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Nonalcoholic fatty liver disease (NAFLD), which has been renamed metabolic dysfunction-associated fatty liver disease, is a growing global medical problem. The incidence of NAFLD and its associated end-stage liver disease is increasing each year, and many research advancements have been achieved to date. This review focuses on the current knowledge of the sex differences in NAFLD and does not elaborate on areas without differences. Studies have revealed significant sex differences in the prevalence, influencing factors, pathophysiology, complications and therapies of NAFLD. Men have a higher incidence than women. Compared with women, men exhibit increased visceral fat deposition, are more susceptible to leptin resistance, lack estrogen receptors, and tend to synthesize fatty acids into fat storage. Male patients will experience more severe hepatic fibrosis and a higher incidence of liver cancer. However, once NAFLD occurs, women show a faster progression of liver fibrosis, higher levels of liver cell damage and inflammation and are less likely to undergo liver transplantation than men. In general, men have more risk factors and more severe pathophysiological reactions than women, whereas the development of NAFLD is faster in women, and the treatments for women are more limited than those for men. Thus, whether sex differences should be considered in the individualized prevention and treatment of NAFLD in the future is worth considering.

Background Nonalcoholic fatty liver disease (NAFLD) is a major chronic liver disorder worldwide, and there is no established treatment for this disease. We conducted a network meta-analysis (NMA) to compare existing treatments, which include four classes of antidiabetic drugs, and examined the optimum treatments for NAFLD. Aim To compare the effectiveness of different treatments for NAFLD. Methods An NMA was conducted using Stata 14.0 (Corporation LLC, College Station, United States) and R (X64 3.6.3 version) in this study. Eligible randomized controlled trials (RCTs) were searched in the PubMed, Cochrane Library, Embase, Medline and Web of Science databases from database inception to April 2021. Two researchers independently screened the available studies in strict accordance with inclusion and exclusion criteria. The Cochrane Risk of Bias tool was used to evaluate the risk of bias of the included studies. The variables with and without dimensional differences were calculated as the standardized mean difference and weighted mean difference, respectively. An inconsistency model and "node-splitting" technique were used to test for inconsistency. Funnel plots were used to evaluate publication bias. Results Twenty-two eligible RCTs involving 1377 participants were eventually included in our analysis. Data were pooled using a random-effects model. Our NMA results revealed that glucagon-like peptide-1 receptor agonists (GLP-1RAs) were the most effective treatment, yielding improvements in hepatic fat content (HFC), alanine aminotransferase (ALT), aspartate aminotransferase (AST), serum γ-glutamyl transferase (GGT) and body weight [surface under the cumulative ranking curve (SUCRA) = 99.6%, 92.6%, 82.8%, 92.3% and 99.6%, respectively], while thiazolidinediones (TZDs) were the best intervention for reducing the NAFLD activity score (NAS; SUCRA = 98.9%). In addition, moderate performance was observed for the sodium glucose cotransporter-2 inhibitors groups (SUCRA = 25.1%, 66.2%, 63.5%, 58.2% and 71.9% for HFC, ALT, AST, GGT and body weight, respectively). However, metformin performed poorly according to most indicators (SUCRA = 54.5%, 0.3%, 19.5%, 33.7%, 57.7% and 44.3% for HFC, NAS, ALT, AST, GGT and body weight, respectively). Conclusion GLP-1RAs may be the optimum choice for most patients with NAFLD. However, TZDs are considered the most effective therapies in NAFLD patients with histological disease activity.

Yang Luo,1,* Min-Hao Yu,1,* Yi-Zhou Huang,1 Ran Jing,1 Jun Qin,1 Shao-Lan Qin,1 Jay N Shah,1,2 Ming Zhong1 1Department of Gastrointestinal Surgery, Renji Hospital, Jiao Tong University School of Medicine, Shanghai, 200127, People’s Republic of China; 2Department of Surgery, Patan Hospital, Patan Academy of Health Sciences, Lalitpur, Kathmandu, 44700, Nepal*These authors contributed equally to this workCorrespondence: Ming Zhong; Jay N Shah Email drzhongming@hotmail.com; drjaywufei@gmail.comBackground: Preservation of the left colic artery in low-tie (LT) of inferior mesenteric artery remains controversial compared to high-tie (HT) in the colon and rectal cancers, for lymph node dissection, anastomotic leakage, and oncological outcome. This cohort study aims to analyze short- and long-term outcomes of laparoscopic anterior resections in LT vs HT for rectal cancers.Methods: We analyzed a cohort of laparoscopic AR for RC from 2013 to 2016 at Renji Hospital, Shanghai, China. Short- and long-term outcome in LT vs HT group were compared for clinico-demographic characteristics, operative-time, lymph node dissection, short-term 30-day outcome, and long-term 3- and 5-year overall survival as well as disease-free survival. The x2, t-test, and logistic regressions analysis were used and p< 0.05 was considered significant.Results: The cohort consisted of 614 laparoscopic AR with LT (236) and HT (378). The clinicodemographic characteristics were comparable among the groups. The surgery took longer in LT. The yield of LND was similar. Leakage occurred in 12.21% (n=75). Leakage was fewer in LT than HT, 8.89% vs 14.28%, p=0.047. The postoperative severe complications were higher in HT. The 30-day mortality was nil. The long-term 3- and 5-year overall survival and disease-free survival were similar in LT and HT.Conclusion: The LT with preservation of left colic artery had similar lymph node yield, but lower leakage and complications than HT in laparoscopic anterior resections for rectal cancers. The long-term 3- and 5-year overall and disease-free survival were similar in the two groups.Keywords: anastomotic leakage, Clavien-Dindo complications, laparoscopic anterior resection, left colic artery, low-tie high-tie of the inferior mesenteric artery, rectal cancer

Ulcerative colitis (UC) is a multifactorial inflammatory disease, and increasing evidence has demonstrated that the mechanism of UC pathogenesis is associated with excessive cellular apoptosis and reactive oxygen species (ROS) production. However, their function and molecular mechanisms related to UC remain unknown. In this study, Rab27A mRNA and protein were proven to be overexpressed in intestinal epithelial cells of UC patients and DSS‐induced colitis mice, compared with control (P

Introduction Anastomotic leakage (AL) is generally accepted as a major complication of rectal resection surgery. However, there is still debate about the definition and evaluation of AL. The International Study Group of Rectal Cancer (ISREC) raised a definition of and grading system for AL in 2010. Aim In our study, we aimed to validate AL's present definition and grading system, which were proposed by ISREC in 2010. Methods Patients who underwent rectal anterior resection in 2 colorectal surgery centers from January 2012 to December 2014 were included and categorized into different groups according to the ISREC criteria; further, the rate, severity and clinical outcomes of their ALs were analyzed and compared. Results During a median follow-up period of 38.9 months, 984 patients were included in total. The overall AL rate was 5.0% (49/984), including 7 grade A patients (14%), 21 grade B patients (43%), and 21 grade C patients (43%). The rate of grade C AL in the protective diverting stoma group was significantly lower than that in the nonstoma group (0.6% versus 2.8%, P = 0.029). Patients with grade B or grade C AL had much longer hospital stays than grade A AL patients (P = 0.016). The overall 3-year survival rates of grades A, B, and C groups were 83.3%, 66.7% and 55.6% respectively, without statistical significance. Conclusions Patients who were divided into different groups according to the grading system proposed by the ISREC criteria had significantly different symptoms, clinical outcomes, management, and duration of hospitalization. Our study supported that the ISREC criteria are a simple but valid classification to evaluate the surgical performance of the rectal cancer resection.

Regenerative medicine based on stem cell research has the potential to provide advanced health care for human beings. Recent studies demonstrate that stem cells in human urine can serve as an excellent source of graft cells for regenerative therapy, mainly due to simple, low-cost, and noninvasive cell isolation. These cells, termed human urine-derived stem cells (USCs), are highly expandable and can differentiate into various cell lineages. They share many biological properties with mesenchymal stem cells, such as potent paracrine effects and immunomodulation ability. The advantage of USCs has motivated researchers to explore their applications in regenerative medicine, including genitourinary regeneration, musculoskeletal repair, skin wound healing, and disease treatment. Although USCs have showed many positive outcomes in preclinical studies, and although the possible applications of USCs for animal therapy have been reported, many issues need to be addressed before clinical translation. This article provides a comprehensive review of USC biology and recent advances in their application for tissue regeneration. Challenges in the clinical translation of USC-based therapy are also discussed. Impact statement Recently, stem cells isolated from urine, referred to as urine-derived stem cells (USCs), have gained much interest in the field of regenerative medicine. Many advantages of human USCs have been found for cell-based therapy: (i) the cell isolation procedure is simple and low cost; (ii) they have remarkable proliferation ability, multidifferentiation potential, and paracrine effects; and (iii) they facilitate tissue regeneration in many animal models. With the hope to facilitate the development of USC-based therapy, we describe the current understanding of USC biology, summarize recent advances in their applications, and discuss future challenges in clinical translation.

BackgroundBreast cancer (BC) is the most frequent cancer in women. The tumor microenvironment (TME), consisting of blood vessels, immune cells, fibroblasts, and extracellular matrix, plays a pivotal role in tumorigenesis and progression. Increasing evidence has emphasized the importance of TME, especially the immune components, in patients with BC. Nevertheless, we still lack a deep understanding of the correlation between tumor invasion and TME status.MethodsTranscriptome and clinical data were retrieved from The Cancer Genome Atlas (TCGA) database. ESTIMATE algorithm was applied for quantifying stromal and immune scores. Then we screened out the differentially expressed genes (DEGs) through the intersection analysis. Furthermore, the establishment of protein-protein interaction (PPI) network and univariate COX regression analysis were utilized to determine the core genes in DEGs. In addition, we also performed Gene Set Enrichment Analysis (GSEA) and CIBERSORT analysis to distinguish the function of crucial gene expression and the proportion of tumor-infiltrating immune cells (TICs), respectively.ResultsA total of 1178 samples (112 normal samples and 1066 tumor samples) were extracted from TCGA for calculation, and 226 DEGs were obtained from this assessment. Further intersection analysis revealed eight key genes, including ITK, CD3E, CCL19, CD2, SH2D1A, CD5, SLAMF6, SPN, which were proven to correlate with BC status. Moreover, ITK was picked out for further study. The results illustrated that high expression of BC patients had a more prolonged overall survival (OS) time than ITK low expression BC patients (p = 0.009), and ITK expression also presented the statistical significance in age, TNM staging, tumor size classification, and metastasis classification. Additionally, GSEA and CIBERSORT analysis indicated that ITK expression had an association with immune activity in TME.ConclusionITK may be a potential indicator for prognosis prediction in patients with BC, and its biological behavior may promote our understanding of the molecular mechanism of tumor progression and targeted therapy.

Membranous extracellular matrix (ECM)-based scaffolds are one of the most promising biomaterials for skin wound healing, some of which, such as acellular dermal matrix, small intestinal submucosa, and amniotic membrane, have been clinically applied to treat chronic wounds with acceptable outcomes. Nevertheless, the wide clinical applications are always hindered by the poor mechanical properties, the uncontrollable degradation, and other factors after implantation. To highlight the feasible strategies to overcome the limitations, in this review, we first outline the current clinical use of traditional membranous ECM scaffolds for skin wound healing and briefly introduce the possible repair mechanisms; then, we discuss their potential limitations and further summarize recent advances in the scaffold modification and fabrication technologies that have been applied to engineer new ECM-based membranes. With the development of scaffold modification approaches, nanotechnology and material manufacturing techniques, various types of advanced ECM-based membranes have been reported in the literature. Importantly, they possess much better properties for skin wound healing, and would become promising candidates for future clinical translation.

Background: Colorectal cancer (CRC) is one of the high incidence tumors and is ranked second in cancer-related mortality. Even though great progress has been made, there are no effective therapeutic strategies for late stage and metastatic CRC patients. Acidity is one characteristic of the tumor microenvironment. However, how cancer cells respond to this acidic environment surrounding them remains largely unknown, especially in colorectal cancer. Methods: Proton sensor receptor expression was analyzed in GEO and TCGA datasets. The expression of GPR4 in CRC specimens was confirmed by western blotting and immunohistochemistry (IHC). The role of GPR4 in CRC progression was analyzed both in vitro and in vivo. Pharmacological intervention, immunofluorescence and gene set enrichment analyses were performed to reveal the underlying molecular mechanisms of GPR4. Findings: We found that GPR4 was upregulated in CRC samples. In addition, its high expression correlated with late stage tumors and poor overall survival in patients. Furthermore, loss-of-function assays proved that GPR4 promoted CRC carcinogenesis and metastatic ability. Mechanistically, GPR4 was activated by extracellular protons in the tumor microenvironment and enhanced RhoA activation and F-actin rearrangement, leading to LATS activity inhibition, YAP1 nuclear translocation and oncogene transcription. Conclusions: The expression of GPR4 is upregulated in colorectal cancer and is associated with shorter overall survival time in CRCpatients. These findings reveal the novel roles of GPR4 in CRC progression and suggest GPR4 might be a new therapeutic target for CRC treatment. Funding Statement: This work was supported by the grant from the National Natural Science Foundation of China (No.81702300 & No.81873555). Declaration of Interests: The authors declare no potential conflicts of interest. Ethics Approval Statement: Study protocol that strictly in line with International Ethical Guidelines for Biomedical Research Involving Human Subjects was approved by the Research Ethics Committee of Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University. Patients that had received no anti-tumor therapy and signed written informed consent were enrolled in this study.

Urine-derived stem cells (USCs) have shown potentials for the treatment of skeletal and urological disorders. Based on published literature and our own data, USCs consist of heterogeneous populations of cells. In this paper, we identify and characterize two morphologically distinct subpopulations of USCs from human urine samples, named as spindle-shaped USCs (SS-USCs) and rice-shaped USCs (RS-USCs) respectively. The two subpopulations showed similar clone-forming efficiency, while SS-USCs featured faster proliferation, higher motility, and greater potential for osteogenic and adipogenic differentiation, RS-USCs showed greater potential for chondrogenic differentiation. POU5F1 was strongly expressed in both subpopulations, but MYC was weakly expressed. Both subpopulations showed similar patterns of CD24, CD29, CD34, CD44, CD73, CD90 and CD105 expression, while a higher percentage of RS-USCs were positive for CD133. SS-USCs were positive for VIM, weakly positive for SLC12A1 and UMOD, and negative for KRT18, NPHS1, AQP1 and AQP2, indicating a renal mesenchyme origin; while RS-USCs are positive for VIM, partially positive for KRT18, NPHS1, AQP1, SLC12A1 and UMOD, and negative for AQP2, indicating a nephron tubule origin. The above results can facilitate understanding of the biological characteristics of subpopulations of USCs, and provide a basis for further research and applications of such cells.

The motility of mesenchymal stem cells (MSCs) is highly related to their homing in vivo, a critical issue in regenerative medicine. Our previous study indicated copper (Cu) might promote the recruitment of endogenous MSCs in canine esophagus defect model. In this study, we investigated the effect of Cu on the motility of bone marrow mesenchymal stem cells (BMSCs) and the underlying mechanism in vitro. Cu supplementation could enhance the motility of BMSCs, and upregulate the expression of hypoxia-inducible factor 1α (Hif1α) at the protein level, and upregulate the expression of rho family GTPase 3 (Rnd3) at messenger RNA and protein level. When Hif1α was silenced by small interfering RNA (siRNA), Cu-induced Rnd3 upregulation was blocked. When Rnd3 was silenced by siRNA, the motility of BMSCs was decreased with or without Cu supplementation, and Cu-induced cytoskeleton remodeling was neutralized. Furthermore, overexpression of Rnd3 also increased the motility of BMSCs and induced cytoskeleton remodeling. Overall, our results demonstrated that Cu enhanced BMSCs migration through, at least in part, cytoskeleton remodeling via Hif1α-dependent upregulation of Rnd3. This study provided an insight into the mechanism of the effect of Cu on the motility of BMSCs, and a theoretical foundation of applying Cu to improve the recruitment of BMSCs in tissue engineering and cytotherapy.

Our previous work suggested that high SIRT1 expression by cancer cells predicted a poor colorectal cancer (CRC) prognosis, but its role in the tumor microenvironment was unclear. Here, we examined tumor-infiltrating lymphocytes (TILs) in CRC expressing different levels of SIRT1. We also established a co-culture system with monocytes, CD8+ T cells and patient-derived tumor organoids (PDOs) to study the relationships between immune cells and cancer cells. The percentage of CD8+ T cells was decreased and the percentage of macrophages was increased in SIRT1-high (SIRT1-hi) CRC. Co-culture results showed that tumor-associated macrophages (TAMs) from SIRT1-hi CRC inhibited the proliferation and anti-tumor activity of CD8+ T cells. Importantly, SIRT1-hi CRC were shown to modulate the migration and the activity of TAMs. RNA sequencing revealed that CD14+ monocytes in SIRT1-hi patients expressed higher levels of CXCR4. Mechanistically, SIRT1 expression was shown to promote CXCL12 expression by inhibiting the acetylation of p53. Our findings indicate that SIRT1 in CRC induces TAM migration through the CXCR4/CXCL12 pathway, and inhibits the proliferation and activity of CD8+ T cells, resulting in promotion of CRC progression.

As an emerging type of adult stem cell featuring non-invasive acquisition, urine-derived stem cells (USCs) have shown great potential for applications in tissue engineering and regenerative medicine. With a growing amount of research on the topic, the effectiveness of USCs in various disease models has been shown and the underlying mechanisms have also been explored, though many aspects still remain unclear. In this review, we aim to provide an up-to-date overview of the biological characteristics of USCs and their applications in skin, bone and articular cartilage repair. In addition to the identification procedure of USCs, we also summarize current knowledge of the underlying repair mechanisms and application modes of USCs. Potential concerns and perspectives have also been summarized.

Absent in melanoma 2 (AIM2), a DNA sensor that plays an important role in natural immunity system, has been reported to participate in colorectal cancer (CRC) development. However, the functional role of AIM2 in BRAF-mutant CRC remains unclear. In this study, we first investigated AIM2 expression level in BRAF-mutant CRC tumor tissues. Overexpression of AIM2 in CRC cells was performed to investigate the effect of AIM2 on CRC cell viability, and cell death detection and caspase activity assay were performed to explore the mechanism that AIM2 impacts the growth of BRAF-mutant CRC cells. Moreover, we confirmed the antitumor effect of AIM2 in BRAF-mutant CRC cell-derived tumor xenograft (CDX) models as well as patient-derived organoids (PDOs). Herein, we reported that AIM2 expression was lower in BRAF-mutant than that in BRAF wild-type CRC tumor tissues. Restoring the expression of AIM2 in BRAF-mutant CRC cells greatly inhibits the tumor cell growth by inducing necrotic cell death. Mechanism studies revealed that AIM2-induced cell death is in a caspase-1-dependent manner. Additionally, overexpression of AIM2 significantly inhibits tumor growth and metastasis in BRAF-mutant CRC in vivo, which was further confirmed in BRAF-mutant CRC PDOs. Taken together, our data suggested that AIM2 inhibits BRAF-mutant colon cancer growth in a caspase-1-dependent manner, which may provide evidence to understand the pathogenesis of CRC with BRAF-mutant, as well as new strategies for manipulation of CRC.

Collagen membranes are widely used in guided bone regeneration (GBR) because of their good biocompatibility and low immunogenicity. As a bioderived collagen membrane, small intestinal submucosa (SIS) has good regenerative potential for soft tissue repair, but it lacks sufficient mechanical properties for GBR application unless properly modifided. Epigallocatechin-3-gallate (EGCG) is a natural cross-linking agent featuring osteoinductive activity. In this study, we modified SIS by EGCG cross-linking, and such modified materials were characterized both in vitro and in vivo. The results showed that EGCG cross-linking significantly improved the mechanical properties and hydrophilicity of SIS while maintaing good cytocompatibility. Compared to SIS, EGCG-cross-linked SIS (E-SIS) enhanced the adhesion of fibroblasts and preosteoblasts and promoted the osteogenic differentiation of MC3T3-E1 cells cultured on the materials. In a rat cranial defect model, E-SIS material showed better occlusion effect than SIS material. Most importantly, E-SIS material accelerated bone regeneration more than SIS material and even a commercially available GBR membrane. Taken together, we conclude that E-SIS is a promising material as a GBR membrane.

Organ transplantation is considered as the gold standard treatment for end-stage organ failure. Because of the severe shortage of donor organs, tremendous efforts, including whole organ engineering, have been made to construct biological substitutes to restore the function of diseased or injured organs. In the field of whole organ engineering, seed cells, acellular whole organ scaffolds, and recellularization strategies make up the essential elements. Both differentiated and stem cells, either autologous or allogenic, have been utilized in the proof-of-concept exploration of whole organ engineering. Based on the encouraging achievements made in the clinical application of decellularized extracellular matrix materials for various diseases, decellularized whole organ scaffolds are proposed as the ideal candidate for whole organ engineering, featuring a beneficial organ-specific microenvironment for seed cells, as well as an intact vasculature for subsequent supply of oxygen and nutrients. These merits of acellular whole organ scaffolds are too sophisticated to mimic artificially. After proper delivery of essential parenchymal and non-parenchymal cells, and following the necessary in vitro bioreactor-based culture to allow the seed cells to proliferate, differentiate, and mature within the scaffolds, bioengineered organs are promising for eventual transplantation. This chapter aims to provide an overview of the recellularization of decellularized whole organ scaffolds, with a focus on the basic elements, current research progresses, and future challenges.

Decellularized tissues, which could maintain cell phenotype or promote stem cell differentiation into specific tissue cells, play a central role in promoting the reconstruction of functional tissue/organ. Tissue ECM in diverse formats has been developed for tissue repair and regeneration, which can generally be divided into five categories: (1) Scaffolds that preserve the morphological structure of original tissues. (2) Powders obtained by cryogenic grinding. (3) Hydrogels. (4) Coatings. (5) 3D-printing. This chapter will elaborate the preparation methods for creating decellularized tissue scaffolds with the above formats. What is more, the characteristics of these materials will be studied, and the respective applications and the efforts in performance optimization in tissue repair will also be introduced.

In recent years, accumulating evidence has indicated that long non-coding RNAs (lncRNAs) are powerful factors influencing the progression of multiple malignancies. Although a relationship between the lncRNA NEAT1 (nuclear enriched abundant transcript 1) and colorectal cancer has previously been reported, the functional mechanism underlying the involvement of NEAT1 in colorectal cancer remains unknown. In this study, we report that NEAT1 expression is up-regulated in colorectal cancer tissues, which correlates with advanced clinical features, poor overall survival and disease free survival. Up-regulated NEAT1 promotes cell proliferation and metastasis of colorectal cancer both in vitro and in vivo. Moreover, NEAT1 functions as an oncogene influencing cell viability and invasion in part by serving as a competing endogenous RNA (ceRNAs) modulating miRNA-34a expression, leading to subsequent repression of the miR-34a/SIRT1 axis and activation of the Wnt/β-catenin signaling pathway. Taken together, our study demonstrates that the lncRNA NEAT1 may serve as a prognostic biomarker and a potential therapeutic target in colorectal cancer.

Treatment of acute and chronic wounds is one of the primary challenges faced by doctors. Bioderived materials have significant potential clinical value in tissue injury treatment and defect reconstruction. Various strategies, including drug loading, addition of metallic element(s), cross-linking and combining two or more distinct types of materials with complementary features, have been used to synthesize more suitable materials for wound healing. In this review, we describe the recent developments made in the processing of bioderived materials employed for cutaneous wound healing, including newly developed materials such as keratin and soy protein. The focus was on the key properties of the bioderived materials that have shown great promise in improving wound healing, restoration and reconstruction. With their good biocompatibility, nontoxic catabolites, microinflammation characteristics, as well as their ability to induce tissue regeneration and reparation, the bioderived materials have great potential for skin tissue repair.

This article provides an overview of the progress made on and the clinical applications of scaffolds in bone tissue engineering. After briefly introducing bone biology and fracture healing, the concept of bone tissue engineering and the requirements for bone scaffolds are described, followed by an examination of the materials, fabrication technologies, cell–surface interactions, and vascularization of bone scaffolds. Finally, current clinical applications of bone tissue engineering are summarized and the challenges in this field are discussed, along with possibilities for future research.

Background: Robot-assisted surgical techniques have been introduced in recent years as an alternative minimally invasive approach for colorectal surgery. In practice, we found that the mon...

The osteogenic potential of mesenchymal stromal cells (MSCs) varies among different tissue sources. Strontium enhances the osteogenic differentiation of bone marrow-derived MSCs (BM-MSCs), but whether it exerts similar effects on placental decidual basalis-derived MSCs (PDB-MSCs) remains unknown. Here, we compared the influence of strontium on the proliferation and osteogenic differentiation of human PDB- and BM-MSCs in vitro. We found that 1 mM and 10 mM strontium, but not 0.1 mM strontium, evidently promoted the proliferation of human PDB- and BM-MSCs. These doses of strontium showed a comparable alkaline phosphatase activity in both cell types, but their osteogenic gene expressions were promoted in a dose-dependent manner. Strontium at doses of 0.1 mM and 1 mM elevated several osteogenic gene expressions of PDB-MSCs, but not those of BM-MSCs at an early stage. Nevertheless, they failed to enhance the mineralization of either cell type. By contrast, 10 mM strontium facilitated the osteogenic gene expression as well as the mineralization of human PDB- and BM-MSCs. Collectively, this study demonstrated that human PDB- and BM-MSCs shared a great similarity in response to strontium, which promoted their proliferation and osteogenic differentiation in a dose-dependent manner.

Human multipotent stem cell-based therapies have shown remarkable potential in regenerative medicine and tissue engineering applications due to their abilities of self-renewal and differentiation into multiple adult cell types under appropriate conditions. Presently, human multipotent stem cells can be isolated from different sources, but variation among their basic biology can result in suboptimal selection of seed cells in preclinical and clinical research. Thus, the goal of this study was to compare the biological characteristics of multipotent stem cells isolated from human bone marrow, placental decidua basalis, and urine, respectively. First, we found that urine-derived stem cells (USCs) displayed different morphologies compared with other stem cell types. USCs and placenta decidua basalis-derived mesenchymal stem cells (PDB-MSCs) had superior proliferation ability in contrast to bone marrow-derived mesenchymal stem cells (BMSCs); these cells grew to have the highest colony-forming unit (CFU) counts. In phenotypic analysis using flow cytometry, similarity among all stem cell marker expression was found, excluding CD29 and CD105. Regarding stem cell differentiation capability, USCs were observed to have better adipogenic and endothelial abilities as well as vascularization potential compared to BMSCs and PDB-MSCs. As for osteogenic and chondrogenic induction, BMSCs were superior to all three stem cell types. Future therapeutic indications and clinical applications of BMSCs, PDB-MSCs, and USCs should be based on their characteristics, such as growth kinetics and differentiation capabilities.

The tartrate-resistant acid phosphatase (TRAP/ACP5) correlated with tumor progression in many malignancies. However, the role of ACP5 in colorectal cancer (CRC) has not been thoroughly elucidated. In this study, we sought to identify the role for ACP5 in CRC progression. Immunohistochemistry revealed that high ACP5 expression is positively associated with tumor size, tumor classification, lymph node metastasis, distant metastasis and advanced stage cancer in 285 CRC patients. Moreover, high ACP5 expression was significantly associated with poor overall survival and disease-free survival. Then, ectopic expression of ACP5 promoted tumor cell proliferation and invasion, whereas suppression of ACP5 expression resulted in decreased cell proliferation and invasion in colorectal cell lines in vitro. And, inhibition of ACP5 also inhibited growth of engrafted tumors in vivo. Furthermore, we found that ACP5 overexpression positively regulated p-FAK, p-PI3K and p-AKT in CRC cells. ACP5 depletion showed the opposite effects. What’s more, overexpression of FAK in CRC cells could restore the reduced abilities of cell proliferation and invasion caused by siRNAs-ACP5. Finally, we found the inhibition of activity by Akt inhibitors, MK2206, could partially decrease the positive effects of ACP5 on CRC cell proliferation and invasion. In conclusion, our results suggest that overexpressed ACP5 might serve as an indicator for poor prognosis in colorectal cancer patients through regulation of FAK/PI3K/AKT signaling pathway, which might be a potential therapeutic approach for colorectal cancer therapy.

Hydrothermal method is an easy-to-use approach for creating nanostructured surfaces on titanium (Ti). However, whether the alkali conditions of this method influence the osteogenic potential of the modified surfaces remains unknown. In this study, we fabricated nanostructured surfaces, termed the Ti-1, Ti-5, and Ti-10 groups, by using the hydrothermal method in 1 M, 5 M, and 10 M NaOH aqueous solutions, respectively. An untreated Ti surface served as a control. The osteogenic performance of modified surfaces was systemically investigated, including the proliferation and osteogenic differentiation of human osteoblast-like MG63 cells in vitro and the osteointegration of implants in a rabbit femoral condyle defect model. After hydrothermal treatment, the hydrophilicity of modified surfaces was greatly enhanced. The Ti-1 group showed a nanowire-like topography, while the Ti-5 and Ti-10 groups exhibited a nanopetal-like topography with different pore sizes. Compared with the untreated Ti surface, the modified surfaces showed good cytocompatibility and enhanced the osteogenic differentiation of MG-63 cells. Compared with the other modified surfaces, the Ti-5 group was the most favourable for the osteogenic differentiation of cells, showing higher levels of alkaline phosphatase activity, osteogenic gene expression, mineralization and osteoprotegerin secretion. Twelve weeks after implantation at the bone defects, the Ti-5 group showed superior peri-implant bone regeneration and higher peak push-out force than the other groups. Overall, this study revealed the crucial role of alkali conditions of hydrothermal method in modulating the material characteristics of modified surfaces and their osteogenic performance in vitro and in vivo, highlighting the need for optimizing the processing conditions of hydrothermal method for enhanced osteointegration.

Acellular bone matrix (ACBM) provides an osteoconductive scaffold for bone repair, but its osteoinductivity is poor. Strontium (Sr) improves the osteoinductivity of bone implants. In this study, we developed an organic composite-mediated strontium coating strategy for ACBM scaffolds by using the ion chelating ability of carboxymethyl cellulose (CMC) and the surface adhesion ability of dopamine (DOPA). The organic coating composite, termed the CMC-DOPA-Sr composite, was synthesized under a mild condition, and its chemical structure and strontium ion chelating ability were then determined. After surface decoration, the physicochemical properties of the strontium-coated ACBM (ACBM-Sr) scaffolds were characterized, and their biocompatibility and osteoinductivity were determined in vitro and in vivo. The results showed that the CMC-DOPA-Sr composite facilitated strontium coating on the surface of ACBM scaffolds. The ACBM-Sr scaffolds possessed a sustained strontium ion release profile, exhibited good cytocompatibility, and enhanced the osteogenic differentiation of mesenchymal stem cells in vitro. Furthermore, the ACBM-Sr scaffolds showed good histocompatibility after subcutaneous implantation in nude mice. Taken together, this study provided a simple and mild strategy to realize strontium coating for ACBM scaffolds, which resulted in good biocompatibility and improved osteoinductivity.

Epidermolytic palmoplantar keratoderma (EPPK) is the most frequent form of such keratodermas. It is inherited in an autosomal dominant pattern and is clinically characterized by diffuse yellowish thickening of the skin on the palms and soles with erythematous borders during the first weeks or months after birth. EPPK is generally caused by mutations of the KRT9 gene. More than 26 KRT9 gene mutations responsible for EPPK have been described (Human Intermediate Filament Database, www.interfil.org), and many of these variants are located within the highly-conserved coil 1A region of the α-helical rod domain of keratin 9. Unfortunately, there is no satisfactory treatment for EPPK. Thus, prenatal molecular diagnosis or pre-pregnancy diagnosis is crucial and benefits those affected who seek healthy descendants. In the present study, we performed amniotic fluid-DNA-based prenatal testing for three at-risk pregnant EPPK women from three unrelated southern Chinese families who carried the KRT9 missense mutations p.Arg163Trp and p.Arg163Gln, and successfully helped two families to bear normal daughters. We suggest that before the successful application of preimplantation genetic diagnosis (PGD), and noninvasive prenatal diagnosis of EPPK that analyzes fetal cells or cell-free DNA in maternal blood, prenatal genetic diagnosis by amniocentesis or chorionic villus sampling (CVS) offers a quite acceptable option for EPPK couples-at-risk to avoid the birth of affected offspring, especially in low- and middle-income countries.

Mesenchymal stem cells (MSCs) have been increasingly offered for tissue regeneration with the premise that they can survive and thrive amidst the microenvironment of injured or degenerate tissues. The role of high mobility group box 1 (HMGB1) and hypoxia in the proliferation and migration of rat bone marrow MSCs (rBM-MSCs) has been investigated. First, the effect of HMGB1 on the proliferation of rBM-MSCs was determined. Second, to evaluate the regulation of hypoxia and HMGB1 in the migration of rBM-MSCs, cells in the wound healing model were exposed to four conditions: normoxia (20% O2) and complete medium, normoxia and HMGB1, hypoxia (1% O2) and complete medium, hypoxia and HMGB1. RT-PCR and Western blotting were used to measure the expression of migration-related genes and proteins. HMGB1 inhibited the proliferation of rBM-MSCs; HMGB1 alone or together with hypoxia and promoted the migration of MSCs and upregulated the expression of HIF-1α and SDF-1. These results demonstrated that HMGB1 arrested the proliferation of rBM-MSCs, but enhanced the migration of rBM-MSCs which could be further improved by hypoxia. This study strengthens current understanding of the interaction between MSCs and the microenvironment of damaged tissues.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) hold great promise for tissue regeneration. With increasing numbers of clinical trials, the safety of BM-MSCs attracts great interest. Previously, we determined that rat BM-MSCs possessed spontaneous calcification without osteogenic induction after continuous culture. However, it is unclear whether BM-MSCs from other species share this characteristic. In this study, spontaneous calcification of BM-MSCs from rat, goat, and human specimens was investigated in vitro. BM-MSCs were cultured in complete medium, and calcification was determined by morphologic observation and alizarin red staining. It was demonstrated that rat BM-MSCs possessed a typically spontaneous calcification, whereas goat and human BM-MSCs under the same system proliferated significantly but did not calcify spontaneously. The significant species variation in spontaneous calcification of BM-MSCs described in this study provides useful information regarding evaluation of numerous BM-MSC-based approaches for bone regeneration and the safety of BM-MSCs.

Large articular cartilage defects remain an immense challenge in the field of regenerative medicine because of their poor intrinsic repair capacity. Currently, the available medical interventions can relieve clinical symptoms to some extent, but fail to repair the cartilaginous injuries with authentic hyaline cartilage. There has been a surge of interest in developing cell-based therapies, focused particularly on the use of mesenchymal stem/progenitor cells with or without scaffolds. Mesenchymal stem/progenitor cells are promising graft cells for tissue regeneration, but the most suitable source of cells for cartilage repair remains controversial. The tissue origin of mesenchymal stem/progenitor cells notably influences the biological properties and therapeutic potential. It is well known that mesenchymal stem/progenitor cells derived from synovial joint tissues exhibit superior chondrogenic ability compared with those derived from non-joint tissues; thus, these cell populations are considered ideal sources for cartilage regeneration. In addition to the progress in research and promising preclinical results, many important research questions must be answered before widespread success in cartilage regeneration is achieved. This review outlines the biology of stem/progenitor cells derived from the articular cartilage, the synovial membrane, and the synovial fluid, including their tissue distribution, function and biological characteristics. Furthermore, preclinical and clinical trials focusing on their applications for cartilage regeneration are summarized, and future research perspectives are discussed.

Although soft tissue replacement has been clinically successful in many cases, the corresponding procedure has many limitations including the lack of resilience and mechanical integrity, significant donor-site morbidity, volume loss with time, and fibrous capsular contracture. These disadvantages can be alleviated by utilizing bio-absorbable scaffolds with high resilience and large strain, which are capable of stimulating natural tissue regeneration. Hence, the chemically crosslinked tridimensional scaffolds obtained by incorporating water-based polyurethane (PU) (which was synthesized from polytetramethylene ether glycol, isophorone diisocyanate, and 2,2-bis(hydroxymethyl) butyric acid) into a bioactive extracellular matrix consisting of small intestinal submucosa (SIS) have been tested in this study to develop a new approach for soft tissue engineering. After characterizing the structure and properties of the produced PU/SIS composites, the strength, Young’s modulus, and resilience of wet PU/SIS samples were compared with those of crosslinked PU. In addition, the fabricated specimens were investigated using human umbilical vein endothelial cells to evaluate their ability to enhance cell attachment and proliferation. As a result, the synthesized PU/SIS samples exhibited high resilience and were capable of enhancing cell viability with no evidence of cytotoxicity. Subcutaneous implantation in animals and the subsequent testing conducted after 2, 4, and 8 weeks indicated that sound implant integration and vascularization occurred inside the PU/SIS composites, while the presence of SIS promoted cell infiltration, angiogenesis, and ultimately tissue regeneration. The obtained results revealed that the produced PU/SIS composites were characterized by high bioactivity and resilience, and, therefore, could be used for soft tissue engineering applications. Statement of Significance Hybrid composites containing synthetic polymers with high mechanical strength and naturally derived components, which create a bio-mimetic environment, are one of the most promising biomaterials. Although synthetic polymer/ECM composites have been previously used for soft tissue repair, their resilience properties were not investigated in sufficient detail, while the development of elastic composites composed of synthetic polymers and ECMs in nontoxic aqueous solutions remains a rather challenging task. In this study, porous PU/SIS composites were fabricated in a non-toxic manner; the obtained materials exhibited sufficient mechanical support, which promote cell growth, angiogenesis, and tissue regeneration. The described method can be adapted for the development of scaffolds with various acellular matrices and subsequently used during the restoration of particular types of tissue.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are the popular seed cells for regenerative medicine, and there has been a rapid increase in the number of BM-MSC-based clinical trials. However, the safety of these cells should also be closely studied. In this study, spontaneous calcification of BM-MSCs from rats was evaluated in normoxia (20% O(2)) without osteogenic medium after continuous culture for 21 days; obvious mineralized nodules were observed, which were positive for Alizarin Red, collagen-I (Col-I), osteocalcin (OC) and alkaline phosphatase (ALP), and mainly consisted of C, O and Ca elements. Interestingly, hypoxia (2% O(2)) significantly inhibited this spontaneous calcification. In addition, the ALP and calcium content of rBM-MSCs were sharply reduced. Based on RT-PCR results, the expression of osteogenic genes (Cbfa1/Runx2, Col-I, ALP, and OC) was reduced compared to that in normoxia. These results demonstrate a natural and unique characterization of rat BM-MSCs in normoxia after continuous culture and highlight the inhibiting effects of hypoxia. Finally, this study contributes to the information regarding the application of BM-MSCs in the regeneration of various tissues.

Background In order to shed light on the regenerative mechanism of mesenchymal stem cells (MSCs) in vivo, the bio-distribution profile of implanted cells using a stable and long-term tracking method is needed. We herein investigated the bio-distribution of human placental deciduas basalis derived MSCs (termed as PDB-MSCs) in nude mice after intravenous injection by carbon radioisotope labeling thymidine (14C-TdR), which is able to incorporate into new DNA strands during cell replication. Results The proliferation rate and radioactive emission of human PDB-MSCs after labeled with different concentrations of 14C-TdR were measured. PDB-MSCs labeled with 1 μCi possessed high radioactivity, and the biological characteristics (i.e. morphology, colony forming ability, differentiation capabilities, karyotype and cell cycle) showed no significant changes after labeling. Thus, 1 μCi was the optimal concentration in this experimental design. In nude mice, 1 × 10614C-TdR-labeled PDB-MSCs were injected intravenously and the organs were collected at days 1, 2, 3, 5, 30 and 180 after injection, respectively. Radiolabeled PDB-MSCs were found mainly in the lung, liver, spleen, stomach and left femur of the recipient nude mice at the whole observation period. Conclusions This work provided solid evidence that 14C-TdR labeling did not alter the biological characteristics of human placental MSCs, and that this labeling method has potential to decrease the signal from non-infused or dead cells for cell tracking. Therefore, this labeling technique can be utilized to quantify the infused cells after long-term follow-up in pre-clinical studies.

Demineralized bone matrix (DBM) has extensive clinical use for bone regeneration because of its osteoinductive and osteoconductive aptitude. It is suggested that the demineralization process in bone matrix preparation is influential in maintaining osteoinductivity; however, relevant investigations, especially into the osteoinductivity of acellular bone matrix, are not often performed. This study addressed the osteoinductive capability of human acellular cancellous bone matrix (ACBM) after subcutaneous implantation in a rat model. The growth and osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBM-MSCs) seeded in this material were also studied. Without the demineralization process, the ACBM we obtained had an interconnected porous network and the micropores in the surface were clearly exposed. After the ACBM was subcutaneously implanted for 4 months, new osteoid formation was noted but not typical mature bone formation. rBM-MSCs grew well in the ACBM and kept a steady morphology after continuous culture for 28 days. However, no mineralized nodule formation was detected and the expression levels of genes encoding osteogenic markers were significantly decreased. These results demonstrated that human ACBM possess the structural features of native bone and poor osteoinductivity; nonetheless this material helped to preserve the undifferentiated phenotype of rBM-MSCs. Such insights may further broaden our understanding of the application of ACBM for bone regeneration and the creation of stem cell niches.

MSCs (mesenchymal stem cells) may be promising seed cells for tissue regeneration because of their self-renewal and multi-differentiation potential. Shh (sonic hedgehog) is involved in the skeletal formation during embryo development and skeletal regeneration. However, how Shh regulates the biological characteristics of BM-MSCs (bone marrow-derived MSCs) is poorly understood. We have investigated the effect of rShh-N (recombinant N-terminal Shh) on the proliferation and osteogenic differentiation of rBM-MSCs (rat BM-MSCs) in vitro. rBM-MSCs were treated with rShh-N at concentrations up to 200 ng/ml. Proliferation and colony-forming ability of rBM-MSCs were increased in a dose-dependent manner. rShh-N increased the ratio of cells in S and G2/M phase, as well as the number of Ki-67+ cells. In addition, ALP (alkaline phosphatase) activity and matrix mineralization were enhanced by 200 ng/ml rShh-N. Real-time PCR showed that rShh-N (200 ng/ml) up-regulated the expression of genes encoding Cbfa-1 (core-binding factor α1), osteocalcin, ALP and collagen type I in rBM-MSCs. This information reveals some potential of rShh-N in the therapeutics of bone-related diseases.