Cells Tissues Organs最新文献

Introduction: Human endometrium is one of peculiar tissues capable of scarless regeneration after injury during every menstrual cycle, birth or surgery. However, it is disputable whether this feature should be attributed to specific regulatory factors of wound environment and menstrual fluid (MF) or to tissue-specific properties of endometrial mesenchymal stromal cells (eMSC), which are pivotal participants of wound healing. We aimed to elucidate the role of eMSC tissue-specificity in wound healing.

Methods: We evaluated changes of eMSC transcriptomic profile in response to MF and their potency to granulation tissue formation in vitro in comparison with those of stromal cells from scar-forming organs - dermal and adipose MSC (dMSC and adMSC).

Results: We have found that MF contains numerous inflammatory factors and induces a profound inflammatory response in both eMSC and dMSC, but a tissue-specific component was identified in their transcriptome profiles. Furthermore, transcriptomic tissue-specificity was stable and present prior to MF treatment as well as after it, so we validated our findings against in vivo single-cell RNA-sequencing data from Human Protein Atlas. Tissue-specificity traits were related to embryonic development and morphogenesis, suggesting a putative contribution of "developmental imprinting" in its establishment. Using in vitro models of fibroplasia, angiogenesis and ECM deposition we showed that eMSC lack the ability to induce these processes in contrast to dMSC and adipose adMSC. Finally, we refined transcription factors from stably tissue-specific genes that may explain the unique properties of eMSC and endometrium itself and can serve as potential targets to induce regeneration in scar-forming organs.

Conclusion: eMSC possess tissue-specific properties including stable expression of transcription factors that may explain the scarless regeneration of endometrium.

Introduction Otic organoids differentiated from human pluripotent stem cells are three-dimensional in vitro cultures that broadly mimic the complexity and functionality of the human inner ear. They provide a valuable model for developmental and disease-related studies. However, current protocols differ substantially in efficiency and reproducibility. In this study, we investigated whether different stem cell maintenance media influence the differentiation of keratinocyte-derived induced pluripotent stem cells (kiPSCs) into the otic lineage. Methods Keratinocyte-derived iPSCs were cultured in either a self-made FTDA medium or the commercially available PeproGrow™ hESC medium and subsequently subjected to an established otic differentiation protocol. Early developmental stages, including the pre-placodal region, the otic placode, and pro-neural sensory regions, were analysed using immunofluorescence and gene expression profiling. Results While no significant differences were observed in iPSC maintenance or pluripotency between the two media, distinct differences emerged during otic differentiation. Media composition influenced the expression of placodal, otic, and pro-sensory markers at multiple stages, indicating differential responsiveness to otic induction cues. Conclusion Our findings demonstrate that stem cell maintenance media composition is a critical determinant of subsequent otic lineage differentiation. These results provide guidance for optimizing stem cell culture conditions and improving the reproducibility of otic organoid differentiation protocols.

Introduction: Features of the superior mesenteric artery (SMA) and its intestinal branches during the embryonic and early fetal periods have not been fully described. We aimed to comprehensively elucidate the characteristics of intestinal branch artery formation in the SMA.

Methods: Serial tissue sections of seven early fetal specimens belonging to the Blechschmidt collection were digitalized and used for segmentation and reconstruction of the intestinal loop, SMA trunk, intestinal branch arteries, and mesentery for further analysis.

Results: The intestinal branch arteries fed the intestinal tract from the oral side to the anal side, according to the order of their origin from the root to the periphery of the SMA trunk. SMA and intestinal branches were not as strongly conserved in their morphology as indicated in previous research but varied between specimens. Most intestinal branch arteries exhibited frequent branching with small intervals at the periphery, whereas the proximal branch exhibited few branches. Only a few peripheral branches made contact with the neighboring intestinal branch arteries. The fetal intestinal branch artery architecture differed greatly from that of adults. There were considerable inter- and intra-specimen variations in the intestinal tract length per feeding intestinal branch artery. The SMA branching arteries did not always supply each tertiary loop individually, and not every loop is connected to one branching artery.

Conclusion: This study elucidates the characteristics of forming the SMA intestinal branch arteries. Specifically, the findings suggest that the SMA is similar to other arteries in that its branches show a level of variability in feeding tissues.

Background: The trachea, a vital conduit in the lower airway system, can be affected by various disorders, such as tracheal neoplasms and tracheoesophageal fistulas, that often necessitate reconstruction. While short-segment defects can sometimes be addressed with end-to-end anastomosis, larger defects require tracheal reconstruction, a complex procedure with no universally successful replacement strategy. Tissue engineering offers a promising solution for tracheal repair, particularly focusing on regenerating its epithelium, which plays a critical role in protecting the respiratory system and facilitating mucociliary clearance. However, replicating the complex structure and functionality of the tracheal epithelium remains a significant challenge, with key hurdles including proper cell differentiation, functional mucociliary clearance, and addressing the relative lack of vascular supply to the trachea.

Summary: Current tissue engineering approaches, including biomaterial scaffolds, decellularized tissues, and scaffold-free methods, have shown varying levels of success, while in vitro air-liquid interface cultures have provided valuable insights into epithelial modeling. Despite these advances, translating these findings into effective in vivo applications remains difficult due to challenges such as immune responses, inadequate integration with host tissue, and limited long-term functionality of engineered constructs. Overcoming these barriers requires further refinement of cell sources, scaffold materials, and bioactive factors that promote vascularization and sustained epithelial function.

Key messages: This review evaluates the current strategies and modeling, biomaterial scaffolds, cells, and bioactive factors used in tracheal epithelium regeneration, as well as the methods employed to assess their success through histological, functional, and molecular analyses. While significant progress has been made, the development of a safe, functional, and clinically viable tracheal graft remains elusive, underscoring the need for continued innovation in airway tissue engineering. Future advancements in biomaterial design, stem cell technology, and bioreactor-based tissue maturation hold promise for addressing challenges.

Introduction: Prolonged space flights negatively affect the skeleton. Stromal cells of mesenchymal origin play a crucial role in maintaining homeostasis and in regulating the physiological remodeling of various tissues, and this has particular significance for bone.

Methods: Hindlimb unloading (HU) of rats as a ground-based model for simulation of microgravity was implemented. The functional activity of skeletal stem and progenitor cells (SSPCs) from rat femoral bones was assessed in vitro after 2 weeks of HU and after 2 weeks of subsequent recovery of load support (HU + reloading [HU + R]). To characterize the growth of the SSPCs, the number of population doublings (PDs) was calculated. Histochemical detection of the activity of alkaline phosphatase (AP) - an early marker of osteo-differentiation - on day 7, and of extracellular matrix (ECM) mineralization - as a sign of late osteo-differentiation - on day 21, were carried out. Quantitative real-time PCR was performed to detect the expression of the genes encoding proteins associated with the functional activity of osteoprogenitor cells (Pparg, Runx2, Alpl, Cxcl12) and bone tissue homeostasis (Mmp9, Spp1, RANKL, OPG, Ibsp, BMP10, Sost).

Results: After HU, a twofold decrease in the PD of the SSPCs, a decrease in AP activity and a significant attenuation of ECM mineralization were detected. There was also significant downregulation of the genes encoding proteins related to bone tissue homeostasis: those for bone matrix proteins (RANKL, OPG, Ibsp), and of the master-genes controlling osteo- and adipo-differentiation (Runx2, Alpl, Pparg), as well as of Mmp9, encoding a regulatory molecule of bone matrix remodeling. By contrast, sclerostin (Sost) was upregulated. After HU + R, the PD, as well as AP activity and the level of ECM mineralization were restored.

Conclusion: HU leads to inhibition of the osteoplastic function of SSPCs. The presented data are significant for the elucidation of microgravity-induced mechanisms of bone impairment and for the development of countermeasures for astronauts as well as for osteo-deficient patients after prolonged immobilization.

Introduction: In vitro expansion of primary human bone marrow stem cells (hBMSCs) is necessary to obtain sufficient cells for therapeutic uses. Unfortunately, hBMSCs rapidly lose their osteogenic differentiation potential during expansion, significantly limiting their applications. Signal transducer and activator of transcription 4 (STAT4) is known to play roles in cell migration, proliferation, and differentiation. This study aimed to determine the expression and the role of STAT4 during the expansion of hBMSCs.

Methods: STAT4 expression in different passages of hBMSCs was evaluated using qRT-PCR and Western blotting. RNA interference and adeno-associated virus serotype 2-mediated gene overexpression were employed to assess the function of STAT4. RNA samples from STAT4-overexpressing hBMSCs were analyzed by RNA-seq to identify differentially expressed genes (DEGs), followed by bioinformatics analyses to determine the pathways affected by STAT4.

Results: STAT4 expression progressively decreases during the in vitro expansion of hBMSCs, concomitant with the loss of osteogenic differentiation potential. STAT4 knockdown in early passage hBMSCs significantly inhibits their osteogenic differentiation, evidenced by markedly reduced calcium deposition and downregulation of osteogenic markers. STAT4 knockdown also reduces hBMSCs' proliferation ability. Conversely, STAT4 overexpression notably increases calcium deposition in passage 3 to passage 7 cells, suggesting that enhanced STAT4 expression can mitigate the loss of osteogenic potential during hBMSC expansion. Transcriptomic analysis revealed DEGs in STAT4-overexpressing hBMSCs. Subsequent bioinformatics analyses indicated that some of these DEGs are involved in pathways regulating cell differentiation and senescence.

Conclusion: The in vitro expansion of hBMSCs leads to the downregulation of STAT4, which contributes to the impairment of their osteogenic potential and may affect cell self-renewability. This study provides insight into the molecular mechanisms underlying the loss of osteogenic differentiation during hBMSC expansion and identifies STAT4 as a potential target for hBMSC-based bone regeneration therapies.

Introduction: Fibroblasts are central to a variety of homeostatic events such as wound healing and tissue regeneration. However, their pathologic activation is thought to play roles in a variety of diseases not only limited to fibrosis, foreign body reaction, scleroderma but also cancer metastasis. Biophysical properties of the extracellular matrix (ECM) deposited by an activated fibroblast determine whether there is a pro-regenerative or scarring response. Compared to aged fibroblasts, embryonic fibroblasts were shown to deposit a pro-regenerative ECM characterized by early hyaluronic acid (HA) deposition and increased levels of pro-regenerative collagens such as type III collagen. Since HA is also a regulator of collagen organization, we propose that early accumulation of HA by fibroblasts can facilitate pro-regenerative matrix formation. Given that the molecular weights of HA present in pro-regenerative matrix are higher than synthetic HA, we strategize attracting HA synthesized by fibroblasts. In this study, we used a synthetic peptide sequence known to have affinity to HA as a strategy to instruct fibroblasts to retain HA on the surface. We hypothesized that hyaluronic acid binding peptide (HABP) may instruct fibroblast endogenous HA deposition onto functionalized surfaces.

Methods: We functionalized silica glass surfaces with HABP using aminoorganosilane mediated chemisorption and screened primary human dermal fibroblasts (HDFs) for cell morphology, cytoskeletal arrangement, and alpha-smooth muscle actin (α-SMA) expression.

Results: Our results show HABP treated surfaces retain higher levels of HA on silica glass compared to control surfaces on fibroblast-derived matrices. Analysis of α-SMA shows increased α-SMA expression on hDFs and increased stress fiber formation. HABP treated surfaces were found to have reduced α-SMA expression. The physical features of collagen fibers deposited by fibroblasts were also organized differently in the presence of HABP.

Conclusion: Due to their ability to diminish fibroblast contractility and promote regenerative ECM production, HABPs are a potentially viable strategy to instruct pro-regenerative fibroblasts and can be used therapeutically to treat fibrotic diseases.

The article "Bathysa cuspidata Extract Modulates the Morphological Reorganization of the Scar Tissue and Accelerates Skin Wound Healing in Rats: A Time-Dependent Study" [Cells Tissues Organs. 2015; 199(4):266-277. https://doi.org/10.1159/000365504] by Reggiani V. Gonçalves, Rômulo D. Novaes, Marli C. Cupertino, Bruna M. Araújo, Emerson F. Vilela, Aline T. Machado, João P.V. Leite and Sérgio L.P. Matta has been retracted by the Publisher and the Editors.After the publication of this article, concerns were raised about the integrity of some of the data presented. Specifically, 4 panels in Figure 5 of this article are the same as 4 panels of Figure 1 of a subsequently published article by the same author group, representing different treatment groups, with image rotation and cropping in some instances, [1]. In addition, 2 panels of Figure 5 of this article are the same as 2 panels of Figure 4 of a previously published paper by the authors, representing different treatment groups, with image rotation [2].When asked to comment, the authors responded to the above concerns and stated that these errors occurred during the formatting of the figures due to the use of previously published figures as templates during training. Editorial review concluded that the errors highlighted issues in the data management and, consequently, the conclusions based on that data may not be reliable, and therefore, this article is being retracted.The authors have not responded to our correspondence regarding this retraction despite multiple attempts of contact.

Introduction: The underlying mechanisms by which these exosomes facilitate healing in deep burns remain unclear. This study aimed to investigate the effect of antler stem cell (AnSC)-derived exosomes (AnSC-exos) on burn wound healing and to provide new insights for the clinical treatment of deep burn wounds.

Methods: AnSC-exos were isolated through ultracentrifugation and subsequently administered to rat models with severe third-degree burn injuries. Wound closure rates, histological analysis, immunohistochemistry results and quantitative real-time PCR analysis were performed. In vitro, we assessed the effects of AnSC-exos on the proliferation and migration of human umbilical vein endothelial cells (HUVECs).

Results: Our results convincingly demonstrate that AnSC-exos significantly enhance the speed and quality of healing in burn wounds. At 28 days post-burn injury, we found elevated levels of CD31 and CD163 in the healing tissues, accompanied by a reduction in iNOS levels. Additionally, the relative mRNA expression levels of ColA2/Col3A1 and TGF-β1 were significantly lower than the AnSC-exos group compared to the control group (p < 0.001, p < 0.0001), while the relative mRNA levels of MMP3 were significantly higher (p < 0.05). In vitro, AnSC-exos promotes the proliferation and migration of HUVECs.

Conclusion: These results suggest that AnSC-exos facilitate burn wound repair by modulating M2 macrophage polarization, promoting angiogenesis, inhibiting myofibroblast production, and enhancing collagen deposition.

Introduction: A previous study confirmed the presence of adipose tissue along the posteromedial tibial border. This tissue may be the cause of medial shin pain, such as in medial tibial stress syndrome. However, the morphological and immunohistochemical characteristics of adipose tissue along the posteromedial tibial border remain unclear. In this study, we investigated the morphological and immunohistochemical characteristics of this tissue and compared them to those of the heel fat pad.

Methods: Seven cadavers were fixed in 10% formalin solution, and specimens were sampled from the adipose tissue along the posteromedial tibial border and heel fat pad.

Results: Scanning electron microscopy images showed a basket-like fibrous structure surrounding the adipocytes. This fibrous structure formed a three-dimensional network connecting adipocytes in both the posteromedial tibial border and the heel fat pad. The area and perimeter of the adipocytes were not significantly different between the adipose tissue along the posteromedial tibial border and the heel fat pads. Additionally, immunohistochemical staining confirmed that the fibres around the adipocytes were type I and III collagen fibres. These adipose tissues also reacted positively to substance P.

Conclusion: The morphological and immunohistochemical characteristics of the adipose tissue along the posteromedial tibial border may be a structure adapted to carry mechanical stress. Additionally, the presence of substance P indicated that the adipose tissue along the posteromedial tibial border may be a source of pain, such as that experienced in medial tibial stress syndrome.