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1.
Proc Natl Acad Sci U S A ; 120(49): e2315096120, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38011564

RESUMO

Hidradenitis suppurativa (HS) is a complex inflammatory skin disease with undefined mechanistic underpinnings. Here, we investigated HS epithelial cells and demonstrated that HS basal progenitors modulate their lineage restriction and give rise to pathogenic keratinocyte clones, resulting in epidermal hyperproliferation and dysregulated inflammation in HS. When comparing to healthy epithelial stem/progenitor cells, in HS, we identified changes in gene signatures that revolve around the mitotic cell cycle, DNA damage response and repair, as well as cell-cell adhesion and chromatin remodeling. By reconstructing cell differentiation trajectory and CellChat modeling, we identified a keratinocyte population specific to HS. This population is marked by S100A7/8/9 and KRT6 family members, triggering IL1, IL10, and complement inflammatory cascades. These signals, along with HS-specific proinflammatory cytokines and chemokines, contribute to the recruitment of certain immune cells during the disease progression. Furthermore, we revealed a previously uncharacterized role of S100A8 in regulating the local chromatin environment of target loci in HS keratinocytes. Through the integration of genomic and epigenomic datasets, we identified genome-wide chromatin rewiring alongside the switch of transcription factors (TFs), which mediated HS transcriptional profiles. Importantly, we identified numerous clinically relevant inflammatory enhancers and their coordinated TFs in HS basal CD49fhigh cells. The disruption of the S100A enhancer using the CRISPR/Cas9-mediated approach or the pharmacological inhibition of the interferon regulatory transcription factor 3 (IRF3) efficiently reduced the production of HS-associated inflammatory regulators. Our study not only uncovers the plasticity of epidermal progenitor cells in HS but also elucidates the epigenetic mechanisms underlying HS pathogenesis.


Assuntos
Hidradenite Supurativa , Humanos , Hidradenite Supurativa/genética , Pele/metabolismo , Epigenômica , Epigênese Genética , Células-Tronco/metabolismo , Cromatina/metabolismo
2.
Proc Natl Acad Sci U S A ; 119(15): e2111445119, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35377804

RESUMO

Volumetric muscle loss (VML) overwhelms the innate regenerative capacity of mammalian skeletal muscle (SkM), leading to numerous disabilities and reduced quality of life. Immune cells are critical responders to muscle injury and guide tissue resident stem cell­ and progenitor-mediated myogenic repair. However, how immune cell infiltration and intercellular communication networks with muscle stem cells are altered following VML and drive pathological outcomes remains underexplored. Herein, we contrast the cellular and molecular mechanisms of VML injuries that result in the fibrotic degeneration or regeneration of SkM. Following degenerative VML injuries, we observed the heightened infiltration of natural killer (NK) cells as well as the persistence of neutrophils beyond 2 wk postinjury. Functional validation of NK cells revealed an antagonistic role in neutrophil accumulation in part via inducing apoptosis and CCR1-mediated chemotaxis. The persistent infiltration of neutrophils in degenerative VML injuries was found to contribute to impairments in muscle stem cell regenerative function, which was also attenuated by transforming growth factor beta 1 (TGFß1). Blocking TGFß signaling reduced neutrophil accumulation and fibrosis and improved muscle-specific force. Collectively, these results enhance our understanding of immune cell­stem cell cross talk that drives regenerative dysfunction and provide further insight into possible avenues for fibrotic therapy exploration.


Assuntos
Células Matadoras Naturais , Músculo Esquelético , Doenças Musculares , Neutrófilos , Regeneração , Células Satélites de Músculo Esquelético , Animais , Fibrose , Células Matadoras Naturais/imunologia , Camundongos , Músculo Esquelético/imunologia , Músculo Esquelético/patologia , Doenças Musculares/imunologia , Doenças Musculares/patologia , Infiltração de Neutrófilos , Neutrófilos/imunologia , Regeneração/imunologia , Células Satélites de Músculo Esquelético/imunologia , Fator de Crescimento Transformador beta/metabolismo
3.
PLoS Med ; 21(9): e1004456, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39226243

RESUMO

BACKGROUND: Comprehensive antenatal care (ANC) must prioritize competent, evidence-based medical attention to ensure a positive experience and value for its users. Unfortunately, there is scarce evidence of implementing this holistic approach to ANC in low- and middle-income countries, leading to gaps in quality and accountability. This study assessed care competence, women's experiences during the first ANC visit, and the factors associated with these care attributes. METHODS AND FINDINGS: The study analyzed cross-sectional baseline data from the maternal eCohort study conducted in Mexico from August to December 2023. The study adapted the Quality Evidence for Health System Transformation (QuEST) network questionnaires to the Mexican context and validated them through expert group and cognitive interviews with women. Pregnant women aged 18 to 49 who had their first ANC visit with a family physician were enrolled in 48 primary clinics of the Instituto Mexicano del Seguro Social across 8 states. Care competence and women's experiences with care were the primary outcomes. The statistical analysis comprised descriptive statistics, multivariable linear and Poisson regressions. A total of 1,390 pregnant women were included in the study. During their first ANC visit, women received only 67.7% of necessary clinical actions on average, and 52% rated their ANC experience as fair or poor. Women with previous pregnancies (adjusted regression coefficient [aCoef.] -3.55; (95% confidence intervals [95% CIs]): -4.88, -2.22, p < 0.001), at risk of depression (aCoef. -3.02; 95% CIs: -5.61, -0.43, p = 0.023), those with warning signs (aCoef. -2.84; 95% CIs: -4.65, -1.03, p = 0.003), common pregnancy discomforts (aCoef. -1.91; 95% CIs: -3.81, -0.02, p = 0.048), or those who had a visit duration of less than 20 minutes (<15 minutes: aCoef. -7.58; 95% CIs: -10.21, -4.95, p < 0.001 and 15 to 19 minutes: aCoef. -2.73; 95% CIs: -4.79, -0.67, p = 0.010) and received ANC in the West and Southeast regions (aCoef. -5.15; 95% CIs: -7.64, -2.66, p < 0.001 and aCoef. -5.33; 95% CIs: -7.85, -2.82, p < 0.001, respectively) had a higher probability of experiencing poorer care competence. Higher care competence (adjusted prevalence ratio [aPR] 1.004; 95% CIs:1.002, 1.005, p < 0.001) and receiving care in a small clinic (aPR 1.19; 95% CIs: 1.06, 1.34, p = 0.003) compared to a medium-sized clinic were associated with a better first ANC visit experience, while common pregnancy discomforts (aPR 0.94; 95% CIs: 0.89, 0.98, p = 0.005) and shorter visit length (aPR 0.94; 95% CIs: 0.88, 0.99, p = 0.039) were associated with lower women's experience. The primary limitation of the study is that participants' responses may be influenced by social desirability bias, leading them to provide socially acceptable responses. CONCLUSIONS: We found important gaps in adherence to ANC standards and that care competence during the first ANC visit is an important predictor of positive user experience. To inform quality improvement efforts, IMSS should institutionalize the routine monitoring of ANC competencies and ANC user experience. This will help identify poorly performing facilities and providers and address gaps in the provision of evidence-based and women-centered care.


Assuntos
Cuidado Pré-Natal , Humanos , Feminino , México , Adulto , Gravidez , Estudos Transversais , Adulto Jovem , Adolescente , Estudos de Coortes , Pessoa de Meia-Idade , Inquéritos e Questionários , Competência Clínica , Satisfação do Paciente/estatística & dados numéricos
4.
Ann Surg ; 278(2): e349-e359, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-36111847

RESUMO

OBJECTIVE: Our objective was to identify macrophage subpopulations and gene signatures associated with regenerative or fibrotic healing across different musculoskeletal injury types. BACKGROUND: Subpopulations of macrophages are hypothesized to fine tune the immune response after damage, promoting either normal regenerative, or aberrant fibrotic healing. METHODS: Mouse single-cell RNA sequencing data before and after injury were assembled from models of musculoskeletal injury, including regenerative and fibrotic mouse volumetric muscle loss (VML), regenerative digit tip amputation, and fibrotic heterotopic ossification. R packages Harmony , MacSpectrum , and Seurat were used for data integration, analysis, and visualizations. RESULTS: There was a substantial overlap between macrophages from the regenerative VML (2 mm injury) and regenerative bone models, as well as a separate overlap between the fibrotic VML (3 mm injury) and fibrotic bone (heterotopic ossification) models. We identified 2 fibrotic-like (FL 1 and FL 2) along with 3 regenerative-like (RL 1, RL 2, and RL 3) subpopulations of macrophages, each of which was transcriptionally distinct. We found that regenerative and fibrotic conditions had similar compositions of proinflammatory and anti-inflammatory macrophages, suggesting that macrophage polarization state did not correlate with healing outcomes. Receptor/ligand analysis of macrophage-to-mesenchymal progenitor cell crosstalk showed enhanced transforming growth factor ß in fibrotic conditions and enhanced platelet-derived growth factor signaling in regenerative conditions. CONCLUSION: Characterization of macrophage subtypes could be used to predict fibrotic responses following injury and provide a therapeutic target to tune the healing microenvironment towards more regenerative conditions.


Assuntos
Músculo Esquelético , Ossificação Heterotópica , Camundongos , Animais , Macrófagos , Cicatrização/fisiologia , Fator de Crescimento Derivado de Plaquetas
5.
J Immunol ; 204(8): 2203-2215, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32161098

RESUMO

Myeloid cells are critical to the development of fibrosis following muscle injury; however, the mechanism of their role in fibrosis formation remains unclear. In this study, we demonstrate that myeloid cell-derived TGF-ß1 signaling is increased in a profibrotic ischemia reperfusion and cardiotoxin muscle injury model. We found that myeloid-specific deletion of Tgfb1 abrogates the fibrotic response in this injury model and reduces fibro/adipogenic progenitor cell proliferation while simultaneously enhancing muscle regeneration, which is abrogated by adaptive transfer of normal macrophages. Similarly, a murine TGFBRII-Fc ligand trap administered after injury significantly reduced muscle fibrosis and improved muscle regeneration. This study ultimately demonstrates that infiltrating myeloid cell TGF-ß1 is responsible for the development of traumatic muscle fibrosis, and its blockade offers a promising therapeutic target for preventing muscle fibrosis after ischemic injury.


Assuntos
Fibrose/imunologia , Fibrose/patologia , Macrófagos/imunologia , Músculo Esquelético/imunologia , Músculo Esquelético/patologia , Células Mieloides/imunologia , Fator de Crescimento Transformador beta1/imunologia , Animais , Cardiotoxinas , Fibrose/complicações , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células Mieloides/patologia , Fenótipo , Traumatismo por Reperfusão/induzido quimicamente , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/imunologia
6.
Molecules ; 26(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34361756

RESUMO

Lignin is the second most abundant component, next to cellulose, in lignocellulosic biomass. Large amounts of this polymer are produced annually in the pulp and paper industries as a coproduct from the cooking process-most of it burned as fuel for energy. Strategies regarding lignin valorization have attracted significant attention over the recent decades due to lignin's aromatic structure. Oxidative depolymerization allows converting lignin into added-value compounds, as phenolic monomers and/or dicarboxylic acids, which could be an excellent alternative to aromatic petrochemicals. However, the major challenge is to enhance the reactivity and selectivity of the lignin structure towards depolymerization and prevent condensation reactions. This review includes a comprehensive overview of the main contributions of lignin valorization through oxidative depolymerization to produce added-value compounds (vanillin and syringaldehyde) that have been developed over the recent decades in the LSRE group. An evaluation of the valuable products obtained from oxidation in an alkaline medium with oxygen of lignins and liquors from different sources and delignification processes is also provided. A review of C4 dicarboxylic acids obtained from lignin oxidation is also included, emphasizing catalytic conversion by O2 or H2O2 oxidation.

7.
Biochem Biophys Res Commun ; 466(3): 381-7, 2015 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-26363459

RESUMO

CD5 has been mainly described as a negative regulator of TCR and BCR signaling and recent evidence has shown an important role for this receptor in delivering pro-survival signals. However, the molecular mechanisms underlying these processes remain unresolved. TCR crosslinking leads to phosphorylation of three tyrosine residues within the cytoplasmic tail of CD5 (Y429, Y441 and Y463) leading to the recruitment of signaling molecules like PI3K, c-Cbl and RasGAP; nevertheless, the role of these residues in T cell survival has not yet been assessed. In this study, we show that alanine-scanning mutagenesis of such tyrosine residues, either singly or in combination, leads to an increased thymocyte cell death with or without α-CD3 stimulation. Remarkably, the T-cell death observed with each individual tyrosine mutant was Caspase 3-independent. Furthermore, Y429 mutation resulted in a hyper-phosphorylation of ERK suggesting that this tyrosine residue regulates cell survival through down modulation of TCR signaling. Mutation of Y441 or Y463 did not induce hyper-responsiveness to TCR activation, indicating that they promoted T-cell survival by a TCR signal-independent pathway. Our results show that three tyrosine-based domains within CD5 cytoplasmic tail promote T-cell survival through non-overlapping mechanisms. This study also reveals that Y429 domain of CD5, previously described as a "pseudo ITAM", is functionally an ITIM domain in T cells.


Assuntos
Antígenos CD5/química , Citoplasma/metabolismo , Regulação da Expressão Gênica , Ativação Linfocitária , Mutação , Tirosina/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Anexina A5/química , Caspase 3/metabolismo , Sobrevivência Celular , Humanos , Camundongos , Dados de Sequência Molecular , Fosforilação , Estrutura Terciária de Proteína , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de Sinais , Linfócitos T/citologia , Timócitos/citologia
8.
Adv Biol (Weinh) ; 8(6): e2400091, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38616175

RESUMO

Adult stem cells occupy a niche that contributes to their function, but how stem cells rebuild their microenvironment after injury remains an open-ended question. Herein, biomaterial-based systems and metabolic labeling are utilized to evaluate how skeletal muscle stem cells deposit extracellular matrix. Muscle stem cells and committed myoblasts are observed to generate less nascent matrix than muscle resident fibro-adipogenic progenitors. When cultured on substrates that matched the stiffness of physiological uninjured and injured muscles, muscle stem cells increased nascent matrix deposition with activation kinetics. Reducing the ability to deposit nascent matrix by an inhibitor of vesicle trafficking (Exo-1) attenuated muscle stem cell function and mimicked impairments observed from muscle stem cells isolated from old muscles. Old muscle stem cells are observed to deposit less nascent matrix than young muscle stem cells, which is rescued with therapeutic supplementation of insulin-like growth factors. These results highlight the role of nascent matrix production with muscle stem cell activation.


Assuntos
Matriz Extracelular , Hidrogéis , Matriz Extracelular/metabolismo , Animais , Camundongos , Músculo Esquelético/metabolismo , Músculo Esquelético/citologia , Células-Tronco/metabolismo , Células-Tronco/efeitos dos fármacos , Diferenciação Celular , Células Cultivadas
9.
bioRxiv ; 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38328131

RESUMO

Adult stem cells occupy a niche that contributes to their function, but how stem cells remodel their microenvironment remains an open-ended question. Herein, biomaterials-based systems and metabolic labeling were utilized to evaluate how skeletal muscle stem cells deposit extracellular matrix. Muscle stem cells and committed myoblasts were observed to generate less nascent matrix than muscle resident fibro-adipogenic progenitors. When cultured on substrates that matched the stiffness of physiological uninjured and injured muscles, the increased nascent matrix deposition was associated with stem cell activation. Reducing the ability to deposit nascent matrix in muscle stem cells attenuated function and mimicked impairments observed from muscle stem cells isolated from old aged muscles, which could be rescued with therapeutic supplementation of insulin-like growth factors. These results highlight how nascent matrix production is critical for maintaining healthy stem cell function.

10.
Res Sq ; 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38410478

RESUMO

Aging is associated with a decline in stem cell functionality and number across the organism. In this study, we aimed to further unravel Muscle Stem Cells (MuSCs) aging by assessing how systemic factors influence MuSC fate decisions through long-term epigenetic landscape remodelling. As aging is intricately linked to a pro-inflammatory shift, we studied the epigenetic effects of inflammatory signals in MuSCs and measured decreased H4K20me1 levels. This loss disrupts MuSC quiescence, largely through epigenetic silencing of Notch target genes. In the setting of inflammatory signals or aging, the lack of Kmt5a and the subsequent absence of de novoH4K20me1 culminate in cell death by ferroptosis. Aged MuSCs manifest abnormal iron metabolism and reduced Gpx4 levels, resulting in the accumulation of intracellular iron, increased reactive oxygen species, genomic instability, and lipid peroxidation. We showed that ferroptosis is the predominant mode of cell death in aged MuSCs, with remarkably high levels of lipid peroxidation; a phenomenon we also observed in aged hematopoietic stem cells. Implementing preventative strategies to inhibit systemic inflammation prevented aged MuSC ferroptosis, preserving their numbers and regenerative capabilities. This intervention significantly enhanced aged muscle regeneration and strength recovery and extended both lifespan and healthspan in mice. This study delineates a previously underappreciated fate trajectory for stem cell aging, and offers meaningful insights into the treatment of age-related disorders.

11.
Anal Chem ; 85(8): 3871-8, 2013 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-23347165

RESUMO

Solid-state nanopores have emerged as versatile single-molecule sensors for applications including DNA sequencing, protein unfolding, micro-RNA detection, label-free detection of single nucleotide polymorphisms, and mapping of DNA-binding proteins involved in homologous recombination. While machining nanopores in dielectric membranes provides nanometer-scale precision, the rigid silicon support for the membrane contributes capacitive noise and limits integration with microfluidic networks for sample preprocessing. Herein, we demonstrate a technique to directly transfer solid-state nanopores machined in dielectric membranes from a silicon support into a microfluidic network. The resulting microfluidic-addressable nanopores can sense single DNA molecules at high bandwidths and with low noise, owing to significant reductions in membrane capacitance. This strategy will enable large-scale integration of solid-state nanopores with microfluidic upstream and downstream processing and permit new functions with nanopores such as complex manipulations for multidimensional analysis and parallel sensing in two and three-dimensional architectures.


Assuntos
DNA Viral/análise , Dimetilpolisiloxanos/química , Técnicas Eletroquímicas/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Bacteriófago lambda/química , Difusão , Técnicas Eletroquímicas/normas , Eletrodos , Corantes Fluorescentes , Membranas Artificiais , Técnicas Analíticas Microfluídicas/normas , Nanoporos , Impressão , Razão Sinal-Ruído
12.
JCI Insight ; 8(7)2023 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-36821376

RESUMO

Volumetric muscle loss (VML) is an acute trauma that results in persistent inflammation, supplantation of muscle tissue with fibrotic scarring, and decreased muscle function. The cell types, nature of cellular communication, and tissue locations that drive the aberrant VML response have remained elusive. Herein, we used spatial transcriptomics on a mouse model of VML and observed that VML engenders a unique spatial profibrotic pattern driven by crosstalk between fibrotic and inflammatory macrophages and mesenchymal-derived cells. The dysregulated response impinged on muscle stem cell-mediated repair, and targeting this circuit resulted in increased regeneration and reductions in inflammation and fibrosis. Collectively, these results enhance our understanding of the cellular crosstalk that drives aberrant regeneration and provides further insight into possible avenues for fibrotic therapy exploration.


Assuntos
Músculo Esquelético , Doenças Musculares , Camundongos , Animais , Músculo Esquelético/metabolismo , Doenças Musculares/patologia , Regeneração , Células-Tronco , Perfilação da Expressão Gênica , Fibrose
13.
Aging Cell ; 22(4): e13789, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36727578

RESUMO

Age-related skeletal muscle atrophy or sarcopenia is a significant societal problem that is becoming amplified as the world's population continues to increase. The regeneration of damaged skeletal muscle is mediated by muscle stem cells, but in old age muscle stem cells become functionally attenuated. The molecular mechanisms that govern muscle stem cell aging encompass changes across multiple regulatory layers and are integrated by the three-dimensional organization of the genome. To quantitatively understand how hierarchical chromatin architecture changes during muscle stem cell aging, we generated 3D chromatin conformation maps (Hi-C) and integrated these datasets with multi-omic (chromatin accessibility and transcriptome) profiles from bulk populations and single cells. We observed that muscle stem cells display static behavior at global scales of chromatin organization during aging and extensive rewiring of local contacts at finer scales that were associated with variations in transcription factor binding and aberrant gene expression. These data provide insights into genome topology as a regulator of molecular function in stem cell aging.


Assuntos
Senescência Celular , Genoma , Senescência Celular/genética , Cromatina/genética , Músculo Esquelético
14.
bioRxiv ; 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36993714

RESUMO

Somatic cell fate is an outcome set by the activities of specific transcription factors and the chromatin landscape and is maintained by gene silencing of alternate cell fates through physical interactions with the nuclear scaffold. Here, we evaluate the role of the nuclear scaffold as a guardian of cell fate in human fibroblasts by comparing the effects of transient loss (knockdown) and mutation (progeria) of functional Lamin A/C, a core component of the nuclear scaffold. We observed that Lamin A/C deficiency or mutation disrupts nuclear morphology, heterochromatin levels, and increases access to DNA in lamina-associated domains. Changes in Lamin A/C were also found to impact the mechanical properties of the nucleus when measured by a microfluidic cellular squeezing device. We also show that transient loss of Lamin A/C accelerates the kinetics of cellular reprogramming to pluripotency through opening of previously silenced heterochromatin domains while genetic mutation of Lamin A/C into progerin induces a senescent phenotype that inhibits the induction of reprogramming genes. Our results highlight the physical role of the nuclear scaffold in safeguarding cellular fate.

15.
Adv Nanobiomed Res ; 3(4)2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37234365

RESUMO

Brain metastases are the most lethal progression event, in part because the biological processes underpinning brain metastases are poorly understood. There is a paucity of realistic models of metastasis, as current in vivo murine models are slow to manifest metastasis. We set out to delineate metabolic and secretory modulators of brain metastases by utilizing two models consisting of in vitro microfluidic devices: 1) a blood brain niche (BBN) chip that recapitulates the blood-brain-barrier and niche; and 2) a migration chip that assesses cell migration. We report secretory cues provided by the brain niche that attract metastatic cancer cells to colonize the brain niche region. Astrocytic Dkk-1 is increased in response to brain-seeking breast cancer cells and stimulates cancer cell migration. Brain-metastatic cancer cells under Dkk-1 stimulation increase gene expression of FGF-13 and PLCB1. Further, extracellular Dkk-1 modulates cancer cell migration upon entering the brain niche.

16.
Elife ; 122023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38131691

RESUMO

The acute traumatic or surgical loss of skeletal muscle, known as volumetric muscle loss (VML), is a devastating type of injury that results in exacerbated and persistent inflammation followed by fibrosis. The mechanisms that mediate the magnitude and duration of the inflammatory response and ensuing fibrosis after VML remain understudied, and as such, the development of regenerative therapies has been limited. To address this need, we profiled how lipid mediators, which are potent regulators of the immune response after injury, varied with VML injuries that heal or result in fibrosis. We observed that non-healing VML injuries displayed increased pro-inflammatory eicosanoids and a lack of pro-resolving lipid mediators. Treatment of VML with a pro-resolving lipid mediator synthesized from docosahexaenoic acid, called Maresin 1, ameliorated fibrosis through reduction of neutrophils and macrophages and enhanced recovery of muscle strength. These results expand our knowledge of the dysregulated immune response that develops after VML and identify a novel immuno-regenerative therapeutic modality in Maresin 1.


Assuntos
Ácidos Docosa-Hexaenoicos , Doenças Musculares , Humanos , Músculo Esquelético/fisiologia , Doenças Musculares/patologia , Fibrose
17.
Biochim Biophys Acta ; 1813(10): 1708-16, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21782856

RESUMO

Parcs/Gpn3 is a putative GTPase that is conserved in eukaryotic cells from yeast to humans, suggesting that it plays a fundamental, but still unknown, cellular function. Suppression of Parcs/Gpn3 expression by RNAi completely blocked cell proliferation in MCF-12A cells and other mammary epithelial cell lines. Unexpectedly, Parcs/Gpn3 knockdown had a more modest effect in the proliferation of the tumorigenic MDA-MB-231 and SK-BR3 cells. RNA polymerase II (RNAP II) co-immunoprecipitated with Parcs/Gpn3. Parcs/Gpn3 depletion caused a reduction in overall RNA synthesis in MCF-12A cells but not in MDA-MB-231 cells, demonstrating a role for Parcs/Gpn3 in transcription, and pointing to a defect in RNA synthesis by RNAP II as the possible cause of halted proliferation. The absence of Parcs/Gpn3 in MCF-12A cells caused a dramatic change in the sub-cellular localization of Rpb1, the largest subunit of RNAP II. As expected, Rpb1 was present only in the nucleus of MCF-12A control cells, whereas in Parcs/Gpn3-depleted MCF-12A cells, Rpb1 was detected exclusively in the cytoplasm. This effect was specific, as histones remained nuclear independently of Parcs/Gpn3. Rpb1 protein levels were markedly increased in Parcs/Gpn3-depleted MCF-12A cells. Interestingly, Rpb1 distribution was only marginally affected after knocking-down Parcs/Gpn3 in MDA-MB-231 cells. In conclusion, we report here, for the first time, that Parcs/Gpn3 plays a critical role in the nuclear accumulation of RNAP II, and we propose that this function explains the relative importance of Parcs/Gpn3 in cell proliferation. Intriguingly, at least some tumorigenic mammary cells have evolved mechanisms that allow them to proliferate in a Parcs/Gpn3-independent manner.


Assuntos
Núcleo Celular/metabolismo , GTP Fosfo-Hidrolases/fisiologia , RNA Polimerase II/metabolismo , Mama/metabolismo , Núcleo Celular/genética , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Células Epiteliais/metabolismo , Feminino , GTP Fosfo-Hidrolases/antagonistas & inibidores , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Humanos , Imunoprecipitação , Ligação Proteica , Transporte Proteico/genética , Interferência de RNA/fisiologia , RNA Interferente Pequeno/farmacologia , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genética
18.
BMC Med Educ ; 12: 53, 2012 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-22784406

RESUMO

BACKGROUND: Evidence suggests that continuing medical education improves the clinical competence of general practitioners and the quality of health care services. Thus, we evaluated the relative impact of two educational strategies, critical reading (CR) and problem based learning (PBL), on the clinical competence of general practitioners in a healthcare system characterized by excessive workload and fragmentation into small primary healthcare centers. METHODS: Clinical competence was evaluated in general practitioners assigned to three groups based on the educational interventions used: 1) critical reading intervention; 2) problem based learning intervention; and 3) no intervention (control group, which continued clinical practice as normal). The effect on the clinical competence of general practitioners was evaluated in three dimensions: the cognitive dimension, via a self-administered questionnaire; the habitual behavioral dimension, via information from patient's medical records; and the affective dimension, through interviews with patients. A paired Student´s t-test was used to evaluate the changes in the mean clinical competence scores before and after the intervention, and a 3 x 2 ANOVA was used to analyze groups, times and their interaction. RESULTS: Nine general practitioners participated in the critical reading workshop, nine in the problem-based learning workshop, and ten were assigned to the control group. The participants exhibited no significant differences in clinical competence measures at baseline, or in socio-demographic or job characteristics (p > 0.05). Significant improvements in all three dimensions (cognitive, 45.67 vs 54.89; habitual behavioral, 53.78 vs 82.33; affective, 4.16 vs 4.76) were only observed in the problem-based learning group after the intervention (p > 0.017). CONCLUSIONS: While no differences in post-intervention scores were observed between groups, we conclude that problem-based learning can be effective, particularly in a small-group context. Indeed, problem-based learning was the only strategy to induce a significant difference between pre- and post- intervention scores for all three CC dimensions.


Assuntos
Competência Clínica , Países em Desenvolvimento , Educação Médica Continuada/métodos , Medicina Geral/educação , Aprendizagem Baseada em Problemas/métodos , Leitura , Currículo , Atenção à Saúde , Humanos , México , Modelos Educacionais , Atenção Primária à Saúde , Melhoria de Qualidade , Carga de Trabalho
19.
Ind Eng Chem Res ; 61(10): 3570-3581, 2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36569588

RESUMO

Innovative methodologies, such as microwave-assisted reaction, can help to valorize lignin with higher productivity and better energy efficiency. In this work, microwave heating was tested in the wet peroxide oxidation of three lignins (Indulin AT, Lignol, and Eucalyptus globulus lignins) as a novel methodology to obtain C4 dicarboxylic acids. The effect of temperature, time, and catalyst type (TS-1 or Fe-TS1) was evaluated in the production of these acids. The TS-1 catalyst improved succinic acid yield, achieving up to 9.4 wt % for Lignol lignin. Moreover, the microwave heating specifically enhanced Lignol conversion to malic acid (34 wt %), even without catalyst, showing to be an attractive path for the future valorization of organosolv lignins. Overall, compared to conventional heating, microwave heating originated a rapid lignin conversion. Nevertheless, for prolonged times, conventional heating led to better results for some target products, e.g., malic and succinic acids.

20.
Adv Sci (Weinh) ; 8(3): 2002825, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33552865

RESUMO

All multicellular organisms rely on intercellular communication networks to coordinate physiological functions. As members of a dynamic social network, each cell receives, processes, and redistributes biological information to define and maintain tissue homeostasis. Uncovering the molecular programs underlying these processes is critical for prevention of disease and aging and development of therapeutics. The study of intercellular communication requires techniques that reduce the scale and complexity of in vivo biological networks while resolving the molecular heterogeneity in "omic" layers that contribute to cell state and function. Recent advances in microengineering and high-throughput genomics offer unprecedented spatiotemporal control over cellular interactions and the ability to study intercellular communication in a high-throughput and mechanistic manner. Herein, this review discusses how salient engineered approaches and sequencing techniques can be applied to understand collective cell behavior and tissue functions.

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