Dietary ellagic acid therapy for CNS autoimmunity: Targeting on Alloprevotella rava and propionate metabolism.

BACKGROUND: Mediterranean diet rich in polyphenolic compounds holds great promise to prevent and alleviate multiple sclerosis (MS), a central nervous system autoimmune disease associated with gut microbiome dysbiosis. Health-promoting effects of natural polyphenols with low bioavailability could be attributed to gut microbiota reconstruction. However, its underlying mechanism of action remains elusive, resulting in rare therapies have proposed for polyphenol-targeted modulation of gut microbiota for the treatment of MS. RESULTS: We found that oral ellagic acid (EA), a natural polyphenol rich in the Mediterranean diet, effectively halted the progression of experimental autoimmune encephalomyelitis (EAE), the animal model of MS, via regulating a microbiota-metabolites-immunity axis. EA remodeled the gut microbiome composition and particularly increased the relative abundances of short-chain fatty acids -producing bacteria like Alloprevotella. Propionate (C3) was most significantly up-regulated by EA, and integrative modeling revealed a strong negative correlation between Alloprevotella or C3 and the pathological symptoms of EAE. Gut microbiota depletion negated the alleviating effects of EA on EAE, whereas oral administration of Alloprevotella rava mimicked the beneficial effects of EA on EAE. Moreover, EA directly promoted Alloprevotella rava (DSM 22548) growth and C3 production in vitro. The cell-free supernatants of Alloprevotella rava co-culture with EA suppressed Th17 differentiation by modulating acetylation in cell models. C3 can alleviate EAE development, and the mechanism may be through inhibiting HDAC activity and up-regulating acetylation thereby reducing inflammatory cytokines secreted by pathogenic Th17 cells. CONCLUSIONS: Our study identifies EA as a novel and potentially effective prebiotic for improving MS and other autoimmune diseases via the microbiota-metabolites-immunity axis. Video Abstract.

Electrospun Nanofiber Scaffold for Skin Tissue Engineering: A Review.

Skin tissue engineering (STE) is widely regarded as an effective approach for skin regeneration. Several synthetic biomaterials utilized for STE have demonstrated favorable fibrillar characteristics, facilitating the regeneration of skin tissue at the site of injury, yet they have exhibited a lack of in situ degradation. Various types of skin regenerative materials, such as hydrogels, nanofiber scaffolds, and 3D-printing composite scaffolds, have recently emerged for use in STE. Electrospun nanofiber scaffolds possess distinct advantages, such as their wide availability, similarity to natural structures, and notable tissue regenerative capabilities, which have garnered the attention of researchers. Hence, electrospun nanofiber scaffolds may serve as innovative biological materials possessing the necessary characteristics and potential for use in tissue engineering. Recent research has demonstrated the potential of electrospun nanofiber scaffolds to facilitate regeneration of skin tissues. Nevertheless, there is a need to enhance the rapid degradation and limited mechanical properties of electrospun nanofiber scaffolds in order to strengthen their effectiveness in soft tissue engineering applications in clinical settings. This Review centers on advanced research into electrospun nanofiber scaffolds, encompassing preparation methods, materials, fundamental research, and preclinical applications in the field of science, technology, and engineering. The existing challenges and prospects of electrospun nanofiber scaffolds in STE are also addressed.

Therapeutic effects and mechanisms of isoxanthohumol on DSS-induced colitis: regulating T cell development, restoring gut microbiota, and improving metabolic disorders.

Ulcerative colitis (UC) is a severe hazard to human health. Since pathogenesis of UC is still unclear, current therapy for UC treatment is far from optimal. Isoxanthohumol (IXN), a prenylflavonoid from hops and beer, possesses anti-microbial, anti-oxidant, anti-inflammatory, and anti-angiogenic properties. However, the potential effects of IXN on the alleviation of colitis and the action of the mechanism is rarely studied. Here, we found that administration of IXN (60 mg/kg/day, gavage) significantly attenuated dextran sodium sulfate (DSS)-induced colitis, evidenced by reduced DAI scores and histological improvements, as well as suppressed the pro-inflammatory Th17/Th1 cells but promoted the anti-inflammatory Treg cells. Mechanically, oral IXN regulated T cell development, including inhibiting CD4+ T cell proliferation, promoting apoptosis, and regulating Treg/Th17 balance. Furthermore, IXN relieved colitis by restoring gut microbiota disorder and increasing gut microbiota diversity, which was manifested by maintaining the ratio of Firmicutes/Bacteroidetes balance, promoting abundance of Bacteroidetes and Ruminococcus, and suppressing abundance of proteobacteria. At the same time, the untargeted metabolic analysis of serum samples showed that IXN promoted the upregulation of D-( +)-mannose and L-threonine and regulated pyruvate metabolic pathway. Collectively, our findings revealed that IXN could be applied as a functional food component and served as a therapeutic agent for the treatment of UC.

Peroxisom proliferator-activated receptor-γ coactivator-1α in neurodegenerative disorders: A promising therapeutic target.

Neurodegenerative disorders (NDDs) are characterized by progressive loss of selectively vulnerable neuronal populations and myelin sheath, leading to behavioral and cognitive dysfunction that adversely affect the quality of life. Identifying novel therapies that attenuate the progression of NDDs would be of significance. Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), a widely expressed transcriptional regulator, modulates the expression of genes engaged in mitochondrial biosynthesis, metabolic regulation, and oxidative stress (OS). Emerging evidences point to the strong connection between PGC-1α and NDDs, suggesting its positive impaction on the progression of NDDs. Therefore, it is urgent to gain a deeper and broader understanding between PGC-1α and NDDs. To this end, this review presents a comprehensive overview of PGC-1α, including its basic characteristics, the post-translational modulations, as well as the interacting transcription factors. Secondly, the pathogenesis of PGC-1α in various NDDs, such as Alzheimer's (AD), Parkinson's (PD), and Huntington's disease (HD) is briefly discussed. Additionally, this study summarizes the underlying mechanisms that PGC-1α is neuroprotective in NDDs via regulating neuroinflammation, OS, and mitochondrial dysfunction. Finally, we briefly outline the shortcomings of current NDDs drug therapy, and summarize the functions and potential applications of currently available PGC-1α modulators (activator or inhibitors). Generally, this review updates our insight of the important role of PGC-1α on the development of NDDs, and provides a promising therapeutic target/ drug for the treatment of NDDs.

Influence of Sand Production Damage in Unconsolidated Sandstone Reservoirs on Pore Structure Characteristics and Oil Recovery at the Microscopic Scale.

Unconsolidated sandstone reservoirs have low rock strength and are easily damaged by sand production. To evaluate the effect of the microscopic pore system on the degree of recovery and sand production damage, five typical unconsolidated sandstone core samples were selected. The nuclear magnetic resonance T2 spectrum of the water-flooding experiments was used to analyze the oil displacement mechanism and sand production damage of the pore throat structure, and the control mechanism of the injection parameters was used to evaluate the recovery and sand production damage degree. The results showed that the recovery of the unconsolidated sandstone core samples was the highest when the injection volume was 6 PV, and the overall pore throat recovery increased from 14.37 to 48.72%. The recovery and sand production damage increased with increasing injection pressure. The overall pore throat recovery was the highest when the pressure was 20 MPa (48.42%), and the sand production damage index was the maximum when the pressure was 25 MPa (19.98%). Under a lower injection pressure, sand production damage mainly originates from loose sand. The main target of loose sand production damage is a smaller pore throat, and the sand production index increases slowly. The recovery increased with the pressure and increased relatively quickly. Under a higher injection pressure, sand production damage mainly comes from loose sand and skeleton sand, causing damage to both smaller and larger pore throats. The sand production damage is positively correlated with injection pressure. The recovery slows down with an increase in pressure or even decreases.

Sequentially releasing self-healing hydrogel fabricated with TGFß3-microspheres and bFGF to facilitate rat alveolar bone defect repair.

Resorption and loss of alveolar bone leads to oral dysfunction and loss of natural or implant teeth. Biomimetic delivery of growth factors based on stem cell recruitment and osteogenic differentiation, as the key steps in natural alveolar bone regenerative process, has been an area of intense research in recent years. A mesoporous self-healing hydrogel (DFH) with basic fibroblast growth factor (bFGF) entrapment and transforming growth factor ß3 (TGFß3) - loaded chitosan microspheres (CMs) was developed. The formulation was optimized by multiple tests of self-healing, in-bottle inversion, SEM, rheological, swelling rate and in vitro degradation. In vitro tubule formation assays, cell migration assays, and osteogenic differentiation assays confirmed the ability of DFH to promote blood vessels, recruit stem cells, and promote osteogenic differentiation. The optimum DFH formula is 0.05 ml 4Arm-PEG-DF (20%) added to 1 ml CsGlu (2%) containing bFGF (80 ng) and TGFß3-microspheres (5 mg). The results of in vitro release studied by Elisa kit, indicated an 95% release of bFGF in 7 d and long-term sustained release of TGFß3. For alveolar defects rat models, the expression levels of CD29 and CD45, the bone volume fraction, trabecular number, and trabecular thickness of new bone monitored by Micro-CT in DFH treatment groups were significantly higher than others (*P < 0.05, vs Model). HE and Masson staining show the same results. In conclusion, DFH is a design of bionic alveolar remodelling microenvironment, that is in early time microvessels formed by bFGF provide nutritious to recruited endogenous stem cells, then TGFß3 slowly released speed up the process of new bones formation to common facilitate rat alveolar defect repair. The DFH with higher regenerative efficiency dovetails nicely with great demand due to the requirement of complicated biological processes.

Up-Regulation of p53/miR-628-3p Pathway, a Novel Mechanism of Shikonin on Inhibiting Proliferation and Inducing Apoptosis of A549 and PC-9 Non-Small Cell Lung Cancer Cell Lines.

Shikonin (SHK) is a pleiotropic agent with remarkable cell growth inhibition activity against various cancer types, especially non-small cell lung cancer (NSCLC), but its molecular mechanism is still unclear. Our previous study found that miR-628-3p could inhibit the growth of A549 cells and induce its apoptosis. Bioinformatics analysis predicted that miR-628-3p promoter sequence contained p53 binding sites. Considering the regulatory effect of SHK on p53, we speculate that SHK may inhibit the growth and induce apoptosis of NSCLC cells by up-regulating miR-628-3p. CCK-8 and EdU assay confirmed the inhibitory effect of SHK on A549 and PC-9 cells. Meanwhile, quantitative reverse transcription-polymerase chain reaction and Western blot showed that SHK could promote the expression of p53 and miR-628-3p in a dose-dependent manner. Overexpression of p53 or miR-628-3p can inhibit the growth and promote apoptosis of A549 and PC-9 cells, while silencing p53 or miR-628-3p has the opposite effect. Dual luciferase reporting assay and ChIP (chromatin immunoprecipitation) assay further verified the direct interaction between p53 and the promoter of miR-628-3p. Gene knockdown for p53 or miR-628-3p confirmed that SHK inhibits the growth and induces apoptosis of A549 and PC-9 cells at least partly by up-regulating p53/miR-628-3p signaling pathway. Therefore, these novel findings provide an alternative approach to target p53/miR-628-3p axis and could be used for the development of new treatment strategies for NSCLC.

Transforming Growth Factor-ß3/Recombinant Human-like Collagen/Chitosan Freeze-Dried Sponge Primed With Human Periodontal Ligament Stem Cells Promotes Bone Regeneration in Calvarial Defect Rats.

Patients with a skull defect are at risk of developing cerebrospinal fluid leakage and ascending bacterial meningitis at >10% per year. However, treatment with stem cells has brought great hope to large-area cranial defects. Having found that transforming growth factor (TGF)-ß3 can promote the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs), we designed a hybrid TGF-ß3/recombinant human-like collagen recombinant human collagen/chitosan (CS) freeze-dried sponge (TRFS) loading hPDLSCs (TRFS-h) to repair skull defects in rats. CFS with 2% CS was selected based on the swelling degree, water absorption, and moisture retention. The CS freeze-dried sponge (CFS) formed a porous three-dimensional structure, as observed by scanning electron microscopy. In addition, cytotoxicity experiments and calcein-AM/PI staining showed that TRFS had a good cellular compatibility and could be degraded completely at 90 days in the implantation site. Furthermore, bone healing was evaluated using micro-computed tomography in rat skull defect models. The bone volume and bone volume fraction were higher in TRFS loaded with hPDLSCs (TRFS-h) group than in the controls (p < 0.01, vs. CFS or TRFS alone). The immunohistochemical results indicated that the expression of Runx2, BMP-2, and collagen-1 (COL Ⅰ) in cells surrounding bone defects in the experimental group was higher than those in the other groups (p < 0.01, vs. CFS or TRFS alone). Taken together, hPDLSCs could proliferate and undergo osteogenic differentiation in TRFS (p < 0.05), and TRFS-h accelerated bone repair in calvarial defect rats. Our research revealed that hPDLSCs could function as seeded cells for skull injury, and their osteogenic differentiation could be accelerated by TGF-ß3. This represents an effective therapeutic strategy for restoring traumatic defects of the skull.

Hybrid Freeze-Dried Dressings Composed of Epidermal Growth Factor and Recombinant Human-Like Collagen Enhance Cutaneous Wound Healing in Rats.

Epidermal growth factor (EGF) is important for promoting skin repair and remodeling. Native collagen is also widely used as a scaffold for skin tissue engineering. The limitations of EGF include easy decomposition or inactivation, whereas native collagen is immunogenic and has poor solubility. Therefore, we constructed a freeze-dried dressing based on the recombinant human-like collagen (RHC) to act as a carrier for EGF (RHC/EGF freeze-dried dressing) and promote skin wound closure. Here, the freeze-dried dressing that combined EGF and RHC significantly enhanced the proliferation, adhesion, and spreading of NIH/3T3 fibroblasts and migration of HaCaT keratinocytes at the wound site. The physicochemical characteristics of the RHC/EGF freeze-dried dressing investigated using scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry revealed that it was a loose and porous cake that redissolved quickly. The molecular mechanisms involved in cell proliferation and angiogenesis were also assessed. The expression levels of the markers Ki-67, proliferating cell nuclear antigen, vascular endothelial growth factor, and cluster of differentiation 31 were significantly increased after treatment with the RHC/EGF freeze-dried dressing (P < 0.01, vs. RHC or EGF alone). This increase indicated that the RHC/EGF freeze-dried dressing significantly accelerated wound closure, re-epithelialization, and the orderly arrangement and deposition of collagen in the Sprague-Dawley rats with full-thickness skin defects. This work describes a significant step toward the development of wound environments conducive to healing, and the RHC/EGF freeze-dried dressing is a potential therapeutic strategy in wound management.

Sulfonated chitosan oligosaccharide alleviates the inhibitory effect of basic fibroblast growth factor on osteogenic differentiation of human periodontal ligament stem cells.

BACKGROUND: Periodontal ligament stem cells (PDLSCs) play an essential role in periodontal tissue repair. Basic fibroblast growth factor (bFGF) has been used in the clinical treatment of periodontal disease. However, studies have shown that bFGF inhibits the osteogenic differentiation of PDLSCs, which is not conducive to alveolar bone repair. Sulfonated chitosan oligosaccharide (SCOS), a heparan-like compound, can maintain the conformation of bFGF and promote its proliferation activity. This study investigated the effects of bFGF in combination with SCOS on the osteogenic differentiation of hPDLSCs. METHODS: hPDLSCs were isolated from healthy human periodontal ligament and identified by flow cytometry and immunofluorescence. The affinity between SCOS and bFGF was analyzed by surface plasmon resonance. Changes in osteogenic differentiation by combination of bFGF with SCOS were analyzed by alkaline phosphatase activity assay, Sirius Red staining, and Alizarin Red staining. Expression of genes and proteins was investigated by western blotting and reverse transcription-quantitative PCR. RESULTS: Extracted hPDLSCs were mesenchymal stem cells with pluripotent differentiation potential. SCOS exhibited an affinity for bFGF. bFGF (20 ng/mL) promoted the proliferation of hPDLSCs, but inhibited their osteogenic differentiation. SCOS alleviated the inhibitory effect of bFGF on the osteogenic differentiation of hPDLSCs. CONCLUSIONS: SCOS can reduce the inhibitory effect of bFGF on the osteogenic differentiation of hPDLSCs. This study provides evidence for the clinical use of bFGF to repair periodontal tissue.

Transforming Growth Factor-ß3/Chitosan Sponge (TGF-ß3/CS) Facilitates Osteogenic Differentiation of Human Periodontal Ligament Stem Cells.

Periodontal disease is the main reason for tooth loss in adults. Tissue engineering and regenerative medicine are advanced technologies used to manage soft and hard tissue defects caused by periodontal disease. We developed a transforming growth factor-ß3/chitosan sponge (TGF-ß3/CS) to repair periodontal soft and hard tissue defects. We investigated the proliferation and osteogenic differentiation behaviors of primary human periodontal ligament stem cells (hPDLSCs) to determine the bioactivity and potential application of TGF-ß3 in periodontal disease. We employed calcein-AM/propidium iodide (PI) double labeling or cell membranes (CM)-Dil labeling coupled with fluorescence microscopy to trace the survival and function of cells after implantation in vitro and in vivo. The mineralization of osteogenically differentiated hPDLSCs was confirmed by measuring alkaline phosphatase (ALP) activity and calcium content. The levels of COL I, ALP, TGF-ßRI, TGF-ßRII, and Pp38/t-p38 were assessed by western blotting to explore the mechanism of bone repair prompted by TGF-ß3. When hPDLSCs were implanted with various concentrations of TGF-ß3/CS (62.5-500 ng/mL), ALP activity was the highest in the TGF-ß3 (250 ng/mL) group after 7 d (p < 0.05 vs. control). The calcium content in each group was increased significantly after 21 and 28 d (p < 0.001 vs. control). The optimal result was achieved by the TGF-ß3 (500 ng/mL) group. These results showed that TGF-ß3/CS promotes osteogenic differentiation of hPDLSCs, which may involve the p38 mitogen-activated protein kinase (MAPK) signaling pathway. TGF-ß3/CS has the potential for application in the repair of incomplete alveolar bone defects.

Improving the protective effects of aFGF for peripheral nerve injury repair using sulfated chitooligosaccharides.

Injury to the peripheral nerves can result in temporary or life-long neuronal dysfunction and subsequent economic or social disability. Acidic fibroblast growth factor (aFGF) promotes the growth and survival of neurons and is a possible treatment for peripheral nerve injury. Yet, the actual therapeutic utility of aFGF is limited by its short half-life and instability in vivo. In the present study, we prepared sulfated chitooligosaccharides (SCOS), which have heparin-like properties, to improve the bioactivity of aFGF. We investigated the protective effects of SCOS with or without aFGF on RSC96 cells exposed to Na2S2O4 hypoxia/reoxygenation injury. Cell viability was measured by MTT assay and cytotoxicity induced by Na2S2O4 was assessed by lactate dehydrogenase (LDH) release into the culture medium. Pretreatment with aFGF and SCOS dramatically decreased LDH release after injury compared to pretreatment with aFGF or SCOS alone. We subsequently prepared an aFGF/SCOS thermo-sensitive hydrogel with poloxamer and examined its effects in vivo. Paw withdrawal thresholds and thermal withdrawal latencies were measured in rats with sciatic nerve injury. Local injection of the aFGF/SCOS hydrogels (aFGF: 40, 80 µg/kg) increased the efficiency of sciatic nerve repair compared to aFGF (80 µg/kg) hydrogel alone. Especially aFGF/SCOS thermo-sensitive hydrogel decreased paw withdrawal thresholds from 117.75 ± 8.38 (g, 4 d) to 65.74 ± 3.39 (g, 10 d), but aFGF alone group were 140.58 ± 27.54 (g, 4 d) to 89.12 ± 5.60 (g, 10 d) (aFGF dose was 80 µg/kg, P < 0.05, n = 8). The thermal withdrawal latencies decreased from 11.61 ± 2.26 (s, 4 d) to 2.37 ±0.67 (s, 10 d). However, aFGF alone group were from 17.69 ± 1.47 (s, 4 d) to 4.65 ± 1.73 (s, 10 d) (P < 0.05, n = 8). Furthermore, the aFGF/SCOS hydrogels also exhibited good biocompatibility in mice. In summary, SCOS improved the protective effects of aFGF in RSC96 cells injured with Na2S2O4 and increased the efficiency of nerve repair and recovery of function in rats with sciatic nerve injury. These findings pave an avenue for the development of novel prophylactic and therapeutic strategies for peripheral nerve injury.

Pilot-scale expression, purification, and bioactivity of recombinant human TGF-ß3 from Escherichia coli.

TGF-ß3, a subtype of transforming growth factor-ß (TGF-ß), is essential to various biological processes, including endoderm development, organogenesis, epithelial hyperplasia, synthesis of extracellular matrix, and immune response. Essentially, TGF-ß3 engages the TGF-ß1/Smad signaling pathway to stimulate mesenchymal lineage cells, inhibit epithelial or neuroectodermal lineage cells, and regulate repair, remodeling, and potential scarring after cutaneous wounding. We have now expressed recombinant human TGF-ß3 in Escherichia coli Origami B (DE3), with yield 300 ±â€¯17 mg/L monomeric protein at pilot scale. Identity was confirmed by western blot and HPLC-based peptide mapping. After purification and refolding, dimeric proteins were found to induce chondro-related genes in adipose-derived stem cells, and to suppress scarring in injured rabbit ears. Thus, the recombinant protein has excellent potential for medical applications.

Research progress on the factors influencing the biological characteristics of dental pulp stem cells / 口腔疾病防治

@#Dental pulp stem cells (DPSCs) are mesenchymal stem cells derived from dental pulp tissue with self-renewal, high proliferative capacity and multidirectional differentiation potential. Under appropriate induction conditions, DPSCs can be differentiated into various types of cells, such as osteoblasts, odontoblasts, chondrocytes, adipocytes, and neuronal cells. DPSCs have been gradually applied to clinical trials and preclinical studies and are important seed cells in the field of periodontal tissue engineering and regenerative medicine. In this paper, the factors affecting the biological characteristics of DPSCs are reviewed together with a review of recent literature published worldwide. The results of the literature review show that the biological characteristics of DPSCs can be influenced by many factors, such as tissue source, culture method, environment and induction conditions, which has guiding significance for research and applications of DPSCs.