Prevalence and risk factors of low vitamin D levels in children and adolescents with familial hypokalemic periodic paralysis.

Patients with familial hypokalemic periodic paralysis (HOKPP) experience episodes of reversible immobility and are at an increased risk of limited sunlight exposure, potentially leading to vitamin D deficiency. However, there is a lack of data on vitamin D levels in this population. We investigated serum vitamin D levels and their associated factors in children with HOKPP. This study included 170 genetically-confirmed children with HOKPP, aged 3-18 years, and 170 age-, sex-, and body mass index (BMI)-matched healthy controls from the Korean Channelopathy Study, a prospective controlled investigation. Anthropometric and clinical characteristics were recorded, and serum levels of calcium, ionized calcium, phosphorus, alkaline phosphatase, 25-hydroxyvitamin D, and intact parathyroid hormone (PTH) were analyzed. Vitamin D deficiency (< 20 ng/mL) was observed in 87.0% of the patients compared to 45.5% of the controls (P < 0.05) during the summer-fall season. During the winter-spring season, 91.7% of the patients and 73.4% of the controls were deficient (P < 0.05). A strong positive correlation was found between onset age of the first paralytic attack and vitamin D levels (r = 0.78, P < 0.01). Conversely, the frequency and duration of paralytic attacks were negatively correlated with vitamin D levels (r = -0.82 and r = -0.65, P < 0.01, respectively). Age, BMI, age at onset, frequency and duration of attacks, and PTH levels were independently associated with vitamin D levels (ß = -0.10, -0.12, 0.19, -0.27, -0.21, and -0.13, P < 0.05, respectively). CONCLUSIONS: Vitamin D deficiency was highly prevalent in children with HOKPP, and vitamin D levels correlated with various disease characteristics. We recommend routine screening for vitamin D levels in these patients to address this prevalent deficiency. Considering the high prevalence of vitamin D deficiency observed, further research on other diseases characterized by reversible immobility is warranted. WHAT IS KNOWN: • A correlation between immobility and low serum vitamin D levels has been established. However, the vitamin D status of patients with familial hypokalemic periodic paralysis (HOKPP) who experience periods of reversible immobility remains unknown. WHAT IS NEW: • Vitamin D deficiency was highly prevalent in children with HOKPP, and vitamin D levels correlated with various disease characteristics.

Knockdown of CPEB1 and CPEB4 Inhibits Scar Formation via Modulation of TAK1 and SMAD Signaling.

BACKGROUND: Cytoplasmic polyadenylation element binding (CPEB) proteins are sequence-specific RNA-binding proteins that control translation via cytoplasmic polyadenylation. We previously reported that CPEB1 or CPEB4 knockdown suppresses TAK1 and SMAD signaling in an in vitro study. OBJECTIVE: This study aimed to investigate whether suppression of CPEB1 or CPEB4 expression inhibits scar formation in a mice model of acute dermal wound healing. METHODS: CPEB1 and CPEB4 expression levels were suppressed by siRNA treatment. Skin wounds were created by pressure-induced ulcers in mice. Images of the wound healing were obtained using a digital camera and contraction was measured by ImageJ. mRNA and protein expression was analyzed using quantitative real time polymerase chain reaction and western blotting, respectively. RESULTS: Wound contraction was significantly decreased by pre-treatment with CPEB1 or CPEB4 siRNA compared to the control. Suppression of CPEB1 or CPEB4 expression decreased TAK1 signaling by reducing the levels of TLR4 and TNF-α, phosphorylated TAK1, p38, ERK, JNK, and NF-κB-p65. Decreased levels of phosphorylated SMAD2 and SMAD3 indicated a reduction in SMAD signaling as well. Consequently, the expression of α-SMA, fibronectin, and type I collagen decreased. CONCLUSION: CPEB1 siRNA or CPEB4 siRNA inhibit scar formation by modulating the TAK1 and SMAD signaling pathways. Our study highlights CPEB1 and CPEB4 as potential therapeutic targets for the treatment of scar formation.

Exosomes derived from human hypertrophic scar fibroblasts induces smad and TAK1 signaling in normal dermal fibroblasts.

Post-burn hypertrophic scars are characterized by excessive accumulation of extracellular matrix secreted by fibroblasts. Exosomes are membrane lipid extracellular vesicles that play a pivotal role in cellular communication. Previous studies revealed the role of stem cell-derived exosomes in repairing damaged tissues, and also showed that cancer cell-derived exosomes could affect the disease pathogenesis. However, the functional properties of exosomes derived from hypertrophic scar fibroblasts (HTSFs) have not yet been studied extensively. In this study, we aimed to investigate whether HTSFs-derived exosomes can change the fibrosis-related signaling pathways in human normal fibroblasts (HNFs). HTSFs and HNFs were isolated from human hypertrophic scar tissues. HTSFs-derived exosomes were extracted and treated to HNFs. Reverse transcription-quantitative polymerase chain reaction and western blotting were used to detect mRNA and protein expression, respectively, and cell proliferation and mobility were also assessed. Exosome treatment markedly increased cell proliferation and migration, and induced small mother against decapentaplegic (SMAD) signaling by increasing the levels of phosphorylated SMAD2 and SMAD1/5/8. The levels of TAK1 signaling components were also increased after exosome treatment to HNFs, including phosphorylated TAK1, p38, ERK, and JNK. HTSFs-derived exosomes further induced the epithelial-mesenchymal transition by decreasing the expression level of E-cadherin and increasing the expression levels of N-cadherin and vimentin. Consequently, the expression levels of fibronectin, type Ⅰ collagen, and type Ⅲ collagen were increased. Our results demonstrate the fibrotic property of HTSFs-derived exosomes, which suggests a potential functional role in hypertrophic scar development and a new therapeutic target.

Effect of extracorporeal shock wave therapy on keratinocytes derived from human hypertrophic scars.

Hypertrophic scars represent a common complication in burn patients. In addition to cosmetic defects, they may cause serious sensory abnormalities such as pain and itching, severe dysfunction depending on the site, and emotional disorders such as anxiety and depression. The present study aimed to identify the molecular mechanisms underlying the use of extracorporeal shock wave therapy in keratinocytes. Keratinocytes derived from hypertrophic scar tissue were cultured and expression of proliferation markers (keratin 5 and 14), activation markers (keratin 6 and 17), differentiation markers (keratin 1, 10, and involucrin), apoptosis factors (Bax, Bcl2, and Caspase 14), and proliferation/differentiation regulators (p21 and p27) was investigated to compared with that of those in keratinocytes derived from normal skin tissue. Scar-derived keratinocytes were treated with extracorporeal shock waves under 1000 impulses at 0.1, 0.2, and 0.3 mJ/mm2. Shock waves altered the molecular pattern of proliferation, activation, differentiation, and apoptosis, as well as proliferation/ differentiation regulators, including Bax, Bcl2, ASK1, p21, p27, and Notch1. In summary, we show that extracorporeal shock wave therapy regulates the proliferation and differentiation of keratinocytes derived from hypertrophic scar to maintain normal epidermal integrity.

Calpastatin-Mediated Inhibition of Calpain Ameliorates Skin Scar Formation after Burn Injury.

Hypertrophic scars, the most common complication of burn injuries, are characterized by excessive deposition of fibroblast-derived extracellular matrix proteins. Calpain, a calcium-dependent protease, is involved in the fibroblast proliferation and extracellular matrix production observed in certain fibrotic diseases. However, its role in the formation of post-burn hypertrophic skin scars remains largely unknown. Here, calpain expression and activity were assessed in skin fibroblasts obtained directly from patients with third-degree burns, who consequently developed post-burn hypertrophic scars. Furthermore, the antifibrotic effect of calpastatin, an endogenous calpain inhibitor, was evaluated in human fibroblasts and a murine burn model. The activity, mRNA levels, and protein levels of calpain were markedly higher in fibroblasts from the burn wounds of patients than in normal cells. Selective calpain inhibition by calpastatin markedly reduced not only the proliferation of burn-wound fibroblasts but also the mRNA and protein expression of calpain, transforming growth factor-beta 1, α-smooth muscle actin, type I and type III collagens, fibronectin, and vimentin in burn-wound fibroblasts. The anti-scarring effects of calpastatin were validated using a murine burn model by molecular, histological, and visual analyses. This study demonstrates the pathological role of calpain and the antifibrotic effect of calpastatin via calpain inhibition in post-burn hypertrophic scar formation.

Altered KCa3.1 expression following burn injury and the therapeutic potential of TRAM-34 in post-burn hypertrophic scar formation.

Hypertrophic scars are the most common post-burn complications characterized by fibroblast proliferation and excessive extracellular matrix deposition. The intermediate-conductance Ca2+-activated K+ channel (KCa3.1) mediates fibroblast activation, resulting in several fibrotic diseases; however, this channel's role in the formation of post-burn hypertrophic skin scars remains unknown. Herein, we investigated the role of KCa3.1 and the therapeutic potential of TRAM-34, a selective inhibitor of KCa3.1, in hypertrophic skin scar formation following burn injury. Cytosolic Ca2+ levels, the expression of KCa3.1 and hypertrophic markers, and the proliferation of skin fibroblasts obtained directly from patients with third-degree burns who consequently developed post-burn hypertrophic scars were assessed. The anti-fibrotic effect of KCa3.1 inhibition by TRAM-34 was evaluated in vitro (fibroblasts) and in vivo (mouse burn models). Fibroblasts from burn wounds exhibited remarkably higher levels of cytosolic Ca2+ than normal cells. KCa3.1 expression was markedly higher in the membrane fraction but lower in the cytosolic fraction of burn wound fibroblasts than in normal cells. Selective inhibition of KCa3.1 by TRAM-34 markedly reduced not only the proliferation of burn wound fibroblasts but also the expression of hypertrophic markers in these cells. Anti-scarring molecular, histological, and visual effects of TRAM-34 were confirmed in murine burn models. Altered subcellular expression of KCa3.1 is a novel mechanism underlying the cellular response to burn injury. Our results suggest that selective inhibition of KCa3.1 by TRAM-34 has therapeutic potential against post-burn hypertrophic scar formation.

Effect of Combining Low Temperature Plasma, Negative Pressure Wound Therapy, and Bone Marrow Mesenchymal Stem Cells on an Acute Skin Wound Healing Mouse Model.

Low-temperature plasma (LTP; 3 min/day), negative pressure wound therapy (NPWT; 4 h/day), and bone marrow mesenchymal stem cells (MSCs; 1×106 cells/day) were used as mono- and combination therapy in an acute excisional skin wound-healing ICR mouse model. These therapies have been beneficial in treating wounds. We investigated the effectiveness of monotherapy with LTP, NPWT, and MSC and combination therapy with LTP + MSC, LTP + NPWT, NPWT + MSC, and LTP + NPWT + MSC on skin wounds in mice for seven consecutive days. Gene expression, protein expression, and epithelial thickness were analyzed using real time polymerase chain reaction (RT-qPCR), western blotting, and hematoxylin and eosin staining (H&E), respectively. Wound closure was also evaluated. Wound closure was significantly accelerated in monotherapy groups, whereas more accelerated in combination therapy groups. Tumor necrosis factor-α (TNF-α) expression was increased in the LTP monotherapy group but decreased in the NPWT, MSC, and combination therapy groups. Expressions of vascular endothelial growth factor (VEGF), α-smooth muscle actin (α-SMA), and type I collagen were increased in the combination therapy groups. Re-epithelialization was also considerably accelerated in combination therapy groups. Our findings suggest that combination therapy with LPT, NPWT, and MSC exert a synergistic effect on wound healing, representing a promising strategy for the treatment of acute wounds.

CPEB1 or CPEB4 knockdown suppresses the TAK1 and Smad signalings in THP-1 macrophage-like cells and dermal fibroblasts.

Post-burn hypertrophic scar (HTS) is a form of excessive dermal fibrosis characterized by cutaneous scarring, which is common in patients following burn injury. Moreover, at least 50% of HTS are accompanied by inflammation. Cytoplasmic polyadenylation element binding (CPEB) proteins are key mRNA-binding proteins that control the translation of several mRNAs. However, their potential roles in treating dermal fibrosis and scarring remain unknown. Therefore, in this study, we aimed to investigate the effects of small interfering RNA (siRNA)-mediated knockdown of CPEB1 or CPEB4 in human THP-1 macrophages and dermal fibroblasts treated with LPS and TGF-ß1. We found significantly increased CPEB1 and CPEB4 mRNA and protein levels in LPS-treated THP-1 cells and TGF-ß1-treated fibroblasts. CPEB1 and CPEB4 knockdowns suppressed LPS-activated TAK1 signaling cascades by reducing the levels of TNF-α and phosphorylated TAK1, p38, ERK, JNK, and NF-κB-p65 in THP-1 cells. CPEB1 and CPEB4 knockdowns also attenuated TGF-ß1-activated Smad-dependent and -independent signaling cascades by reducing the levels of TAK1, p38, ERK, JNK, and phosphorylated Smad 2 and Smad 1/5/8 in fibroblasts. Furthermore, CPEB1 or CPEB4 knockdown markedly decreased the levels of fibrosis markers, including α-SMA, type I collagen, and fibronectin in fibroblasts. Our findings indicate that CPEB1 and CPEB4 are involved in the regulation of the TAK1 and Smad signalings in human macrophages and dermal fibroblasts. These activities may play a role in cutaneous scarring responses.

Wound Healing Potential of Low Temperature Plasma in Human Primary Epidermal Keratinocytes.

BACKGROUND: Low temperature plasma (LTP) was recently shown to be potentially useful for biomedical applications such as bleeding cessation, cancer treatment, and wound healing, among others. Keratinocytes are a major cell type that migrates directionally into the wound bed, and their proliferation leads to complete wound closure during the cutaneous repair/regeneration process. However, the beneficial effects of LTP on human keratinocytes have not been well studied. Therefore, we investigated migration, growth factor production, and cytokine secretion in primary human keratinocytes after LTP treatment. METHODS: Primary cultured keratinocytes were obtained from human skin biopsies. Cell viability was measured with the EZ-Cytox cell viability assay, cell migration was evaluated by an in vitro wound healing assay, gene expression was analyzed by quantitative real-time polymerase chain reaction, and protein expression was measured by enzyme-linked immunosorbent assays and western blotting after LTP treatment. RESULTS: Cell migration, the secretion of several cytokines, and gene and protein levels of angiogenic growth factors increased in LTP-treated human keratinocytes without associated cell toxicity. LTP treatment also significantly induced the expression of hypoxia inducible factor-1α (HIF-1α), an upstream regulator of angiogenesis. Further, the inhibition of HIF-1α expression blocked the production of angiogenic growth factors induced by LTP in human keratinocytes. CONCLUSION: Our results suggest that LTP treatment is an effective approach to modulate wound healing-related molecules in epidermal keratinocytes and might promote angiogenesis, leading to improved wound healing.

Effect of cold pack therapy for management of burn scar pruritus: A pilot study.

PURPOSE: Pruritus, a common, chronically disabling condition is often refractory to treatment. The pruritus sensation is mediated in the spinal cord and post-burn pruritus is considered a form of neuropathic pain. We investigated cold pack therapy as a treatment modality for post-burn pruritus. METHODS: We studied 23 patients with severe pruritus scoring at least 5 on the visual analogue scale (VAS) and refractory to antihistamine and gabapentin administration. Each cold pack therapy lasted more than 20min. Patients participated in more than three sessions daily for 4 consecutive weeks. The numerical rating scale (NRS), 5-D Itch Scale, Leuven Itch Scale, and perfusion units were evaluated before, within 30min after, 2, and 4 weeks cold pack therapy. RESULTS: In all patients, the NRS was 9.37±1.47 pre-therapy, 3.48±2.19 at 2 weeks, and 2.78±2.13 at 4 weeks following therapy, the pre-scores being significantly different (p<0.001). Pruritus severity and consequences scores (Leuven Itch Scale) were improved after therapy compared to pre-therapy. Perfusion unit (PU) scores were statistically insignificant compared to PU scores measured before the application of cold pack therapy. Degree, direction, and disability scores (5-D Itch scale) significantly differed (p<.05). CONCLUSION: Cold pack therapy, a non-invasive, non-pharmacological treatment modality significantly reduces post-burn pruritus and could be useful in burn patients.

Extracorporeal Shock Wave Therapy Alters the Expression of Fibrosis-Related Molecules in Fibroblast Derived from Human Hypertrophic Scar.

Extracorporeal shock wave therapy (ESWT) considerably improves the appearance and symptoms of post-burn hypertrophic scars (HTS). However, the mechanism underlying the observed beneficial effects is not well understood. The objective of this study was to elucidate the mechanism underlying changes in cellular and molecular biology that is induced by ESWT of fibroblasts derived from scar tissue (HTSFs). We cultured primary dermal fibroblasts derived from human HTS and exposed these cells to 1000 impulses of 0.03, 0.1, and 0.3 mJ/mm². At 24 h and 72 h after treatment, real-time PCR and western blotting were used to detect mRNA and protein expression, respectively, and cell viability and mobility were assessed. While HTSF viability was not affected, migration was decreased by ESWT. Transforming growth factor beta 1 (TGF-ß1) expression was reduced and alpha smooth muscle actin (α-SMA), collagen-I, fibronectin, and twist-1 were reduced significantly after ESWT. Expression of E-cadherin was increased, while that of N-cadherin was reduced. Expression of inhibitor of DNA binding 1 and 2 was increased. In conclusion, suppressed epithelial-mesenchymal transition might be responsible for the anti-scarring effect of ESWT, and has potential as a therapeutic target in the management of post-burn scars.

Low temperature plasma induces angiogenic growth factor via up-regulating hypoxia-inducible factor 1α in human dermal fibroblasts.

Numerous studies on the application of low temperature plasma (LTP) have produced impressive results, including antimicrobial, antitumor, and wound healing effects. Although LTP research has branched out to include medical applications, the detailed effects and working mechanisms of LTP on wound healing have not been fully investigated. Here, we investigated the potential effect of inducing growth factor after exposure to LTP and demonstrated the increased expression of angiogenic growth factor mediated by LTP-induced HIF1α expression in primary cultured human dermal fibroblasts. In cell viability assays, fibroblast viability was reduced 6 h and 24 h after LTP treatment for only 5 min, and pre-treating with NAC, a ROS scavenger, prevented cell loss. Fibroblast migration significantly increased at 6 h and 24 h in scratch wound healing assays, the expression of cytokines significantly changed, and regulatory growth factors were induced at 6 h and 24 h after exposure to LTP in RT-PCR or ELISAs. Specifically, LTP treatment significantly induced the expression of HIF1α, an upstream regulator of angiogenesis. Pre-treatment with the inhibitor CAY10585 abolished HIF1α expression and prevented LTP-induced angiogenic growth factor production according to immunoblotting, immunocytochemistry, and ELISA results. Taken together, our results provide information on the molecular mechanism by which LTP application may promote angiogenesis and will aid in developing methods to improve wound healing.

Effects of sustained release growth hormone treatment during the rehabilitation of adult severe burn survivors.

OBJECTIVES: The catabolic phase following burn injuries increases caloric imbalance and results in substantial weight loss because of hypermetabolism; energy expenditures as high as twice the normal limit have been documented during the first 3 weeks. Furthermore, the wound size and healing duration seem to be related to the length of stay in the intensive care unit, which results in the loss of muscle mass, the so-called sarcopenia; weakness; and physical frailty. Possible therapeutic strategies include exercises, use of anabolic steroids, or replacement with human growth hormone (hGH). To determine the clinical effects of hGH on sarcopenia after burn injuries, we compared patients who received subcutaneous hGH injections during rehabilitation with control patients who received placebo treatment. METHODS: A total of 33 patients with third degree burn injuries covering a total body surface area of >20% were randomly divided into a test group (n=18), which received 2-mg injections of sustained release hGH (SR-hGH) weekly for 3 months during rehabilitation, and a control group (n=15), which followed the same rehabilitation protocol with placebo injections. Muscular strength, cardiopulmonary function, body composition, and body weight were measured at baseline and 1 and 3 months after SR-hGH or placebo administration. RESULTS: The mean age of patients was 37.67 ± 7.64 years in the SR-hGH group and 37.22 ± 8.19 years in the control group, while the interval between injury and SR-hGH or placebo injection was 123.7 ± 53.6 and 126.6 ± 43.5 days, respectively. The oxygen consumption at the lactate threshold, maximum oxygen consumption, lean body mass, knee extensor peak torque, and insulin-like growth factor 1 (IGF-1) and adiponectin levels were significantly higher in the SR-hGH group than in the control group at 3 months. There were no differences in the body weight, systolic and diastolic blood pressure (BP), bone mineral content, percentage body fat, and burn scar characteristics between groups. CONCLUSION: Our results suggest that SR-hGH treatment during the rehabilitation of adult burn survivors positively affects physical fitness levels, muscle power, and metabolic processes, although further confirmation through research of metabolic pathways in burn survivors is required.

Anti-apoptotic and Beneficial Metabolic Activities of Resveratrol in Type II Gaucher Disease.

Gaucher disease (GD) is one of the most common lysosomal storage disorders and is caused by an inherited deficiency in glucocerebrosidase. Resveratrol is a phytoalexin that has many beneficial activities, including anti-oxidant, anti-apoptotic, and neuroprotective effects. The aim of this study was to determine if resveratrol has a therapeutic effect on primary fibroblast cells derived from a patient with type II GD. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were performed to determine the effect of resveratrol on cell viability. The expression patterns of apoptosis-inducing factor (AIF), Bcl-2-associated X protein (Bax), caspase-3, acetyl-coenzyme A acetyltransferase 1 (ACAT1), E3-binding protein (E3BP), and citrate synthase (CS) were evaluated by Western blotting to characterize the effect of resveratrol treatment on GD cells. TLC was performed to determine glucosylceramide levels in resveratrol-treated GD cells. Resveratrol increased GD cell viability compared to untreated control cells. Further, resveratrol treatment dose-dependently decreased the apoptotic factors AIF, Bax, and cleaved caspase-3 levels, whereas ACAT1, E3BP, and CS expression dose-dependently increased. TLC analysis showed reduced levels of intracellular glucosylceramides in resveratrol-treated GD cells. These findings demonstrate that resveratrol can reduce cellular stress resulting from glucosylceramide accumulation, and suggest that resveratrol should be studied further as a novel therapeutic agent for GD.

Therapeutic Potential of Resveratrol in Type I Gaucher Disease.

Resveratrol is a natural polyphenol that possesses various beneficial properties, such as anti-inflammatory, anti-oxidant, and neuroprotective effects. This study evaluated the potential therapeutic effects of resveratrol on primary fibroblasts derived from a patient with Gaucher disease. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were carried out to determine whether resveratrol affects cell survival. Changes in the expression levels of apoptosis-inducing factor (AIF), Bax, cleaved caspase-3, acetyl-coenzyme A acetyltransferase 1 (ACAT1), E3-binding protein (E3BP), and citrate synthase (CS) were determined by western immunoblot to characterize the effect of resveratrol treatment on Gaucher disease cells. Intracellular glucosylceramide levels in resveratrol-treated patient cells were determined by thin-layer chromatography (TLC). Resveratrol significantly increased the viability of patient cells in comparison with that of control cells. After exposure to resveratrol, expression levels of the apoptotic factors AIF, Bax, and cleaved caspase-3 dose-dependently decreased, while those of ACAT1, E3BP, and CS dose-dependently increased. TLC showed a significant decrease in glucosylceramide levels in patient cells treated with resveratrol. These findings demonstrate that resveratrol can reduce apoptotic events and glucosylceramide levels in Gaucher disease cells, and that it merits further research as a possible therapeutic compound.

The large-conductance calcium-activated potassium channel holds the key to the conundrum of familial hypokalemic periodic paralysis.

PURPOSE: Familial hypokalemic periodic paralysis (HOKPP) is an autosomal dominant channelopathy characterized by episodic attacks of muscle weakness and hypokalemia. Mutations in the calcium channel gene, CACNA1S, or the sodium channel gene, SCN4A, have been found to be responsible for HOKPP; however, the mechanism that causes hypokalemia remains to be determined. The aim of this study was to improve the understanding of this mechanism by investigating the expression of calcium-activated potassium (KCa) channel genes in HOKPP patients. METHODS: We measured the intracellular calcium concentration with fura-2-acetoxymethyl ester in skeletal muscle cells of HOKPP patients and healthy individuals. We examined the mRNA and protein expression of KCa channel genes (KCNMA1, KCNN1, KCNN2, KCNN3, and KCNN4) in both cell types. RESULTS: Patient cells exhibited higher cytosolic calcium levels than normal cells. Quantitative reverse transcription polymerase chain reaction analysis showed that the mRNA levels of the KCa channel genes did not significantly differ between patient and normal cells. However, western blot analysis showed that protein levels of the KCNMA1 gene, which encodes KCa1.1 channels (also called big potassium channels), were significantly lower in the membrane fraction and higher in the cytosolic fraction of patient cells than normal cells. When patient cells were exposed to 50 mM potassium buffer, which was used to induce depolarization, the altered subcellular distribution of BK channels remained unchanged. CONCLUSION: These findings suggest a novel mechanism for the development of hypokalemia and paralysis in HOKPP and demonstrate a connection between disease-associated mutations in calcium/sodium channels and pathogenic changes in nonmutant potassium channels.

Channelopathies.

Channelopathies are a heterogeneous group of disorders resulting from the dysfunction of ion channels located in the membranes of all cells and many cellular organelles. These include diseases of the nervous system (e.g., generalized epilepsy with febrile seizures plus, familial hemiplegic migraine, episodic ataxia, and hyperkalemic and hypokalemic periodic paralysis), the cardiovascular system (e.g., long QT syndrome, short QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia), the respiratory system (e.g., cystic fibrosis), the endocrine system (e.g., neonatal diabetes mellitus, familial hyperinsulinemic hypoglycemia, thyrotoxic hypokalemic periodic paralysis, and familial hyperaldosteronism), the urinary system (e.g., Bartter syndrome, nephrogenic diabetes insipidus, autosomal-dominant polycystic kidney disease, and hypomagnesemia with secondary hypocalcemia), and the immune system (e.g., myasthenia gravis, neuromyelitis optica, Isaac syndrome, and anti-NMDA [N-methyl-D-aspartate] receptor encephalitis). The field of channelopathies is expanding rapidly, as is the utility of molecular-genetic and electrophysiological studies. This review provides a brief overview and update of channelopathies, with a focus on recent advances in the pathophysiological mechanisms that may help clinicians better understand, diagnose, and develop treatments for these diseases.

Cell cycle arrest in Batten disease lymphoblast cells.

Batten disease is an inherited neurodegenerative disorder caused by a CLN3 gene mutation. Batten disease is characterized by blindness, seizures, cognitive decline, and early death. Although apoptotic cell death is one of the pathological hallmarks of Batten disease, little is known about the regulatory mechanism of apoptosis in this disease. Since the CLN3 gene is suggested to be involved in the cell cycle in a yeast model, we investigated the cell cycle profile and its regulatory factors in lymphoblast cells from Batten disease patients. We found G1/G0 cell cycle arrest in Batten disease cells, with overexpression of p21, sphingosine, glucosylceramide, and sulfatide as possible cell cycle regulators.

Myxobacterial metabolites enhance cell proliferation and reduce intracellular stress in cells from a Parkinson's disease mouse model.

Parkinson's disease is a degenerative disorder of the central nervous system and is regarded as one of the most common neurologic diseases. Myxobacterial metabolites have been shown to possess a wide range of beneficial physiological effects, including anti-fungal, antibiotic, and anti-tumor activities. We aimed to determine whether myxobacterial metabolites exhibit a potential therapeutic effect in cells from a Parkinson's disease mouse model. The screening process identified 4 compounds, which were found to increase cell growth rate by >1.3 times that observed on the vehicle. These compounds promoted regeneration of the cells from a Parkinson's mouse model following the appearance of acute lesions, and reduced the levels of proteins associated with endoplasmic reticulum stress and apoptotic cell death. These compounds could lead to the development of novel therapies for Parkinson's disease and provide insight into the mechanisms through which apoptotic cell death takes place in this disorder.