Tissue engineering and regenerative medicine最新文献

Background: Cell replacement therapy is the only treatment that restores or repairs the function of impaired tissues in neurodegenerative diseases, including vascular dementia (VaD); however, current VaD treatments focus on slowing or mitigating the underlying small vessel disease progression. We aimed to verify the improvement in neurocognition after administering human-induced pluripotent stem cell (hiPSC)-derived neural progenitor cells (NPCs) from in a VaD animal model.

Methods: After anesthesia, 10-12-week-old male C5BL/6 mice underwent sham or bilateral carotid artery stenosis (BCAS) surgeries. For BCAS, 0.18-mm micro-coils were wound around the bilateral common carotid arteries to induce chronic vascular insufficiency in the global brain. One day after surgery, the mice were administered phosphate buffer solution or NPC from hiPSCs via the tail vein for 15 d, and divided into sham (n = 6), VEH (n = 6), and NPC (n = 7) groups. Three months after the surgery, neurobehavioral tests including the Y-maze test (YMT), passive avoidance test (PAT), and novel object recognition test (NORT) were performed. Finally, mice brains were sectioned for evaluating microglia (Iba-1), astrocyte (GFAP) activation, and myelin (MBP) degeneration through immunohistochemistry (IHC).

Results: PAT latency (p = 0.01) and discrimination index in the NORT (p = 0.043) increased considerably in the NPC group than in the VEH group. However, alterations in YMT were not considerably higher in the NPC group than in the VEH group (p = 0.65). IHC tests revealed that the GFAP- and IBA-1-positive cell number was remarkably lower in the NPC group than in the VEH group (p < 0.05). Moreover, MBP density was higher in the NPC group.

Conclusion: hiPSC-derived NPCs have therapeutic potential in cerebral hypoperfusion VaD mice; it improves the working memory of VaD animals by diminishing inflammatory reactions and protecting them from demyelination.

Background: Mild head trauma often leads to long-term cognitive and neurological deficits. PLX3397, an inhibitor of colony-stimulating factor 1 receptor (CSF1R), offers promise as a therapeutic agent for traumatic brain injury (TBI) by targeting neuro-inflammation. Stem cell-based approaches are widely studied for neurological disorders. The objective of this study was to investigate therapeutic effect of intranasal administration of human neural crest-derived nasal turbinate stem cells (hNTSCs) on mild TBI in comparison with that of PLX3397.

Methods: We developed a model of mice with repetitive and mild TBI following a weight-drop once a day for 5 days. PLX3397 (50 mg/kg, p. o.) was administered for 21 days. Intranasal administration of hNTSCs (1 × 10⁶) was performed once.

Results: Iba1 + and GFAP + cells were increased in the cortex and hippocampus of TBI models. Iba1 + cells and GFAP + cells were remarkably decreased in PLX3397 or hNTSC-treated TBI models. Administration of PLX3397 attenuated the decrease in neurobehavioral activity. Similar effects were observed in a TBI model with a single dose of hNTSC.

Conclusion: Intranasal administration of hNTSCs had a microglia-depleting effect. Administered hNTSCs were found around the cortex and hippocampus of TBI brains. This investigation may provide a promising path for therapeutic initiatives for repetitive and mild TBI.

Background: Buccal mucosa urethroplasty represents the primary strategy for reconstruction of long urethral strictures (US). However, significant complications including stricture recurrence and donor site morbidity currently hamper this approach. The goal of this study was to determine the efficacy of acellular, bi-layer silk fibroin (BLSF) biomaterials to serve as superior alternatives to buccal mucosal (BM) grafts for repair of 4 cm long US in female swine.

Methods: Urethral mucosal damage was induced over 4-5 cm long segments via electrocoagulation in adult female swine (N = 10) to promote US over the course of 2-4 weeks. Onlay urethroplasty with BLSF scaffolds or autologous BM grafts (N = 5 per group, ~ 4 cm²) was subsequently performed and animals were maintained for 3 months. Outcome analyses included urethroscopy, retrograde urethrography (RUG), and histological and immunohistochemical (IHC) analyses. Non operated urethral segments served as internal controls (N = 10).

Results: All swine survived the study with no severe complications and exhibited US formation following electrocoagulation with a 43-57% reduction in baseline calibers. At 3 months post-op, imaging modalities revealed both graft cohorts promoted > 80% restoration of native urethral calibers. Histological and IHC evaluations showed BLSF grafts supported the formation of innervated, vascularized urethral-like neotissues with α-smooth muscle actin + and SM22α + smooth muscle bundles as well as pan-cytokeratin + epithelia reminiscent of controls. In contrast, BM grafts primarily retained native oral tissue morphology after urethral transposition exhibiting cytokeratin 1 + stratified, squamous epithelia and scant muscle formation.

Conclusions: BLSF matrices can promote functional restoration of long US via regeneration of native urethral tissues.

Background: The bone lacunar-canalicular system (LCS) is an important microscopic infrastructure for signaling and solute transport in bone tissue, which guarantees the normal physiological processes of bone tissue, and there is a direct relationship between osteoporosis and intrabody mass transfer; however, the mass transfer pattern of the LCS has not yet been clarified under different intensities of in extracorporeal shock waves. The present study aims to assess the effect of extracorporeal shock waves on mass transfer in LCS.

Methods: Sodium fluorescein tracer was taken as the transport substance, and the fluorescence intensities of osteocytes at lacuna in bovine cortical bone were used to indicate the mass transfer effect. The free diffusion and different extracorporeal shock waves were performed in LCS experiments and the fluorescence intensities of the superficial, shallow, middle, and deep layers of osteocytes, which were arranged in a proximity-to-distant order away from the Haversian canal, were detected by laser scanning confocal microscopy.

Results: The results showed that, under different shock waves, the fluorescence intensities of superficial lacunae were the highest in an osteon, followed by shallow and middle layers, and the fluorescence intensities of deep lacunae furthest from the Haversian canal were the lowest, with a decreasing trend and a decreased range of 44.75-97.11%. Relative to free diffusion, the fluorescence intensities of the lacunae in each layer increased by 33.16%, 20.56%, 16.11%, and 26.64% in the superficial, shallow, middle, and deep layers of osteocytes, respectively, under the effect of the extracorporeal shock waves at 1 bar; the fluorescence intensities of the middle layer increased by 100.03% when the intensity was 5 bar, and average fluorescence intensities increased the most with an incremental value of 81.34% in all different shock waves; the fluorescence intensities of the lacunae of each layer was enhanced with a range of 110.93-161.03% by 8 bar.

Conclusion: Extracorporeal shock waves promoted tracer mass transfer within the LCS, and the higher the shock wave magnitudes, the larger the mass transfer in LCS. The transport of solute molecules, nutrients, and signaling molecules within the LCS was facilitated by the extracorporeal shock waves, which may help to address bone diseases such as osteoporosis from the direction of mass transfer in LCS.

Background: Systemic inflammation, often induced by elevated circulating lipopolysaccharide (LPS) levels, is a common consequence of intestinal epithelial barrier damage and microbial translocation. This condition is particularly prevalent in menopausal women, who are at increased risk for chronic inflammation and metabolic syndrome due to physiological changes during menopause. Myo-inositol has been shown to improve metabolic profiles in menopausal women with metabolic syndrome. In this study, we investigated whether small extracellular vesicles (sEVs) from human palatine tonsil-derived mesenchymal stem cells (T-MSCs) can restore circulating myo-inositol levels and promote myo-inositol synthesis in skeletal muscle under repeated LPS exposure, mimicking the intestinal leakage seen in menopausal women.

Methods: Over 2 weeks period, LPS was repeatedly administered to mice, along with a group that also received T-MSC-derived sEVs. After 15 days, the expression of proteins involved in inositol synthesis in skeletal muscle, and serum inositol levels were measured. Additionally, intracellular inositol expression was compared in LPS-treated skeletal muscle cells with and without T-MSC sEVs treatment in vitro. Lastly, the protein and microRNA composition of T-MSC sEVs was analyzed.

Results: Our results demonstrated that T-MSC-derived sEVs significantly increased serum myo-inositol levels and enhanced the expression of myo-inositol synthesis proteins in mice exposed to LPS. Similarly, LPS-treated myotubes supplemented with T-MSC sEVs exhibited restored myo-inositol expression. Moreover, T-MSC sEVs were found to contain high levels of muscle-related proteins.

Conclusion: These findings suggest that T-MSC sEVs may serve as a promising therapeutic strategy for mitigating the effects of intestinal leakage and chronic inflammation in menopausal women. By improving skeletal muscle mass and maintaining myo-inositol levels, T-MSC sEVs offer potential for addressing metabolic disturbances associated with menopause.

Background: The contraction behaviors of cardiomyocytes (CMs), especially contraction synchrony, are crucial factors reflecting their maturity and response to drugs. A wider field of view helps to observe more pronounced synchrony differences, but the accompanied greater computational load, requiring more computing power or longer computational time.

Methods: We proposed a method that directly correlates variations in optical field brightness with cardiac tissue contraction status (CVB method), based on principles from physics and photometry, for rapid video analysis in wide field of view to obtain contraction parameters, such as period and contraction propagation direction and speed.

Results: Through video analysis of human induced pluripotent stem cell (hiPSC)-derived CMs labeled with green fluorescent protein (GFP) cultured on aligned and random nanofiber scaffolds, the CVB method was demonstrated to obtain contraction parameters and quantify the direction and speed of contraction within regions of interest (ROIs) in wide field of view. The CVB method required less computation time compared to one of the contour tracking methods, the Lucas-Kanade (LK) optical flow method, and provided better stability and accuracy in the results.

Conclusion: This method has a smaller computational load, is less affected by motion blur and out-of-focus conditions, and provides a potential tool for accurate and rapid analysis of cardiac tissue contraction synchrony in wide field of view without the need for more powerful hardware.

Background: Bone marrow aspiration concentrate (BMAC) has gained acceptance as a safe orthobiologic for treating osteoarthritis (OA), despite lacking robust supporting evidence. Although several publications have documented the use of BMAC in OA, evidence confirming its unequivocal efficacy remains limited.

Methods: This review aims to summarize the current clinical evidence regarding BMAC as a therapeutic for OA, while also presenting the author's perspective. Sixteen studies were reviewed, including ten randomized clinical trials (RCTs) and six cohort studies.

Results: From the review of existing literature, BMAC injections do not appear to significantly improve pain and function compared to conventional therapies such as hyaluronic acid and corticosteroids, although some studies report a longer duration of effectiveness. Furthermore, the evidence for structural improvement, which was the original rationale for cell therapy, is seldom reported.

Conclusion: In light of these findings, it is suggested that high-quality data from a large patient cohort is needed to determine the role of BMAC injections in OA treatment and address reimbursement issues. From the author's perspective, the introduction of a national registry system that provides valuable information on the cost-effectiveness of various orthopedic procedures may offer a solution.

Background: Because of its biocompatibility and its soft and dynamic nature, the grafting of adipose tissue is regarded an ideal technique for soft-tissue repair. The adipose stem cells (ASCs) contribute significantly to the regenerative potential of adipose tissue, because they can differentiate into adipocytes and release growth factors for tissue repair and neovascularization to facilitate tissue survival. The present study tested the effect of administering a chronic low dose of ∆⁹-tetrahydrocannabinol (THC) on these regenerative properties, in vitro and in vivo.

Methods: Human ASCs were exposed to increasing concentrations of THC. Resazurin conversion was applied to investigate the effect on metabolic activity, cell number was assessed by crystal violet staining, tri-linear differentiation was evaluated by specific colorimetric approaches, and the release of growth factors was analyzed by ELISA. Two groups of mice were treated daily either with a low dose of THC (3 mg/kg) or a vehicle solution. After 3 weeks, adipose tissue was obtained from excised fat deposits, homogenized and tested for growth factor contents.

Results: THC decreased ASC proliferation but increased metabolic activity as well as adipogenic and chondrogenic differentiation. A low concentration of THC (1 µM) enhanced the growth factor release by ASCs. The concentration of these cytokines was also increased in adipose tissue of mice treated with THC.

Conlusion: Our results indicate that chronic activation of the endocannabinoid system promoted differentiation and growth factor release of ASCs, which could be of specific value for enhancing the regenerative potential of adipose tissue.

Background: Regulatory T cells (Tregs) are essential for maintaining immune homeostasis and facilitating tissue regeneration by fostering an environment conducive to tissue repair. However, in damaged tissues, excessive inflammatory responses can overwhelm the immunomodulatory capacity of Tregs, compromising their functionality and potentially hindering effective regeneration. Mesenchymal stem cells (MSCs) play a key role in enhancing Treg function. MSCs enhance Treg activity through indirect interactions, such as cytokine secretion, and direct interactions via membrane proteins.

Methods: This review examines the regenerative functions of Tregs across various tissues, including bone, cartilage, muscle, and skin, and explores strategies to enhance Treg functionality using MSCs. Advanced techniques, such as the overexpression of relevant genes in MSCs, are highlighted for their potential to further enhance Treg function. Additionally, emerging technologies utilizing extracellular vesicles (EVs) and cell membrane-derived vesicles derived from MSCs offer promising alternatives to circumvent the potential side effects associated with live cell therapies. This review proposes approaches to enhance Treg function and promote tissue regeneration and also outlines future research directions.

Results and conclusion: This review elucidates recent technological advancements aimed at enhancing Treg function using MSCs and examines their potential to improve tissue regeneration efficiency.

Background: Exogenous Cushing's syndrome, which results from prolonged glucocorticoid treatment, is associated with metabolic abnormalities. Previously, we reported the inhibitory effect of tonsil-derived mesenchymal stem cell conditioned medium (T-MSC CM) on glucocorticoid signal transduction. In this study, we investigated the therapeutic efficacy of T-MSCs in a mouse model of exogenous Cushing's syndrome.

Methods: Exogenous Cushing's syndrome model mice was generated by corticosterone administration in the drinking water for 5 weeks, and T-MSCs were injected intraperitoneally twice during the third week. Serum lipid profiles were measured using a chemistry analyzer. HepG2 cells were treated with dexamethasone and co-cultured with T-MSCs. Expression levels of genes involved in cholesterol metabolism were examined using real-time PCR. Low-density lipoprotein receptor (LDLR) protein levels were determined using western blotting and immunohistochemistry. Liver RNA extracted from the CORT and CORT + MSC mouse groups was used for transcriptome sequencing analysis and protein-protein interaction analysis.

Results: Weight reduction and improvements in dyslipidemia by T-MSC administration were observed only in female mice. T-MSCs reduce circulating LDL cholesterol levels by downregulating liver X receptor α (LXRα) and inducible degrader of LDLR (IDOL) expression, thereby stabilizing LDLRs in the liver. Transcriptome analysis of liver tissue revealed pathways that are regulated by T-MSCs administration.

Conclusion: Administration of MSCs to female mice receiving chronic corticosterone treatment reduced the circulating LDL cholesterol level by downregulating the LXRα-IDOL axis in hepatocytes. These results suggest that T-MSCs may offer a novel therapeutic strategy for managing exogenous Cushing's syndrome by regulating cholesterol metabolism.