Oxygen-Glucose Deprived Peripheral Blood Mononuclear Cells Protect Against Ischemic Stroke.

Stroke is the leading cause of severe long-term disability. Cell therapy has recently emerged as an approach to facilitate functional recovery in stroke. Although administration of peripheral blood mononuclear cells preconditioned by oxygen-glucose deprivation (OGD-PBMCs) has been shown to be a therapeutic strategy for ischemic stroke, the recovery mechanisms remain largely unknown. We hypothesised that cell-cell communications within PBMCs and between PBMCs and resident cells are necessary for a polarising protective phenotype. Here, we investigated the therapeutic mechanisms underlying the effects of OGD-PBMCs through the secretome. We compared levels of transcriptomes, cytokines, and exosomal microRNA in human PBMCs by RNA sequences, Luminex assay, flow cytometric analysis, and western blotting under normoxic and OGD conditions. We also performed microscopic analyses to assess the identification of remodelling factor-positive cells and evaluate angiogenesis, axonal outgrowth, and functional recovery by blinded examination by administration of OGD-PBMCs after ischemic stroke in Sprague-Dawley rats. We found that the therapeutic potential of OGD-PBMCs was mediated by a polarised protective state through decreased levels of exosomal miR-155-5p, and upregulation of vascular endothelial growth factor and a pluripotent stem cell marker stage-specific embryonic antigen-3 through the hypoxia-inducible factor-1α axis. After administration of OGD-PBMCs, microenvironment changes in resident microglia by the secretome promoted angiogenesis and axonal outgrowth, resulting in functional recovery after cerebral ischemia. Our findings revealed the mechanisms underlying the refinement of the neurovascular unit by secretome-mediated cell-cell communications through reduction of miR-155-5p from OGD-PBMCs, highlighting the therapeutic potential carrier of this approach against ischemic stroke.

Cell Therapies under Clinical Trials and Polarized Cell Therapies in Pre-Clinical Studies to Treat Ischemic Stroke and Neurological Diseases: A Literature Review.

Stroke remains a major cause of serious disability because the brain has a limited capacity to regenerate. In the last two decades, therapies for stroke have dramatically changed. However, half of the patients cannot achieve functional independence after treatment. Presently, cell-based therapies are being investigated to improve functional outcomes. This review aims to describe conventional cell therapies under clinical trial and outline the novel concept of polarized cell therapies based on protective cell phenotypes, which are currently in pre-clinical studies, to facilitate functional recovery after post-reperfusion treatment in patients with ischemic stroke. In particular, non-neuronal stem cells, such as bone marrow-derived mesenchymal stem/stromal cells and mononuclear cells, confer no risk of tumorigenesis and are safe because they do not induce rejection and allergy; they also pose no ethical issues. Therefore, recent studies have focused on them as a cell source for cell therapies. Some clinical trials have shown beneficial therapeutic effects of bone marrow-derived cells in this regard, whereas others have shown no such effects. Therefore, more clinical trials must be performed to reach a conclusion. Polarized microglia or peripheral blood mononuclear cells might provide promising therapeutic strategies after stroke because they have pleiotropic effects. In traumatic injuries and neurodegenerative diseases, astrocytes, neutrophils, and T cells were polarized to the protective phenotype in pre-clinical studies. As such, they might be useful therapeutic targets. Polarized cell therapies are gaining attention in the treatment of stroke and neurological diseases.

A novel therapeutic approach using peripheral blood mononuclear cells preconditioned by oxygen-glucose deprivation.

Cell therapies that invoke pleiotropic mechanisms may facilitate functional recovery in patients with stroke. Based on previous experiments using microglia preconditioned by oxygen-glucose deprivation, we hypothesized that the administration of peripheral blood mononuclear cells (PBMCs) preconditioned by oxygen-glucose deprivation (OGD-PBMCs) to be a therapeutic strategy for ischemic stroke. Here, OGD-PBMCs were identified to secrete remodelling factors, including the vascular endothelial growth factor and transforming growth factor-ß in vitro, while intra-arterial administration of OGD-PBMCs at 7 days after focal cerebral ischemia prompted expression of such factors in the brain parenchyma at 28 days following focal cerebral ischemia in vivo. Furthermore, administration of OGD-PBMCs induced an increasing number of stage-specific embryonic antigen-3-positive cells both in vitro and in vivo. Finally, it was found to prompt angiogenesis and axonal outgrowth, and functional recovery after cerebral ischemia. In conclusion, the administration of OGD-PBMCs might be a novel therapeutic strategy against ischemic stroke.

Application of Regenerative Treatment for Tympanic Membrane Perforation With Cholesteatoma, Tumor, or Severe Calcification.

OBJECTIVE: To apply regenerative treatment for tympanic membrane (TM) perforation to patients with severe calcification of the TM, cholesteatomas, or tumors localized to the tympanic cavity. STUDY DESIGN: Controlled clinical pilot study. SETTING: General hospitals. PATIENTS: Forty-five patients (age: 8-85; M = 19, F = 26) were selected from patients with or without TM perforation for the regenerative treatment. Twenty-five patients had cholesteatomas, 3 had tumors, and 17 had severe TM calcification. Patients were classified into three groups based on TM perforation size: less than 1/3 of the TM as Grade I (n = 5), 1/3 to 2/3 as Grade II (n = 19), and over 2/3 as Grade III (n = 21). Twenty patients who underwent standard tympanoplasty type I were selected as historical controls. MATERIALS AND METHODS: Materials for the TM repair included gelatin sponge with basic fibroblast growth factor and fibrin glue. After lesions were removed through the TM perforation, gelatin sponge immersed in basic fibroblast growth factor was placed over the perforation. Fibrin glue was then dripped onto the sponge. Treatment efficacy was evaluated 6 months posttreatment. RESULTS: Complete closure of the TM perforation was achieved in 91% (n = 41/45) of the patients in this regenerative treatment. Improvement in average hearing levels and air-bone gap were much better with this treatment than in the historical control group. CONCLUSION: This new regenerative therapy is useful not only for patients with simple TM perforations but also for those with cholesteatomas, tumors, or severe calcification without requiring conventional surgical procedures. This regenerative therapy is an easy, safe, cost-effective, and minimally-invasive treatment.

Regenerative treatment for tympanic membrane perforation using gelatin sponge with basic fibroblast growth factor.

OBJECTIVE: The objective of this study was to evaluate safety and efficacy of regenerative treatment using gelatin sponge with basic fibroblast growth factor (bFGF) in patients with tympanic membrane perforation (TMP). METHODS: The current study was a prospective, multicenter, open-label, single-arm, and exploratory clinical trial to evaluate the safety and efficacy of the TM regeneration procedure (TMRP). Myringotomy was used to mechanically disrupt the edge of the TMP, and a gelatin sponge immersed in bFGF was then placed over the perforation. Fibrin glue was dripped over the sponge as a sealant. TMP closure was examined 4 weeks later and, if insufficient, TMRP was repeated a maximum of three more times. TMP closure and hearing improvement 12 weeks after the final TMRP as well as safety were evaluated. RESULTS: Of the 11 patients with TMP who participated in this study, one who fulfilled the exclusion criteria and did not undergo TMRP and one with cholesteatoma were excluded from the efficacy analysis. TMP closure and hearing improvement 12 weeks after the final TMRP were achieved in eight out of nine patients (88.9%). Mean bone conduction threshold significantly improved 12 weeks after the TMRP compared with baseline (35.7±20.3 vs 29.4±21.0dB, P=0.015). Six out of ten patients receiving TMRP experienced temporary adverse events: appendicitis (serious, severe), otorrhea (mild), otitis media (mild), and sudden hearing loss (mild). However, none were related to the protocol treatment. CONCLUSION: TMP closure and hearing improvement were frequently confirmed following the TMRPs which were safely performed. These favorable outcomes were accompanied with significant improvement of the bone conduction threshold. These promising outcomes would encourage a large-scaled, randomized and pivotal clinical trial in the future. This trial is registered at http://www.umin.ac.jp/ctr/index.htm (identifier: UMIN000006585).

Bone marrow-derived mononuclear cell transplantation in spinal cord injury patients by lumbar puncture.

PURPOSE: This study was conducted to assess the safety and feasibility of intrathecal transplantation of autologous bone marrow-derived mononuclear cells for the treatment of patients with spinal cord injury. METHODS: Ten patients were included in the study. Approximately 120 ml of bone marrow aspirate was obtained from bilateral iliac bone of patients with spinal cord injury. Isolation of mononuclear cells was performed using Ficoll density-gradient centrifugation. Bone marrow mononuclear cells were transplanted into cerebrospinal fluid by lumbar puncture. Functional tests were performed prior to the cell transplantation and six months after cell transplantation. The patients were carefully observed for up to six months. RESULTS: In 5 patients with AIS A prior to cell transplantation, 1 patient converted to AIS B six months after cell transplantation. In 5 patients with AIS B, 1 patient converted to AIS D and 2 patients to AIS C. MRI did not show any complication. Two patients showed slight anemia after aspiration of bone-marrow cells, which returned to normal level within a several weeks. CONCLUSION: The results of this study suggest that this method may be safe and feasible.

Stoichiometric analysis of oligomerization of membrane proteins on living cells using coiled-coil labeling and spectral imaging.

Many membrane proteins are proposed to work as oligomers; however, the conclusion is sometimes controversial, as for ß2-adorenergic receptor (ß2AR), which is one of the best-studied family A G-protein-coupled receptors. This is due to the lack of methods for easy and precise detection of the oligomeric state of membrane proteins on living cells. Here, we show that a combination of the coiled-coil tag-probe labeling method and spectral imaging enable a stoichiometric analysis of the oligomeric state of membrane proteins on living cells using monomeric, dimeric, and tetrameric standard membrane proteins. Using this method, we found that ß2ARs do not form constitutive homooligomers, while they exhibit their functions such as the cyclic adenosine 5'-monophosphate (cAMP) signaling and internalization upon agonist stimulation.

Coiled-coil tag-probe labeling methods for live-cell imaging of membrane receptors.

Tag-probe labeling methods have advantages over conventional fusion with fluorescent proteins in terms of smaller labels, surface specificity, availability of pulse labeling, and ease of multicolor labeling. With this method, the gene of the target protein is fused with a short tag sequence, expressed in cells, and the protein is labeled with exogenous fluorescent probes that specifically bind to the tag. Various labeling principles, such as protein-ligand interaction, peptide-peptide interaction, peptide-metal interaction, and enzymatic reactions, have been applied to the tag-probe labeling of membrane receptors. We describe our coiled-coil tag-probe method in detail, including the design and synthesis of the tag and probe, labeling procedures, and observations by confocal microscopy. Applications to the analysis of receptor internalization and oligomerization are also introduced.

Novel culture system of mesenchymal stromal cells from human subcutaneous adipose tissue.

Accumulating evidence suggests that the delivery of human adipose tissue-derived stromal cells (hASCs) has great potential as regenerative therapy. This was performed to develop a method for expanding hASCs by reducing the amount of serum required. We demonstrate that hASCs were able to expand efficiently in media containing 2% serum and fibroblast growth factor-2. These cells, or low serum cultured hASCs (hLASCs), expressed cell surface markers similar to those on bone marrow-derived mesenchymal stem cells, and could be differentiated into cells of mesenchymal lineage. Of interest, hLASCs secreted higher levels of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) than hASCs cultured in 20% serum (hHASCs). Moreover, hLASC-conditioned media significantly increased endothelial cell (EC) proliferation and decreased EC apoptosis compared to that obtained from hHASCs or control media only. Antibodies against VEGF and HGF virtually negated these effects. When hASCs were administered into the ischemic hindlimbs of nude rats, hLASCs improved blood flow, increased capillary density, and raised the levels of VEGF and HGF in the muscles as compared with hHASCs. In conclusion, we demonstrate a novel low serum culture system for hASCs, which may have great potential in regenerative cell therapy for damaged organs in the clinical setting.