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Cell-biomaterial interactions are primarily governed by cell adhesion, which arises from the binding of cellular integrins to the extracellular matrix (ECM). Integrins drive the assembly of focal contacts that serve as mechanotransducers and signaling nexuses for stem cells, for example integrin α4β1 plays pivotal roles in regulating mesenchymal stem cell (MSC) homing, adhesion, migration and differentiation. The strategy to control the integrin-mediated cell adhesion to bioinspired, ECM-mimicking materials is essential to regulate cell functions and tissue regeneration. Previously, using one-bead one-compound (OBOC) combinatorial technology, we discovered that LLP2A was a high-affinity peptidomimetic ligand (IC50 = 2 pM) against integrin α4β1. In this study, we identified that LLP2A had a strong binding to human early gestation chorionic villi-derived MSCs (CV-MSCs) via integrin α4β1. To improve CV-MSC seeding, expansion and delivery for regenerative applications, we constructed artificial scaffolds simulating the structure of the native ECM by immobilizing LLP2A onto the scaffold surface as cell adhesion sites. LLP2A modification significantly enhanced CV-MSC adhesion, spreading and viability on the polymeric scaffolds via regulating signaling pathways including phosphorylation of focal adhesion kinase (FAK), and AKT, NF-kB and Caspase 9. In addition, we also demonstrated that LLP2A had strong binding to MSCs of other sources, such as bone marrow-derived mesenchymal stem cells (BM-MSCs) and adipose tissue-derived mesenchymal stem cells (AT-MSCs). Therefore, LLP2A and its derivatives not only hold great promise for improving CV-MSC-mediated treatment of fetal diseases, but they can also be widely applied to functionalize various biological and medical materials, which are in need of MSC recruitment, enrichment and survival, for regenerative medicine applications.

Endothelial cell (EC) transplantation via injectable collagen hydrogel has received much attention as a potential treatment for various vascular diseases. However, the therapeutic effect of transplanted ECs is limited by their poor viability, which partially occurs as a result of cellular apoptosis triggered by the insufficient cell-extracellular matrix (ECM) engagement. Integrin binding to the ECM is crucial for cell anchorage to the surrounding matrix, cell spreading and migration, and further activation of intracellular signaling pathways. Although collagen contains several different types of integrin binding sites, it still lacks sufficient specific binding sites for ECs. Previously, using one-bead one-compound (OBOC) combinatorial technology, we identified LXW7, an integrin αvβ3 ligand, which possessed a strong binding affinity to and enhanced functionality of ECs. In this study, to improve the EC-matrix interaction, we developed an approach to molecularly conjugate LXW7 to the collagen backbone, via a collagen binding peptide SILY, in order to increase EC specific integrin binding sites on the collagen hydrogel. Results showed that in the in vitro 2-dimensional (2D) culture model, the LXW7-treated collagen surface significantly improved EC attachment and survival and decreased caspase 3 activity in an ischemic-mimicking environment. In the in vitro 3-dimensional (3D) culture model, LXW7-modified collagen hydrogel significantly improved EC spreading, proliferation, and survival. In a mouse subcutaneous implantation model, LXW7-modified collagen hydrogel improved the engraftment of transplanted ECs and supported ECs to form vascular network structures. Therefore, LXW7-functionalized collagen hydrogel has shown promising potential to improve vascularization in tissue regeneration and may be used as a novel tool for EC delivery and the treatment of vascular diseases.

AbsractBACKGROUND: Tumor metastasis is the major reason for poor prognosis of hepatocellular carcinoma (HCC) patients after hepatic resection. SMYD3 has been demonstrated to promote liver tumor metastasis in mice. However, the detailed molecular mechanism is still largely unknown.MethodsThe effect of SMYD3 on invasiveness and metastasis of HCC was analyzed by immunohistochemistry, migration assay, invasion assay, wound healing assay and in vivo lung metastasis assay. Mass spectrometry analysis was conducted using proteins pulled down by H3K4me3 antibody in SMYD3-overexpressing cells. Luciferase reporter, chromatin immunoprecipitation, Electrophoretic mobility shift assay were used to measure the regulation of SLUG transcription by SMYD3-ANKHD1. In addition, the role of SMYD3-ANKHD1 in determining clinical outcomes for HCC patients was investigated by immunohistochemistry in 243 HCC tissues.ResultsSMYD3 was an independent prognostic factor of HCC and promoted migration and invasion of human HCC cells. ANKHD1 was identified by mass spectrometry as a co-regulator with SMYD3. ANKHD1 interacted with H3K4me3 when cells were overexpressing SMYD3. The pro-migratory and pro-invasive effects of SMYD3 were attenuated when ANKHD1 was knocked down by siRNA. Furthermore, we found that SMYD3 bound and activated the SLUG gene promoter in a manner associated with elevating H3K4me3, H3K9Ac and H3K14Ac. Knockdown of ANKHD1 could attenuate the SMYD3-dependent activation of Slug expression. We further detected the expression of SMYD3 and ANKHD1 in 243 HCC patients and found that patients with positive coexpression of SMYD3 and ANKHD1 (SMYD3+ANKHD1+) had the shortest overall and recurrence-free survival.ConclusionOur findings provide a novel molecular mechanism for the SMYD3-regulated HCC migration and metastasis, and indicates that SMYD3-ANKHD1 may be a potential target for treating HCC.

Prenatal stem cell-based regenerative therapies have progressed substantially and have been demonstrated as effective treatment options for fetal diseases that were previously deemed untreatable. Due to immunoregulatory properties, self-renewal capacity, and multilineage potential, autologous human placental chorionic villus-derived mesenchymal stromal cells (CV-MSCs) are an attractive cell source for fetal regenerative therapies. However, as a general issue for MSC transplantation, the poor survival and engraftment is a major challenge of the application of MSCs. Particularly for the fetal transplantation of CV-MSCs in the naturally hypoxic fetal environment, improving the survival and engraftment of CV-MSCs is critically important. Hypoxic preconditioning (HP) is an effective priming approach to protect stem cells from ischemic damage. In this study, we developed an optimal HP protocol to enhance the survival and proangiogenic capacity of CV-MSCs for improving clinical outcomes in fetal applications. Total cell number, DNA quantification, nuclear area test, and cell viability test showed HP significantly protected CV-MSCs from ischemic damage. Flow cytometry analysis confirmed HP did not alter the immunophenotype of CV-MSCs. Caspase-3, MTS, and Western blot analysis showed HP significantly reduced the apoptosis of CV-MSCs under ischemic stimulus via the activation of the AKT signaling pathway that was related to cell survival. ELISA results showed HP significantly enhanced the secretion of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) by CV-MSCs under an ischemic stimulus. We also found that the environmental nutrition level was critical for the release of brain-derived neurotrophic factor (BDNF). The angiogenesis assay results showed HP-primed CV-MSCs could significantly enhance endothelial cell (EC) proliferation, migration, and tube formation. Consequently, HP is a promising strategy to increase the tolerance of CV-MSCs to ischemia and improve their therapeutic efficacy in fetal clinical applications.

Macrovascular invasion, such as tumor thrombus in the major portal vein (mPVTT) or major hepatic vein (mHVTT), is regarded as indicative of an advanced stage of hepatocellular carcinoma (HCC). To date, no effective treatment has been established for this kind of HCC. We herein present a case of huge HCC with intrahepatic metastasis, mPVTT, and mHVTT. The patient was successfully treated with surgical resection-based multidisciplinary treatment. The clinical presentation, treatment strategy, and outcome of this case were presented. [ABSTRACT FROM AUTHOR]

Hepatitis B virus X protein (HBx) is considered as an oncogene in tumorigenesis and progression of hepatocellular carcinoma (HCC). In recent years, the important role of circular RNAs (circRNAs) in HCC has been increasingly demonstrated. However, the regulatory mechanisms of HBx on circRNAs remains largely unknown. In this study, we identified that a novel circRNA, circSFMBT2, was markedly downregulated by HBx. Low expression of circSFMBT2 was correlated with poor prognosis and vascular invasion. Functionally, overexpression of circSFMBT2 significantly inhibited HCC metastasis both in vitro and in vivo . The mechanism of circSFMBT2 was to as a sponge of miR-665, which is a negative regulator of tissue inhibitor of metalloproteinases 3 (TIMP3). However, HBx downregulated circSFMBT2 via the interaction with DExH-box helicase 9 (DHX9), which binds to flanking circRNA-forming introns. In conclusion, circSFMBT2, which is downregulated by HBx, acts as a tumor suppressor to inhibit tumor metastasis through the miR-665/TIMP3 axis. Our study suggests that circSFMBT2 could be a potential prognostic biomarker and therapeutic target for HCC., Competing Interests: The authors declare no competing interests., (© 2022 The Author(s).)