Treatment of aged wound healing models with FGF2 and ABT-737 reduces the senescent cell population and increases wound closure rate.

Delayed tissue repair in the aged presents a major socio-economic and clinical problem. Age-associated delay in wound healing can be attributed to multiple factors, including an increased presence of senescent cells persisting in the wound. Although the transient presence of senescent cells is physiologic during the resolution phase of normal healing, increased senescent cell accumulation with age can negatively impact tissue repair. The objective of the study was to test interventional strategies that could mitigate the negative effect of senescent cell accumulation and possibly improve the age-associated delay in wound healing. We utilised a 3D in vitro senescent fibroblast populated collagen matrix (FPCM) to study cellular events associated with senescence and delayed healing. Senescent fibroblasts showed an increase in anti-apoptotic B-cell lymphoma 2 (BCL-2) family proteins. We hypothesized that reducing the senescent cell population and promoting non-senescent cell functionality would mitigate the negative effect of senescence and improve healing kinetics. BCL-2 inhibition and mitogen stimulation (FGF2) improved healing in the in vitro senescent models. These results were confirmed with an ex vivo human skin biopsy model. These data suggested that modulation of the senescent cell population with soluble factors improved the healing outcome in our in vitro and ex vivo healing models.

Downregulation of the Protein C Signaling System Is Associated with COVID-19 Hypercoagulability-A Single-Cell Transcriptomics Analysis.

Because of the interface between coagulation and the immune response, it is expected that COVID-19-associated coagulopathy occurs via activated protein C signaling. The objective was to explore putative changes in the expression of the protein C signaling network in the liver, peripheral blood mononuclear cells, and nasal epithelium of patients with COVID-19. Single-cell RNA-sequencing data from patients with COVID-19 and healthy subjects were obtained from the COVID-19 Cell Atlas database. A functional protein-protein interaction network was constructed for the protein C gene. Patients with COVID-19 showed downregulation of protein C and components of the downstream protein C signaling cascade. The percentage of hepatocytes expressing protein C was lower. Part of the liver cell clusters expressing protein C presented increased expression of ACE2. In PBMC, there was increased ACE2, inflammatory, and pro-coagulation transcripts. In the nasal epithelium, PROC, ACE2, and PROS1 were expressed by the ciliated cell cluster, revealing co-expression of ACE-2 with transcripts encoding proteins belonging to the coagulation and immune system interface. Finally, there was upregulation of coagulation factor 3 transcript in the liver and PBMC. Protein C could play a mechanistic role in the hypercoagulability syndrome affecting patients with severe COVID-19.

Accelerative action of topical piperonylic acid on mice full thickness wound by modulating inflammation and collagen deposition.

Epidermal growth factor (EGF) promotes cell growth, proliferation, and survival in numerous tissues. Piperonylic acid, a metabolite present in peppers (Piper nigrum L. and Piper longum L.), can bind to the epidermal growth factor receptor (EGFR) and induce an intracellular signaling cascade leading to the transcription of genes responsible for these actions, especially in keratinocytes. These cells are fundamental in maintaining cutaneous homeostasis and are the first to be damaged in the case of a wound. Thus, we hypothesized that piperonylic acid improves wound healing. C57BL6/J male mice were submitted to dorsal skin wounds caused by a 6 mm punch and treated topically with piperonylic acid or vehicle. The wounds were evaluated macro- and microscopically, and tissue samples were collected for immunofluorescence and real-time PCR analyses on days 6, 9 and 19 post-injury. Topical piperonylic acid improved wound healing from day 6 post-injury until closure. This phenomenon apparently occurred through EGFR activation. In addition, piperonylic acid modulated the gene expression of interleukin (Il)-6, il-1ß, tumor necrosis factor (Tnf)-α, il-10, monocyte chemoattractant protein (Mcp)-1 and insulin-like growth factor (Igf)-1, which are important for the healing process. By day 19 post-injury, the new tissue showed greater deposition of type I collagen and a morphology closer to intact skin, with more dermal papillae and hair follicles. We conclude that piperonylic acid may be a viable option for the treatment of skin wounds.

Interleukin-6 actions in the hypothalamus protects against obesity and is involved in the regulation of neurogenesis.

BACKGROUND: Interleukin-6 (IL6) produced in the context of exercise acts in the hypothalamus reducing obesity-associated inflammation and restoring the control of food intake and energy expenditure. In the hippocampus, some of the beneficial actions of IL6 are attributed to its neurogenesis-inducing properties. However, in the hypothalamus, the putative neurogenic actions of IL6 have never been explored, and its potential to balance energy intake can be an approach to prevent or attenuate obesity. METHODS: Wild-type (WT) and IL6 knockout (KO) mice were employed to study the capacity of IL6 to induce neurogenesis. We used cell labeling with Bromodeoxyuridine (BrdU), immunofluorescence, and real-time PCR to determine the expression of markers of neurogenesis and neurotransmitters. We prepared hypothalamic neuroprogenitor cells from KO that were treated with IL6 in order to provide an ex vivo model to further characterizing the neurogenic actions of IL6 through differentiation assays. In addition, we analyzed single-cell RNA sequencing data and determined the expression of IL6 and IL6 receptor in specific cell types of the murine hypothalamus. RESULTS: IL6 expression in the hypothalamus is low and restricted to microglia and tanycytes, whereas IL6 receptor is expressed in microglia, ependymocytes, endothelial cells, and astrocytes. Exogenous IL6 reduces diet-induced obesity. In outbred mice, obesity-resistance is accompanied by increased expression of IL6 in the hypothalamus. IL6 induces neurogenesis-related gene expression in the hypothalamus and in neuroprogenitor cells, both from WT as well as from KO mice. CONCLUSION: IL6 induces neurogenesis-related gene expression in the hypothalamus of WT mice. In KO mice, the neurogenic actions of IL6 are preserved; however, the appearance of new fully differentiated proopiomelanocortin (POMC) and neuropeptide Y (NPY) neurons is either delayed or disturbed.

A Smartphone App for Individual Xylazine/Ketamine Calculation Decreased Anesthesia-Related Mortality in Mice.

Currently, experimental animals are widely used in biological and medical research. However, the scientific community has raised several bioethical concerns, such as the number of animals required to achieve reproducible and statistically relevant results. These concerns involve aspects related to pain, discomfort, and unwanted animal loss. Retrospectively, we compare two different approaches for anesthesia dosage: a mobile app for dose calculation and a standard dose calculation. A total of 939 C57BL/6J and Swiss mice were analyzed. We collected data on intraoperative and anesthesia-related mortality as described in electronic or physical handwritten records. Our results showed that the mobile app approach significantly reduces anesthetic-related deaths upon using doses of ketamine and xylazine. The results suggest that anesthesia-related mortality can be minimized even more using information technology approaches, helping to solve an old but transversal challenge for researchers working with experimental mice. The mobile app is a free and open code which could be implemented worldwide as an essential requirement for all anesthetic procedures in mice using xylazine and ketamine combination. As an open code app, the Labinsane initiative could also represent the starting point to unify and validate other anesthetic procedures in different species and strains.

Glutamic acid promotes hair growth in mice.

Glutamic acid is the main excitatory neurotransmitter acting both in the brain and in peripheral tissues. Abnormal distribution of glutamic acid receptors occurs in skin hyperproliferative conditions such as psoriasis and skin regeneration; however, the biological function of glutamic acid in the skin remains unclear. Using ex vivo, in vivo and in silico approaches, we showed that exogenous glutamic acid promotes hair growth and keratinocyte proliferation. Topical application of glutamic acid decreased the expression of genes related to apoptosis in the skin, whereas glutamic acid increased cell viability and proliferation in human keratinocyte cultures. In addition, we identified the keratinocyte glutamic acid excitotoxic concentration, providing evidence for the existence of a novel skin signalling pathway mediated by a neurotransmitter that controls keratinocyte and hair follicle proliferation. Thus, glutamic acid emerges as a component of the peripheral nervous system that acts to control cell growth in the skin. These results raise the perspective of the pharmacological and nutritional use of glutamic acid to treat skin diseases.

Hypothalamic Microglial Heterogeneity and Signature under High Fat Diet-Induced Inflammation.

Under high-fat feeding, the hypothalamus atypically undergoes pro-inflammatory signaling activation. Recent data from transcriptomic analysis of microglia from rodents and humans has allowed the identification of several microglial subpopulations throughout the brain. Numerous studies have clarified the roles of these cells in hypothalamic inflammation, but how each microglial subset plays its functions upon inflammatory stimuli remains unexplored. Fortunately, these data unveiling microglial heterogeneity have triggered the development of novel experimental models for studying the roles and characteristics of each microglial subtype. In this review, we explore microglial heterogeneity in the hypothalamus and their crosstalk with astrocytes under high fat diet-induced inflammation. We present novel currently available ex vivo and in vivo experimental models that can be useful when designing a new research project in this field of study. Last, we examine the transcriptomic data already published to identify how the hypothalamic microglial signature changes upon short-term and prolonged high-fat feeding.

SARS-CoV-2 receptor is co-expressed with elements of the kinin-kallikrein, renin-angiotensin and coagulation systems in alveolar cells.

SARS-CoV-2, the pathogenic agent of COVID-19, employs angiotensin converting enzyme-2 (ACE2) as its cell entry receptor. Clinical data reveal that in severe COVID-19, SARS-CoV-2 infects the lung, leading to a frequently lethal triad of respiratory insufficiency, acute cardiovascular failure, and coagulopathy. Physiologically, ACE2 plays a role in the regulation of three systems that could potentially be involved in the pathogenesis of severe COVID-19: the kinin-kallikrein system, resulting in acute lung inflammatory edema; the renin-angiotensin system, promoting cardiovascular instability; and the coagulation system, leading to thromboembolism. Here we assembled a healthy human lung cell atlas meta-analysis with ~ 130,000 public single-cell transcriptomes and show that key elements of the bradykinin, angiotensin and coagulation systems are co-expressed with ACE2 in alveolar cells and associated with their differentiation dynamics, which could explain how changes in ACE2 promoted by SARS-CoV-2 cell entry result in the development of the three most severe clinical components of COVID-19.

Novel fibrin-fibronectin matrix accelerates mice skin wound healing.

Plasma fibrinogen (F1) and fibronectin (pFN) polymerize to form a fibrin clot that is both a hemostatic and provisional matrix for wound healing. About 90% of plasma F1 has a homodimeric pair of γ chains (γγF1), and 10% has a heterodimeric pair of γ and more acidic γ' chains (γγ'F1). We have synthesized a novel fibrin matrix exclusively from a 1:1 (molar ratio) complex of γγ'F1 and pFN in the presence of highly active thrombin and recombinant Factor XIII (rFXIIIa). In this matrix, the fibrin nanofibers were decorated with pFN nanoclusters (termed γγ'F1:pFN fibrin). In contrast, fibrin made from 1:1 mixture of γγF1 and pFN formed a sporadic distribution of "pFN droplets" (termed γγF1+pFN fibrin). The γγ'F1:pFN fibrin enhanced the adhesion of primary human umbilical vein endothelium cells (HUVECs) relative to the γγF1+FN fibrin. Three dimensional (3D) culturing showed that the γγ'F1:pFN complex fibrin matrix enhanced the proliferation of both HUVECs and primary human fibroblasts. HUVECs in the 3D γγ'F1:pFN fibrin exhibited a starkly enhanced vascular morphogenesis while an apoptotic growth profile was observed in the γγF1+pFN fibrin. Relative to γγF1+pFN fibrin, mouse dermal wounds that were sealed by γγ'F1:pFN fibrin exhibited accelerated and enhanced healing. This study suggests that a 3D pFN presentation on a fibrin matrix promotes wound healing.

Bioactive Fatty Acids in the Resolution of Chronic Inflammation in Skin Wounds.

Significance: Optimal skin wound healing is crucial for maintaining tissue homeostasis, particularly in response to an injury. The skin immune system is under regulation of mediators such as bioactive lipids and cytokines that can initiate an immune response with controlled inflammation, followed by efficient resolution. However, nutritional deficiency impacts wound healing by hindering fibroblast proliferation, collagen synthesis, and epithelialization, among other crucial functions. In this way, the correct nutritional support of bioactive lipids and of other essential nutrients plays an important role in the outcome of the wound healing process. Recent Advances and Critical Issues: Several studies have revealed the potential role of lipids as a treatment for the healing of skin wounds. Unsaturated fatty acids such as linoleic acid, α-linolenic acid, oleic acid, and most of their bioactive products have shown an effective role as a topical treatment of chronic skin wounds. Their effect, when the treatment starts at day 0, has been observed mainly in the inflammatory phase of the wound healing process. Moreover, some of them were associated with different dressings and were tested for clinical purposes, including pluronic gel, nanocapsules, collagen films and matrices, and polymeric bandages. Therefore, future research is still needed to evaluate these dressing technologies in association with different bioactive fatty acids in a wound healing context. Future Directions: This review summarizes the main results of the available clinical trials and basic research studies and provides evidence-based conclusions. Together, current data encourage the use of bioactive fatty acids for an optimal wound healing resolution.

Topical Topiramate Improves Wound Healing in an Animal Model of Hyperglycemia.

Wound healing is severely affected in hyperglycemia and other metabolic conditions. Finding new therapeutic approaches that accelerate wound healing and improve the quality of the scar may reduce the morbidity commonly associated with skin lesions in diabetes. This study evaluated the effect of topical topiramate (TPM) on wound healing in C57 mice. Streptozotocin-induced hyperglycemic mice were subjected to a wound on the back and randomly allocated for treatment with either vehicle or topical TPM cream (2%) once a day for 14 days. Polymerase chain reaction, Western blotting, and microscopy were performed for the analysis. TPM improved wound healing (complete resolution at Day 10, 98% ± 5 for TPM vs. 81% ± 28 for vehicle), increased organization and deposition of collagen Type I, and enhanced the quality of the scars as determined by microscopy. In addition, TPM modulated the expression of cytokines and proteins of the insulin-signaling pathway: In early wound-healing stages, expression of interleukin-10, an anti-inflammatory marker, increased, whereas at the late phase, the pro-inflammatory markers tumor necrosis factor-α and monocyte chemoattractant protein-1 increased and there was increased expression of a vascular endothelial growth factor. Proteins of the insulin-signaling pathway were stimulated in the late wound-healing phase. Topical TPM improves the quality of wound healing in an animal model of hyperglycemia. The effect of TPM is accompanied by modulation of inflammatory and growth factors and proteins of the insulin-signaling pathway. Therefore, topical TPM presents as a potential therapeutic agent in skin wounds in patients with hyperglycemia.

Limitação da utilização do acesso intraósseo: aspectos da enfermagem e da instituição de saúde / Limitation of the use of intraosseous access: aspects of nursing and health institution

Objetivo: Verificar a realização do acesso intraósseo por enfermeiros. Método: Estudo analítico transversal, realizado por meio da aplicação de um questionário. Resultados: Demonstrou-se que 97,0% dos profissionais nunca realizaram o acesso (p<0,001), e 48,5% tiveram um treinamento adequado. Apenas 9,1% relatou se sentir seguro para executar a técnica (p<0,001) e 69,7% responderam que não possuem apoio técnico, e não possuem material apropriado. Conclusão: Demonstrou-se que existe uma limitação do uso do acesso intraósseo. A falta de autonomia para realizar a técnica pode se explicar pela falta de habilidade prática e conhecimento teórico dos enfermeiros, e pela falta de protocolos e acesso à informações institucionais, treinamentos e insumos.

Objective: To verify the achievement of intraosseous access by nurses. Method: Cross-sectional analytical study, carried out through the application of a questionnaire. Results: It was demonstrated that 97,0% of the professionals never performed access (p <0.001), and 48,5% had adequate training. Only 9,1% reported feeling safe to perform the technique (p <0.001) and 69,7% answered that they do not have technical support, and do not have appropriate material. Conclusion: It has been demonstrated that there is a limitation of the use of intraosseous access. The lack of autonomy to perform the technique can be explained by the lack of practical skills and theoretical knowledge of nurses, and the lack of protocols and access to institutional information, training and inputs.

Objetivo: Verificar la realización del acceso intraóseo para las enfermeras. Método: Estudio transversal analítico realizado mediante la aplicación de un cuestionario. Resultados: Se demostró que 97,0% de los encuestados nunca hizo de acceso (p <0,001), y 48,5% tenía una formación adecuada. Sólo 9.1% reportó sentirse seguro para llevar a cabo la técnica (p <0,001) y 69,7% dijeron que no tienen soporte, y no tienen ningún material adecuado. Conclusión: Se ha demostrado que existe una limitación del uso de la vía intraósea. La falta de autonomía para llevar a cabo la técnica puede explicarse por la falta de habilidades prácticas y conocimientos teóricos de las enfermeras, y la falta de protocolos y el acceso a la información institucional, la capacitación y los insumos.

Effects of topical topiramate in wound healing in mice.

Recent studies have indicated that systemic topiramate can induce an improvement on the aesthetic appearance of skin scars. Here, we evaluated topical topiramate as an agent to improve wound healing in C57/BL6 mice. Mice were inflicted with a 6.0 mm punch to create two wounds in the skin of the dorsal region. Thereafter, mice were randomly assigned to either vehicle or topical topiramate (20 µl of 2% cream) once a day for 14 days, beginning on the same day as wound generation. We analyzed the wound samples over real-time PCR, Western blotting, and microscopy. There was no effect of the topiramate treatment on the time for complete reepithelization of the wound. However, on microscopic analysis, topiramate treatment resulted in increased granulation tissue, thicker epidermal repair, and improved deposition of type I collagen fibers. During wound healing, there were increased expressions of anti-inflammatory markers, such as IL-10, TGF-ß1, and reduced expression of the active form of JNK. In addition, topiramate treatment increased the expression of active forms of two intermediaries in the insulin-signaling pathway, IRS-1 and Akt. Finally, at the end of the wound-healing process, topiramate treatment resulted in increased expression of SOX-2, a transcription factor that is essential to maintain cell self-renewal of undifferentiated embryonic stem cells. We conclude that topical topiramate can improve the overall quality of wound healing in the healthy skin of mice. This improvement is accompanied by reduced expression of markers involved in inflammation and increased expression of proteins of the insulin-signaling pathway.

Biofilme e feridas crônicas: reflexões para o cuidado de enfermagem / Biofilm and chronic wound: reflections for nursing care

Objetiva-se refletir sobre o tema biofilme e ferida crônica para o cuidado de enfermagem. Estudo teórico-reflexivo, no qual os dados foram baseados em pesquisa na base de dados Scientific Electronic Library Online (SciELO) e PubMed, no período de 2010 à 2015, utilizando-se os descritores infecção, biofilmes e cicatrização de feridas. Os resultados apresentaram o crescimento microbiano em feridas crônicas é uma preocupação na prática clínica e a presença do biofilme prejudica o processo de cicatrização. O biofilme obtém nutrientes do plasma e do exsudato presentes no leito da ferida, e regula o metabolismo, a virulência e motilidade pela liberação e detecção de moléculas denominadas de quorum sensing. Abordagens no tratamento de feridas crônicas com foco no biofilme consistem na avaliação das características da ferida e na utilização de métodos de desbridamento para remoção da necrose e do esfacelo. Concluí-se que a limpeza do leito da ferida e o uso de antimicrobianos contribuem para o controle da carga microbiana, mas a administração destes produtos requer uma avaliação criteriosa. Novos métodos de diagnóstico para o controle do biofilme são necessários com vistas à prevenção, ao tratamento e cura das lesões em menor tempo

The aim is to reflect on biofilms in chronic wound for nursing care. A theoretical and reflective study based on Scientific Electronic Library Online (SciELO) and PubMed database, on the period 2010 to 2015. The used descriptors were infection, biofilms and wound healing. The results showed the microbial growth in chronic wounds is a concern in a clinical practice, and the presence of biofilm harms the healing process. The biofilm obtains plasma and exudate nutrients found in the wound bed, and regulates metabolism, virulence and motility by releasing and detecting molecules named quorum sensing. Approaches on treatment of chronic wounds focused on biofilm consist on the evaluation of the wound characteristics and on the usage of debridement methods to remove necrotic tissue and slough. It concludes that cleaning the wound bed help on controlling microbial load, but the usage of antimicrobial agents is also an expedient currently employed to control biofilm. The search for new diagnostic methods and biofilm control is necessary in order to prevent, to treat and to heal the wound in lesser time