Human cholesteatoma perimatrix fibroblasts (hCPFs) can stimulate the endothelial cells of nearby microvessels to proliferate and migrate in a paracrine manner. Exosomes, secreted from various cell types, are one of the most important paracrine factors and play critical roles in intercellular communication. However, whether exosomes derived from human cholesteatoma perimatrix fibroblasts (hCPFs-Exo) can promote angiogenesis has not been reported. In this study, we isolated exosomes secreted by hCPFs and observed that hCPFs-Exo was able to promote migration and tube formation in human umbilical vein endothelial cells (HUVECs). Advanced studies revealed hCPFs-Exo with low expression of miR-106b-5p was transferred into HUVECs, and decreased expression of miR-106b-5p could promote angiogenesis by targeting Angiopoietin 2 (Angpt2) via binding to its 3'-UTR. Furthermore, low levels of miR-106b-5p triggered overexpression of Angpt2, and significantly increased HUVEC migration and tube formation. Taken together, our results suggest that hCPFs-Exo transports low expressed exosomal miR-106b-5p to endothelial cells and promotes angiogenesis by overexpression of Angpt2.

Acute spinal cord injury (SCI) is a devastating condition that results in tremendous physical and psychological harm and a series of socioeconomic problems. Although neurons in the spinal cord need neurotrophic factors for their survival and development to reestablish their connections with their original targets, endogenous neurotrophic factors are scarce and the sustainable delivery of exogeneous neurotrophic factors is challenging. The widely studied neurotrophic factors such as brain-derived neurotrophic factor, neurotrophin-3, nerve growth factor, ciliary neurotrophic factor, basic fibroblast growth factor, and glial cell-derived neurotrophic factor have a relatively short cycle that is not sufficient enough for functionally significant neural regeneration after SCI. In the past decades, scholars have tried a variety of cellular and viral vehicles as well as tissue engineering scaffolds to safely and sustainably deliver those necessary neurotrophic factors to the injury site, and achieved satisfactory neural repair and functional recovery on many occasions. Here, we review the neurotrophic factors that have been used in trials to treat SCI, and vehicles that were commonly used for their sustained delivery.

Rationale:Spinal cord infarction is one of the complications of epidural steroid injections (ESIs), but has only been reported in cervical vertebra by transforaminal injection and lumbar vertebra by transforaminal injection; and up to now, there is no reporting about spinal cord infarction caused by caudal injection. Here, we report a case.Patient concerns:A 52-year-old man was admitted to our hospital. He was diagnosed as lumbar disc herniation in other hospital, and the patient suffered bilateral lower limb motor and sensory disorders after administration of caudal ESI.Diagnosis:Spinal cord infarction, tethered cord syndrome (TCS), and acute myelitis.Interventions:High doses of hormones, gamma globulin impact therapy, and rehabilitation were performed.Outcomes:The patient's condition was stable when he discharged from the hospital after 20 days of treatment. Discharge status: grade 0 of bilateral lower limbs muscle strength, inability to urinate and defecate by himself, slightly decreased touch, and needling sensation below the umbilical plane.Lessons:When patients are diagnosed with lumbar disc herniation and need to receive invasive treatments, magnetic resonance imaging (MRI) should be performed before the invasive procedures.

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Human umbilical cord blood-derived mesenchymal stem cells (hUC-MSCs) have been widely used in tissue engineering. The aim of this study is to evaluate the ability of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) scaffolds coated with polyhydroxyalkanoate binding protein fused with arginyl-glycyl-aspartic acid (PhaP-RGD) to promote the proliferation and chondrogenic differentiation of hUC-MSCs seeded on them. The PhaP-RGD fusion protein was expressed by Escherichia coli. PHBHHx films were coated with PhaP-RGD fusion protein and the physiochemical properties were examined. hUC-MSCs were seeded on PHBHHx films with or without PhaP-RGD precoating and tested for changes in morphology, viability, and chondrogenic differentiation. We found that PhaP-RGD-coated PHBHHx films had similar surface morphology to uncoated PHBHHx. The water contact angle of the coated PHBHHx surface was lower than that of the uncoated surface (10.63° vs. 98.69°). At 7 and 14 days after seeding, the PhaP-RGD-coated PHBHHx group showed greater numbers of viable cells compared to the uncoated PHBHHx group. The expression levels of aggrecan and collagen II were enhanced in the PhaP-RGD-coated PHBHHx group relative to the uncoated PHBHHx group. Histological analysis using toluidine blue staining showed elevated formation of proteoglycan producing chondrocytes in the PhaP-RGD-coated PHBHHx group. Additionally, the synthesis of proteoglycan and collagen was significantly enhanced within the PhaP-RGD constructs. Taken together, PhaP-RGD coating promotes the proliferation and chondrogenic differentiation of hUC-MSCs seeded on PHBHHx films. PhaP-RGD-coated PHBHHx may be a useful scaffold for cartilage tissue engineering.