Exosomal MicroRNA-23-5p Derived from Bone Marrow Mesenchymal Stem Cells Relieves Inflammatory Response in Rheumatoid Arthritis

We aimed to explore the mechanism underlying microRNA-23-5p from exosomes (exo-miR-23-5p) of BMSCs in rheumatoid arthritis (RA). The candidate related genes of miR-23-5p were screened in RA by bioinformatics analysis through gain- and loss-function method along with analysis of histopathological changes in mice and RAC2 expression as well as the level of pro-inflammatory factors. In vivo RA model was established to detect miR-23-5p’s effect on RA. miR-23-5p level was significantly reduced in RA cells and RAC2 was highly expressed. Expression of RAC2 was inhibited and targeted by miR-23-5p in RA. Exo-miR-23-5p treatment effectively alleviated joint destruction, reduced inflammatory factor secretion in tissues and serum, as well as decreased RAC2 expression in RA model. In conclusion, the miR-23-5p in the BMSC-exo delays the inflammatory response in RA, indicating that it might be a new target for treating RA.

Human iPSC-Derived Vascular Smooth Muscle Cells in a Fibronectin Functionalized Collagen Hydrogel Augment Endothelial Cell Morphogenesis

Tissue-engineered constructs have immense potential as autologous grafts for wound healing. Despite the rapid advancement in fabrication technology, the major limitation is controlling angiogenesis within these constructs to form a vascular network. Here, we aimed to develop a 3D hydrogel that can regulate angiogenesis. We tested the effect of fibronectin and vascular smooth muscle cells derived from human induced pluripotent stem cells (hiPSC-VSMC) on the morphogenesis of endothelial cells. The results demonstrate that fibronectin increases the number of EC networks. However, hiPSC-VSMC in the hydrogel further substantiated the number and size of EC networks by vascular endothelial growth factor and basic fibroblast growth factor secretion. A mechanistic study shows that blocking αvβ3 integrin signaling between hiPSC-VSMC and fibronectin impacts the EC network formation via reduced cell viability and proangiogenic growth factor secretion. Collectively, this study set forth initial design criteria in developing an improved pre-vascularized construct.

Syntaxin 5 determines Weibel-Palade body size and Von Willebrand factor secretion by controlling Golgi architecture

Von Willebrand factor (VWF) is a multimeric hemostatic protein primarily synthesized in endothelial cells (ECs). VWF is stored in endothelial storage organelles, the Weibel-Palade bodies (WPBs), whose biogenesis strongly depends on VWF anterograde trafficking and Golgi architecture. Elongated WPB morphology is correlated to longer VWF strings with better adhesive properties. We previously identified the SNARE SEC22B, which is involved in anterograde ER-to-Golgi transport, as a novel regulator of WPB elongation. To elucidate novel determinants of WPB morphology we explored endothelial SEC22B interaction partners in a mass spectrometrybased approach, identifying the Golgi SNARE Syntaxin 5 (STX5). We established STX5 knockdown in ECs using shRNA-dependent silencing and analyzed WPB and Golgi morphology, using confocal and electron microscopy. STX5-depleted ECs exhibited extensive Golgi fragmentation and decreased WPB length, which was associated with reduced intracellular VWF levels, and impaired stimulated VWF secretion. However, the secretion-incompetent organelles in shSTX5 cells maintained WPB markers such as Angiopoietin 2, P-selectin, Rab27A, and CD63. Taken together, our study has identified SNARE protein STX5 as a novel regulator of WPB biogenesis.

A Mouse Model of Nigrostriatal Dopaminergic Axonal Degeneration As a Tool for Testing Neuroprotectors

Degeneration of nigrostriatal dopaminergic neurons in Parkinsons disease begins from the axonal terminals in the striatum and, then, in retrograde fashion, progresses to the cell bodies in the substantia nigra. Investigation of the dynamics of axonal terminal degeneration may help in the identification of new targets for neuroprotective treatment and be used as a tool for testing potential drugs. We have shown that the degeneration rate of dopaminergic axonal terminals changes over time, and that the striatal dopamine concentration is the most sensitive parameter to the action of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). This model was validated using neuroprotectors with well-known mechanisms of action: the dopamine transporter inhibitor nomifensine and SEMAX peptide that stimulates the secretion of endogenous neurotrophic factors or acts as an antioxidant. Nomifensine was shown to almost completely protect dopaminergic fibers from the toxic effect of MPTP and maintain the striatal dopamine concentration at the control level. However, SEMAX, slightly but reliably, increased striatal dopamine when administered before MPTP treatment, which indicates that it is more effective as an inductor of endogenous neurotrophic factor secretion rather than as an antioxidant.

Anti-senescence ion-delivering nanocarrier for recovering therapeutic properties of long-term-cultured human adipose-derived stem cells

Background Human adipose-derived stem cells (hADSCs) have been used in various fields of tissue engineering because of their promising therapeutic efficacy. However, the stemness of hADSCs cannot be maintained for long durations, and their therapeutic cellular functions, such as paracrine factor secretion decrease during long-term cell culture. To facilitate the use of long-term-cultured hADSCs (L-ADSCs), we designed a novel therapeutic anti-senescence ion-delivering nanocarrier (AIN) that is capable of recovering the therapeutic properties of L-ADSCs. In the present study, we introduced a low-pH-responsive ion nanocarrier capable of delivering transition metal ions that can enhance angiogenic paracrine factor secretion from L-ADSCs. The AINs were delivered to L-ADSCs in an intracellular manner through endocytosis. Results Low pH conditions within the endosomes induced the release of transition metal ions (Fe) into the L-ADSCs that in turn caused a mild elevation in the levels of reactive oxygen species (ROS). This mild elevation in ROS levels induced a downregulation of senescence-related gene expression and an upregulation of stemness-related gene expression. The angiogenic paracrine factor secretion from L-ADSCs was significantly enhanced, and this was evidenced by the observed therapeutic efficacy in response to treatment of a wound-closing mouse model with conditioned medium obtained from AIN-treated L-ADSCs that was similar to that observed in response to treatment with short-term-cultured adipose-derived stem cells. Conclusions This study suggests a novel method and strategy for cell-based tissue regeneration that can overcome the limitations of the low stemness and therapeutic efficacy of stem cells that occurs during long-term cell culture. Graphical Abstract

MiR-193b-3p–ERBB4 axis regulates psoriasis pathogenesis via modulating cellular proliferation and inflammatory-mediator production of keratinocytes

Psoriasis is an auto-inflammatory skin disease characterized by abnormal activation of epidermal keratinocytes, aberrant neovascularization, and dysregulation of immune cells. MicroRNAs are small non-coding RNAs that mainly function in the post-transcriptional regulation of gene expression. Recently, accumulating evidence has demonstrated that expression of microRNAs is dysregulated in psoriasis patients and microRNAs play key roles in psoriasis pathogenesis. Downregulation of miR-193b-3p has been identified to be associated with psoriasis development. However, the precise functions and action mechanisms of miR-193b-3p in psoriasis pathogenesis remain unclear. In this study, we confirmed the downregulation of miR-193b-3p in psoriasis patients, psoriasis-like inflammatory cellular models, and an imiquimod (IMQ) -induced mouse model. A negative correlation was found between miR-193b-3p level and patient Psoriasis Area and Severity Index (PASI) score. Furthermore, miR-193b-3p suppressed proliferation, inflammatory-factor secretion, and the STAT3 and NF-κB signaling pathways in keratinocytes. Importantly, intradermal injection of agomiR-193b-3p blocked, whereas antagomiR-193b-3p augmented, the psoriasis-like inflammation in the IMQ-induced mouse model. Bioinformatics analysis and the dual-luciferase reporter assay showed that miR-193b-3p targets ERBB4 3ʹ untranslated region (UTR). In addition, ERBB4 induced proliferation, inflammatory-factor production, and the STAT3 and NF-κB pathways in keratinocytes. Most importantly, forced expression of ERBB4 could attenuate the effects of miR-193b-3p in keratinocytes, indicating that miR-193b-3p inhibits keratinocyte activation by directly targeting ERBB4. In conclusion, our findings demonstrated that the miR-193b-3p–ERBB4 axis underlies the hyperproliferation and aberrant inflammatory-factor secretion of psoriatic keratinocytes, providing a novel, microRNA-related causal mechanism and a potential therapeutic target in psoriasis.