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This article defines immunophenotypes of stromal inflammatory and endothelial cells and fibroblasts 3 months after augmentation of the peri-implant soft tissue using a porcine cross-linked collagen matrix (VCMX). Peri-implant soft tissue samples were obtained from 12 patients at the lining mucosa (LM)-masticatory mucosa (MM) junction before (1) and 3 months after (2) augmentation. Immu-nohistochemical stains were performed to identify inflammatory cells (T [CD3] and B [CD20] lymphocytes, plasma cells [CD138]), macrophages (CD68-proinflammatory, CD163-anti-inflammatory/ reparative), endothelial cells (CD31, CD34), and fibroblasts (CD90, TE-7). Differences in the mean positively stained cells pre- and postaugmentation were analyzed by Wilcoxon signed-rank test. CD31+ endothelial cells showed increased mean numbers in MM2 compared to MM1 (P = .025) and in LM2 compared to LM1 (P = .047). CD163+ anti-inflammatory macrophages showed higher mean numbers in MM2 than in MM1 (P = .021) and in LM2 than in LM1 (P = .012). All other cell phenotypes showed nonsignificant changes between pre- and postaugmentation. This molecular study provides novel insight on the frequency of stromal cell phenotypes in the wound healing process at 3 months postaugmentation with VCMX, with anti-inflammatory CD163+ macrophages being predominant. This should be further investigated to help find novel therapeutic approaches to modulate and promote the VCMX-related healing process. [ABSTRACT FROM AUTHOR]

The progression and malignancy of many tumors are associated with increased tissue stiffness. Conversely, the oncogenically transformed cells can be confined in soft stroma. Yet, the underlying mechanisms by which soft matrix confines tumorigenesis and metastasis remain elusive. Here, we show that pancreatic cancer cells are suppressed in the soft extracellular matrix, which is associated with YAP1 degradation through autophagic-lysosomal pathway rather than Hippo signal mediated proteasome pathway. In the soft stroma, PTEN is upregulated and activated, which consequently promotes lysosomal biogenesis, leading to the activation of cysteine-cathepsins for YAP1 degradation. In vitro, purified cathepsin L can directly digest YAP1 under acidic conditions. Lysosomal stress, either caused by chloroquine or overexpression of cystatin A/B, results in YAP1 accumulation and malignant transformation. Likewise, liver fibrosis induced stiffness can promote malignant potential in mice. Clinical data show that down-regulation of lysosomal biogenesis is associated with pancreatic fibrosis and stiffness, YAP1 accumulation, and poor prognosis in PDAC patients. Together, our findings suggest that soft stroma triggers lysosomal flux-mediated YAP1 degradation and induces cancer cell dormancy.

This article focuses on screening the major secreted proteins by the ischemia-challenged cardiac stromal fibroblasts (CF), the assessment of their expression status and functional role in the post-ischemic left ventricle (LV) and in the ischemia-challenged CF culture and to phenotype CF at single cell resolution based on the positivity of the identified mediators. The expression level of CRSP2, HSP27, IL-8, Cofilin-1, and HSP90 in the LV tissues following coronary artery bypass graft (CABG) and myocardial infarction (MI) and CF cells followed the screening profile derived from the MS/MS findings. The histology data unveiled ECM disorganization, inflammation and fibrosis reflecting the ischemic pathology. CRSP2, HSP27, and HSP90 were significantly upregulated in the LV-CABG tissues with a concomitant reduction ion LV-MI whereas Cofilin-1, IL8, Nrf2, and Troponin I were downregulated in LV-CABG and increased in LV-MI. Similar trends were exhibited by ischemic CF. Single cell transcriptomics revealed multiple sub-phenotypes of CF based on their respective upregulation of CRSP2, HSP27, IL-8, Cofilin-1, HSP90, Troponin I and Nrf2 unveiling pathological and pro-healing phenotypes. Further investigations regarding the underlying signaling mechanisms and validation of sub-populations would offer novel translational avenues for the management of cardiac diseases.

Brain metastatic breast cancer is particularly lethal largely due to therapeutic resistance. Almost half of the patients with metastatic HER2-positive breast cancer develop brain metastases, representing a major clinical challenge. We previously described that cancer-associated fibroblasts are an important source of resistance in primary tumors. Here, we report that breast cancer brain metastasis stromal cell interactions in 3D cocultures induce therapeutic resistance to HER2-targeting agents, particularly to the small molecule inhibitor of HER2/EGFR neratinib. We investigated the underlying mechanisms using a synthetic Notch reporter system enabling the sorting of cancer cells that directly interact with stromal cells. We identified mucins and bulky glycoprotein synthesis as top-up-regulated genes and pathways by comparing the gene expression and chromatin profiles of stroma-contact and no-contact cancer cells before and after neratinib treatment. Glycoprotein gene signatures were also enriched in human brain metastases compared to primary tumors. We confirmed increased glycocalyx surrounding cocultures by immunofluorescence and showed that mucinase treatment increased sensitivity to neratinib by enabling a more efficient inhibition of EGFR/HER2 signaling in cancer cells. Overexpression of truncated MUC1 lacking the intracellular domain as a model of increased glycocalyx-induced resistance to neratinib both in cell culture and in experimental brain metastases in immunodeficient mice. Our results highlight the importance of glycoproteins as a resistance mechanism to HER2-targeting therapies in breast cancer brain metastases.

BACKGROUND: Colitis caused by checkpoint inhibitors (CPI) is frequent and is treated with empiric steroids, but CPI colitis mechanisms in steroid-experienced or refractory disease are unclear. METHODS: Using colon biopsies and blood from predominantly steroid-experienced CPI colitis patients, we performed multiplexed single-cell transcriptomics and proteomics to nominate contributing populations. RESULTS: CPI colitis biopsies showed enrichment of CD4+resident memory (RM) T cells in addition to CD8+ RM and cytotoxic CD8+ T cells. Matching T cell receptor (TCR) clonotypes suggested that both RMs are progenitors that yield cytotoxic effectors. Activated, CD38+ HLA-DR+ CD4+ RM and cytotoxic CD8+ T cells were enriched in steroid-experienced and a validation data set of steroid-naïve CPI colitis, underscoring their pathogenic potential across steroid exposure. Distinct from ulcerative colitis, CPI colitis exhibited perturbed stromal metabolism (NAD+, tryptophan) impacting epithelial survival and inflammation. Endothelial cells in CPI colitis after anti-TNF and anti-cytotoxic T-lymphocyte-associated antigen 4 (anti-CTLA-4) upregulated the integrin α4β7 ligand molecular vascular addressin cell adhesion molecule 1 (MAdCAM-1), which may preferentially respond to vedolizumab (anti-α4β7). CONCLUSIONS: These findings nominate CD4+ RM and MAdCAM-1+ endothelial cells for targeting in specific subsets of CPI colitis patients.

BackgroundRecently shown to regulate cardiac development, the secreted axon guidance molecule SLIT3 maintains its expression in the postnatal heart. Despite its known expression in the cardiovascular system after birth, SLIT3's relevance to cardiovascular function in the postnatal state remains unknown. As such, the objectives of this study were to determine the postnatal myocardial sources of SLIT3 and to evaluate its functional role in regulating the cardiac response to pressure overload stress.MethodsWe performed in vitro studies on cardiomyocytes and myocardial tissue samples from patients and performed in vivo investigation with SLIT3 and ROBO1 (roundabout homolog 1) mutant mice undergoing transverse aortic constriction to establish the role of SLIT3-ROBO1 in adverse cardiac remodeling.ResultsWe first found that SLIT3 transcription was increased in myocardial tissue obtained from patients with congenital heart defects that caused ventricular pressure overload. Immunostaining of hearts from WT (wild-type) and reporter mice revealed that SLIT3 is secreted by cardiac stromal cells, namely fibroblasts and vascular mural cells, within the heart. Conditioned media from cardiac fibroblasts and vascular mural cells both stimulated cardiomyocyte hypertrophy in vitro, an effect that was partially inhibited by an anti-SLIT3 antibody. Also, the N-terminal, but not the C-terminal, fragment of SLIT3 and the forced overexpression of SLIT3 stimulated cardiomyocyte hypertrophy and the transcription of hypertrophy-related genes. We next determined that ROBO1 was the most highly expressed roundabout receptor in cardiomyocytes and that ROBO1 mediated SLIT3's hypertrophic effects in vitro. In vivo, Tcf21+ fibroblast and Tbx18+ vascular mural cell-specific knockout of SLIT3 in mice resulted in decreased left ventricular hypertrophy and cardiac fibrosis after transverse aortic constriction. Furthermore, α-MHC+ cardiomyocyte-specific deletion of ROBO1 also preserved left ventricular function and abrogated hypertrophy, but not fibrosis, after transverse aortic constriction.ConclusionsCollectively, these results indicate a novel role for the SLIT3-ROBO1-signaling axis in regulating postnatal cardiomyocyte hypertrophy induced by pressure overload.

Peripheral artery disease is an atherosclerotic disease associated with limb ischemia that necessitates limb amputation in severe cases. Cell therapies comprised of adult mononuclear or stromal cells have been clinically tested and show moderate benefits. Bioengineering strategies can be applied to modify cell behavior and function in a controllable fashion. Using mechanically tunable or spatially controllable biomaterials, we highlight examples in which biomaterials can increase the survival and function of the transplanted cells to improve their revascularization efficacy in preclinical models. Biomaterials can be used in conjunction with soluble factors or genetic approaches to further modulate the behavior of transplanted cells and the locally implanted tissue environment in vivo. We critically assess the advances in bioengineering strategies such as 3-dimensional bioprinting and immunomodulatory biomaterials that can be applied to the treatment of peripheral artery disease and then discuss the current challenges and future directions in the implementation of bioengineering strategies.

We previously demonstrated that Alcaligenes-derived lipid A (ALA), which is produced from an intestinal lymphoid tissue-resident commensal bacterium, is an effective adjuvant for inducing antigen-specific immune responses. To understand the immunologic characteristics of ALA as a vaccine adjuvant, we here compared the adjuvant activity of ALA with that of a licensed adjuvant (monophosphoryl lipid A, MPLA) in mice. Although the adjuvant activity of ALA was only slightly greater than that of MPLA for subcutaneous immunization, ALA induced significantly greater IgA antibody production than did MPLA during nasal immunization. Regarding the underlying mechanism, ALA increased and activated CD11b+ CD103- CD11c+ dendritic cells in the nasal tissue by stimulating chemokine responses. These findings revealed the superiority of ALA as a mucosal adjuvant due to the unique immunologic functions of ALA in nasal tissue.

Triple-negative breast cancer (TNBC) is highly aggressive with limited available treatments. Stromal cells in the tumor microenvironment (TME) are crucial in TNBC progression; however, understanding the molecular basis of stromal cell activation and tumor-stromal crosstalk in TNBC is limited. To investigate therapeutic targets in the TNBC stromal niche, we used an advanced human in vitro microphysiological system called the vascularized micro-tumor (VMT). Using single-cell RNA sequencing, we revealed that normal breast tissue stromal cells activate neoplastic signaling pathways in the TNBC TME. By comparing interactions in VMTs with clinical data, we identified therapeutic targets at the tumor-stromal interface with potential clinical significance. Combining treatments targeting Tie2 signaling with paclitaxel resulted in vessel normalization and increased efficacy of paclitaxel in the TNBC VMT. Dual inhibition of HER3 and Akt also showed efficacy against TNBC. These data demonstrate the potential of inducing a favorable TME as a targeted therapeutic approach in TNBC.

Background: Standard approaches to the treatment of chronic post-radiation proctitis are associated with a high risk of complications and a high percentage of unsatisfactory results due to the reduced regenerative potential of irradiated tissues. Regenerative surgery techniques using the stromal-vascular cell fraction (SVF) based on the patient's autologous adipose tissue are a promising direction for study. Clinical case description: A 76-year-old patient suffering from chronic post-radiation erosive-ulcerative proctitis, grade 4 according to RTOG–EORTC, complicated by recurrent profuse rectal bleeding, underwent local autotransplantation of SVF into the submucosal layer of the rectum and pararectal connective tissue. The follow-up colonoscopies 1 and 6 months after the surgery and histological examination showed the complete epithelialization of ulcerative defects and a decrease in proctitis activity. There were no bleeding episodes during the 12-month postoperative observation period. Conclusion: The proangiogenic, wound-healing, and anti-apoptotic effects of the SVF cell suspension provided reduction of inflammation activity, epithelialization of ulcers, and elimination of defecation-associated hemorrhage, following the SVF injection into the submucosal layer of the rectal wall and pararectal connective tissue in a patient with post-radiation proctitis with ulcers and recurrent bleeding. [ABSTRACT FROM AUTHOR]

Background: Acute myeloid leukemia (AML) is a rapidly progressing blood cancer. The prognosis of AML can be challenging, emphasizing the need for ongoing research and innovative approaches to improve outcomes in individuals affected by this formidable hematologic malignancy. Methods: In this study, we used single-cell RNA sequencing (scRNA-seq) from AML patients to investigate the impact of L-glutamine metabolism-related genes on disease progression. Results: Our analysis revealed increased glutamine-related activity in CD34 + pre-B cells, suggesting a potential regulatory role in tumorigenesis and AML progression. Furthermore, intercellular communication analysis revealed a significant signaling pathway involving macrophage migration inhibitory factor signaling through CD74 + CD44 within CD34 + pre-B cells, which transmit signals to pre-dendritic cells and monocytes. Ligands for this pathway were predominantly expressed in stromal cells, naïve T cells, and CD34 + pre-B cells. CD74, the pertinent receptor, was predominantly detected in a variety of cellular components, including stromal cells, pre-dendritic cells, plasmacytoid dendritic cells, and hematopoietic progenitors. The study's results provide insights into the possible interplay among these cell types and their collective contribution to the pathogenesis of AML. Moreover, we identified 10 genes associated with AML prognosis, including CCL5, CD52, CFD, FABP5, LGALS1, NUCB2, PSAP, S100A4, SPINK2, and VCAN. Among these, CCL5 and CD52 have been implicated in AML progression and are potential therapeutic targets. Conclusions: This thorough examination of AML biology significantly deepens our grasp of the disease and presents pivotal information that could guide the creation of innovative treatment strategies for AML patients. [ABSTRACT FROM AUTHOR]

Knee meniscus tearing is a common orthopaedic injury that can heal poorly if left untreated, increasing the risk of post‐traumatic Osteoarthritis. Intraarticular injection of human cartilage‐derived progenitor cells (CPCs) has been shown to promote meniscus healing after injury. However, the mechanism by which CPCs stimulated this effect was unclear. The purpose of this study was to determine the paracrine effects that CPC‐derived extracellular vesicles (EVs) have on native meniscal cells during healing. EVs from human CPCs and marrow‐derived stromal cells were isolated via ultracentrifugation. EVs produced by each cell type were quantified, and their sizes were determined via NanoSight. EV protein expression was characterized via western blot. Meniscal fibrochondrocyte cellular metabolic activity (as an indicator of cell viability and proliferation) following treatment with EVs, was quantified using MTT and ATP assays. A 2D wound healing assay was used to determine the effects of treating inner meniscal fibrochondrocytes with EVs in a dose‐dependent manner. Gene expression analysis for chondrogenesis genes was performed via RT‐qPCR on inner meniscal fibrochondrocytes following treatment with EVs. Our results showed that CPCs produced a wide size range of EVs expressing CD9, CD81, and HSP70. Treatment of inner meniscal fibrochondrocytes with CPC‐EVs improved 2D wound healing, in comparison to EVs isolated from marrow‐derived stromal cell controls. CPC‐EV treatment increased Type II Collagen mRNA expression in inner meniscal fibrochondrocytes. These findings demonstrate that CPC‐EVs stimulate chondrogenic matrix production and wound healing in meniscal cells at the optimal dose of 1.0 × 107 particles/mL, significantly outperforming the effects of marrow stromal cell‐derived EVs. [ABSTRACT FROM AUTHOR]

Addressing the complexities and challenges inherent in endometrial biology and regeneration, this study develops a uterus‐mimetic microenvironment to reconstitute the female reproductive system. Leveraging a decellularized uterus extracellular matrix (UEM), this approach supports the development and functions of endometrial organoids (EOs) more effectively than the current gold standard, Matrigel. Extensive proteomic analysis across eight different tissue‐derived matrices reveals that those closely mirroring the protein profile of UEM–especially those abundant in proteins specific to the female reproductive system–more effectively support EO growth. These proteins, particularly fibronectin, and decorin, are identified as key enhancers of EO development, with decorin notably amplifying Wnt7a gene expression, a pathway important for endometrial development. In vivo, UEM demonstrates remarkable efficacy in regenerative applications, notably enhancing epithelial regeneration and increasing pregnancy rates in an endometrium injury model. Moreover, the sophisticated in vitro modeling provided by UEM facilitates effective decidualization of endometrial stromal cells and structural superiority when co‐cultured with EOs, thus offering an enhanced platform for studying blastocyst implantation. Collectively, these findings demonstrate UEM's pivotal role in reconstituting the reproductive system, highlighting its effectiveness in producing organoids that are not only structurally and functionally robust but also therapeutically potent. [ABSTRACT FROM AUTHOR]

Introduction: Distinct androgen formulations have been used as gender-affirming hormone treatment, but little is known about the specific changes that may occur in the ovary depending on the testosterone preparation used. The study aims to evaluate the histological modifications of the ovarian tissue and the hormonal changes after gender-affirming surgery based on the testosterone preparation employed, such as testosterone cypionate or undecanoate. Design: Unicenter transversal cohort study. Materials and methods: Sixty transmasculine persons before and after gender-affirming surgery. A histological examination of the ovaries was conducted, including the follicular population and the characterization of the ovarian stroma. Hormonal status (testosterone, estradiol, FSH, and LH) were also assessed before and after the procedure. Results: The median age of participants was similar between the two groups (27.9 vs. 26.7 years, p = 0.27). There were no differences in all hormonal determinations before gender-affirming surgery between the groups. After surgery, FSH levels increased significantly, especially in the testosterone undecanoate group compared to the cypionate group (72.3 vs. 38.3 U/L, p = 0.02), consistent with LH determinations (43.0 vs. 23.4 U/L, p = 0.02). However, no regimen modification was required for any individual. No statistical differences were observed in any parameter concerning the follicular population, nor were there any variances in the thickness of the tunica albuginea (p = 0.85) or the proportion of luteinized stromal cells. Nevertheless, there was a tendency toward increased luteinization in the testosterone cypionate group (88.2% vs. 76.9%, p > 0.05). Conclusions: In a cohort of transmasculine individuals using different androgen preparations, histological analysis of ovarian tissue revealed comparable findings. Both groups exhibited similar follicular populations and comparable modifications in stromal tissue. However, significant differences were observed in hormonal profiles, although no modification in testosterone dosage was needed. [ABSTRACT FROM AUTHOR]

Background: Acetaminophen (APAP) overdose is a significant cause of drug-induced liver injury (DILI). N-acetylcysteine (NAC) is the first-line agent used in the clinic. However, it rarely benefits patients with advanced APAP toxicity. Mesenchymal stromal cells (MSCs) have demonstrated potential in treating DILI. However, the specific mechanism by which MSCs protect against APAP-induced liver injury remains unclear. Methods: APAP was injected intraperitoneally to induce a liver injury model. We then detected histopathology, biochemical indices, and inflammatory cytokine levels to assess the efficacy of MSCs and MSC extracellular vesicles (MSC-EVs). Flow cytometry was performed to reveal the immunoregulatory effects of MSCs and MSC-EVs on the neutrophils. RNA sequencing (RNA-Seq) of liver tissues was used to identify critical target genes for MSC treatment. Results: MSC and MSC-EV treatment effectively alleviated APAP-induced liver injury and inhibited neutrophil infiltration. RNA-Seq analysis and ELISA data indicated that C-X-C motif chemokine 1 (CXCL1), a chemoattractant for neutrophils, was a key molecule in the MSC-mediated amelioration of APAP-induced liver damage. In addition, neutralization of CXCL1 reduced APAP-induced liver damage, which was accompanied by decreased neutrophil infiltration. Importantly, we verified that MSC-EV-derived miR-186-5p directly binds to the 3'-UTR of Cxcl1 to inhibit its expression in hepatocytes. The agomir miR-186-5p showed excellent potential for the treatment of DILI. Conclusions: Our findings suggest that MSCs and MSC-EVs are an effective approach to mitigate DILI. Targeting the miR-186-5p/CXCL1 axis is a promising approach to improve the efficacy of MSCs and MSC-EVs in the treatment of DILI. [ABSTRACT FROM AUTHOR]

Background:. CD8+ Cytotoxic T lymphocytes play a key role in the pathogenesis of autoimmune diseases and clinical conditions such as graft versus host disease and graft rejection. Mesenchymal Stromal Cells (MSCs) are multipotent cells with tissue repair and immunomodulatory capabilities. Since they are able to suppress multiple pathogenic immune responses, MSCs have been proposed as a cellular therapy for the treatment of immune-mediated diseases. However, the mechanisms underlying their immunosuppressive properties are not yet fully understood. MSCs have the remarkable ability to sense tissue injury and inflammation and respond by donating their own mitochondria to neighboring cells. Whether mitochondrial transfer has any role in the repression of CD8+ responses is unknown. Methods and results:. We have utilized CD8+ T cells from Clone 4 TCR transgenic mice that differentiate into effector cells upon activation in vitro and in vivo to address this question. Allogeneic bone marrow derived MSCs, co-cultured with activated Clone 4 CD8+ T cells, decreased their expansion, the production of the effector cytokine IFNγ and their diabetogenic potential in vivo. Notably, we found that during this interaction leading to suppression, MSCs transferred mitochondria to CD8+ T cells as evidenced by FACS and confocal microscopy. Transfer of MSC mitochondria to Clone 4 CD8+ T cells also resulted in decreased expansion and production of IFNγ upon activation. These effects overlapped and were additive with those of prostaglandin E2 secreted by MSCs. Furthermore, preventing mitochondrial transfer in co-cultures diminished the ability of MSCs to inhibit IFNγ production. Finally, we demonstrated that both MSCs and MSC mitochondria downregulated T-bet and Eomes expression, key transcription factors for CTL differentiation, on activated CD8+ T cells. Conclusion:. In this report we showed that MSCs are able to interact with CD8+ T cells and transfer them their mitochondria. Mitochondrial transfer contributed to the global suppressive effect of MSCs on CD8+ T cell activation by downregulating T-bet and Eomes expression resulting in impaired IFNγ production of activated CD8+ T cells. [ABSTRACT FROM AUTHOR]

Adipose-derived stromal cells (ASCs) and cancer-associated fibroblasts (CAFs) play pivotal roles in the tumor microenvironment (TME), significantly influencing cancer progression and metastasis. This review explores the plasticity of ASCs, which can transdifferentiate into CAFs under the influence of tumor-derived signals, thus enhancing their secretion of extracellular matrix components and pro-inflammatory cytokines that promote tumorigenesis. We discuss the critical process of the epithelial-to-mesenchymal transition (EMT) facilitated by ASCs and CAFs, highlighting its implications for increased invasiveness and therapeutic resistance in cancer cells. Key signaling pathways, including the transforming growth factor-β (TGF-β), Wnt/β-catenin, and Notch, are examined for their roles in regulating EMT and CAF activation. Furthermore, we address the impact of epigenetic modifications on ASC and CAF functionality, emphasizing recent advances in targeting these modifications to inhibit their pro-tumorigenic effects. This review also considers the metabolic reprogramming of ASCs and CAFs, which supports their tumor-promoting activities through enhanced glycolytic activity and lactate production. Finally, we outline potential therapeutic strategies aimed at disrupting the interactions between ASCs, CAFs, and tumor cells, including targeted inhibitors of key signaling pathways and innovative immunotherapy approaches. By understanding the complex roles of ASCs and CAFs within the TME, this review aims to identify new therapeutic opportunities that could improve patient outcomes in cancer treatment. [ABSTRACT FROM AUTHOR]

Acute myeloid leukemia (AML) is a heterogeneous group of hematological malignancies characterized by differentiation arrest, high relapse rates, and poor survival. The bone marrow (BM) microenvironment is recognized as a critical mediator of drug resistance and a primary site responsible for AML relapse. Our previous study reported that 5-aminoimidazole-4-carboxamide ribonucleoside (AICAr) induces AML cell differentiation by inhibiting pyrimidine synthesis and activating Checkpoint kinase 1. Although the protective effect of BM stroma on leukemia cells in response to cytotoxic drugs is well-documented, its effect on AML differentiation remains less explored. In this study, we investigated the impact of stromal cell lines and primary mesenchymal stromal cells (MSCs) on AML cell line differentiation triggered by AICAr and brequinar, a known dihydroorotate dehydrogenase (DHODH) inhibitor. Our findings indicate that the mouse MS-5 stromal cell line, known for its cytoprotective effects, does not inhibit AML cell differentiation induced by pyrimidine synthesis inhibitors. Interestingly, AICAr caused morphological changes and growth arrest in MS-5 stromal cells via an AMP-activated protein kinase (AMPK)-dependent pathway. Human stromal cell lines HS-5 and HS-27, as well as primary MSCs isolated from patient bone marrow, were superior in promoting AML differentiation compared with mouse cells in response to AICAr and brequinar, with the inhibitors not significantly affecting the stromal cells themselves. In conclusion, our study highlights the supportive role of human BM MSCs in enhancing the differentiation effects of pyrimidine synthesis inhibitors on AML cells, suggesting that AML treatment strategies focusing on differentiation rather than cell killing may be successful in clinical settings. NEW & NOTEWORTHY: This study is the first to demonstrate that human stromal cell lines and primary mesenchymal stromal cells from patients enhance the in vitro differentiation of acute myeloid leukemia (AML) cells induced by pyrimidine synthesis inhibitors, 5-aminoimidazole-4-carboxamide ribonucleoside (AICAr), and brequinar. Furthermore, this is the first report to show that AICAr affects mouse bone marrow stromal cells by activating AMP-activated protein kinase (AMPK) and that human stromal cells are superior to mouse cells for testing the effects of drugs on AML differentiation. [ABSTRACT FROM AUTHOR]

Endometriosis is a multifactorial gynecological disease, with angiogenesis as a key hallmark. The role of exosomal microRNAs (miRNAs) in endometriosis is not well understood. This study investigates differentially expressed exosomal miRNAs linked to angiogenesis in endometriosis, clarifies their molecular mechanisms, and identifies potential targets. Primary endometrial stromal cells (ESCs) were cultured, and exosomes were extracted. In a co-culture system, ESC-derived exosomes were taken up by human umbilical vein endothelial cells (HUVECs). Endometriosis implant-ESC-derived exosomes (EI-EXOs) significantly promoted HUVEC proliferation, migration and tube formation compared to normal endometrium-exosomes (NE-EXOs), a finding consistent in vivo in mice. MiRNA sequencing and bioinformatics identified differentially expressed miR-21-5p from EI-EXOs, confirmed by RT-qPCR. The miR-21-5p inhibitor or GW4869 attenuated EI-EXO-induced HUVEC proliferation, migration, and tube formation. TIMP3 overexpression diminished the pro-angiogenic effect of EI-EXOs, which was reversed by adding EI-EXOs or upregulating miR-21-5p. These findings validate the crosstalk between ESCs and HUVECs mediated by exosomal miR-21-5p, and confirm the miR-21-5p-TIMP3 axis in promoting angiogenesis in endometriosis. Key messages: ESC-derived exosomes were found to be taken up by recipient cells, i.e. HUVECs. Functionally, endometriosis implant-ESC-derived exosomes (EI-EXOs) could significantly promote the proliferation, migration and tube formation of HUVECs compared to normal endometrium-exosomes (NE-EXOs). Through miRNA sequencing and bioinformatics analysis, differentially expressed miR-21-5p released by EI-EXOs was chosen, as confirmed by qRT-PCR. miR-21-5p inhibitor or GW4869 was found to attenuate the proliferation, migration, and tube formation of HUVECs induced by EI-EXOs. In turn, TIMP3 overexpression diminished the pro-angiogenic effect of EI-EXOs, and this angiogenic phenotype was reversed once EI-EXOs were added or miR-21-5p was upregulated. [ABSTRACT FROM AUTHOR]

Introduction: In congenital aniridia caused by mutations in paired box 6 (PAX6), PAX6 influences the migration and differentiation of limbal epithelial cells (LECs), thereby playing a pivotal role in aniridia-associated keratopathy. The antidepressants ritanserin and duloxetine affect PAX6 expression in LECs. Limbal stromal cells, which support limbal epithelial stem cells, are crucial in the limbal stem cell niche. This study explores how ritanserin and duloxetine influence gene expression in primary human limbal stromal cells from subjects with congenital aniridia and from healthy subjects, in vitro. Methods: Primary human limbal stromal cells from corneas affected by aniridia (AN-LSCs) (n = 8) and from healthy corneas (LSCs) (n = 8) were isolated and cultured in either low-glucose serum-free (LGSF) or normal-glucose serum-containing (NGSC) media. Cells were treated with 4 µM ritanserin or duloxetine for 24 h. Quantitative PCR (qPCR) and western blot were used to assess the expression of PAX6, FOSL2, TGF-β1, ACTA2A1, LUM, COL1A1, COL5A1, DSG1, FABP5 and ADH7. Results: In AN-LSCs with LGSF-medium, ritanserin increased PAX6 messenger RNA (mRNA) (p = 0.007) and decreased TGF-β1 and FOSL2 mRNA levels (P = 0.005, P = 0.038). In addition, TGF-β1 protein levels decreased with both treatments (P = 0.02, P = 0.007), and FABP5 protein level increased, using ritanserin (P = 0.019). In LSCs with LGSF-medium, ACTA2A1 mRNA levels decreased using ritanserin and duloxetine (P = 0.028; P = 0.031), while FABP5 mRNA levels increased with ritanserin treatment (P = 0.003). Also, duloxetine use reduced α-SMA protein (P = 0.013) and increased FABP5 protein levels (P = 0.029). In LSCs with NGSC-medium, ritanserin elevated LUM, FABP5 and ADH7 mRNA and protein levels (P = 0.025, P = 0.003, P = 0.047, P = 0.024, P = 0.013, P = 0.039). Conclusions: The results of our study confirmed that the antipsychotropic drugs ritanserin and duloxetine alter PAX6 and TGF-β1 gene expression in AN-LSCs cultured in LGSF-medium. These drugs were found to have an impact on retinoic acid signaling pathways and keratocyte characteristic markers both in LSCs and AN-LSCs, using different culture media. [ABSTRACT FROM AUTHOR]

Pulmonary fibrosis, a debilitating lung disorder characterised by excessive fibrous tissue accumulation in lung parenchyma, compromises respiratory function leading to a life‐threatening respiratory failure. While its origins are multifaceted and poorly understood, the urokinase system, including urokinase‐type plasminogen activator (uPA) and its receptor (uPAR), plays a significant role in regulating fibrotic response, extracellular matrix remodelling, and tissue repair. Mesenchymal stem/stromal cells (MSCs) hold promise in regenerative medicine for treating pulmonary fibrosis. Our study aimed to investigate the potential of MSCs to inhibit pulmonary fibrosis as well as the contribution of uPAR expression to this effect. We found that intravenous MSC administration significantly reduced lung fibrosis in the bleomycin‐induced pulmonary fibrosis model in mice as revealed by MRI and histological evaluations. Notably, administering the MSCs isolated from adipose tissue of uPAR knockout mice (Plaur‐/‐ MSCs) attenuated lung fibrosis to a lesser extent as compared to WT MSCs. Collagen deposition, a hallmark of fibrosis, was markedly reduced in lungs treated with WT MSCs versus Plaur‐/‐ MSCs. Along with that, endogenous uPA levels were affected differently; after Plaur‐/‐ MSCs were administered, the uPA content was specifically decreased within the blood vessels. Our findings support the potential of MSC treatment in attenuating pulmonary fibrosis. We provide evidence that the observed anti‐fibrotic effect depends on uPAR expression in MSCs, suggesting that uPAR might counteract the uPA accumulation in lungs. [ABSTRACT FROM AUTHOR]

The biological properties of human mesenchymal stromal cells (hMSCs) have been explored in over a thousand clinical trials in the last decade. Although hMSCs can be isolated from multiple sources, the degree of biological similarity between cell populations from these sources remains to be determined. A comparative study was performed investigating the growth kinetics and functionality of hMSCs isolated from adipose tissue (AT), bone marrow (BM) and umbilical cord tissue (UCT) expanded in monolayer over five passages. Adult hMSCs (AT, BM) had a slower proliferation ability than the UCT-hMSCs, with no apparent differences in their glucose consumption profile. BM-hMSCs produced higher concentrations of endogenous vascular endothelial growth factor (VEGF) compared to AT- and UCT-hMSCs. This study also revealed that UCT-hMSCs were more efficiently transduced by a lentiviral vector carrying a VEGF gene than their adult counterparts. Following cellular immunophenotypic characterization, no differences across the sources were found in the expression levels of the typical markers used to identify hMSCs. This work established a systematic approach for cell source selection depending on the hMSC's intended clinical application. [ABSTRACT FROM AUTHOR]

Profiling studies using reverse transcription quantitative PCR (RT-qPCR) require reliable normalization to reference genes to accurately interpret the results. A stable reference gene panel was established to profile metastatic and non-metastatic lymph nodes in patients with oral squamous cell carcinoma. The stability of 18S ribosomal RNA (18SrRNA), ribosomal Protein Lateral Stalk Subunit P0 (RPLP0), ribosomal Protein L27 (RPL27), TATA-box binding protein (TBP), hypoxanthine phosphoribosyl-transferase 1 (HPRT1), beta-actin (ACTB), glyceraldehyde-3-Phosphate Dehydrogenase (GAPDH) and vimentin (VIM) was evaluated, as reference genes for profiling patient-derived lymph node stromal cells (LNSCs; N=8; N0:6, N+:2) and lymph node tissues (Patients:14, Nodes=20; N0:7; N+:13). The genes were initially assessed based on their expression levels, specificity, and stability rankings to identify the best combination of reference genes. VIM was excluded from the final analysis because of its low expression (high quantification cycle >32) and multiple peaks in the melting curve. The stability analysis was performed using Reffinder, which utilizes four tools; geNorm, NormFinder, BestKeeper and Comparative ΔCt methods, thereby enabling the computing of a comprehensive ranking. Evaluation of the gene profiles indicated that while RPLP0 and 18SrRNA were stable in both lymph node tissues and LNSCs, HPRT1, RPL27 were uniquely stable in these tissues whereas ACTB and TBP were most stable in LNSCs. The present study identified the most stable reference gene panel for the RT-qPCR profiling of lymph node tissues and patient-derived LNSCs. The observation that the gene panel differed between the two model systems further emphasized the need to evaluate the reference gene subset based on the disease and cellular context. [ABSTRACT FROM AUTHOR]

The effect of silica (SiO 2) addition (0 wt%-20 wt%) on the microstructural and mechanical properties, as well as the in vitro response of calcium phosphate scaffolds for potential application in bone tissue engineering (BTE) was investigated in this research. Scaffolds characterized by high porosity (77%–88 %) and interconnected spherical pores with a broad range of pore sizes (5–600 μm) were fabricated using in-situ foaming method. Incorporated silica affected the phase transformation of hydroxyapatite (HA) to β-tricalcium phosphate (β-TCP) and led to the development of new crystalline silica-rich phases like silicocarnotite and wollastonite. The reinforcement of silica became apparent during the tests of mechanical properties. Scaffolds with 5 wt% of SiO 2 exhibited compressive strength (1.13 MPa) higher than pure HA scaffolds (0.93 MPa). Bone bonding potential of the materials was tested in simulated body fluid (SBF), demonstrating this potential in silica-doped samples. Additionally, degradation experiments showed gradual material degradation, making it suitable for BTE applications. Furthermore, cell culture studies using human mesenchymal stromal cells (MSC) confirmed the scaffold's non-toxicity and provided insights into how the silica content influences cell viability, morphology, and osteogenic potential. The findings of this study offer valuable insights into the design and development of advanced scaffolds with tailored properties for effective BTE applications. [Display omitted] • In vitro evaluation of bioactive potential of multiphase porous ceramic materials for non-loadbearing bone regeneration. • In-situ foaming technique was used to produce porous bioceramic. • Si-containing phases undergo selective degradation under conditions that simulate osteoclastic activity. • Si-containing phases release Si into test media during degradation tests – possible osteoblastogenetic response in vivo. [ABSTRACT FROM AUTHOR]

Telocytes (TCs) are characterized by a small oval-shaped cell body with long prolongations that are called telopods (Tps). PDGFR-β and c-kit markers may assist for the immunohistochemical identification of TCs; however, by these means they cannot be identified with absolute specificity. Transmission electron microscopy (TEM) is considered as a gold standard method for TCs observation. Studies on TCs in the female reproductive system are limited, and there is a lack of awareness regarding TCs in rat ovaries. We aimed to demonstrate the existence and morphology of TCs in rat ovaries, alongside previously studied TCs in rat uteri. Thus, ovaries and uteri from young adult Sprague–Dawley female rats (n = 8) with regular estrous cycles were collected. Then, left ovaries and uteri were proccessed for TEM analysis, while the right ones were used for immunohistochemistry. As a result, TCs were seen throughout the rat's ovarian stroma with their characteristic cell bodies, Tps, podomes (Pds) and podomers (Pdms). Tps were situated within the thecal layer of the follicles, surrounding the corpus luteum and blood vessels. Ovarian TCs were recognized to have relationship with other TCs/stromal cells. Subsequently, TCs were seen in stroma of endometrium with surrounding blood vessels and uterine glands, myometrium and perimetrium in rat uteri. There was also no statistical significance between the number of c-kit+ and PDGFR-β+ telocyte-like cells in both rat ovarian (p = 0.137) and endometrial stroma (p = 0.450). Further investigation of the roles and functions of TCs in the female reproductive system is needed. [ABSTRACT FROM AUTHOR]

Peripheral arterial disease (PAD) is associated with lower-extremity muscle wasting. Hallmark features of PAD-associated skeletal muscle pathology include loss of skeletal muscle mass, reduced strength and physical performance, increased inflammation, fibrosis, and adipocyte infiltration. At the molecular level, skeletal muscle ischemia has also been associated with gene and microRNA (miRNA) dysregulation. Mesenchymal stromal cells (MSCs) have been shown to enhance muscle regeneration and improve muscle function in various skeletal muscle injuries. This study aimed to evaluate the effects of intramuscularly delivered human umbilical cord-derived MSCs (hUC-MSCs) on skeletal muscle ischemia. Herein, we report an hUC-MSC-mediated amelioration of ischemia-induced skeletal muscle atrophy and function via enhancement of myofiber regeneration, reduction of tissue inflammation, adipocyte accumulation, and tissue fibrosis. These changes were observed in the absence of cell-mediated enhancement of blood flow recovery as measured by laser Doppler imaging. Furthermore, reduced tissue fibrosis in the hUC-MSC-treated group was associated with upregulation of miR-1, miR-133a, and miR-29b and downregulation of targeted pro-fibrotic genes such as Col1a1 and Fn1. Our results support the use of hUC-MSCs as a novel approach to reduce fibrosis and promote skeletal muscle regeneration after ischemic injury in patients with PAD. [ABSTRACT FROM AUTHOR]

Introduction: The growing problem of antimicrobial resistance (AMR) poses a significant challenge to public health; This is partly due to the lack of advancements in the development of novel antibiotics and the pressing need for alternative treatment options. Mesenchymal stem cells (MSC) possess secretory components that enhance the immune response and peptides that disrupt the bacteria constitution. The isolation of various human tissues has facilitated the investigation of the diverse potentials of MSC and their components. Further research is needed to fully understand the spectrum and efficacy of these elements and their differences. The primary aim of this study was to perform a thorough review of the current literature related to the antimicrobial properties of MSC and their associated components. The objective was to establish an insight into the results and effects of utilizing MSC in relation to bacterial colonization, and to present an overview of previously documented findings. Methods: This systematic literature review was conducted using the PubMed, Embase, and Web of Science databases. Data on the effect of MSC or their derivatives were measured by calculating the percentage of bacterial counts reduction after treatment with MSC in comparison to the control. Results: A total of 3,911 articles were screened, and 31 eligible publications were selected for inclusion in the analysis. In the current systematic review, the majority of the experimental designs showed positive outcomes in terms of bacterial load reduction when MSC or their derivatives were used, with bone marrow being the most effective tissue. The rest of the findings exhibited heterogeneity in the spectrum of outcomes that could be attributed to the effects of using various tissues derived MSC in both in vivo and in vitro studies. Conclusion: The findings of our study indicate the potential antibacterial characteristics of MSC. The direct antimicrobial activity of these cells was demonstrated by our results, which quantitatively showed a decrease in bacterial growth after treatment with MSC. However, additional research is required to clarify the factors that determine the efficacy of their antimicrobial activity and their various components. [ABSTRACT FROM AUTHOR]

Mesenchymal stromal cells (MSCs) have immunomodulatory properties and are therefore considered promising tools in kidney transplantation. Although most studies have been conducted with autologous MSCs, using allogeneic MSCs as an off-the-shelf product is more feasible in clinical settings. However, allogeneic MSCs could potentially induce an immune response, which might eventually be directed towards the kidney allograft because of shared human leukocyte antigen (HLA) epitope mismatches between the kidney and MSC donor. In this study, we performed in-depth analyses of two cohorts (n = 20) that received third-party MSC therapy after kidney transplantation. While the Neptune Study from Leiden University Medical Center specifically selected MSC to avoid repeated HLA antigen mismatches between kidney and MSC donors, the study from the University of Liège did not perform specific MSC selection. The comparative analyses of amino acid mismatches between these cohorts showed that MSC selection to avoid repeated HLA mismatches at the split antigen level was not sufficient to prevent repeated mismatches at the amino acid level. However, repeated amino acid mismatches were not associated with the occurrence of donor-specific antibodies (DSAs). Thus, the clinical relevance of repeated amino acid mismatches seems to be limited with regard to the risk of DSA formation. Since DSA formation was limited (3 of 20 patients) in this study, larger studies are required to investigate the relevance of preventing repeated HLA mismatches in allogeneic MSC therapy in kidney transplantation. [ABSTRACT FROM AUTHOR]

Background: Breast cancer (BC) remains a significant health issue globally and most common cause of mortality in women. Enhancing our understanding on biomarkers may greatly improve both diagnostic and therapeutic approaches to this disease. Methods: We retrospectively assessed tumor samples from 228 BC cases and 51 normal samples, alongside relevant clinical data. Neuronal vesicle trafficking associated 2(NSG2) expression was evaluated through bioinformatics and multiplex immunohistochemistry. Associations between NSG2 expression, tumor-infiltrating immune cells (TIICs), immune checkpoints, and clinical outcomes were investigated. Results: NSG2 was present in both breast cancer cells and adjacent stromal cells. Increased NSG2 expression in cancer cells correlated with greater tumor size, distant metastasis, and more advanced clinical stages. Kaplan-Meier survival and multivariate analyses identified NSG2 expression in both cancer and stromal cells as an independent prognostic factor for breast cancer survival. Elevated NSG2 levels both in cancer and stroma cells were linked to increased CD4+ T, CD8+ T, and Lamp3+ dendritic cells infiltration in stromal regions (P < 0.05). Conversely, the expression of NSG2 in the stroma was negatively correlated with CD20+ B cells (P < 0.05). Additionally, NSG2 expression was found to be associated with CTLA-4 levels (P < 0.05). Conclusion: NSG2 seems to be a significant component of the BC immune microenvironment and may serve as an important prognostic marker. [ABSTRACT FROM AUTHOR]

Biofilms reduce antibiotic efficacy and lead to complications and mortality in human and equine patients with orthopedic infections. Equine bone marrow-derived mesenchymal stromal cells (MSC) kill planktonic bacteria and prevent biofilm formation, but their ability to disrupt established orthopedic biofilms is unknown. Our objective was to evaluate the ability of MSC to reduce established S. aureus or E. coli biofilms in vitro. We hypothesized that MSC would reduce biofilm matrix and colony-forming units (CFU) compared to no treatment and that MSC combined with the antibiotic, amikacin sulfate, would reduce these components more than MSC or amikacin alone. MSC were isolated from 5 adult Thoroughbred horses in antibiotic-free medium. 24-hour S. aureus or E. coli biofilms were co-cultured in triplicate for 24 or 48 hours in a transwell plate system: untreated (negative) control, 30 μg/mL amikacin, 1 x 106 passage 3 MSC, and MSC with 30 μg/mL amikacin. Treated biofilms were photographed and biofilm area quantified digitally. Biomass was quantified via crystal violet staining, and CFU quantified following enzymatic digestion. Data were analyzed using mixed model ANOVA with Tukey post-hoc comparisons (p < 0.05). MSC significantly reduced S. aureus biofilms at both timepoints and E. coli biofilm area at 48 hours compared to untreated controls. MSC with amikacin significantly reduced S. aureus biofilms versus amikacin and E. coli biofilms versus MSC at 48 hours. MSC significantly reduced S. aureus biomass at both timepoints and reduced S. aureus CFU at 48 hours versus untreated controls. MSC with amikacin significantly reduced S. aureus biomass versus amikacin at 24 hours and S. aureus and E. coli CFU versus MSC at both timepoints. MSC primarily disrupted the biofilm matrix but performed differently on S. aureus versus E. coli. Evaluation of biofilm-MSC interactions, MSC dose, and treatment time are warranted prior to testing in vivo. [ABSTRACT FROM AUTHOR]

Introduction: Human periodontal ligament-derived mesenchymal stromal cells (hPDL-MSCs) possess a strong ability to modulate the immune response, executed via cytokine-boosted paracrine and direct cell-to-cell contact mechanisms. This reciprocal interaction between immune cells and hPDL-MSCs is influenced by 1,25-dihydroxyvitamin-D3 (1,25(OH)2D3). In this study, the participation of different immunomodulatory mechanisms on the hPDL-MSCs-based effects of 1,25(OH)2D3 on CD4+ T lymphocytes will be elucidated using different co-culture models with various cytokine milieus.Material and methods: hPDL-MSCs and CD4+ T lymphocytes were co-cultured indirectly and directly with inserts (paracrine interaction only) or directly without inserts (paracrine and direct cell-to-cell contact interaction). They were stimulated with TNF-α or IL-1β in the absence/presence of 1,25(OH)2D3. After five days of co-cultivation, the CD4+ T lymphocyte proliferation, viability, and cytokine secretion were analyzed. Additionally, the gene expression of soluble and membrane-bound immunomediators was determined in hPDL-MSCs.Results: In the indirect and direct co-culture model with inserts, 1,25(OH)2D3 decreased CD4+ T lymphocyte proliferation and viability. The direct co-culture model without inserts caused the opposite effect. 1,25(OH)2D3 mainly decreased the CD4+ T lymphocyte-associated secretion of cytokines via hPDL-MSCs. The degree of these inhibitions varied between the different co-culture setups. 1,25(OH)2D3 predominantly decreased the expression of the soluble and membrane-bound immunomediators in hPDL-MSCs to a different extent, depending on the co-culture models. The degree of all these effects depended on the absence and presence of exogenous TNF-α and IL-1β.Conclusion: These data assume that 1,25(OH)2D3 differently affects CD4+ T lymphocytes via the paracrine and direct cell-to-cell contact mechanisms of hPDL-MSCs, showing anti-or pro-inflammatory effects depending on the co-culture model type. The local cytokine microenvironment seems to be involved in fine-tuning these effects. Future studies should consider this double-edged observation by executing different co-culture models in parallel. [ABSTRACT FROM AUTHOR]

Background: Mesenchymal stem/stromal cells (MSCs) have attracted interest as a potential therapy given their anti-inflammatory and immunomodulatory properties. However, clinical trials using MSCs for acute respiratory distress syndrome (ARDS) have produced mixed and inconclusive data. In previous work, we performed a "head-to-head" comparison between different sources of MSCs and showed that each source had a unique genomic and proteomic "signature". Method: This study investigated which sources of MSC: bone marrow derived-MSCs (BM-MSCs), adipose tissue derived-MSCs (AD-MSCs) and umbilical cord derived-MSCs (UC-MSCs) would be the optimal candidate to be used as a therapy in an LPS-induced mouse model of ARDS. Immune cells assessment, tissue transcriptomics, animal survival, and endothelial-epithelial barrier assessment were used to evaluate their effects. Results: When comparing the three most commonly used MSC sources, we found that UC-MSCs exhibited greater efficacy compared to other MSCs in improving animal survival, mitigating epithelial/endothelial damage, decreasing lung inflammation via reducing neutrophil infiltration, T cell proliferation, and M1 polarization. Bulk RNA sequencing of lung tissue also showed that UC-MSCs have the capability to downregulate extracellular trap formation, by the downregulation of key genes like Elane and Padi4. Notably, treatment with UC-MSCs demonstrated a significant reduction in Fc-γ R mediated phagocytosis, which has been associated with monocyte pyroptosis and intense inflammation in the context of COVID-19. Conclusion: Our findings suggest that UC-MSCs are an optimal source of MSC to treat acute inflammatory conditions in the lungs, such as ARDS. [ABSTRACT FROM AUTHOR]

Diabetes mellitus (DM), a chronic metabolic disease, poses a significant global health challenge, with current treatments often fail to prevent the long-term disease complications. Mesenchymal stem/stromal cells (MSCs) are, adult progenitors, able to repair injured tissues, exhibiting regenerative effects and immunoregulatory and anti-inflammatory responses, so they have been emerged as a promising therapeutic approach in many immune-related and inflammatory diseases. This review summarizes the therapeutic mechanisms and outcomes of MSCs, derived from different human tissue sources (hMSCs), in the context of DM type 1 and type 2. Animal model studies and clinical trials indicate that hMSCs can facilitate pleiotropic actions in the diabetic milieu for improved metabolic indices. In addition to modulating abnormally active immune system, hMSCs can ameliorate peripheral insulin resistance, halt beta-cell destruction, preserve residual beta-cell mass, promote beta-cell regeneration and insulin production, support islet grafts, and correct lipid metabolism. Moreover, hMSC-free derivatives, importantly extracellular vesicles, have shown potent experimental anti-diabetic efficacy. Moreover, the review discusses the diverse priming strategies that are introduced to enhance the preclinical anti-diabetic actions of hMSCs. Such strategies are recommended to restore the characteristics and functions of MSCs isolated from patients with DM for autologous implications. Finally, limitations and merits for the wide spread clinical applications of MSCs in DM such as the challenge of autologous versus allogeneic MSCs, the optimal MSC tissue source and administration route, the necessity of larger clinical trials for longer evaluation duration to assess safety concerns, are briefly presented. [ABSTRACT FROM AUTHOR]

Introduction: Diabetic retinopathy (DR) is a microvascular complication of diabetes in which neurodegeneration has been recently identified as a driving force. In the last years, mesenchymal stromal cells (MSCs) and neurotrophins like Nerve Growth Factor (NGF), have garnered significant attention as innovative therapeutic approaches targeting DR-associated neurodegeneration. However, delivering neurotrophic factors directly in the eye remains a challenge. Hence, this study evaluated the effects of MSCs from human amniotic fluids (hAFSCs) and recombinant human NGF (rhNGF) delivered by human corneal lenticule (hCL) on a high glucose (HG) induced ex vivo model simulating the molecular mechanisms driving DR. Methods: Porcine neuroretinal explants exposed to HG (25 mM for four days) were used to mimic DR ex vivo. hCLs collected from donors undergoing refractive surgery were decellularized using 0.1% sodium dodecyl sulfate and then bioengineered with hAFSCs, microparticles loaded with rhNGF (rhNGF-PLGA-MPs), or both simultaneously. Immunofluorescence (IF) and scanning electron microscopy (SEM) analyses were performed to confirm the hCLs bioengineering process. To assess the effects of hAFSCs and rhNGF, bioengineered hCLs were co-cultured with HG-treated neuroretinal explants and following four days RT-PCR and cytokine array experiments for inflammatory, oxidative, apoptotic, angiogenic and retinal cells markers were performed. Results: Data revealed that HG-treated neuroretinal expiants exhibit a characteristic DR-phenotype, including increased level of NF-kB, NOS2, NRF2 GFAP, VEGFA, Bax/Bcl2 ratio and decreased expression of TUBB3 and Rho. Then, the feasibility to bioengineer decellularized hCLs with hAFSCs and rhNGF was demonstrated. Interestingly, co-culturing hAFSCs- and rhNGF- bioengineered hCLs with HG-treated neuroretinal explants for four days significantly reduced the expression of inflammatory, oxidative, apoptotic, angiogenic and increased retinal markers. Conclusion: Overall, we found for the first time that hAFSCs and rhNGF were able to modulate the molecular mechanisms involved in DR and that bioengineered hCLs represents a promising ocular drug delivery system of hAFSCs and rhNGF for eye diseases treatment. In addition, results demonstrated that porcine neuroretinal explants treated with HG is a useful model to reproduce ex vivo the DR pathophysiology. [ABSTRACT FROM AUTHOR]

The nasal mucosa forms a critical barrier against the invasion of respiratory pathogens. Composed of a heterogeneous assortment of cell types, the nasal mucosa relies on the unique characteristics and complex intercellular dynamics of these cells to maintain their structural integrity and functional efficacy. In this study, single-cell RNA sequencing (scRNA-seq) of porcine nasal mucosa was performed, and nineteen distinct nasal cell types, including nine epithelial cell types, five stromal cell types, and five immune cell types, were identified. The distribution patterns of three representative types of epithelial cells (basal cells, goblet cells, and ciliated cells) were subsequently detected by immunofluorescence. We conducted a comparative analysis of these data with published human single-cell data, revealing consistent differentiation trajectories among porcine and human nasal epithelial cells. Specifically, basal cells serve as the initial stage in the differentiation process of nasal epithelial cells, which then epithelial cells. This research not only enhances our understanding of the composition and transcriptional signature of porcine nasal mucosal cells but also offers a theoretical foundation for developing alternative models for human respiratory diseases. [ABSTRACT FROM AUTHOR]

CXCL13 is a chemokine that plays an important role in the regulation and development of secondary lymphoid organs. CXCL13 is also involved in the regulation of pathological processes, particularly inflammatory responses, of many diseases. The function of CXCL13 varies depending on the condition of the host. In a healthy condition, CXCL13 is mainly secreted by mouse stromal cells or human follicular helper T cells, whereas in diseases conditions, they are produced by human peripheral helper T cells and macrophages in non-lymphoid tissues; this is termed ectopic expression of CXCL13. Ectopic CXCL13 expression is involved in the pathogenesis of various immune-mediated inflammatory diseases as it regulates the migration of B lymphocytes, T lymphocytes, and other immune cells in inflammatory sites as well as influences the expression of inflammatory factors. Additionally, ectopic expression of CXCL13 plays a key role in ectopic lymphoid organ formation. In this review, we focused on the sources of CXCL13 in different conditions and its regulatory mechanisms in immune-mediated inflammatory diseases, providing novel ideas for further research on targeting CXCL13 for the treatment of immune-mediated inflammatory diseases. [ABSTRACT FROM AUTHOR]

Cellular senescence leads to the functional decline of regenerative cells such as mesenchymal stromal/stem cells (MSCs), which gives rise to chronic conditions and contributes to poor cell therapy outcomes. Aging tissues are associated with extracellular matrix (ECM) dysregulation, including loss of elastin. However, the role of the ECM in modulating senescence is underexplored. In this work, it is shown that tropoelastin, the soluble elastin precursor, is not only a marker of young MSCs but also actively preserves cell fitness and delays senescence during replicative aging. MSCs briefly exposed to tropoelastin exhibit upregulation of proliferative genes and concurrent downregulation of senescence genes. The seno‐protective benefits of tropoelastin persist during continuous, long‐term MSC culture, and significantly extend the MSC replicative lifespan. Tropoelastin‐expanded MSCs further maintain youth‐associated phenotype and function compared to age‐matched controls, including preserved clonogenic potential, minimal senescence‐associated beta‐galactosidase activity, maintained cell sizes, reduced expression of senescence markers, suppressed secretion of senescence‐associated factors, and increased production of youth‐associated proteins. This work points to the utility of exogenously‐supplemented tropoelastin for manufacturing MSCs that robustly maintain regenerative potential with age. It further reveals the active role of classical structural ECM proteins in driving cellular age‐associated fitness, potentially leading to future interventions for aging‐related pathologies. [ABSTRACT FROM AUTHOR]

The stromal vascular fraction of adipose tissue has gained popularity as regenerative therapy for tissue repair. Both enzymatic and mechanical intraoperative SVF isolation procedures exist. To date, the quest for the preferred isolation procedure persists, due to the absence of standardised yield measurements and a defined clinical threshold. This systematic review is an update of the systematic review published in 2018, where guidelines were proposed to improve and standardise SVF isolation procedures. An elaborate data search in MEDLINE (PubMed), EMBASE (Ovid) and the Cochrane Central Register of Controlled Trials was conducted from September 2016 to date. A total of 26 full‐text articles met inclusion criteria, evaluating 33 isolation procedures (11 enzymatic and 22 mechanical). In general, enzymatic and mechanical SVF isolation procedures yield comparable outcomes concerning cell yield (2.3–18.0 × 105 resp. 0.03–26.7 × 105 cells/ml), and cell viability (70%–99% resp. 46%–97.5%), while mechanical procedures are more time consuming (8–20 min vs. 50–210 min) and cost‐efficient. However, as most studies used poorly validated outcome measures on SVF characterisation, it still remains unclear which intraoperative SVF isolation method is preferred. Future studies are recommended to implement standardised guidelines to standardise methods and improve comparability between studies. [ABSTRACT FROM AUTHOR]

Adipose tissue is a rich source of diverse cell populations, including immune cells, adipocytes and stromal cells. Interactions between these different cell types are now appreciated to be critical for maintaining tissue structure and function, by governing processes such as adipogenesis, lipolysis and differentiation of white to beige adipocytes. Interactions between these cells also drive inflammation in obesity, leading to an expansion of adipose tissue immune cells, and the secretion of proinflammatory cytokines from immune cells and from adipocytes themselves. However, in evolutionary terms, obesity is a recent phenomenon, raising the question of why adipocytes evolved to express factors that influence the immune response. Studies of various pathogens indicate that adipocytes are highly responsive to infection, altering their metabolic profiles in a way that can be used to release nutrients and fuel the immune response. In the case of infection with the extracellular parasite Trypanosoma brucei, attenuating the ability of adipocytes to sense the cytokine IL‐17 results in a loss of control of the local immune response and an increased pathogen load. Intriguingly, comparisons of the adipocyte response to infection suggest that the immune responses of these cells occur in a pathogen‐dependent manner, further confirming their complexity. Here, with a focus on murine adipose tissue, we discuss the emerging concept that, in addition to their canonical function, adipocytes are immune signalling hubs that integrate and disseminate signals from the immune system to generate a local environment conducive to pathogen clearance. [ABSTRACT FROM AUTHOR]

In this article, site‐specific functionalized keratoprosthesis (KPro) was accomplished to meet epithelial on‐growth on the anterior optical surface, inhibit cell adhesion on the posterior optic surface, and promote cell ingrowth at the peripheral tissue‐haptic‐flange interface toward tissue integration. Gelatin immobilization on PC4 hydrogel surfaces was achieved through acid hydrolysis followed by EDC/NHS chemistry, and polyethylene glycol‐diacrylate (PEGDA)‐modified inter‐penetrating network (IPN) surfaces were prepared using photo‐polymerization of ethylene glycol‐diacrylate (EGDA) for enhancing and inhibiting cellular growth, respectively. The surface chemical structures of modified hydrogels were characterized using attenuated total reflectance‐infrared (ATR‐IR) spectroscopy and a bicinchoninic acid (BCA) protein adsorption assay. Further, suitable differentially functionalized surfaces were prepared and characterized using the universal testing machine (UTM), refractometer, atomic force microscopy (AFM), and contact angle measurements to understand mechanical, optical, surface morphological, and wettability properties, respectively. Finally, in vitro site‐specific cell adhesion, cell inhibition, and cell ingrowth functionalities were tested using isolated goat corneal limbal epithelial stem cells and corneal stromal fibroblast cells, respectively. Overall, the two connective articles represent a successful endeavor to develop a more esthetically pleasing, mechanically stable, tissue‐free hydrogel KPro with site‐specific surface functionality nearly mimicking the cornea's functionality. A further pre‐clinical investigation is necessary to advance this functional novel KPro to reality, especially the tissue integration aspect. [ABSTRACT FROM AUTHOR]

The tumor microenvironment (TME) is emerging as a tool for the development of improved patient prognosis and the development of novel antitumor drugs. As the most important stromal cells in the tumor microenvironment, cancer-associated fibroblasts (CAFs) play an important role in the development of TNBC. The rise of single-cell sequencing technology has facilitated our study of the various cell types in TME. In this study, we interpreted the heterogeneity of TNBCs from the perspective of tumor-associated fibroblasts in the tumor microenvironment based on the TNBC single-cell sequencing dataset GSE118389, in the hope of providing help for individualised treatment. Combining the TCGA database and the GSE103091 dataset, four genes associated with CAFs in TNBC (CERCAM, KLF10, ECM1,HGF) were identified using the R package Seurat as well as correlation consensus clustering analysis. Meanwhile, qRT-PCR, WB and IHC experiments confirmed their expression in TNBC. Based on these genes, CAFs Score was established and validated to correlate with the prognosis of patients with TNBC, with patients in the high score group surviving significantly worse than those in the low score group (P<0.001). In addition, there were significant differences in immune cell infiltration and expression of immune checkpoints between the high and low scoring groups. Compared to Stage I & II, the CAFs Score was higher in Stage III & IV TNBC patients (P = 0.043) and higher in N1-3 TNBC patients than in N0 TNBC patients (P = 0.035). EMT scores were higher within the high CAFs Score group (P = 1.4e-11) and there was a positive correlation between Stemness Score and CAFs Score (R = 0.61, P = 3.6e-09). Drug sensitivity analysis combining the GSE128099 showed a higher sensitivity to Gemcitabine in the low CAFs Score group (P = 0.0048). We speculate that these four CAFs-related genes are likely to be involved in regulating gemcitabine resistance in TNBC patients. [ABSTRACT FROM AUTHOR]

Simple Summary: This study establishes in vitro criteria for the safe and effective use of allogeneic canine mesenchymal stromal cells for potential orthopedic and therapeutic use. Allogeneic canine adipose-derived MSCs demonstrated MSC-specific characteristics and met in vitro requirements, providing a solid foundation for future in vivo research and clinical applications. Importantly, their shipping and cryobanking conditions and related procedures were also tested and validated. This validation ensures the establishment of an allogeneic canine adipose-derived mesenchymal stromal cell bank that can be used as an off-the-shelf therapy. In allogeneic MSC implantation, the cells are isolated from a donor different from the recipient. When tested, allogeneic MSCs have several advantages over autologous ones: faster cell growth, sufficient cell concentration, and readily available cells for clinics. To ensure the safe and efficient use of allogeneic MSCs in clinics, the MSCs need to be first tested in vitro. With this study, we paved the way by addressing the in vitro aspects of canine adipose-derived MSCs, considering the limited studies on the clinical use of canine cells. We isolated cAD-MSCs from canine falciform ligament fat and evaluated their viability and proliferation using an MTS assay. Then, we characterized the MSC-specific antigens using immunophenotyping and immunofluorescence and demonstrated their potential for in vitro differentiation. Moreover, we established shipping and cryobanking procedures to lead the study to become an off-the-shelf therapy. During expansion, the cells demonstrated a linear increase in cell numbers, confirming their proliferation quantitatively. The cells showed viability before and after cryopreservation, demonstrating that cell viability can be preserved. From a clinical perspective, the established shipping conditions demonstrated that the cells retain their viability for up to 48 h. This study lays the groundwork for the potential use of allogeneic cAD-MSCs in clinical applications. [ABSTRACT FROM AUTHOR]

In recent years, clinical studies have shown positive results of the application of Mesenchymal Stromal Cells (MSCs) in severe cases of COVID-19. However, the mechanisms of immunomodulation of IFN-γ licensed MSCs in SARS-CoV-2 infection are only partially understood. In this study, we first tested the effect of IFN-γ licensing in the MSC immunomodulatory profile. Then, we established an in vitro model of inflammation by exposing Calu-3 lung cells to SARS-CoV-2 nucleocapsid and spike (NS) antigens, and determined the toxicity of SARS-CoV-2 NS antigen and/or IFN-γ stimulation to Calu-3. The conditioned medium (iCM) generated by Calu-3 cells exposed to IFN-γ and SARS-CoV-2 NS antigens was used to stimulate T-cells, which were then co-cultured with IFN-γ-licensed MSCs. The exposure to IFN-γ and SARS-CoV-2 NS antigens compromised the viability of Calu-3 cells and induced the expression of the inflammatory mediators ICAM-1, CXCL-10, and IFN-β by these cells. Importantly, despite initially stimulating T-cell activation, IFN-γ-licensed MSCs dramatically reduced IL-6 and IL-10 levels secreted by T-cells exposed to NS antigens and iCM. Moreover, IFN-γ-licensed MSCs were able to significantly inhibit T-cell apoptosis induced by SARS-CoV-2 NS antigens. Taken together, our data show that, in addition to reducing the level of critical cytokines in COVID-19, IFN-γ-licensed MSCs protect T-cells from SARS-CoV-2 antigen-induced apoptosis. Such observations suggest that MSCs may contribute to COVID-19 management by preventing the lymphopenia and immunodeficiency observed in critical cases of the disease. [ABSTRACT FROM AUTHOR]

Endometriosis, a chronic inflammatory disease, significantly impairs the quality of life of women in their reproductive years; however, its pathogenesis remains poorly understood. The accumulation of retrograde menstruation and recurrent bleeding fosters a high‐iron environment in ectopic lesions, triggering ferroptosis in ectopic endometrial stromal cells (EESCs), thereby hindering the establishment of endometriosis. However, abnormal EESCs demonstrate resistance to ferroptosis in high‐iron environments, promoting the progression of this disease. Here, novel findings on the accumulation of creatine, derived from endogenous synthesis, in both peritoneal fluid and EESCs of patients with endometriosis are presented. Creatine supplementation reduces cellular iron concentrations, mitigating oxidative stress and lipid peroxidation, thereby enhancing cell viability and preventing ferroptosis under high‐iron conditions. Utilizing the drug affinity–responsive target stabilization (DARTS) assay, prion protein (PrP) as a potential creatine‐sensing protein is identified. Mechanistically, creatine binds to the active site of PrP, inhibits the conversion of trivalent iron to divalent iron, and decreases iron uptake, promoting the tolerance of EESCs to ferroptosis. This interaction contributes to the development of endometriosis. The novel association between creatine and ferroptosis provides valuable insights into the role of creatine in endometriosis progression and highlights its potential as a therapeutic target for endometriosis. [ABSTRACT FROM AUTHOR]

Introduction: Mesenchymal stromal cell (MSC)-based cell therapy is a promising approach for various inflammatory disorders based on their immunosuppressive capacity. Osteopontin (OPN) regulates several cellular functions including tissue repair, bone metabolism and immune reaction. However, the biological function of OPN in regulating the immunosuppressive capacity of MSCs remains elusive. Objectives: This study aims to highlight the underlying mechanism of the proinflammatory cytokines affect the therapeutic ability of MSCs through OPN. Methods: MSCs in response to the proinflammatory cytokines were collected to determine the expression profile of OPN. In vitro T-cell proliferation assays and gene editing were performed to check the role and mechanisms of OPN in regulating the immunosuppressive capacity of MSCs. Inflammatory disease mouse models were established to evaluate the effect of OPN on improving MSC-based immunotherapy. Results: We observed that OPN, including its two isoforms iOPN and sOPN, was downregulated in MSCs upon proinflammatory cytokine stimulation. Interestingly, iOPN, but not sOPN, greatly enhanced the immunosuppressive activity of MSCs on T-cell proliferation and thus alleviated the inflammatory pathologies of hepatitis and colitis. Mechanistically, iOPN interacted with STAT1 and mediated its deubiquitination, thereby inducing the master immunosuppressive mediator inducible nitric oxide synthase (iNOS) in MSCs. In addition, iOPN expression was directly downregulated by activated STAT1, which formed a negative feedback loop to restrain MSC immunosuppressive capacity. Conclusion: Our findings demonstrated that iOPN expression modulation in MSCs is a novel strategy to improve MSC-based immunotherapy. [ABSTRACT FROM AUTHOR]

The tumour microenvironment represents a novel frontier in oncological research. Over the past decade, accumulating evidence has underscored the importance of the tumour microenvironment (TME), including tumour cells, stromal cells, immune cells, and various secreted factors, which collectively influence tumour growth, invasion, and responses to therapeutic agents. Immune cells within the TME are now widely acknowledged to play pivotal roles in tumour development and treatment. While some perspectives have posited that immune cells within the TME facilitate tumour progression and confer resistance to therapeutic interventions, contrasting conclusions also exist. Affirmative and negative conclusions appear to be context dependent, and a unified consensus has yet to be reached. The burgeoning body of research on the relationship between the gut microbiota and tumours in recent years has led to a growing understanding. Most studies have indicated that specific components of the gut microbiota, such as unique bacterial communities or specific secretory factors, play diverse roles in regulating immune cells within the TME, thereby influencing the prognosis and outcomes of cancer treatments. A detailed understanding of these factors could provide novel insights into the TME and cancer therapy. In this study, we aimed to synthesise information on the interactions between the gut microbiota and immune cells within the TME, providing an in-depth exploration of the potential guiding implications for future cancer therapies. [ABSTRACT FROM AUTHOR]

Background: The prostaglandin receptor PTGER4 facilitates homeostasis in the gut. Previous reports indicate that goblet cells, marked by SPINK4 expression, might be affected by PTGER4 activity. Current evidence suggests that prostaglandin E2 (PGE2) produced by mesenchymal stromal cells (MSC) stimulates PTGER4 in epithelial cells during inflammatory conditions. Here, we investigate the subcellular mechanisms and mRNA levels downstream of PTGER4 activity in epithelial cells. Methods: Mucosal cells, organoids, and MSC were obtained from patient biopsies harvested by endoscopy. Using independent and co-cultures, we manipulated the activity of PTGER4, the downstream enzymes, and mRNA levels, by using PGE2, in combination with chemical inhibitors, L-161982, H89, LB100, DAPT, LMK-235, or with butyrate. Immunofluorescence, single cell sequencing, RNAscope, ELISA, real time PCR, and Western blotting were used to examine these samples. Results: SPINK4 mRNA levels were increased in organoids by co-culture with MSC or exogenous stimulation with PGE2 that could be blocked by L-161982 or LMK-235, PTGER4 or HDAC4 inhibitors, respectively. Expression of PTGER4 was co-localized with JAM-A in the basolateral surfaces in rectal epithelial cells grown as organoids. PGE2 treatment of rectal organoids decreased HDAC4, 5, and 7 phosphorylation levels that could be blocked by L-161982 treatment. Butyrate treatment, or addition of L-161982, increased the phosphorylated levels of HDAC4, 5, and 7. Conclusions: These findings suggest a mechanism during mucosal injury whereby MSC production of PGE2 increases HDAC4, 5, and 7 activities in epithelial cells by upregulating PTGER4 signaling, ultimately increasing SPINK4 mRNA levels and extracellular release of SPINK4. [ABSTRACT FROM AUTHOR]

Telocytes (TCs) are a distinctive cell entity of the stromal microenvironment of multiple tumors; to date, their existence in infantile hemangioma (IH) remains almost unexplored. This study was therefore undertaken to characterize the immunophenotype, location, morphology, and ultrastructure of telocytes in the IH by means of immunohistochemistry, immunofluorescence confocal microscopy, and transmission electron microscopy. Telocytes were initially identified by CD34, PDGFR-α, Vimentin, and AQP-1 immunostaining. Analyzing the spatial relationship among telocytes, stem cells, endothelial cells, pericytes in the IH with AQP-1/CD31, AQP-1/Glut-1, AQP-1/α-SMA, AQP-1/CD146 and AQP-1/CD133 double immunofluorescence. TCs were immunonegative for CD31, Glut-1, CD146, α-SMA, CD133, and C-kit in the IH. The ultrastructural examination confirmed the presence of TCs, namely stromal cells with characteristic cytoplasmic processes (i.e. telopodes) forming labyrinthine networks around microvessels and releasing extracellular vesicles. Our study provides evidence that telocytes are present and PDGFR-α and AQP-1 are specific antigenic markers in the IH. [ABSTRACT FROM AUTHOR]

Background: Cell therapy can protect cardiomyocytes from hypoxia, primarily via paracrine secretions, including extracellular vesicles (EVs). Since EVs fulfil specific biological functions based on their cellular origin, we hypothesised that EVs from human cardiac stromal cells (CMSCLCs) obtained from coronary artery bypass surgery may have cardioprotective properties. Objectives: This study characterises CMSCLC EVs (C_EVs), miRNA cargo, cardioprotective efficacy and transcriptomic modulation of hypoxic human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). C_EVs are compared to bone marrow mesenchymal stromal cell EVs (B_EVs) which are a known therapeutic EV type. Methods: Cells were characterised for surface markers, gene expression and differentiation potential. EVs were compared for yield, phenotype, and ability to protect hiPSC-CMs from hypoxia/reoxygenation injury. EV dose was normalised by both protein concentration and particle count, allowing direct comparison. C_EV and B_EV miRNA cargo was profiled and RNA-seq was performed on EV-treated hypoxic hiPSC-CMs, then data were integrated by multi-omics. Confirmatory experiments were carried out using miRNA mimics. Results: At the same dose, C_EVs were more effective than B_EVs at protecting CM integrity, reducing apoptotic markers, and cell death during hypoxia. While C_EVs and B_EVs shared 70–77% similarity in miRNA content, C_EVs contained unique miRNAs, including miR-202-5p, miR-451a and miR-142-3p. Delivering miRNA mimics confirmed that miR-1260a and miR-202/451a/142 were cardioprotective, and the latter upregulated protective pathways similar to whole C_EVs. Conclusions: This study demonstrates the potential of cardiac tissues, routinely discarded following surgery, as a valuable source of EVs for myocardial infarction therapy. We also identify miR-1260a as protective of CM hypoxia. [ABSTRACT FROM AUTHOR]

Background: Prostate cancer (PCa) is one of the most prevalent malignancies in males worldwide. Increasing research attention has focused on the PCa microenvironment, which plays a crucial role in tumor progression and therapy resistance. This review aims to provide a comprehensive overview of the key components of the PCa microenvironment, including immune cells, vascular systems, stromal cells, and microbiota, and explore their implications for diagnosis and treatment. Methods: Keywords such as "prostate cancer", "tumor microenvironment", "immune cells", "vascular system", "stromal cells", and "microbiota" were used for literature retrieval through online databases including PubMed and Web of Science. Studies related to the PCa microenvironment were selected, with a particular focus on those discussing the roles of immune cells, vascular systems, stromal cells, and microbiota in the development, progression, and treatment of PCa. The selection criteria prioritized peer-reviewed articles published in the last five years, aiming to summarize and analyze the latest research advancements and clinical relevance regarding the PCa microenvironment. Results: The PCa microenvironment is highly complex and dynamic, with immune cells contributing to immunosuppressive conditions, stromal cells promoting tumor growth, and microbiota potentially affecting androgen metabolism. Vascular systems support angiogenesis, which fosters tumor expansion. Understanding these components offers insight into the mechanisms driving PCa progression and opens avenues for novel therapeutic strategies targeting the tumor microenvironment. Conclusions: A deeper understanding of the PCa microenvironment is crucial for advancing diagnostic techniques and developing precision therapies. This review highlights the potential of targeting the microenvironment to improve patient outcomes, emphasizing its significance in the broader context of PCa research and treatment innovation. [ABSTRACT FROM AUTHOR]