Deficiency in infiltration of CD8/CD3 positive lymphocytes and macrophages plays a role in lip carcinogenesis: an immunohistochemical study

Abstract Objective To evaluate the immunoexpression profile for CD8, CD3, CD20 and CD68 in the process and carcinogenesis of Carcinoma of the vermilion lip. Methods Average cell count with positive expression for CD3, CD8, CD20 and CD68. The CD8/CD3 ratio calculated in the region was based on the percentage of positive cells in a total of malignant cells. Kruska-Wallis/Dunn, Mann-Whitney and Spearman correlation tests (SPSS, p< 0.05) were used. Results In the Aquitic Cheilitis samples, there was an increase in intraepithelial CD8+ and CD68+. In LSCCs, there was an increase in peritumoral and intratumoral CD3+, CD8+, CD20+ and CD68+ cells. In peritumoral LSCC, CD3+ and CD8+ showed a direct correlation (p= 0.004), and CD68+ and CD8+ (p= 0.017). In the intraepithelial region, CD8+ correlated with CD20+ (p= 0.014) and CD68+ (p= 0.013). In the CAs, CD3 (p< 0.001) and CD8 (p= 0.025) correlated intraepithelial and subepithelial. In LSCC CD3+ (p= 0.002), CD8+ (p= 0.001) and CD68+ (p= 0.030) had intra and peritumoral correlation. Conclusion CD68+ is the first interacting cell with the greatest capacity to migrate to the tumor and interact with CD3, CD8 and CD20. Apparently, CD20 affects perineural invasion. Level of evidence: Level 2.

Research progress on m5C methylation and its prospects in tumor immunotherapy / 口腔疾病防治

@#Epigenetic modification plays an important role in the biological regulatory process of eukaryotic cells. Tumor immunotherapy is an important means and clinical strategy for the treatment of some cancers. 5-Methylcytosine (m5C) is an important component of the epigenetic regulatory network discovered after m6A and has become a new topic for life science research in recent years. The m5C methylation of RNA can affect the fate of the modified RNA molecules and play an important role in various biological processes, including RNA stability, protein synthesis and transcriptional regulation. Recent studies have shown that m5C writers, erasers and readers are related to a variety of cellular biological processes and systemic diseases, including the occurrence, metastasis and tumor immune microenvironment. m5C methylation can widely affect gene expression and the biological process of tumorigenesis and development at multiple levels, but its specific mechanism and potential interaction with other epigenetic modifications in tumor immunotherapy are still unclear, and its regulatory mechanism, risk assessment and role in targeted therapy for malignant tumors need to be further studied. This article will review the dynamic regulatory network of m5C, the biological role of m5C modification in solid tumors and potential targets in tumor immunotherapy.

Development and application of in vitro intestinal absorption model based on microfluidic chips / 药学实践杂志

The intestine is the main site of oral drug absorption, and the epithelial cells of the intestine contain villi and microvilli, which promote secretion, cell adhesion, and absorption by increasing surface area and other factors. Traditional two-dimensional/three-dimensional (2D/3D) cell culture models and animal models have played an important role in studying drug absorption, but their application is limited due to the lack of sufficient predictability of human pharmacokinetics or ethical issues, etc. Therefore, mimicking the core structure and key functions of the human intestine based on in vitro live cells has been the focus of research on constructing a microfluidic chip-based intestinal model. The model is a microfluidic chip bionic system that simulates the complex microstructure, microenvironment, and physiological functions of the human intestine using microfabrication technology. Compared with 2D cell culture and animal experiments, the intestinal microarray model can effectively simulate the human in vivo environment and is more specific in drug screening. The research progress and applications in disease modeling, drug absorption and transport of intestinal microarray models and intestine-related multi-organ coupled microarray models at home and abroad were reviewed in this paper. The current challenges of intestinal chip simulating intestinal homeostasis and diseases were summarized，in order to provide reference for the further establishment of a more reliable in vitro intestinal chip model.

Research Progress of Granulocytic Myeloid-derived Suppressor Cells in Non-small Cell Lung Cancer / 中国肺癌杂志

Granulocytic myeloid-derived suppressor cells (G-MDSCs) are one of the main subgroups of MDSCs, which are widely enriched in most cancers. It can inhibit the killing function of T-lymphocyte through the expression of arginase-1 (Arg-1) and reactive oxygen species (ROS), reshape the tumor immune microenvironment, and promote the occurrence and development of tumors. In recent years, more and more studies have found that G-MDSCs are significantly correlated with the prognosis and immunotherapy efficacy of patients with non-small cell lung cancer, and the use of drugs specifically targeting the recruitment, differentiation and function of G-MDSCs can effectively inhibit tumor progression. This article reviews the immunosuppressive effect of G-MDSCs in non-small cell lung cancer and the progress of related pathway targeting drugs.
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Research progress on mitochondria regulating anti-tumor immunity / 浙江大学学报·医学版

Tumor cells adaptively reforge their metabolism to meet the demands of energy and biosynthesis. Mitochondria, pivotal organelles in the metabolic reprogramming of tumor cells, contribute to tumorigenesis and cancer progression significantly through various dysfunctions in both tumor and immune cells. Alterations in mitochondrial dynamics and metabolic signaling pathways exert crucial regulatory influence on the activation, proliferation, and differentiation of immune cells. The tumor microenvironment orchestrates the activation and functionality of tumor-infiltrating immune cells by reprogramming mitochondrial metabolism and inducing shifts in mitochondrial dynamics, thereby facilitating the establishment of a tumor immunosuppressive microenvironment. Stress-induced leakage of mitochondrial DNA contributes multifaceted regulatory effects on anti-tumor immune responses and the immunosuppressive microenvironment by activating multiple natural immune signals, including cGAS-STING, TLR9, and NLRP3. Moreover, mitochondrial DNA-mediated immunogenic cell death emerges as a promising avenue for anti-tumor immunotherapy. Additionally, mtROS, a crucial factor in tumorigenesis, drives the formation of tumor immunosuppressive microenvironment by changing the composition of immune cells within the tumor microenvironment. This review focuses on the intrinsic relationship between mitochondrial biology and anti-tumor immune responses from multiple angles. We expect to explore the core role of mitochondria in the dynamic interplay between the tumor and the host, in order to facilitate the development of targeted mitochondrial strategies for anti-tumor immunotherapy.

Cell-to-Cell Communications of cGAS-STING Pathway in Tumor Immune Microenvironment / 浙江大学学报·医学版

Targeting cGAS-STING pathway is a promising strategy in tumor treatment. The pattern recognition receptor cGAS identifies dsDNA and catalyzes the formation of the second messenger 2'3'-cGAMP, activating the downstream interferons and pro-inflammatory cytokines through the adaptor protein STING. Notably, in tumor immune microenvironment, key components of cGAS-STING pathway are transferred among neighboring cells. The intercellular transmission under these contexts serves to sustain and amplify innate immune responses while facilitating the emergence of adaptive immunity. The membrane-based system, including extracellular vesicles transport, phagocytosis and membrane fusion transmit dsDNA, cGAMP and activated STING, enhancing the immune surveillance and inflammatory. The membrane proteins, including specific protein channel and intercellular gap junctions, transfer cGAMP and dsDNA, which are crucial to regulate immune responses. And the ligand-receptor interactions for interferons transmission amplifies the anti-tumor response. This review elaborates on the regulatory mechanisms of cell-to-cell communications of cGAS-STING pathway in tumor immune microenvironment. We further explore how these mechanisms modulate immunological processes and discuss potential interventions and immunotherapeutic strategies targeting these signaling cascades.

Research progress on the mechanisms of microglia in retinal angiogenesis / 国际眼科杂志(Guoji Yanke Zazhi)

As resident immune cells of the retina, retinal microglia constantly monitor the changes of their surroundings and maintain homeostasis through signal transduction with other retinal cells. Retinal microglia play a crucial role not only in the development and physiological processes of the retinal vascular system, but also in pathological neovascularization. In certain retinopathies, activated microglia can stimulate abnormal angiogenesis through neurovascular coupling, leading to irreversible damage. However, the exact mechanisms underlying this process are still unclear. In this review, a brief overview of the relationship between microglia and retinal neovascularization was provided, and the involved cellular and molecular signaling mechanisms were reviewed, aiming to offer new and effective strategies for the prevention and treatment of retinal neovascularization diseases.

The role of glucose metabolism reprogramming and its targeted therapeutic agents in inflammation-related diseases / 药学学报

Cells undergo glucose metabolism reprogramming under the influence of the inflammatory microenvironment, changing their primary mode of energy supply from oxidative phosphorylation to aerobic glycolysis. This process is involved in all stages of inflammation-related diseases development. Glucose metabolism reprogramming not only changes the metabolic pattern of individual cells, but also disrupts the metabolic homeostasis of the body microenvironment, which further promotes aerobic glycolysis and provides favourable conditions for the malignant progression of inflammation-related diseases. The metabolic enzymes, transporter proteins, and metabolites of aerobic glycolysis are all key signalling molecules, and drugs can inhibit aerobic glycolysis by targeting these specific key molecules to exert therapeutic effects. This paper reviews the impact of glucose metabolism reprogramming on the development of inflammation-related diseases such as inflammation-related tumours, rheumatoid arthritis and Alzheimer's disease, and the therapeutic effects of drugs targeting glucose metabolism reprogramming on these diseases.

Role of the Hedgehog signaling pathway in hepatocellular carcinoma and its tumor microenvironment / 临床肝胆病杂志

The Hedgehog （Hh） signaling pathway plays an important role in the development and progression of hepatocellular carcinoma and its tumor microenvironment， and abnormal activation of Hh signal can accelerate the growth of tumor. The crosstalk between the Hh signaling pathway and TME is closely associated with tumor growth and the formation of inhibitory tumor microenvironment. Evidence shows that inhibition of Hh signal plays an important role in inhibiting the growth of hepatocellular carcinoma. This article reviews the current research status of the role， mechanism， and potential therapeutic significance of abnormal activation of Hh signal in hepatocellular carcinoma and its tumor microenvironment， so as to provide new ideas for the treatment of hepatocellular carcinoma.

Effects of hypoxia-inducible factors on tumor mesenchymal cells: a review / 预防医学

@#Hypoxia is the most common tumor microenvironment caused by rapid proliferation of tumor cells, and hypoxia-inducible factor (HIF) is the main transcription factor for tumor cells to adapt to hypoxia. Current research has found that HIF can interact with a variety of mesenchymal cells such as fibroblasts, endothelial cells and immune cells in the tumor microenvironment, leading to the transcription and expression of target genes in response to hypoxia, which ultimately promotes tumor angiogenesis, and induces physiological changes such as migration, invasion, and immune escape of tumor cells. However, the signaling pathways involved in the HIF regulatory mechanism are complex, and the mechanism of HIF in the tumor microenvironment need to be further investigated, also most HIF inhibitors are still in the preclinical research stage. This paper reviews the research progress on the effects of HIF on tumor mesenchymal stromal cells to provide a theoretical basis for the diagnosis, prevention and treatment of tumors targeting HIF.

Treatment Strategy and Research Progress of Immune Microenvironment for Liver Metastasis of Non-small Cell Lung Cancer / 肿瘤防治研究

Liver is the common site for metastasis and spread of non-small cell lung cancer (NSCLC). Lung cancer patients with liver metastasis have poor prognosis, which may be related to liver-specific microenvironment composition. The metastasis of lung cancer to the liver is regulated by various pathophysiological factors, including the liver immune microenvironment, related cells, proteins, signaling molecules, and gene changes. These factors will affect the consistent disease process and subsequent treatment strategies. Immune checkpoint inhibitors (ICIs) have made breakthroughs in treatment of patients with advanced NSCLC. However, NSCLC patients with liver metastasis, a unique population of advanced lung cancer, are characterized by poor immunotherapeutic effect. This paper reviews the related mechanisms of the immune microenvironment in affecting the occurrence and development of liver metastases and summarizes the achievements and prospects of anti-tumor immunotherapy in liver metastases of NSCLC.

Investigating the effect and mechanism of Sophorae Flavescentis Radix and Rhizoma Smilacis Glabrae combination in ameliorating psoriatic lesions / 中国药理学通报

Aim In this study, a mouse model of psoriasis-like lesions induced by 62. 5 mg imiquimod was used to explore the effect and mechanism of Sophorae Flavescentis Radix and Rhizoma Smilacis Glabrae combination for the topical treatment of psoriasis. Methods Firstly, the topical administration of Sophorae Flavescentis Radix and Rhizoma Smilacis Glabrae combination for treating psoriasis in progressive and recurrent stages was evaluated by psoriatic mouse model and HE staining. Secondly, immunohistochemistry was used to study the regulatory effects of Sophorae Flavescentis Radix and Rhizoma Smilacis Glabrae combination on the pivotal pathological mechanism of psoriasis-the positive feedback loop between the abnormal proliferation of keratinocytes and skin immune microenvironment. Finally, metabolomics technology was used to explore whether Sophorae Flavescentis Radix and Rhizoma Smilacis Glabrae combination topically treat psoriasis by regulating inflammation-related metabolism and lipid metabolism pathways. Results The combination of Sophorae Flavescentis Radix and Rhizoma Smilacis Glabrae alleviated psoriasis-like lesions in mice. It effectively relieved the recurrence after the cure of psoriatic lesions in mice, and the efficacy is comparable to that of benweimod. The combination of Sophorae Flavescentis Radix and Rhizoma Smilacis Glabrae inhibited the proliferation of mouse epidermal keratinocytes and reduced the number of T cells in the skin. The potential molecular mechanism was that the combination of Sophorae Flavescentis Radix and Rhizoma Smilacis Glabrae regulated arachidonic acid metabolism, sphin- golipid metabolism, tryptophan metabolism and phenylalanine metabolism. Conclusions The combination of Sophora Flavescens Radix and Rhizoma Smilacis Glabrae can relieve psoriasis-like lesions in mice by inhibiting the proliferation of epidermal keratinocytes and reducing the number of T cells in the skin and regulating metabolism to intervene psoriasis recurrence. This study provides a potential topical drug of psoriasis for relieving psoriasis recurrence.

Ideas and methods of in vitro model establishment for cell microenvironment in COPD / 中国药理学通报

Chronic obstructive pulmonary disease ( COPD ) major chronic disease threatening public health with complex pathological mechanisms. The change of the cell microenvironment of the lung is an important part of the pathophysiology of COPD. Cell culture technology is an important method to investigate the pathological mechanism of COPD and evaluate the pharmacological effect of medicine. Here we introduce the composition of the cell microenvironment of the lung, the change of the cell microenvironment in the pathological process of COPD, and summarize the application of in vitro model mimics cell microenvironment of COPD in the study of mechanism. In addition, we aim to put forward the ideas of the in vitro model establishment of cell microenvironment of COPD.

Anti-cancer Effect of Traditional Chinese Medicine in Regulating Cellular Senescence： A Review / 中国实验方剂学杂志

In recent years， the incidence and mortality rates of cancer have been increasing， posing a serious threat to human health. Western medicine mainly uses treatments such as surgical resection， chemotherapy， immunotherapy and targeted therapy， but they are prone to complications， drug resistance and adverse reactions. A growing number of studies have shown that traditional Chinese medicine has obvious advantages in the treatment of cancer， reducing the recurrence rate of cancer and improving the quality of survival of patients. Cellular senescence refers to a state of irreversible cell cycle growth arrest when cells cease to proliferate after a limited number of divisions， resulting in a decline in cell proliferation and differentiation capacities and physiological functions， accompanied by morphological changes such as flattening and multinuclear morphology. At the molecular level， it shows increased expression of DNA damage-related genes， reduced expression of cell cycle-related factors and significant secretory activity. The malignant development of cancer is closely related to cellular senescence. With the increasing number of cancer cell proliferation， cancer-related genes undergo continuous mutations， freeing them from cellular senescence and thus achieving unlimited proliferation. Through recent studies， it has been found that induction of tumor cell senescence， possibly through modulation of cellular DNA damage， cell cycle arrest and senescence-associated secretory phenotype （SASP）， which converts the suppressive immune tumor microenvironment to an activated immune tumor microenvironment and thus reverses the escape of tumor cell senescence， is a promising strategy for cancer therapy. However， the mechanism of cellular senescence in cancer progression is not fully understood， especially the anti-cancer role played by traditional Chinese medicine in regulating cellular senescence. This article summarized and concluded the specific molecular mechanisms of cellular senescence， the role of cellular senescence in cancer progression， and the mechanism of anti-cancer effects of traditional Chinese medicine based on cellular senescence from the perspective of regulating cellular senescence， with a view to providing ideas and methods for the anti-cancer effects of traditional Chinese medicine and the development of new drugs.

Dual-responsive supramolecular photodynamic nanomedicine with activatable immunomodulation for enhanced antitumor therapy

A major challenge facing photodynamic therapy (PDT) is that the activity of the immune-induced infiltrating CD8+ T cells is subject to the regulatory T lymphocytes (Tregs), leaving the tumor at risk of recurrence and metastasis after the initial ablation. To augment the antitumor response and reprogram the immunosuppressive tumor microenvironment (TME), a supramolecular photodynamic nanoparticle (DACss) is constructed by the host-guest interaction between demethylcantharidin-conjugated β-cyclodextrin (DMC-CD) and amantadine-terminated disulfide-conjugated FFVLGGGC peptide with chlorin e6 decoration (Ad-ss-pep-Ce6) to achieve intelligent delivery of photosensitizer and immunomodulator for breast cancer treatment. The acid-labile β-carboxamide bond of DMC-CD is hydrolyzed in response to the acidic TME, resulting in the localized release of DMC and subsequent inhibition of Tregs. The guest molecule Ad-ss-pep-Ce6 can be cleaved by a high level of intracellular GSH, reducing photosensitizer toxicity and increasing photosensitizer retention in the tumor. With a significant increase in the CTL/Treg ratio, the combination of Ce6-based PDT and DMC-mediated immunomodulation adequately achieved spatiotemporal regulation and remodeling of the TME, as well as improved primary tumor and in situ lung metastasis suppression with the aid of PD-1 antibody.

Immunostimulatory gene therapy combined with checkpoint blockade reshapes tumor microenvironment and enhances ovarian cancer immunotherapy

Immune evasion has made ovarian cancer notorious for its refractory features, making the development of immunotherapy highly appealing to ovarian cancer treatment. The immune-stimulating cytokine IL-12 exhibits excellent antitumor activities. However, IL-12 can induce IFN-γ release and subsequently upregulate PDL-1 expression on tumor cells. Therefore, the tumor-targeting folate-modified delivery system F-DPC is constructed for concurrent delivery of IL-12 encoding gene and small molecular PDL-1 inhibitor (iPDL-1) to reduce immune escape and boost anti-tumor immunity. The physicochemical characteristics, gene transfection efficiency of the F-DPC nanoparticles in ovarian cancer cells are analyzed. The immune-modulation effects of combination therapy on different immune cells are also studied. Results show that compared with non-folate-modified vector, folate-modified F-DPC can improve the targeting of ovarian cancer and enhance the transfection efficiency of pIL-12. The underlying anti-tumor mechanisms include the regulation of T cells proliferation and activation, NK activation, macrophage polarization and DC maturation. The F-DPC/pIL-12/iPDL-1 complexes have shown outstanding antitumor effects and low toxicity in peritoneal model of ovarian cancer in mice. Taken together, our work provides new insights into ovarian cancer immunotherapy. Novel F-DPC/pIL-12/iPDL-1 complexes are revealed to exert prominent anti-tumor effect by modulating tumor immune microenvironment and preventing immune escape and might be a promising treatment option for ovarian cancer treatment.

Self-sufficient nanoparticles with dual-enzyme activity trigger radical storms and activate cascade-amplified antitumor immunologic responses

Radiotherapy (RT) can potentially induce systemic immune responses by initiating immunogenic cell death (ICD) of tumor cells. However, RT-induced antitumor immunologic responses are sporadic and insufficient against cancer metastases. Herein, we construct multifunctional self-sufficient nanoparticles (MARS) with dual-enzyme activity (GOx and peroxidase-like) to trigger radical storms and activate the cascade-amplified systemic immune responses to suppress both local tumors and metastatic relapse. In addition to limiting the Warburg effect to actualize starvation therapy, MARS catalyzes glucose to produce hydrogen peroxide (H2O2), which is then used in the Cu+-mediated Fenton-like reaction and RT sensitization. RT and chemodynamic therapy produce reactive oxygen species in the form of radical storms, which have a robust ICD impact on mobilizing the immune system. Thus, when MARS is combined with RT, potent systemic antitumor immunity can be generated by activating antigen-presenting cells, promoting dendritic cells maturation, increasing the infiltration of cytotoxic T lymphocytes, and reprogramming the immunosuppressive tumor microenvironment. Furthermore, the synergistic therapy of RT and MARS effectively suppresses local tumor growth, increases mouse longevity, and results in a 90% reduction in lung metastasis and postoperative recurrence. Overall, we provide a viable approach to treating cancer by inducing radical storms and activating cascade-amplified systemic immunity.

Elastin remodeling: Does it play a role in priming the malignant phenotype of oral mucosa?

Background: The extracellular matrix (ECM) is a dynamic tissue that provides nutrition and support to overlying epithelium. During tumorigenesis, the tumor microenvironment (TME) dysregulates the ECM. This is reflected by morphological changes seen in collagen and elastic fibers and is thought to facilitate metastasis. Aim: To study the degradation of elastic fibers in different grades of oral squamous cell carcinoma (OSCC) and in oral epithelial dysplasia (OED) using histochemistry and to correlate it to the TNM stage of OSCC. Materials and Methods: Tumor cores from 38 cases of OSCC (well-differentiated[15], moderately differentiated[14], and poorly differentiated[9]) and 15 incisional biopsies of OED were analyzed. Hematoxylin-eosin and Verhoeff's–Van Gieson (VVG) stains were used. The stained sections were assessed for morphological changes in elastic fibers. Statistical Analysis: Data were analyzed using Statistical Package for Social Sciences (SPSS) version 22 software. Fisher's exact, Kruskal–Wallis, one-way ANOVA, and Turkey post hoc tests were used to establish significance (P ? 0.05). Spearman's correlation test was used to correlate elastin fiber degradation with TNM stage of OSCC. Results: All grades of OSCC showed absence of elastic fibers around the tumor islands. Elastic fiber degradation (fragmented and clumped type fibers) increased proportionately with the grade and TNM stage of OSCC. In OED, A significant reduction in the amount of elastic fibers with increasing grade was noted. Conclusion: A positive correlation was noted between elastin degradation and grade and stage of OSCC. Therefore, it may be implicated in tumor progression of OSCC.

Expression of cytotoxic T lymphocyte-associated antigen 4, CD44, and E-cadherin in the microenvironment of breast carcinomas

SUMMARY OBJECTIVE: The expression of cytotoxic T lymphocyte-associated antigen 4, E-cadherin, and CD44 in the area of tumor budding was investigated in breast carcinomas in our study. METHODS: Tumor budding was counted at the invasive margins in 179 breast carcinomas. To understand the microenvironment of tumor budding, we examined the expression status of the immune checkpoint molecules such as cytotoxic T lymphocyte-associated antigen 4, E-cadherin, and CD44. RESULTS: Tumors were separated into low (≤5) and high tumor budding groups (>5) based on the median budding number. Lymphovascular, perineural invasion, and the number of metastatic lymph nodes were significantly higher in high-grade budding tumors (p=0.001, p<0.001, and p=0.019, respectively). Tumor-infiltrating lymphocytes were significantly higher in tumors without tumor buddings (p<0.001). When the number of budding increases by one unit, overall survival decreases by 1.07 times (p=0.013). Also, it increases the risk of progression by 1.06 times (p=0.048). In high tumor budding groups, the cytotoxic T lymphocyte-associated antigen 4 staining percentage of lymphocytes was significantly higher (p=0.026). With each increase in the number of buds, an increase in the percentage of cytotoxic T lymphocyte-associated antigen 4 staining was seen in lymphocytes in the microenvironment of TB (p=0.034). CONCLUSION: Tumor budding could predict poor prognosis in breast carcinomas, and anti-cytotoxic T lymphocyte-associated antigen 4 immunotherapies may be beneficial in patients with high tumor budding tumors.

Avaliação dos efeitos modulatórios da hematopoese no envelhecimento: Papel das células tronco mesenquimais medulares / Evaluation of the modulatory effects of hematopoiesis during aging: Role of bone marrow mesenchymal stem cells

O envelhecimento é um processo fisiológico que traz consigo uma série de alterações no organismo que se estendem até o nível molecular. Diante disto, este é um processo complexo que afeta diversos tecidos, sendo um deles o hematopoético, local onde, através de interações da Célula Tronco Hematopoética (CTH) com o ambiente ao seu redor, incluindo a Célula Tronco Mesenquimal (CTM), ocorre a hematopoese. Embora já sejam descritas na literatura algumas alterações na medula óssea consequentes do envelhecimento, os mecanismos por trás de tais mudanças permanecem elusivas, principalmente no âmbito das interações celulares ocorrentes na medula óssea. Portanto, este trabalho buscou investigar como o envelhecimento afeta a regulação hematopoética no contexto de sua relação com as CTM medulares. Para esta pesquisa, foram utilizados camundongos machos isogênicos da linhagem C57BL/6, dividindoos em grupos conforme sua idade: jovens (3 ­ 5 meses) e idosos (18 ­ 19 meses). Foi realizada a caracterização do modelo através de aspectos físicos como consumo proteico, variação de peso, entre outros, seguido de avaliação bioquímica e hematológica. Adicionalmente, foram coletadas células medulares e, posteriormente, realizado o isolamento das CTMs. Para estudar a relação destas células com a hematopoese, foram realizados ensaios in vitro utilizando a linhagem celular leucêmica C1498 (TIB-49™, ATCC®) mantidas em contato com o sobrenadante das CTMs isoladas. Quanto aos parâmetros bioquímicos, os animais idosos apresentaram menores níveis de albumina, aspartato alanina transferase (ALT) e de triglicerídeos quando comparados aos animais jovens. Contrariamente, os animais idosos apresentaram um maior nível de colesterol. Na avaliação hematológica, foi constatado pelo hemograma que os animais idosos apresentaram valores comparáveis aos animais jovens, todavia, o mielograma mostrou menor celularidade geral, seguido de menor número de células da linhagem eritroide e maior número de precursores granulocíticos. Através da imunofenotipagem, foi revelado um maior número de CTHs e de precursores grânulosmonocíticos na medula de animais idosos quando comparado aos jovens, e uma menor frequência de progenitores linfoides. Na imunofenotipagem de sangue periférico de animais idosos houve uma redução no número de linfócitos B e de eritrócitos, e aumento na população de células natural killers. Na imunofenotipagem de CTMs, o marcador CD73 apresentou menor expressão nos animais idosos. Avaliando o secretoma destas células estromais, foram encontrados no sobrenadante de CTMs de animais idosos aumentos significativos nas concentrações de CXCL12 e SCF e redução de IL-11. No âmbito molecular, as CTMs de animais idosos apresentaram aumento na expressão de Akt1, Nos e Ppar-γ, e redução na expressão de Csf3 e Cdh2. Adicionalmente, quando comparado a ação das CTMs de animais idosos em relação as CTMs de animais jovens, observou-se que CTMs de animais idosos foram capazes de aumentar a expressão de Sox2, Pou5f1 e Nanog e diminuir a expressão de Cdkn1a de células da linhagem C1498. O sobrenadante de CTMs de animais idosos também resultou na maior proliferação e migração de células da linhagem C1498. Portanto, levando em consideração a importância das CTMs sobre a regulação do sistema hematopoético, pode-se concluir que, no envelhecimento, as CTMs criam um ambiente propício para a proliferação celular no qual a manutenção da pluripotência é estimulada, o que pode acarretar em uma desregulação do sítio hematopoético quando habitado por células malignas

Aging is a physiological process in which occurs a series of alterations in an organism that extend to a molecular level. It is a complex process that affects various tissues, one of them being the bone marrow, wherethrough the interactions of the hematopoietic stem cell (CTH) with its surrounding environment, including with the mesenchymal stem cell (CTM), hematopoiesis takes place. Although some aging-associated alterations in the bone marrow can be found described in the literature, the mechanisms behind said changes remain elusive, especially when regarding the cellular interactions present inside the bone marrow. Therefore, this research aimed to investigate how aging affects the regulation of hematopoiesis in the context of its interactions with bone marrow-derived CTMs. For this investigation, male isogenic C57BL/6 mice were used as animal models. These were separated in two groups according to their age: young (3 ­ 5 months) and aged (18 ­ 19 months). The animal models were characterized by their physical properties such as protein intake and weight variation, followed by biochemical and hematological evaluation. Bone marrow cells were obtained and identified through immunophenotyping, thus isolating different cell populations, including the CTMs. To study the relationship between these cells and hematopoiesis, in vitro assays were conducted utilizing the leukemic cell lineage C1498 (TIB-49™, ATCC®) maintained in contact with the supernatant of isolated CTMs. By their biochemical profile, aged mice showed lower levels of albumin, alanine-aspartate transferase (ALT) and triglycerides compared to the young group. In contrast, aged mice had a higher cholesterol level. Hematological evaluation by total blood count showed similar results between the two groups, however, the myelogram revealed that the aged animals had lower cellularity, with less frequent cells from the erythroid lineage, with an increase in granulocytic precursors. Through immunophenotyping, it was also revealed that aged mice have higher numbers of hematopoietic stem cells, while also being noted a reduced population of lymphoid progenitors. An increase in the granulomonocytic progenitors was also found. Immunophenotyping peripheral blood cells of aged mice revealed reduced numbers of B lymphocytes and erythrocytes, and an increased natural killer cell population. Additionally, the cell surface marker CD73 was found to be less expressed in aged mice CTMs. The secretome of these stromal cells obtained from aged mice showed higher levels of CXCL12 and SCF, and lower levels of IL-11when compared to the young counterparts. At a molecular level, CTMs obtained from aged mice expressed more Akt1, Nos and Ppar-γ, while the expression of Csf3 and Cdh2 was reduced. Additionally, when comparing the effects of aged mice CTMs with young mice CTMs, it was observed that the first expressed were capable of increasing the expression of Sox2, Pou5f1 and Nanog, while decreasing Cdkn1a expression in the C1498 cell lineage. The supernatant obtained from aged mice also favored the proliferation and cell migration of the C1498 cell line. Thus, considering the importance that CTMs have over the hematopoietic system, we can conclude that, in aging, CTMs create a special environment which favors cell proliferation and maintenance of pluripotency, which can result in a dysregulation of the hematopoietic tissue when malignant cells are present