammatory effects. In this study, we evaluated the effects of PPB effect M1 polarization and inflammation and its ability to restore the effects of leptin, such as a decrease in appetite and body weight. We administered PPB to diet-induced obesity (DIO) and leptin-deficient (ob/ob) mice, evaluated macrophage activation, polarization, and changes of inflammatory cytokine level in adipose tissue and brain, and determined the effect of PPB on leptin resistance or leptin sensitivity in the brain. The levels of activated macrophage marker, M1/M2, and pro-inflammatory cytokines were increased in the adipose tissue and brain of DIO and ob/ob mice than control. TLR4 expression, endoplasmic reticulum (ER) stress, and NF-κB expression in the brain of DIO and ob/ob mice were also increased; this increase was related to the upregulation of SOCS3 and decreased phosphorylated STAT3, which decreased leptin sensitivity in the brain. PPB decreased inflammation in the brain, restored leptin sensitivity, and decreased food intake and weight gain in both DIO and ob/ob mice.
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Encéfalo/efeitos dos fármacos , Inflamação/tratamento farmacológico , Leptina/metabolismo , Obesidade/tratamento farmacológico , Phaeophyceae/química , Floroglucinol/uso terapêutico , Pirogalol/uso terapêutico , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Dieta/efeitos adversos , Modelos Animais de Doenças , Ingestão de Alimentos/efeitos dos fármacos , Estresse do Retículo Endoplasmático , Inflamação/etiologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , NF-kappa B , Obesidade/complicações , Obesidade/metabolismo , Floroglucinol/farmacologia , Pirogalol/farmacologia , Células RAW 264.7 , Fator de Transcrição STAT3/metabolismo , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Receptor 4 Toll-Like , Aumento de Peso/efeitos dos fármacosRESUMO
Ecklonia cava (E. cava) can alleviate diet-induced obesity in animal models, and phlorotannins contained in E. cava help prevent hypertrophy-induced adipocyte differentiation. Receptor for advanced glycation end-products (RAGE) is well known to induce hypertrophy of visceral fat and to trigger inflammation substantially. While the relationship between RAGE and obesity and inflammation has been well-characterized, few studies describe the effects of phlorotannin on RAGE. In this study, we investigated the anti-obesity effects of pyrogallol-phloroglucinol-6,6-bieckol (PPB)-a single compound from the ethanoic extract of E. cava-mediated by a reduction in the inflammation caused by RAGE and RAGE ligands. In visceral fat, PPB (i) significantly inhibited RAGE ligands, (ii) reduced the expression of RAGE, and (iii) reduced the binding ratio between RAGE and RAGE ligands. Under lower expression of RAGE, RAGE ligands and their cognate binding, the differentiation of macrophages found in visceral fat into M1-type-the pro-inflammatory form of this immune cell-was reduced. As the M1-type macrophage decreased, pro-inflammatory cytokines, which cause obesity, decreased in visceral fat. The results of this study highlight the anti-obesity effects of PPB, with the effects mediated by reductions in RAGE, RAGE ligands, and inflammation.
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Inflamação/tratamento farmacológico , Obesidade/tratamento farmacológico , Floroglucinol/farmacologia , Pirogalol/farmacologia , Receptor para Produtos Finais de Glicação Avançada/antagonistas & inibidores , Animais , Fármacos Antiobesidade/farmacologia , Citocinas/metabolismo , Dieta , Dioxinas , Modelos Animais de Doenças , Hipertrofia/tratamento farmacológico , Ligantes , Macrófagos/efeitos dos fármacos , Camundongos , Obesidade/induzido quimicamente , Phaeophyceae/química , Extratos Vegetais/farmacologia , Taninos/farmacologiaRESUMO
O-Linked α-N-acetylgalactosamine (O-GalNAc) glycans constitute a major part of the human glycome. They are difficult to study because of the complex interplay of 20 distinct glycosyltransferase isoenzymes that initiate this form of glycosylation, the polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts). Despite proven disease relevance, correlating the activity of individual GalNAc-Ts with biological function remains challenging due to a lack of tools to probe their substrate specificity in a complex biological environment. Here, we develop a "bump-hole" chemical reporter system for studying GalNAc-T activity in vitro. Individual GalNAc-Ts were rationally engineered to contain an enlarged active site (hole) and probed with a newly synthesized collection of 20 (bumped) uridine diphosphate N-acetylgalactosamine (UDP-GalNAc) analogs to identify enzyme-substrate pairs that retain peptide specificities but are otherwise completely orthogonal to native enzyme-substrate pairs. The approach was applicable to multiple GalNAc-T isoenzymes, including GalNAc-T1 and -T2 that prefer nonglycosylated peptide substrates and GalNAcT-10 that prefers a preglycosylated peptide substrate. A detailed investigation of enzyme kinetics and specificities revealed the robustness of the approach to faithfully report on GalNAc-T activity and paves the way for studying substrate specificities in living systems.
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Acetilgalactosamina/metabolismo , N-Acetilgalactosaminiltransferases/metabolismo , Engenharia de Proteínas , Difosfato de Uridina/metabolismo , Acetilgalactosamina/química , Sequência de Aminoácidos , Domínio Catalítico , Humanos , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , Cinética , Modelos Moleculares , Mutagênese , N-Acetilgalactosaminiltransferases/química , N-Acetilgalactosaminiltransferases/genética , Especificidade por Substrato , Difosfato de Uridina/química , Polipeptídeo N-AcetilgalactosaminiltransferaseRESUMO
The main causes of Alzheimer's disease (AD) have not determined and effective treatment has not been developed yet, even though extensive researches and several clinical trials have been conducted.. Fortunately, stem cell transplantation is emerging as a potential therapeutic candidate for AD, but the success of stem cell based therapy depends on the survival of transplanted cells. Here, we generated sRAGE secreting mesenchymal stem cells (sRAGE-MSCs) and then injected these MSCs or control MSCs with amyloid beta 1-42 (Aß1-42) into the entorhinal cortices of male Sprague Dawley rats. The survival of transplanted cell, the number of T lymphocytes and microglia, expression of RAGE and its ligands and neuronal cell death were determined, 4 weeks after sRAGE-MSC transplantation. Transplanted sRAGE-MSCs survived longer than control MSCs and sRAGE-MSCs showed reduced level of CD4 and CD3d positive T lymphocyte. Furthermore, the number of M1 microglia in MSCs was more than that of sRAGE-MSCs as well. On the other hand, the number of M2 microglia in sRAGE-MSCs was increased compared with that of MSCs. In addition, sRAGE-MSCs decreased RAGE and RAGE ligand expressions and their interactions more effectively than those of MSCs. Finally, sRAGE-MSC transplantation protected from apoptosis and prevented decreasing numbers of neuron in Aß1-42 treated rat brains. These observations suggest continuous sRAGE secretion from sRAGE-MSCs might appreciably improve the effectiveness of cell therapy in Aß1-42 injected rat brains.
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Doença de Alzheimer/imunologia , Doença de Alzheimer/patologia , Microglia/imunologia , Células-Tronco Neurais/imunologia , Receptor para Produtos Finais de Glicação Avançada/imunologia , Linfócitos T/patologia , Doença de Alzheimer/metabolismo , Animais , Encéfalo/imunologia , Encéfalo/patologia , Sobrevivência Celular/imunologia , Células Cultivadas , Masculino , Microglia/patologia , Ratos , Ratos Sprague-Dawley , Linfócitos T/imunologiaRESUMO
Post-ischemic reperfusion injury (PIRI) triggers an intense inflammatory response which is essential for repair but is also implicated in pathogenesis of post-ischemic remodeling in several organs in human. Stem cell therapy has recently emerged as a promising method for treatment of PIRI in human. However, satisfactory results have not been reported due to severe loss of injected stem cells in PIRI including critical limb ischemia (CLI). For investigating the advanced glycation end-product-albumin (AGE-albumin) from activated macrophages is critical in both muscle cell and stem cell death, we evaluated the recovery of PIRI-CLI by injection of human bone marrow derived mesenchymal stem cells (hBD-MSCs) with or without soluble receptor for AGEs (sRAGE). Our results showed that activated M1 macrophages synthesize and secrete AGE-albumin, which induced the skeletal muscle cell death and injected hBD-MSCs in PIRI-CLI through RAGE increase. Combined injection of sRAGE and hBD-MSCs resulted in enhanced survival of hBD-MSCs and angiogenesis in PIRI-CLI mice. Taken together, AGE-albumin from activated macrophages is critical for both skeletal muscle cell and hBD-MSCs death in PIRI-CLI. Therefore, the inhibition of AGE-albumin from activated macrophages could be a successful therapeutic strategy for treatment of PIRI including CLI with or without stem cell therapy.
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Comunicação Celular , Sobrevivência Celular , Produtos Finais de Glicação Avançada/metabolismo , Macrófagos/metabolismo , Células-Tronco Mesenquimais/metabolismo , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/metabolismo , Albuminas , Animais , Morte Celular , Modelos Animais de Doenças , Humanos , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Masculino , Transplante de Células-Tronco Mesenquimais/métodos , Camundongos , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Neovascularização Patológica/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/terapiaRESUMO
Alzheimer's disease (AD), which is the most commonly encountered neurodegenerative disease, causes synaptic dysfunction and neuronal loss due to various pathological processes that include tau abnormality and amyloid beta (Aß) accumulation. Aß stimulates the secretion and the synthesis of Receptor for Advanced Glycation End products (RAGE) ligand by activating microglial cells, and has been reported to cause neuronal cell death in Aß1-42 treated rats and in mice with neurotoxin-induced Parkinson's disease. The soluble form of RAGE (sRAGE) is known to reduce inflammation, and to decrease microglial cell activation and Aß deposition, and thus, it protects from neuronal cell death in AD. However, sRAGE protein has too a short half-life for therapeutic purposes. We developed sRAGE-secreting umbilical cord derived mesenchymal stem cells (sRAGE-MSCs) to enhance the inhibitory effects of sRAGE on Aß deposition and to reduce the secretion and synthesis of RAGE ligands in 5xFAD mice. In addition, these cells improved the viability of injected MSCs, and enhanced the protective effects of sRAGE by inhibiting the binding of RAGE and RAGE ligands in 5xFAD mice. These findings suggest sRAGE protein from sRAGE-MSCs has better protection against neuronal cell death than sRAGE protein or single MSC treatment by inhibiting the RAGE cell death cascade and RAGE-induce inflammation.
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Peptídeos beta-Amiloides/metabolismo , Apoptose , Encéfalo/metabolismo , Células-Tronco Mesenquimais/metabolismo , Neurônios/metabolismo , Fragmentos de Peptídeos/metabolismo , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Doença de Alzheimer/metabolismo , Animais , Transplante de Células-Tronco de Sangue do Cordão Umbilical , Modelos Animais de Doenças , Humanos , Inflamação/metabolismo , Masculino , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/fisiologia , Camundongos Transgênicos , Microglia/metabolismo , Receptor para Produtos Finais de Glicação Avançada/genéticaRESUMO
An asymmetric decarboxylative Csp(3)-Csp(2) cross-coupling has been achieved via the synergistic merger of photoredox and nickel catalysis. This mild, operationally simple protocol transforms a wide variety of naturally abundant α-amino acids and readily available aryl halides into valuable chiral benzylic amines in high enantiomeric excess, thereby producing motifs found in pharmacologically active agents.