Enhanced neural differentiation of neural stem cells by sustained release of Shh from TG2 gene-modified EMSC co-culture in vitro.

As a promising cell therapy, neural crest-derived ectoderm mesenchymal stem cells (EMSCs) secrete high amounts of extracellular matrix (ECM) and neurotrophic factors, promoting neural stem cell (NSC) differentiation into neuronal lineages and aiding tissue regeneration. Additionally, the forced overexpression of secreted proteins can increase the therapeutic efficacy of the secretome. Tissue transglutaminase (TG2) is a ubiquitously expressed member of the transglutaminase family of calcium-dependent crosslinking enzymes, which can stabilize the ECM, inducing smart or living biomaterial to stimulate differentiation and enhance the neurogenesis of NSCs. In this study, we examined the neuronal differentiation of NSCs induced by TG2 gene-modified EMSCs (TG2-EMSCs) in a co-culture model directly. Two weeks after initiating differentiation, levels of the neuronal markers, tubulin beta 3 class III and growth-associated protein 43, were higher in NSCs in the TG2-EMSC co-culture group and those of the astrocytic marker glial fibrillary acidic protein were lower, compared with the control group. These results were confirmed by immunofluorescence, and laminin, fibronectin and sonic hedgehog (Shh) contributed to this effect. The results of western blot analysis and the enzyme-linked immunoassay showed that after TG2-EMSCs were co-cultured for 2 weeks, they expressed much higher levels of Shh than the control group. Moreover, the sustained release of Shh was observed in the TG2-EMSC co-culture group. Overall, our findings indicate that EMSCs can induce the differentiation of NSCs, of which TG2-EMSCs can promote the differentiation of NSCs compared with EMSCs.

Inhaled aerosolized algal polysaccharides: A novel and reliable strategy for treating pneumonia through inflammation and oxidative stress inhibition.

Sepsis-associated acute lung injury (ALI) poses a significant threat, characterized by inflammation and oxidative damage. Effective drugs targeting these aspects with reliable drug delivery systems are vital for ALI management. This study aimed to evaluate the influence of algal polysaccharides (APs) with aerosolized drug delivery in ALI mice and clarify the underlying mechanism. To induce the sepsis-associated acute lung injury (ALI) model, mice were administered intraperitoneal injections of 10 mg/kg LPS for 48 h in vivo. ALI mice received APs via atomization to arrive at different sites within the lungs. Lung tissue samples and bronchoalveolar lavage fluid (BALF) were collected to access lung injury parameters. Concurrently, western blotting, H&E staining, and immunofluorescence (IF) were applied to investigate the specific impact of APs on ALI. The results showed that APs protect lung tissue against ALI by inhibiting inflammation and mitigating oxidative stress-induced damage. This study highlights promising avenues for ALI intervention using natural compounds with anti-inflammatory and antioxidant properties.

LPS­mediated adaptation accelerates ecto­MSCs differentiation into osteoblasts.

Addressing the repair and regeneration of large bone defects poses significant challenges in bone tissue engineering. Despite the abundant evidence demonstrating the positive role of MSCs in osteogenesis, their limited osteogenic differentiation ability still needs to be improved. The present study used lipopolysaccharide (LPS) to enhance the osteogenic properties of ecto­mesenchymal stem cells (EMSCs). Human nasal respiratory mucosa­derived EMSCs were cultured on plates and stimulated with LPS for 5 days prior to undergoing osteogenic differentiation. The findings revealed that LPS effectively stimulated the osteogenic differentiation capacity of EMSCs, as evidenced by heightened alkaline phosphatase activity, elevated expression levels of osteogenic­related proteins and enhanced mineralization of EMSCs. The present study also demonstrated that the augmentation occurred due to increased IL­10 levels, although it was not solely attributable to this factor. Together, the findings illustrated that the LPS­mediated adaptation of EMSCs is an active process driving osteogenic differentiation and could be a novel strategy for bone regeneration.

Overexpression of TG2 enhances the differentiation of ectomesenchymal stem cells into neuron­like cells and promotes functional recovery in adult rats following spinal cord injury.

Ectomesenchymal stem cells (EMSCs) represent a type of adult stem cells derived from the cranial neural crest. These cells are capable of self­renewal and have the potential for multidirectional differentiation. Tissue transglutaminase type 2 (TG2) is a ubiquitously expressed member of the transglutaminase family of Ca2+­dependent crosslinking enzymes. However, the effect of TG2 on neural differentiation and proliferation of EMSCs remains unknown. To determine whether TG2 improves EMSC proliferation and neurogenesis, a stable TG2­overexpressing EMSC cell line (TG2­EMSCs) was established by using an adenovirus system. Immunofluorescence staining and western blot analyses demonstrated that TG2 overexpression had beneficial effects on the rate of EMSC neurogenesis, and that the proliferative capacity of TG2­EMSCs was higher than that of controls. Furthermore, the results of western blotting revealed that extracellular matrix (ECM) and neurotrophic factors were upregulated during the differentiation of TG2­EMSCs. Notably, TG2­EMSC transplantation in an animal model of spinal cord injury (SCI), TG2­EMSCs differentiated into neuron­like cells and enhanced the repair of SCI. Taken together, these results demonstrated that TG2 gene transfection may offer a novel strategy to enhance EMSC proliferation and neurogenesis in vivo and in vitro, which may ultimately facilitate EMSC­based transplantation therapy in patients with SCI.