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.

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.

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.

Multicenter phase III trial of regenerative treatment for chronic tympanic membrane perforation.

OBJECTIVE: To evaluate the efficacy and safety of regenerative treatment for tympanic membrane perforation (TMP) using gelatin sponge, basic fibroblast growth factor (bFGF), and fibrin glue. METHODS: This was a multicenter, non-randomized, single-arm study conducted at tertiary referral centers. Twenty patients with chronic TMP (age 23-78 years, 6 males, 14 females) were registered from three institutions. All treated patients were included in the safety analysis population. The edges of the TMP were disrupted mechanically by myringotomy and several pieces of gelatin sponge immersed in bFGF were placed and fixed with fibrin glue to cover the perforation. The TMP was examined 4 ± 1 weeks later. The protocol was repeated up to four times until closure was complete. The main outcome measures were closure or a decrease in size of the TMP, hearing improvement, and air-bone gap evaluated 16 weeks after the final regenerative procedure (FRP). Adverse events (AEs) were monitored throughout the study. RESULTS: Total closure of the TMP at 16 weeks was achieved in 15 out of 20 patients (75.0%, 95% confidence interval [CI]: 50.9%-91.3%) and the mean decrease in size was 92.2% (95%CI: 82.9%-100.0%). The ratio of hearing improvement and the air-bone gap at 16 weeks after FRP were 100% (20/20; 95%CI: 83.2%-100%) and 5.3 ± 4.2 dB (p <0.0001), respectively. Thirteen out of 20 patients (65.0%) experienced at least one AE, but no serious AEs occurred. CONCLUSION: The results indicate that the current regenerative treatment for TMP using gelatin sponge, bFGF, and fibrin glue is safe and effective.

Reduced nucleotomy-induced intervertebral disc disruption through spontaneous spheroid formation by the Low Adhesive Scaffold Collagen (LASCol).

Back pain is a global health problem with a high morbidity and socioeconomic burden. Intervertebral disc herniation and degeneration are its primary cause, further associated with neurological radiculopathy, myelopathy, and paralysis. The current surgical treatment is principally discectomy, resulting in the loss of spinal movement and shock absorption. Therefore, the development of disc regenerative therapies is essential. Here we show reduced disc damage by a new collagen type I-based scaffold through actinidain hydrolysis-Low Adhesive Scaffold Collagen (LASCol)-with a high 3D spheroid-forming capability, water-solubility, and biodegradability and low antigenicity. In human disc nucleus pulposus and annulus fibrosus cells surgically obtained, time-dependent spheroid formation with increased expression of phenotypic markers and matrix components was observed on LASCol but not atelocollagen (AC). In a rat tail nucleotomy model, LASCol-injected and AC-injected discs presented relatively similar radiographic and MRI damage control; however, LASCol, distinct from AC, decelerated histological disc disruption, showing collagen type I-comprising LASCol degradation, aggrecan-positive and collagen type II-positive endogenous cell migration, and M1-polarized and also M2-polarized macrophage infiltration. Reduced nucleotomy-induced disc disruption through spontaneous spheroid formation by LASCol warrants further investigations of whether it may be an effective treatment without stem cells and/or growth factors for intervertebral disc disease.

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.

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

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Age-specific characterization of spinal cord injuries over a 19-year period at a Japanese rehabilitation center.

Regional demographics of spinal cord injuries (SCIs) are fundamental to identifying and implementing appropriate preventive measures. The current study was conducted as a longitudinal analysis of all patients with SCIs admitted to the Hyogo Rehabilitation Center over a 19-year period. The sex and age of the patient, time and nature of injury (i.e., cause, level, and extent), and period from injury to admission were evaluated retrospectively. Pertinent tests, including Poisson regression analysis, and the Cochran-Armitage, Kruskal-Wallis, and chi-square tests, were applied to assess demographic variables, with statistical significance set at p < 0.05. Between 1995 and 2013, a total of 632 patients with SCIs (predominantly male and largely < 60 years old) were admitted to our center for rehabilitation. Although the male: female ratio remained unchanged throughout the study period, the ratio of older adults increased over time. In assessing the cause of injury, the majority of the patients involved in road traffic accidents were aged ≤ 44 years, whereas patients aged ≥ 45 years accounted for the majority of low-distance falls and disease-related SCIs, the proportions of which gradually increased. Complete paralysis and paraplegia primarily occurred in patients aged ≤ 44 years, whereas the majority of incomplete injuries and tetraplegia were limited to those aged ≥ 45 years. The patient age at the time of SCI and the nature of the injury sustained were interrelated. Age-specific strategies thus offered the best means of preventing/reducing the incidence of SCIs in Hyogo prefecture.

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).

[A visualization tool for oligomerization and internalization of membrane proteins in living cells: coiled-coil labeling method].

Genetic fusion of fluorescent/luminescent proteins to a target protein for specific labeling in living cells has been widely used to investigate the intracellular trafficking and oligomerization of the proteins. However, several limitations of fluorescent/luminescent proteins, such as considerable size, difficulty in controlling labeling ratio in multicolor labeling, can obscure true behaviors of the target proteins. To overcome these difficulties, post-translational labeling methods using pairs of small genetically-encodable 'tags' and synthetic 'probes' targeting the tags have been widely studied in recent years. We have developed a quick tag-probe labeling method using a high-affinity heterodimeric coiled-coil formation between the E3 tag (EIAALEK)3 attached to the target protein and the K4 probe (KIAALKE)4 labeled with a fluorophore. The labeling is cell-surface-specific and completed within 1 min, therefore suitable for monitoring oligomerization/internalization of membrane proteins on living cell surface. Taking advantage of easiness in multicolor labeling, we show that the oligomeric state of membrane proteins can be precisely analyzed based on fluorescence resonance energy transfer. By using this method, we found that ß2 adrenergic receptors do not form constitutive homooligomers, and homooligomerization is not necessary for the receptor function. Furthermore, the degree of internalization of the ß2 receptors following agonist stimulation was evaluated by ratiometric detection of pH decrease in endosomes.

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.

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.

Identification of two myo-inositol transporter genes of Bacillus subtilis.

Among hundreds of mutants constructed systematically by the Japanese groups participating in the functional analysis of the Bacillus subtilis genome project, we found that a mutant with inactivation of iolT (ydjK) exhibited a growth defect on myo-inositol as the sole carbon source. The putative product of iolT exhibits significant similarity with many bacterial sugar transporters in the databases. In B. subtilis, the iolABCDEFGHIJ and iolRS operons are known to be involved in inositol utilization, and its transcription is regulated by the IolR repressor and induced by inositol. Among the iol genes, iolF was predicted to encode an inositol transporter. Inactivation of iolF alone did not cause such an obvious growth defect on inositol as the iolT inactivation, while simultaneous inactivation of the two genes led to a more severe defect than the single iolT inactivation. Determination of inositol uptake by the mutants revealed that iolT inactivation almost completely abolished uptake, but uptake by IolF itself was slightly detectable. These results, as well as the K(m) and V(max) values for the IolT and IolF inositol transporters, indicated that iolT and iolF encode major and minor inositol transporters, respectively. Northern and primer extension analyses of iolT transcription revealed that the gene is monocistronically transcribed from a promoter likely recognized by final sigma(A) RNA polymerase and negatively regulated by IolR as well. The interaction between IolR and the iolT promoter region was analyzed by means of gel retardation and DNase I footprinting experiments, it being suggested that the mode of interaction is quite similar to that found for the promoter regions of the iol divergon.

Differential effect of green tea catechins on three endothelial cell clones isolated from rat adipose tissue and on human umbilical vein endothelial cells.

By single colony isolation from the cells in stromal vascular fraction (SVF) dispersed from rat adipose tissues, we isolated three independent clones with different proliferation potential. All clones showed cobblestone-like morphology at the confluence and incorporated fluorescent Dil acetylated low density lipoprotein. When plated on Matrigel, they formed a capillary network-like structure. These rat adipose tissue endothelial cell (RATEC) clones showed higher expression of wnt2, wnt4, wnt5a, wnt5b, fzd1 and fzd5 whereas lower expression of cell cycle controlling genes such as CIP1, KIP1, KIP2, CDKN2A, CDKN2B, CDKN2C and CDKN2D compared to human umbilical vein endothelial cell (HUVEC). As reported for HUVEC, the growth of RATEC was inhibited by green tea catechins such as epigallocatechin, epicatechin gallate, epicatechin and epigallocatechin gallate but with higher sensitivity than HUVEC. The sensitivity of RATEC to catechins was higher for the cultures with low plating density and for the clone with higher proliferation potential.

The fifth gene of the iol operon of Bacillus subtilis, iolE, encodes 2-keto-myo-inositol dehydratase.

The myo-inositol catabolism pathway of Bacillus subtilis has not been fully characterized but was proposed to involve step-wise multiple reactions that finally yielded acetyl-CoA and dihydroxyacetone phosphate. It is known that the iolABCDEFGHIJ operon is responsible for the catabolism of inositol. IolG catalyses the first step of myo-inositol catabolism, the dehydrogenation of myo-inositol, producing 2-keto-myo-inositol (inosose). The second step was thought to be the dehydration of inosose. Genetic and biochemical analyses of the iol genes led to the identification of iolE, encoding the enzyme for the second step of inositol catabolism, inosose dehydratase. The reaction product of inosose dehydratase was identified as D-2,3-diketo-4-deoxy-epi-inositol.