A diminutive perivascular epithelioid cell tumor in the colon.

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal tumor. Some papers have reported that colonoscopy could be used to treat PEComa with a predominantly pedunculated polyp, whereas surgical intervention is often required for cases with submucosal-type tumors. These findings suggest that the morphology of PEComa changes dramatically with disease progression. Because of the rapid progression of PEComa, endoscopic treatment remains challenging, and early-stage PEComa morphology is not well understood. A 64-year-old man presented to our hospital for a follow-up colonoscopy after undergoing multiple polypectomies. He had a medical history of colorectal adenoma and prostate cancer. A 4-mm pale blue elevated but not pedunculated lesion was observed in the transverse colon, an area where he had not had polyps previously. Since no epithelial change was observed, the presence of a submucosal tumor, such as a gastrointestinal stromal tumor, was suspected. Cold snare polypectomy was performed, and the lesion was completely resected. Histological evaluation using hematoxylin and eosin staining identified that the submucosal tumor included thickened vascular walls and adipose tissue. Although fragmented due to significant degeneration, spindle-shaped cells staining positive for smooth muscle actin were observed within and surrounding the unstructured hyalinized tissue with calcifications. Based on these findings, the lesion was diagnosed as angiomyolipoma, a subtype of PEComa. Complete resection was confirmed by histopathology. To our knowledge, this PEComa is the smallest of any PEComa reported in the literature. Our finding provides valuable insights into the very early stage of colorectal PEComas.

Improved Preservation of Rat Small Intestine Transplantation Graft by Introduction of Mesenchymal Stem Cell-Secreted Fractions.

Segmental grafts from living donors have advantages over grafts from deceased donors when used for small intestine transplantation. However, storage time for small intestine grafts can be extremely short and optimal graft preservation conditions for short-term storage remain undetermined. Secreted factors from mesenchymal stem cells (MSCs) that allow direct activation of preserved small intestine grafts. Freshly excised Luc-Tg LEW rat tissues were incubated in preservation solutions containing MSC-conditioned medium (MSC-CM). Preserved Luc-Tg rat-derived grafts were then transplanted to wild-type recipients, after which survival, injury score, and tight junction protein expression were examined. Luminance for each graft was determined using in vivo imaging. The findings indicated that 30-100 and 3-10 kDa fractions of MSC-CM have superior activating effects for small intestine preservation. Expression of the tight-junction proteins claudin-3, and zonula occludens-1 preserved for 24 h in University of Wisconsin (UW) solution containing MSC-CM with 50-100 kDa, as shown by immunostaining, also indicated effectiveness. Reflecting the improved graft preservation, MSC-CM preloading of grafts increased survival rate from 0% to 87%. This is the first report of successful transplantation of small intestine grafts preserved for more than 24 h using a rodent model to evaluate graft preservation conditions that mimic clinical conditions.

USP9X inhibits metastasis in pulmonary sarcomatoid carcinoma by regulating epithelial-mesenchymal transition, angiogenesis and immune infiltration.

BACKGROUND: Pulmonary sarcomatoid carcinoma (PSC) is a highly invasive pulmonary malignancy with an extremely poor prognosis. The results of previous studies suggest that ubiquitin-specific peptidase 9X (USP9X) contributes to the progression of numerous types of cancer. Nevertheless, there is little knowledge about the molecular mechanisms and functions of USP9X in the metastasis of PSC. METHODS: Immunohistochemistry and western blotting were used to detect USP9X expression levels in PSC tissues and cells. Wound healing, transwell, enzyme-linked immunosorbent assay (ELISA), tube formation, and aortic ring assays were used to examine the function and mechanism of USP9X in the metastasis of PSC. RESULTS: Expression of USP9X was markedly decreased and significantly correlated with metastasis and prognosis of patients with PSC. Then we revealed that USP9X protein levels were negatively associated with the levels of epithelial-mesenchymal transition (EMT) markers and the migration of PSC cells. It was confirmed that USP9X in PSC cells reduced VEGF secretion and inhibited tubule formation of human umbilical vein endothelial cells (HUVEC) in vitro. USP9X was detected to downregulate MMP9. Meanwhile, MMP9 was positively related to EMT, angiogenesis and was negatively related to immune infiltration in the public databases. USP9X was significantly negatively associated with the expression of MMP9, EMT markers, CD31, and positively associated with CD4, and CD8 in PSC tissues. CONCLUSION: The present study reveals the vital role of USP9X in regulating EMT, angiogenesis and immune infiltration and inhibiting metastasis of PSC via downregulating MMP9, which provides a new effective therapeutic target for PSC.

Extracellular vesicles derived from "serum and glucose" deprived HUCMSCs promoted skin wound healing through enhanced angiogenesis.

Extracellular vesicles (EVs) produced from MSCs were currently considered as a novel therapeutic agent for skin tissue regeneration and repair. Preconditioning stem cells may activate more molecular pathways and release more bioactive agents. In this study, we obtained EVs from normal (N-EVs) and serum- and glucose-deprived (SGD-EVs) human umbilical cord mesenchymal stem cells (HUCMSCs), and showed that SGD-EVs promoted the migration, proliferation, and tube formation of HUVECs in vitro. In vivo experiments utilizing a rat model show that both N-EVs and SGD-EVs boosted angiogenesis of skin defects and accelerated skin wound healing, while treating wounds with SGD-EVs led to faster skin healing and enhanced angiogenesis. miRNA sequencing showed that miR-29a-3p was abundant in SGD-EVs, and overexpressing miR-29a-3p enhanced the angiogenic ability of HUVECs, while inhibiting miR-29a-3p presented the opposite effect. Further studies demonstrated that miR-29a-3p directly targeted CTNNBIP1, which mediated angiogenesis of HUCMSCs-derived EVs through inhibiting CTNNBIP1 to activate Wnt/ß-catenin signaling pathway. Taken together, these findings suggested that SGD-EVs promote angiogenesis via transferring miR-29a-3p, and activation of Wnt/ß-catenin signaling pathway played a crucial role in SGD-EVs-induced VEGFA production during wound angiogenesis. Our results offered a new avenue for modifying EVs to enhance tissue angiogenesis and augment its role in skin repair.

Upstream Process Protocol for MSCs Isolated from Different Human-Based Tissue Origins.

This chapter introduces the increasing significance of mesenchymal stromal/stem cell (MSC) production in regenerative medicine and cellular therapeutics, outlines the growing interest in MSCs for various medical applications, and highlights their potential in advanced therapy medicinal products (ATMPs) and the advancements in cell culture technologies that have facilitated large-scale MSC production under Good Manufacturing Practices (GMP), ensuring safety and efficacy. This chapter describes an optimized upstream protocol for laboratory-scale MSC production from different tissue sources. This protocol, conducted in flasks, controls critical parameters and lays the foundation for downstream processing to generate ATMPs. This comprehensive approach underscores the potential of MSCs in clinical applications and the importance of tailored production processes.

A Gastrointestinal Stromal Tumor (GIST) and a Pseudocyst of the Pancreas: A Peculiar Case of Both Co-existing in the Same Patient.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal (GI) tract, typically originating from the interstitial cells of Cajal. The clinical presentations are variable according to their size and shape but rarely present as a palpable abdominal mass. Pancreatic pseudocysts are common complications of chronic pancreatitis characterized by fluid collections surrounded by a non-epithelialized wall of fibrous and granulation tissue. Patients may present with non-specific symptoms like abdominal pain, nausea, and vomiting and they generally have a history of acute pancreatitis. Small pseudocysts often resolve spontaneously, but larger ones often become symptomatic and may lead to complications. It is rare to find both a GIST of the stomach and a pseudocyst of the pancreas in the same patient. We present a unique case of a giant GIST and a pancreatic pseudocyst in a 72-year-old male who was experiencing abdominal pain and distension. Imaging revealed a massive lesion originating from the posterior gastric wall, which resembled a pseudocyst, along with a distinct cystic lesion adjacent to the pancreatic body. During surgical exploration, a complex interplay of both pathologies was discovered, requiring a comprehensive resection approach. The successful outcome highlights the importance of careful evaluation and personalized management in such rare cases.

Human placental mesenchymal stromal cells promote the formation of CD8+CD122+PD-1+Tregs via CD73/Foxo1 to alleviate liver injury in graft-versus-host disease mice.

BACKGROUND: Human placental mesenchymal stromal cells (hPMSCs) are known to limit graft-versus-host disease (GVHD). CD8+CD122+PD-1+Tregs have been shown to improve the survival of GVHD mice. However, the regulatory roles of hPMSCs in this subgroup remain unclear. Here, the regulatory mechanism of hPMSCs in reducing liver fibrosis in GVHD mice by promoting CD8+CD122+PD-1+Tregs formation and controlling the balance of IL-6 and IL-10 were explored. METHODS: A GVHD mouse model was constructed using C57BL/6J and BALB/c mice and treated with hPMSCs. LX-2 cells were explored to study the effects of IL-6 and IL-10 on the activation of hepatic stellate cells (HSCs). The percentage of CD8+CD122+PD-1+Tregs and IL-10 secretion were determined using FCM. Changes in hepatic tissue were analysed by HE, Masson, multiple immunohistochemical staining and ELISA, and the effects of IL-6 and IL-10 on LX-2 cells were detected using western blotting. RESULTS: hPMSCs enhanced CD8+CD122+PD-1+Treg formation via the CD73/Foxo1 and promoted IL-10, p53, and MMP-8 levels, but inhibited IL-6, HLF, α-SMA, Col1α1, and Fn levels in the liver of GVHD mice through CD73. Positive and negative correlations of IL-6 and IL-10 between HLF were found in liver tissue, respectively. IL-6 upregulated HLF, α-SMA, and Col1α1 expression via JAK2/STAT3 pathway, whereas IL-10 upregulated p53 and inhibited α-SMA and Col1α1 expression in LX-2 cells by activating STAT3. CONCLUSIONS: hPMSCs promoted CD8+CD122+PD-1+Treg formation and IL-10 secretion but inhibited HSCs activation and α-SMA and Col1α1 expression by CD73, thus controlling the balance of IL-6 and IL-10, and alleviating liver injury in GVHD mice.

Functional variation among mesenchymal stem cells derived from different tissue sources.

Background: Mesenchymal stem cells (MSCs) are increasingly recognized for their regenerative potential. However, their clinical application is hindered by their inherent variability, which is influenced by various factors, such as the tissue source, culture conditions, and passage number. Methods: MSCs were sourced from clinically relevant tissues, including adipose tissue-derived MSCs (ADMSCs, n = 2), chorionic villi-derived MSCs (CMMSCs, n = 2), amniotic membrane-derived MSCs (AMMSCs, n = 3), and umbilical cord-derived MSCs (UCMSCs, n = 3). Passages included the umbilical cord at P0 (UCMSCP0, n = 2), P3 (UCMSCP3, n = 2), and P5 (UCMSCP5, n = 2) as well as the umbilical cord at P5 cultured under low-oxygen conditions (UCMSCP5L, n = 2). Results: We observed that MSCs from different tissue origins clustered into six distinct functional subpopulations, each with varying proportions. Notably, ADMSCs exhibited a higher proportion of subpopulations associated with vascular regeneration, suggesting that they are beneficial for applications in vascular regeneration. Additionally, CMMSCs had a high proportion of subpopulations associated with reproductive processes. UCMSCP5 and UCMSCP5L had higher proportions of subpopulations related to female reproductive function than those for earlier passages. Furthermore, UCMSCP5L, cultured under low-oxygen (hypoxic) conditions, had a high proportion of subpopulations associated with pro-angiogenic characteristics, with implications for optimizing vascular regeneration. Conclusions: This study revealed variation in the distribution of MSC subpopulations among different tissue sources, passages, and culture conditions, including differences in functions related to vascular and reproductive system regeneration. These findings hold promise for personalized regenerative medicine and may lead to more effective clinical treatments across a spectrum of medical conditions.

Desmoid Tumor of the Rectus Abdominis Muscle: A Case Report.

Desmoid tumors, also referred to as aggressive fibromatosis, represent an uncommon form of fibroblastic proliferation. These neoplasms may arise within any musculoaponeurotic structure throughout the body. They are classified as benign due to several distinctive features: histologically, they exhibit regular mitotic activity and are devoid of metastatic potential. Computed tomography (CT) remains the definitive modality for precise diagnosis, and surgical excision is strongly advised. This account details the manifestation of a desmoid tumor located in the anterior abdominal wall of a 31-year-old female patient who notably lacks any prior surgical interventions. The surgical intervention entailed the excision of the neoplasm and subsequent reconstruction of the abdominal wall utilizing a polypropylene mesh. Postoperatively, the patient was released from the medical facility after a period of three days, having experienced no post-surgical complications. This was followed by a six-month interval free of any adverse events.

A Giant Malignant Solitary Fibrous Tumor of the Pancreas: A Case Report and Review of the Literature.

We present a case report of a giant solitary fibrous tumor (SFT) with a review of the literature and discuss its biological features and diagnosis. A 43-year-old man presented to our emergency department with abdominal pain and distension with an evolution of two days. Contrast-enhanced computed tomography (CT) showed a large, well-circumscribed semisolid mass (12 cm x 10 cm x 12 cm) localized in the pancreatic head. The histological diagnosis obtained by endoscopic ultrasound-guided trans-duodenal tumor biopsy with fine-needle aspiration showed proliferating short spindle-shaped cells, suggesting a mesenchymal neoplasia of low grade. We proceeded to a Whipple surgical technique. The histopathological study of the resected tumor confirmed proliferating spindle-shaped cells in the tissue, and one mitotic figure was observed in 10 high-power fields (HPFs). Immunostaining was positive for CD34 and STAT-6. The histological diagnosis was a malignant pancreatic SFT. In the six months posterior to the surgical procedure, the patient has been free of recurrent disease. Preoperative diagnosis is difficult and requires comprehensive evidence including clinical, immunohistochemistry, and histological features. Since there are currently no recognized best practices, we advise total surgical excision and careful clinical monitoring.

Combined effect of naringin and adipose tissue-derived mesenchymal stem cell on cisplatin nephrotoxicity through Sirtuin1/Nrf-2/HO-1 signaling pathway: a promising nephroprotective candidate.

Cisplatin nephrotoxicity is a well-known emergency clinical condition caused by oxidative stress and inflammation. Naringin (NAR) is considered an antioxidant agent with renoprotective effects capable of removing reactive oxygen species. Adipose tissue-derived mesenchymal stem cells (AD-MSCs) are reported to have anti-inflammatory and antioxidant properties. The present research examined the renoprotective effect of the combination of NAR and AD-MSCs as opposed to each one alone on cisplatin-induced nephrotoxicity through SIRT-1/Nrf-2/HO-1 pathway. This study included five groups (n = 8 each) of male Sprague-Dawley rats (200 - 220 g): sham, cisplatin: rats receiving cisplatin (6.5 mg/kg, i.p.) on the 4th day; NAR+cisplatin: rats pretreated with NAR (1 week, i.p.) + cisplatin on the 4th day; AD-MSCs: rats receiving AD-MSCs (1 × 106) by injection through the tail vein on the 5th day + cisplatin on the 4th day; and NAR+AD-MSCs+cisplatin. On the 8th day, the animals were anesthetized to obtain tissue and blood samples. Biochemical factors, inflammation, oxidative stress, and gene expression were explored. Cisplatin increased blood urea nitrogen, creatinine, inflammation, and oxidative stress. Moreover, mRNA expression of Sirtuin1, nuclear factor erythroid 2-related factor 2 (Nrf-2), and heme oxygenase-1 (HO-1) remarkably reduced. Furthermore, cisplatin led to a disturbance in kidney structure (glomerular atrophy, cell infiltrations, and tubular dysfunction) as confirmed by histology findings. However, NAR pretreatment, AD-MSC administration, or a combination of both significantly reversed these changes. Overall, when used together, NAR and AD-MSCs had stronger cisplatin-induced effects on kidney dysfunction by inhibiting inflammation, reducing oxidative stress, and increasing the Sirtuin1/Nrf-2/HO-1 pathway.

SARS-CoV-2-related peptides induce endothelial-to-mesenchymal transition in endothelial capillary cells derived from different body districts: focus on membrane (M) protein.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19, may lead to multiple organ dysfunctions and long-term complications. The induction of microvascular dysfunction is regarded as a main player in these pathological processes. To investigate the possible impact of SARS-CoV-2-induced endothelial-to-mesenchymal transition (EndMT) on fibrosis in "long-COVID" syndrome, we used primary cultures of human microvascular cells derived from the lungs, as the main infection target, compared to cells derived from different organs (dermis, heart, kidney, liver, brain) and to the HUVEC cell line. To mimic the virus action, we used mixed SARS-CoV-2 peptide fragments (PepTivator®) of spike (S), nucleocapsid (N), and membrane (M) proteins. TGFß2 and cytokine mix (IL-1ß, IL-6, TNFα) were used as positive controls. The percentage of cells positive to mesenchymal and endothelial markers was quantified by high content screening. We demonstrated that S+N+M mix induces irreversible EndMT in all analyzed endothelial cells via the TGFß pathway, as demonstrated by ApoA1 treatment. We then tested the contribution of single peptides in lung and brain cells, demonstrating that EndMT is triggered by M peptide. This was confirmed by transfection experiment, inducing the endogenous expression of the glycoprotein M in lung-derived cells. In conclusion, we demonstrated that SARS-CoV-2 peptides induce EndMT in microvascular endothelial cells from multiple body districts. The different peptides play different roles in the induction and maintenance of the virus-mediated effects, which are organ-specific. These results corroborate the hypothesis of the SARS-CoV-2-mediated microvascular damage underlying the multiple organ dysfunctions and the long-COVID syndrome.

The Effect of Exercise on Mesenchymal Stem Cells and their Application in Obesity Treatment.

Mesenchymal stem cells (MSCs) have demonstrated considerable potential in tissue repair and the treatment of immune-related diseases, but there are problems with homing efficiency during MSCs transplantation. Exercise, as an intervention, has been shown to have an important impact on the properties of MSCs. This review summarizes the effects of exercise on the properties (including proliferation, apoptosis, differentiation, and homing) of bone marrow-derived MSCs and adipose-derived MSCs. Studies indicated that exercise enhances bone marrow-derived MSCs proliferation, osteogenic differentiation, and homing while reducing adipogenic differentiation. For adipose-derived MSCs, exercise enhances proliferation and reduces adipogenic differentiation. In addition, studies have investigated the therapeutic effects of combined therapy of MSCs transplantation with exercise on diseases of the bone, cardiac, and nervous systems. The combined therapy improves tissue repair by increasing the homing of transplanted MSCs and cytokine secretion (such as neurotrophin 4). Furthermore, MSCs transplantation also has potential for the treatment of obesity. Although the effect is not significant in weight loss, MSCs transplantation shows effects in controlling blood glucose, improving dyslipidemia, reducing inflammation, and improving liver disease. Finally, the potential role of combined MSCs transplantation and exercise therapy in addressing obesity is discussed.

Structurally and mechanically tuned macroporous hydrogels for scalable mesenchymal stem cell-extracellular matrix spheroid production.

Mesenchymal stem cells (MSCs) are essential in regenerative medicine. However, conventional expansion and harvesting methods often fail to maintain the essential extracellular matrix (ECM) components, which are crucial for their functionality and efficacy in therapeutic applications. Here, we introduce a bone marrow-inspired macroporous hydrogel designed for the large-scale production of MSC-ECM spheroids. Through a soft-templating approach leveraging liquid-liquid phase separation, we engineer macroporous hydrogels with customizable features, including pore size, stiffness, bioactive ligand distribution, and enzyme-responsive degradability. These tailored environments are conducive to optimal MSC proliferation and ease of harvesting. We find that soft hydrogels enhance mechanotransduction in MSCs, establishing a standard for hydrogel-based 3D cell culture. Within these hydrogels, MSCs exist as both cohesive spheroids, preserving their innate vitality, and as migrating entities that actively secrete functional ECM proteins. Additionally, we also introduce a gentle, enzymatic harvesting method that breaks down the hydrogels, allowing MSCs and secreted ECM to naturally form MSC-ECM spheroids. These spheroids display heightened stemness and differentiation capacity, mirroring the benefits of a native ECM milieu. Our research underscores the significance of sophisticated materials design in nurturing distinct MSC subpopulations, facilitating the generation of MSC-ECM spheroids with enhanced therapeutic potential.

Compact bone mesenchymal stem cells-derived paracrine mediators for cell-free therapy in sepsis.

Sepsis, a life-threatening condition resulting in multiple organ dysfunction, is characterized by a dysregulated immune response to infection. Current treatment options are limited, leading to unsatisfactory outcomes for septic patients. Here, we present a series of studies utilizing compact bone mesenchymal stem cells (CB-MSCs) and their derived paracrine mediators, especially exosome (CB-MSCs-Exo), to treat mice with cecal ligation and puncture-induced sepsis. Our results demonstrate that CB-MSCs treatment significantly improves the survival rate of septic mice by mitigating excessive inflammatory response and attenuating sepsis-induced organ injuries. Furthermore, CB-MSCs-conditioned medium, CB-MSCs secretome (CB-MSCs-Sec), and CB-MSCs-Exo exhibit potent anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated murine macrophage (RAW264.7). Intriguingly, intravenous administration of CB-MSCs-Exo confers superior protection against inflammation and organ damage in septic mice compared to CB-MSCs in certain aspects. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS) shotgun proteomic analysis, we identify a range of characterized proteins derived from the paracrine activity of CB-MSCs, involved in critical biological processes such as immunomodulation and apoptosis. Our findings highlight that the paracrine products of CB-MSCs could serve as a promising cell-free therapeutic agent for sepsis.

Accumulation of DNA G-quadruplex in mitochondrial genome hallmarks mesenchymal senescence.

Searching for biomarkers of senescence remains necessary and challenging. Reliable and detectable biomarkers can indicate the senescence condition of individuals, the need for intervention in a population, and the effectiveness of that intervention in controlling or delaying senescence progression and senescence-associated diseases. Therefore, it is of great importance to fulfill the unmet requisites of senescence biomarkers especially when faced with the growing global senescence nowadays. Here, we established that DNA G-quadruplex (G4) in mitochondrial genome was a reliable hallmark for mesenchymal senescence. Via developing a versatile and efficient mitochondrial G4 (mtG4) probe we revealed that in multiple types of senescence, including chronologically healthy senescence, progeria, and replicative senescence, mtG4 hallmarked aged mesenchymal stem cells. Furthermore, we revealed the underlying mechanisms by which accumulated mtG4, specifically within respiratory chain complex (RCC) I and IV loci, repressed mitochondrial genome transcription, finally impairing mitochondrial respiration and causing mitochondrial dysfunction. Our findings endowed researchers with the visible senescence biomarker based on mitochondrial genome and furthermore revealed the role of mtG4 in inhibiting RCC genes transcription to induce senescence-associated mitochondrial dysfunction. These findings depicted the crucial roles of mtG4 in predicting and controlling mesenchymal senescence.

The differences between pure and mixed invasive micropapillary breast cancer: the epithelial-mesenchymal transition molecules and prognosis.

PURPOSE: Invasive micropapillary carcinoma (IMPC) of the breast is known for its high metastatic potential, but the definition of pure and mixed IMPC remains unclear. This retrospective cohort study aims to investigate the prognostic significance of the micropapillary component ratio and the expression of critical molecules of epithelial-mesenchymal transition (EMT), including E-cadherin (E-cad), N-cadherin (N-cad), CD44s, and ß-catenin (ß-cat), in distinguishing between pure and mixed IMPCs. METHODS: We analyzed 100 cases of locally advanced IMPC between 2000 and 2018 and excluded patients who received neoadjuvant chemotherapy. Pure IMPC was defined as having a micropapillary component of over 90%. A comprehensive recording of prognostic parameters was conducted. The IMPC areas were analyzed using the immunohistochemical (IHC) staining method on the microarray set for pure and mixed IMPC patients. Pearson's chi-square, Fisher's exact tests, Kaplan-Meier analysis, and Cox proportional hazards analysis were employed. RESULTS: The comparative survival analysis of the entire group, based on overall survival (OS) and disease-free survival (DFS), revealed no significant difference between the pure and mixed groups (P = 0.480, HR = 1.474 [0.502-4.325] and P = 0.390, HR = 1.587 [0.550-4.640], respectively). However, in the pure IMPC group, certain factors were found to be associated with a higher risk of short survival. These factors included skin involvement (P = 0.050), pT3&4 category (P = 0.006), a ratio of intraductal component (> 5%) (P = 0.032), and high-level expression of N-cad (P = 0.020). Notably, none of the risk factors identified for short OS in pure IMPC cases were observed as significant risks in mixed cases and vice versa. Furthermore, N-cad was identified as a poor prognostic marker for OS in pure IMPCs (P = 0.002). CONCLUSION: The selection of a 90% ratio for classifying pure IMPCs revealed significant differences in certain molecular and prognostic parameters between pure and mixed groups. Notably, the involvement of N-cadherin in the epithelial-mesenchymal transition (EMT) process provided crucial insights for predicting OS and DFS while also distinguishing between the two groups. These findings strongly support the notion that the pure IMPC subgroup represents a distinct entity characterized by unique molecular characteristics and behavioral patterns.

T. gondii excretory proteins promote the osteogenic differentiation of human bone mesenchymal stem cells via the BMP/Smad signaling pathway.

BACKGROUND: Bone defects, resulting from substantial bone loss that exceeds the natural self-healing capacity, pose significant challenges to current therapeutic approaches due to various limitations. In the quest for alternative therapeutic strategies, bone tissue engineering has emerged as a promising avenue. Notably, excretory proteins from Toxoplasma gondii (TgEP), recognized for their immunogenicity and broad spectrum of biological activities secreted or excreted during the parasite's lifecycle, have been identified as potential facilitators of osteogenic differentiation in human bone marrow mesenchymal stem cells (hBMSCs). Building on our previous findings that TgEP can enhance osteogenic differentiation, this study investigated the molecular mechanisms underlying this effect and assessed its therapeutic potential in vivo. METHODS: We determined the optimum concentration of TgEP through cell cytotoxicity and cell proliferation assays. Subsequently, hBMSCs were treated with the appropriate concentration of TgEP. We assessed osteogenic protein markers, including alkaline phosphatase (ALP), Runx2, and Osx, as well as components of the BMP/Smad signaling pathway using quantitative real-time PCR (qRT-PCR), siRNA interference of hBMSCs, Western blot analysis, and other methods. Furthermore, we created a bone defect model in Sprague-Dawley (SD) male rats and filled the defect areas with the GelMa hydrogel, with or without TgEP. Microcomputed tomography (micro-CT) was employed to analyze the bone parameters of defect sites. H&E, Masson and immunohistochemical staining were used to assess the repair conditions of the defect area. RESULTS: Our results indicate that TgEP promotes the expression of key osteogenic markers, including ALP, Runx2, and Osx, as well as the activation of Smad1, BMP2, and phosphorylated Smad1/5-crucial elements of the BMP/Smad signaling pathway. Furthermore, in vivo experiments using a bone defect model in rats demonstrated that TgEP markedly promoted bone defect repair. CONCLUSION: Our results provide compelling evidence that TgEP facilitates hBMSC osteogenic differentiation through the BMP/Smad signaling pathway, highlighting its potential as a therapeutic approach for bone tissue engineering for bone defect healing.

Revisiting the role of mesenchymal stromal cells in cancer initiation, metastasis and immunosuppression.

Immune checkpoint blockade (ICB) necessitates a thorough understanding of intricate cellular interactions within the tumor microenvironment (TME). Mesenchymal stromal cells (MSCs) play a pivotal role in cancer generation, progression, and immunosuppressive tumor microenvironment. Within the TME, MSCs encompass both resident and circulating counterparts that dynamically communicate and actively participate in TME immunosurveillance and response to ICB. This review aims to reevaluate various facets of MSCs, including their potential self-transformation to function as cancer-initiating cells and contributions to the creation of a conducive environment for tumor proliferation and metastasis. Additionally, we explore the immune regulatory functions of tumor-associated MSCs (TA-MSCs) and MSC-derived extracellular vesicles (MSC-EVs) with analysis of potential connections between circulating and tissue-resident MSCs. A comprehensive understanding of the dynamics of MSC-immune cell communication and the heterogeneous cargo of tumor-educated versus naïve MSCs may unveil a new MSC-mediated immunosuppressive pathway that can be targeted to enhance cancer control by ICB.