Senescence-Associated Secretory Phenotype Suppression Mediated by Small-Sized Mesenchymal Stem Cells Delays Cellular Senescence through TLR2 and TLR5 Signaling.

In order to provide a sufficient number of cells for clinical use, mesenchymal stem cells (MSCs) must be cultured for long-term expansion, which inevitably triggers cellular senescence. Although the small size of MSCs is known as a critical determinant of their fate, the main regulators of stem cell senescence and the underlying signaling have not been addressed. Umbilical cord blood-derived MSCs (UCB-MSCs) were obtained using size-isolation methods and then cultured with control or small cells to investigate the major factors that modulate MSC senescence. Cytokine array data suggested that the secretion of interukin-8 (IL-8) or growth-regulated oncogene-alpha (GROa) by senescent cells was markedly inhibited during incubation of small cells along with suppression of cognate receptor (C-X-C motif chemokine receptor2, CXCR2) via blockade of the autocrine/paracrine positive loop. Moreover, signaling via toll-like receptor 2 (TLR2) and TLR5, both pattern recognition receptors, drove cellular senescence of MSCs, but was inhibited in small cells. The activation of TLRs (2 and 5) through ligand treatment induced a senescent phenotype in small cells. Collectively, our data suggest that small cell from UCB-MSCs exhibit delayed cellular senescence by inhibiting the process of TLR signaling-mediated senescence-associated secretory phenotype (SASP) activation.

Analysis of seasonal tendencies in pediatric Henoch-Schönlein purpura and comparison with outbreak of infectious diseases.

Henoch-Schönlein purpura (HSP) is one of the most common vasculitis in children. This study was aimed at identifying seasonal trends and epidemiologic features of pediatric HSP patients through public data to analyze the correlation of HSP and prevalence of a specific respiratory or enteric virus.We extracted information on pediatric HSP patients categorized into 4 age groups and data on 8 respiratory and 4 enteric viruses were extracted from national data. We used the decomposition of time series analysis and correlation analysis to identify the incidence of HSP and the prevalence of each virus.From 2013 to 2016, 16,940 patients under the age of 18 were diagnosed with HSP in Korea, 6203 (36.6%) were diagnosed with HSP in middle childhood. Spring had the largest number of patients (5252, 31.0%), and summer had the smallest number of patients (3224, 19.0%). The largest and smallest number of cases occurred in March (1949, 11.5%) and August (959, 5.7%), respectively. However, among the adolescents, more patients were diagnosed in the summer (985, 24.8%) than in the fall (760, 19.1%). The positive detection counts of most viruses showed apparent seasonal variations. Depending on the age group, the epidemic patterns of influenza and rotaviruses were temporally and statistically similar to that of HSP.We have confirmed that the occurrence of pediatric HSP in Korea shows a seasonal tendency, which is age-dependent and related to exposure to infectious agents and suggest some respiratory or enteric viruses may play an important role in pathophysiology.

Thrombospondin-1 secreted by human umbilical cord blood-derived mesenchymal stem cells rescues neurons from synaptic dysfunction in Alzheimer's disease model.

Alzheimer's disease (AD) is an incurable neurodegenerative disease characterised clinically by learning and memory impairments. Amyloid beta (Aß) peptide-induced synaptic dysfunction is a pathological process associated with early-stage AD. Here, we show that paracrine action of human umbilical cord blood-derived-mesenchymal stem cells (hUCB-MSCs) protects the hippocampus from synaptic-density loss in in vitro and in vivo AD models. To identify paracrine factors underlying this rescue effect, we analysed hUCB-MSCs' secretome co-cultured with Aß42-treated mouse hippocampal neurons. Thrombospondin-1 (TSP-1), a protein secreted by hUCB-MSCs in in vitro and 5XFAD AD mouse models, was selected for study. Treatment with exogenous recombinant TSP-1 or co-cultures with hUCB-MSCs significantly increased expression of synaptic-density markers, such as synaptophysin (SYP) and post-synaptic density protein-95 (PSD-95) in Aß42-treated mouse hippocampal neurons. Knockdown of TSP-1 expression in hUCB-MSCs through small interfering RNA (siRNA) abolished the reversal of Aß42-induced hippocampal synaptic-density loss. We demonstrate that the rescue effect of hUCB-MSC-secreted TSP-1 was mediated by neuroligin-1 (NLGN1) or α2δ-1 receptors. Interestingly, NLGN1 and α2δ-1 expression, which was reduced in Aß42-treated hippocampal neurons, increased in co-cultures with hUCB-MSCs or exogenous TSP-1. Together, these findings suggest that hUCB-MSCs can attenuate Aß42-induced synaptic dysfunction by regulating TSP-1 release, thus providing a potential alternative therapeutic option for early-stage AD.

Small hypoxia-primed mesenchymal stem cells attenuate graft-versus-host disease.

Mesenchymal stem cells (MSCs) are of particular interest for the treatment of immune-related diseases due to their immunosuppressive capacity. Here, we show that Small MSCs primed with Hypoxia and Calcium ions (SHC-MSCs) exhibit enhanced stemness and immunomodulatory functions for treating allogeneic conflicts. Compared with naïve cultured human umbilical cord blood-derived MSCs, SHC-MSCs were resistant to passage-dependent senescence mediated via the monocyte chemoattractant protein-1 and p53/p21 cascade and secreted large amounts of pro-angiogenic and immunomodulatory factors, resulting in suppression of T-cell proliferation. SHC-MSCs showed DNA demethylation in pluripotency, germline, and imprinted genes similarly to very small embryonic-like stem cells, suggesting a potential mutual relationship. Genome-wide DNA methylome and transcriptome analyses indicated that genes related to immune modulation, cell adhesion, and the cell cycle were up-regulated in SHC-MSCs. Particularly, polo-like kinase-1 (PLK1), zinc-finger protein-143, dehydrogenase/reductase-3, and friend-of-GATA2 play a key role in the beneficial effects of SHC-MSCs. Administration of SHC-MSCs or PLK1-overexpressing MSCs significantly ameliorated symptoms of graft-versus-host disease (GVHD) in a humanized mouse model, resulting in significantly improved survival, less weight loss, and reduced histopathologic injuries in GVHD target organs compared with naïve MSC-infused mice. Collectively, our findings suggest that SHC-MSCs can improve the clinical treatment of allogeneic conflicts, including GVHD.

Change in penile length in children: preliminary study.

PURPOSE: Studies of penile length in children have been rarely conducted. In Korea, great improvements in height and weight have been observed because of economic development over the past 25 years. We investigated the current status of penile length in Korean children and compared the results with those of a previous Korean study conducted in 1987. MATERIALS AND METHODS: The subjects in this study were 233 boys aged 1 to 158 months, each of whom had been brought to outpatient clinics between April and October 2011. Penile length was measured according to the stretched penile length (SPL) technique; testicular size was measured (in ml) by using orchidometry. A comparison of penile lengths between the current study and the 1987 study was made by using Student's t-test. RESULTS: SPL increased significantly by 0.7 to 1.1 cm in most age groups (p<0.05). Current anthropometric measures of Korean children such as height, body weight, and testicular size have increased compared with those from 1987. CONCLUSIONS: Penile length has increased significantly over the last quarter century. Therefore, it is suggested that novel reference values for penile length in prepubertal Korean children be determined in studies with a larger community-based population in order to diagnose and treat size-related penile disorders.

Identification of the target proteins of rosiglitazone in 3T3-L1 adipocytes through proteomic analysis of cytosolic and secreted proteins.

Rosiglitazone, one of the thiazolidinedione (TZD), is an oral antidiabetic drug that activates a gamma isoform of peroxisome proliferator-activated receptor (PPARγ). To identify target proteins induced by rosiglitazone in adipocytes, we first performed simultaneous in-depth proteomic profiling of cytosolic proteins and secreted proteins (secretome) from 3T3-L1 adipocytes using a label-free quantification method with nano-UPLC MS/MS. In total, we identified 646 proteins from 3T3-L1 adipocytes, of which 172 and 162 proteins were upregulated and downregulated >1.5-fold, respectively, in rosiglitazone-treated cells, as compared to controls. Some differentially expressed proteins in particular, including fatty acid translocase (FAT)/CD36, fatty acid binding protein, lipoprotein lipase, acetyl CoA acyltransferase, carnitine O-palmitoyltransferase 2, sterol carrier protein, adiponectin, and phosphoenolpyruvate carboxykinase could explain the current action mechanism of TZDs. Furthermore, this study is the first to report on two potential target proteins of rosiglitazone, such as adenomatosis polyposis coli 2 (APC2), and eukaryotic translation initiation factor 5A-1 (eIF5A) related to apoptosis and cell division. Our data clearly suggest that in-depth proteomic approaches using cytosolic and secreted proteins are important and necessary for identification of drug targets at the protein level.

Identification of rat urinary glycoproteome captured by three lectins using gel and LC-based proteomics.

Many different types of urine proteome studies have been done, but urine glycoprotein studies are insufficient. Therefore, we studied the glycoproteins from rat urine, which could be used to identify biomarkers in an animal model. First, urinary proteins were prepared by using the dialysis and lyophilizing methods from rat urine. Glycoproteins enriched with lectin affinity purification, concanavalin A, jacalin and wheat germ agglutinin from the urinary proteins were separated by means of reverse-phase fast protein LC (FPLC) or 1-D PAGE. Each FPLC fraction and 1-D PAGE gel band were trypsin-digested and analyzed by means of nanoLC-MS/MS. LC-MS/MS analyses were carried out by using linear ion trap MS. A total of 318 rat urinary glycoproteins were identified from the FPLC fractions and gel bands; approximately 90% of identified proteins were confirmed as glycoproteins in Swiss-Prot. Many glycoproteins, known as biomarkers, including C-reactive protein, uromodulin, amyloid beta A4 protein, alpha-1-inhibitor 3, vitamin D-binding protein, kallikrein 3 and fetuin-A were identified in this study. By studying urinary glycoproteins collected from rat, these results may help to assist in identifying urinary biomarkers regarding various types of disease models.