Despite the potential importance of the human regulator of calcineurin 1 (RCAN-1) gene in the modulation of cell survival under stress, little is known about its role in death-inducing signal pathways. In this study, we addressed the effects of RCAN1.4 knockdown on cellular susceptibility to apoptosis and the activation of death pathway proteins. Transfection of siRNAs against RCAN1.4 resulted in enhanced Fas- and etoposide-induced apoptosis, which was associated with increased expression and translocation of Bax to mitochondria. Our results suggest that enhanced expression and activation of p53 was responsible for the upregulation of Bax and the increased sensitivity to apoptosis, which could be reversed by p53 knockdown. To explain the observed upregulation of p53, we propose a downregulation of the ubiquitin ligase HDM2, probably translationally. These findings show the importance of appropriate RCAN1.4 expression in the modulation of cell survival and reveal a link between RCAN1.4 and p53.
Aluminum Hydroxide ; Apoptosis ; Calcineurin ; Carbonates ; Cell Survival ; Down-Regulation ; Humans ; Mitochondria ; Proteins ; RNA, Small Interfering ; Signal Transduction ; Transfection ; Ubiquitin ; Up-Regulation

Calcineurin (CaN) is activated in diabetes and plays a role in glomerular hypertrophy and extracellular matrix (ECM) accumulation. Here, kidneys from diabetic model mice were investigated for the expression of the regulator of CaN 1 (RCAN1) isoform 4 (RCAN1.4) which had been shown to be transcriptionally upregulated by CaN activation. We found the increased immunoreactivity for RCAN1 in the glomerular cells of db/db mice and streptozotocin-induced diabetic mice. In concordance, the expression of RCAN1 protein and RCAN1.4 mRNA were elevated in the whole kidney sample from db/db mice. Interleukin-1beta (IL-1beta), tumor necrosis factor-alpha, and glycated albumin (AGE-BSA) were identified as inducers of RCAN1.4 in mesangial cells. Pretreatment of cyclosporine A blocked the increases of RCAN1.4 stimulated by IL-1beta or AGE-BSA, suggesting that activation of CaN is required for the RCAN1.4 induction. Stable transfection of RCAN1.4 in Mes-13 mesangial cells upregulated several factors relevant to ECM production and degradation. These results suggested that RCAN1.4 might act as a link between CaN activation and ECM turnover in diabetic nephropathy.
Aluminum Hydroxide ; Animals ; Calcineurin ; Carbonates ; Cyclosporine ; Diabetic Nephropathies ; Extracellular Matrix ; Glycosylation End Products, Advanced ; Hypertrophy ; Interleukin-1beta ; Kidney ; Mesangial Cells ; Mice ; RNA, Messenger ; Serum Albumin ; Serum Albumin, Bovine ; Transfection ; Tumor Necrosis Factor-alpha

BACKGROUND: Macrophages have been known to have diverse roles either after tissue damage or during the wound healing process; however, their roles in flap wound healing are poorly understood. In this study, we aimed to evaluate how macrophages contribute to the flap wound regeneration.METHODS: A murine model of a pedicled flap was generated, and the time-course of the wound healing process was determined. Especially, the interface between the flap and the residual tissue was histopathologically evaluated. Using clodronate liposome, a macrophage-depleting agent, the functional role of macrophages in flap wound healing was investigated. Coculture of human keratinocyte cell line HaCaT and monocytic cell line THP-1 was performed to unveil relationship between the two cell types.RESULTS: Macrophage depletion significantly impaired flap wound healing process showing increased necrotic area after clodronate liposome administration. Interestingly, microscopic evaluation revealed that epithelial remodeling between the flap tissue and residual normal tissue did not occurred under the lack of macrophage infiltration. Coculture and scratch wound healing assays indicated that macrophages significantly affected the migration of keratinocytes.CONCLUSION: Macrophages play a critical role in the flap wound regeneration. Especially, epithelial remodeling at the flap margin is dependent on proper macrophage infiltration. These results implicate to support the cellular mechanisms of impaired flap wound healing.
Cell Line ; Clodronic Acid ; Coculture Techniques ; Humans ; Keratinocytes ; Liposomes ; Macrophages ; Regeneration ; Surgical Flaps ; Wound Healing ; Wounds and Injuries

PURPOSE: Croup is known to have epidemics in seasonal and biennial trends, and to be strongly associated with epidemics of parainfluenza virus. However, seasonal and annual epidemics of croup have not been clearly reported in Korea. This study aimed to examine the seasonal/annual patterns and etiologies of childhood croup in Korea during a consecutive 6-year period. METHODS: Pediatric croup data were collected from 23 centers in Korea from 1 January 2010 to 31 December 2015. Electronic medical records, including multiplex reverse transcription polymerase chain reaction (RT-PCR) results, demographics and clinical information were cross-sectionally reviewed and analyzed. RESULTS: Overall, 2,598 childhood croup patients requiring hospitalization were identified during the study period. Among them, a total of 927 who underwent RT-PCR were included in the analysis. Males (61.5%) predominated, and most (63.0%) of them were younger than 2 years of age (median, 19 months; interquartile range, 11–31 months). Peak hospitalization occurred in 2010 and 2012 in even-numbered years, and parainfluenza virus (PIV, 39.7%) was the most common cause of childhood croup requiring hospitalization, followed by respiratory syncytial virus (14.9%), human rhinovirus (12.5%), Mycoplasma pneumonaie (10.6%), and human coronavirus (7.3%). CONCLUSION: It is concluded that croup hospitalization has a biennial pattern in even-numbered years. PIV may be the most common cause of childhood croup; however, croup epidemics could be attributed to other viruses.
Child ; Coronavirus ; Croup ; Demography ; Electronic Health Records ; Hospitalization ; Humans ; Korea ; Male ; Mycoplasma ; Paramyxoviridae Infections ; Polymerase Chain Reaction ; Respiratory Syncytial Viruses ; Retrospective Studies ; Reverse Transcription ; Rhinovirus ; Seasons

Purpose: Mycoplasma pneumoniae pneumonia (MP) is a major cause of community-acquired pneumonia (CAP) in children and is associated with extrapulmonary manifestations (EPM). The incidence and risk factors for EPM in children are unknown. Methods: This was a retrospective study involving 65,243 pediatric patients with CAP between 2010 and 2015 at 23 nationwide hospitals in South Korea. Medical records were reviewed to collect information regarding the clinical characteristics, radiological results, and laboratory findings. Logistic regression with multivariate analysis was performed to evaluate the risk factors associated with EPM in MP. Results: The incidence of EPM was 23.9%, including elevation of liver enzymes (18.1%), mucocutaneous manifestations (4.4%), proteinuria (4.1%), cardiovascular and neurological manifestations (0.4%), hematologic manifestations (0.2%), and arthritis (0.2%). Statistical analysis showed that mucocutaneous manifestations significantly increased with elevated alanine aminotransferase (adjusted odds ratio [aOR], 3.623; 95% confidence interval [CI], 1.933-6.790) and atopic sensitization (aOR, 2.973; 95% CI, 1.615–5.475) and decreased with respiratory virus coinfection (aOR, 0.273; 95% CI, 0.084–0.887). Elevated liver enzymes were significantly associated with elevated lactate dehydrogenase (aOR, 3.055; 95% CI, 2.257–4.137), presence of pleural effusion (aOR, 2.635; 95% CI, 1.767–3.930), and proteinuria with respiratory virus coinfection (aOR, 2.245; 95% CI, 1.113–4.527). Conclusion Approximately 24% of pediatric patients with MP had various EPM. As the risk factors associated with each EPM were different, it is necessary to evaluate the various clinical aspects and findings of MP to predict and prepare for the occurrence of EPM.