The pilot study of group robot intervention on pediatric inpatients and their caregivers, using 'new aibo'.

The study on robot-assisted therapy in a pediatric field has not been applied sufficiently in clinical settings. The purpose of this pilot study is to explore the potential therapeutic effects of a group robot intervention (GRI), using dog-like social robot (SR) 'aibo' in pediatric ward. GRI by aibo was conducted for those children with chronic illness (127 in total) who are hospitalized in National Centre for Child Health and Development (NCCHD), and their caregivers (116 in total), from March to April 2018. The observer made structured behavioural observation records, based on which qualitative research on the features of their words and conducts, were carried out. As a result, first, during the GRI, about 2/3 of total expression by children were positive, while about 1/4 were negative or inappropriate. On the other hand, as seen in the 'change' group, those children who had originally responded with negative expression eventually came to express positive expression, while getting involved in a ternary relationship or participating in a session more than once. Secondly, as for the expression from the caregivers during the GRI, active expressions such as 'participation' and 'exploration' accounted for the 2/3, while 1/3 turned out to be rather placid expressions such as 'watch over' or 'encourage.'Conclusion: There has not been any precedent study on the features of words and conducts expressed by patients and their caregivers during the GRI by aibo. The outcome suggests that aibo could possibly be used as a tool for group robot-assisted therapy in the pediatric treatment setting. What is Known: • The study on robot-assisted therapy in a pediatric field has only just begun. • Though many kinds of social robot have been reportedly used so far, none has yet to be applied in clinical settings What is New: • Our study revealed the features of words and behaviour expressed by the patients and their caregivers, when dog-like social robot 'aibo' was used for a group robot intervention in the pediatric ward. • The outcome suggests that aibo could possibly be used as a tool for group robot-assisted therapy in the pediatric treatment setting.

Intrauterine hyperglycemia-induced inflammatory signalling via the receptor for advanced glycation end products in the cardiac muscle of the infants of diabetic mother rats.

PURPOSE: Gestational diabetes is associated with increased risk to the health of the mother and her offspring. In particular, the infants of diabetic mothers (IDMs) exhibit elevated levels of preterm birth, macrosomia, hypoglycemia, hypocalcemia, and cardiomyopathy. We have previously reported that IDMs showed abnormalities in cardiac Akt-related insulin signalling, and that these deficiencies in Akt-related signalling were attenuated by supplementing the maternal diet with fish-oil. Herein, we investigated whether the eicosapentaenoic acid (EPA) found in fish oil can be used to attenuate diabetes associated impairments in cardiomyocyte signalling. METHODS: Pregnant diabetic rats were administered streptozotocin before receiving EPA or water, and their infants were designated IDM/EPA, IDM/W. We assessed the potential molecular pathway for this effect in the primary cardiac cell from newborn rat hearts. RESULTS: Insulin resistance as determined by diminished GLUT4 translocation following insulin stimulation, the levels of advanced glycation end products (AGEs) and reactive oxygen species were elevated in the neonatal hearts of IDM/W compared with that seen in the offspring born from non-diabetic control animals. Similarly, the receptor of AGEs (RAGE) mRNA levels, reactive oxygen species and the amount of nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) mRNA were higher in the hearts from the IDM/W when compared to that observed in the hearts of offspring born to non-diabetic animals. These deleterious effects of gestational diabetes were significantly decreased in the offspring of diabetic mothers receiving EPA supplementation. CONCLUSIONS: Taken together, our data suggest that the EPA in fish oil may improve the impaired signalling and the excessive protein glycation in the cardiac muscles of infants exposed to intrauterine hyperglycemia.

NOX1/NADPH Oxidase Expressed in Colonic Macrophages Contributes to the Pathogenesis of Colonic Inflammation in Trinitrobenzene Sulfonic Acid-Induced Murine Colitis.

NOX1/NADPH oxidase, a nonphagocytic isoform of reactive oxygen species-producing enzymes, is highly expressed in the colon, but the physiologic and pathophysiologic roles of this isoform are not fully understood. The present study investigated the role of NOX1 in the development of colonic inflammation in a trinitrobenzene sulfonic acid (TNBS)-induced murine colitis model. Intrarectal injection of TNBS caused severe colitis accompanied by body weight loss, diarrhea, and increased myeloperoxidase (MPO) activity in wild-type (WT) mice. In contrast, the severity of colitis was significantly attenuated in NOX1-deficient (NOX1KO) mice (the inhibitions of macroscopic damage score, body weight loss, diarrhea score, and MPO activity were 73.1%, 36.8%, 83.3%, and 98.4%, respectively). TNBS-induced upregulation of inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-1ß), chemokines (CXCL1 and CXLC2), and inducible nitric oxide synthase (iNOS) was also significantly less in NOX1KO than in WT mice (the inhibitions were 100.8%, 89.0%, 63.5%, 96.7%, and 97.1%, respectively). Expression of NOX1 mRNA was detected not only in the lamina propria but also in peritoneal macrophages isolated from WT mice. Increased expression of TNF-α, IL-1ß, and iNOS in peritoneal macrophages exposed to lipopolysaccharide was significantly attenuated in macrophages isolated from NOX1KO mice (68.1%, 67.0%, and 79.3% inhibition, respectively). These findings suggest that NOX1/NADPH oxidase plays an important role in the pathogenesis of TNBS-induced colonic inflammation via upregulation of inflammatory cytokines, chemokines, and iNOS. NOX1 in colonic macrophages may become a potential target in pharmacologic intervention for inflammatory bowel disease.

Calcium-mediated regulation of recombinant hybrids of full-length Physarum myosin heavy chain with Physarum/scallop myosin light chains.

Physarum myosin is a Ca(2+)-binding protein and its activity is inhibited by Ca(2+) In the present study, to clarify the light chains (LCs) from the different species (Physarum and scallop) and to determine the specific Ca(2+)-regulated effects, we constructed hybrid myosins with a Physarum myosin heavy chain (Ph·HC) and Physarum and/or scallop myosin LCs, and examined Ca(2+)-mediated regulation of ATPases and motor activities. In these experiments, it was found that Ca(2+) inhibited motilities and ATPase activities of Physarum hybrid myosin with scallop regulatory light chain (ScRLC) and Physarum essential light chain (PhELC) but could not inhibit those of the Physarum hybrid myosin mutant Ph·HC/ScRLC/PhELC-3A which lacks Ca(2+)-binding ability, indicating that PhELC plays a critical role in Ca(2+)-mediated regulation of Physarum myosin. Furthermore, the effects of Ca(2+) on ATPase activities of Physarum myosin constructs are in the following order: Ph·HC/PhRLC/PhELC > Ph·HC/ScRLC/PhELC > Ph·HC/PhRLC/ScELC > Ph·HC/ScRLC/ScELC, suggesting that the presence of PhRLC and PhELC leads to the greatest Ca(2+) sensitivity of Physarum myosin. Although we did not observe the motilities of Physarum hybrid myosin Ph·HC/PhRLC/ScELC and Ph·HC/ScRLC/ScELC, our results suggest that Ca(2+)-binding to the PhELC may alter the flexibility of the regulatory domain and induce a 'closed' state, which may consequently prevent full activity and force generation.

Genotypes of the renin-angiotensin system and glucocorticoid complications.

BACKGROUND: Angiotensinogen (AGT) and angiotensin-converting enzyme (ACE) are recognized as important regulators of body mass index (BMI) and systemic blood pressure (BP). An association between these single nucleotide polymorphisms (SNP) of AGT and ACE genes and obesity or hypertension has been established. This study examined relationships between the molecular variants of the AGT and ACE genes and bodyweight or BP in children treated with glucocorticoids for nephrotic syndrome. METHODS: Twenty Japanese children (male, n = 14; female, n = 6; age, 2-13 years) were genotyped for AGT polymorphisms (M235T and A-6G) and the ACE polymorphisms (insertion/deletion: I/D and rs4341). All of the children studied were treated with daily prednisolone 2 mg/kg for 4 weeks and thereafter alternate-day prednisolone for 8 weeks. BMI, BMI z-scores, blood lipids, renal function and BP in each group were evaluated during the study period. RESULTS: BMI and BMI z-scores during the glucocorticoid therapy were significantly higher in the TT genotype of the AGT M235T polymorphisms and the AA genotype of the AGT A-6G polymorphisms compared to other genotypes (P < 0.05). In contrast, the molecular variant of ACE I/D and rs4341 genotypes did not change bodyweight during the glucocorticoid exposure. It was evident, however, that the BP and blood lipids and renal function were not significantly influenced by the AGT and ACE polymorphisms. CONCLUSIONS: The TT genotype of the AGT M235T and the AA genotype of the A-6G polymorphisms may predispose children to bodyweight gain when initially treated with glucocorticoids for nephrotic syndrome.

Nonmuscle myosin II folds into a 10S form via two portions of tail for dynamic subcellular localization.

Nonmuscle myosin II forms a folded conformation (10S form) in the inactivated state; however, the physiological importance of the 10S form is still unclear. To investigate the role of 10S form, we generated a chimeric mutant of nonmuscle myosin IIB (IIB-SK1·2), in which S1462-R1490 and L1551-E1577 were replaced with the corresponding portions of skeletal muscle myosin heavy chain. The IIB-SK1·2 mutant did not fold into a 10S form under physiological condition in vitro. IIB-SK1·2 was less dynamic by stabilizing the filamentous form and accumulated in the posterior region of migrating cells. IIB-SK1·2 functioned properly in cytokinesis but altered migratory properties; the rate and directional persistence were increased by IIB-SK1·2 expression. Surprisingly, endogenous nonmuscle myosin IIA was excluded from the posterior region of migrating cells expressing IIB-SK1·2, which may underlie the change of the cellular migratory properties. These results suggest that the 10S form is necessary for maintaining nonmuscle myosin II in an unassembled state and for recruitment of nonmuscle myosin II to a specific region of the cell.

Unveiling the Threat of Maternal Advanced Glycation End Products to Fetal Muscle: Palmitoleic Acid to the Rescue.

Advanced glycation end products (AGEs) accumulate in the plasma of pregnant women with hyperglycemia, potentially inducing oxidative stress and fetal developmental abnormalities. Although intrauterine hyperglycemia has been implicated in excessive fetal growth, the effects of maternal AGEs on fetal development remain unclear. We evaluated the differentiation regulators and cellular signaling in the skeletal muscles of infants born to control mothers (ICM), diabetic mothers (IDM), and diabetic mothers supplemented with either cis-palmitoleic acid (CPA) or trans-palmitoleic acid (TPA). Cell viability, reactive oxygen species levels, and myotube formation were assessed in AGE-exposed C2C12 cells to explore potential mitigation by CPA and TPA. Elevated receptors for AGE expression and decreased Akt and AMPK phosphorylation were evident in rat skeletal muscles in IDM. Maternal palmitoleic acid supplementation alleviated insulin resistance by downregulating RAGE expression and enhancing Akt phosphorylation. The exposure of the C2C12 cells to AGEs reduced cell viability and myotube formation and elevated reactive oxygen species levels, which were attenuated by CPA or TPA supplementation. This suggests that maternal hyperglycemia and plasma AGEs may contribute to skeletal muscle disorders in offspring, which are mitigated by palmitoleic acid supplementation. Hence, the maternal intake of palmitoleic acid during pregnancy may have implications for fetal health.

Effects of inhaled (S)-linalool on hypothalamic gene expression in rats under restraint stress.

Linalool has two enantiomers, (R)-linalool and (S)-linalool. Both are known to possess several biological activities in stressed animals. Our previous work revealed that inhalation of (R)-linalool altered hypothalamic gene expression in rats under stress. In the present study, we monitored hypothalamic gene expression in restrained rats with and without (S)-linalool inhalation by DNA microarray. The entire gene expression profile showed that inhalation of (S)-linalool significantly changed the expression levels of 316 hypothalamic genes in the restrained rats. The differentially expressed genes (e.g., App, Avp, Igf2, Igfbp2, Sst and Syt5) were found to relate to cell-to-cell signaling and nervous system development. These results indicate that (S)-linalool influences hypothalamic gene expression in restrained rats, and that inhalation of (S)-linalool under the stressed condition has some effects on stress-related biological responses.

Maternal n-7 Unsaturated Fatty Acids Protect the Fetal Brain from Neuronal Degeneration in an Intrauterine Hyperglycemic Animal Model.

We previously reported that glycation induces insulin resistance in the hearts of newborn pups from a gestational diabetes mellitus (GDM) rat model. Administration of n-3 unsaturated fatty acids suppressed glycation and improved signaling in GDM rat pups. In this study, we investigated their effects on cranial neurons using the GDM rat model and PC12 cells derived from rat adrenal pheochromocytomas. Additionally, we examined whether n-3 and n-7 unsaturated fatty acids (cis-palmitoleic acid [CPA] and trans-palmitoleic acid [TPA]) ameliorate the detrimental effects of high glucose exposure on rats. In the neonatal cerebrum of GDM rats, increased levels of advanced glycation end products (AGEs) inhibited Akt phosphorylation; however, CPA and TPA intake during pregnancy ameliorated these abnormalities. Furthermore, exposure to high-glucose-induced apoptosis in PC12 cells compared to the cells cultured in control glucose. PC12 cells exposed to high-glucose with fatty acids exhibited reduced AGE production and apoptosis induction compared to the high-glucose group. These findings suggest that a hyperglycemic environment during pregnancy promotes AGE formation in brain neuronal proteins and induces apoptosis. Both TPA and CPA mitigated these abnormalities; however, CPA is cytotoxic, highlighting its safety in pregnant women.

Tunicate cytostatic factor TC14-3 induces a polycomb group gene and histone modification through Ca(2+) binding and protein dimerization.

BACKGROUND: As many invertebrate species have multipotent cells that undergo cell growth and differentiation during regeneration and budding, many unique and interesting homeostatic factors are expected to exist in those animals. However, our understanding of such factors and global mechanisms remains very poor. Single zooids of the tunicate, Polyandrocarpa misakiensis, can give off as many as 40 buds during the life span. Bud development proceeds by means of transdifferentiation of very limited number of cells and tissues. TC14-3 is one of several different but closely related polypeptides isolated from P. misakiensis. It acts as a cytostatic factor that regulates proliferation, adhesion, and differentiation of multipotent cells, although the molecular mechanism remains uncertain. The Polycomb group (PcG) genes are involved in epigenetic control of genomic activity in mammals. In invertebrates except Drosophila, PcG and histone methylation have not been studied so extensively, and genome-wide gene regulation is poorly understood. RESULTS: When Phe(65) of TC14-3 was mutated to an acidic amino acid, the resultant mutant protein failed to dimerize. The replacement of Thr(69) with Arg(69) made dimers unstable. When Glu(106) was changed to Gly(106), the resultant mutant protein completely lost Ca(2+) binding. All these mutant proteins lacked cytostatic activity, indicating the requirement of protein dimerization and calcium for the activity. Polyandrocarpa Eed, a component of PcG, is highly expressed during budding, like TC14-3. When wild-type and mutant TC14-3s were applied in vivo and in vitro to Polyandrocarpa cells, only wild-type TC14-3 could induce Eed without affecting histone methyltransferase gene expression. Eed-expressing cells underwent trimethylation of histone H3 lysine27. PmEed knockdown by RNA interference rescued cultured cells from the growth-inhibitory effects of TC14-3. CONCLUSION: These results show that in P. misakiensis, the cytostatic activity of TC14-3 is mediated by PmEed and resultant histone modification, and that the gene expression requires both the protein dimerization and Ca(2+)-binding of TC14-3. This system consisting of a humoral factor, PcG, and histone methylation would contribute to the homeostatic regulation of cell growth and terminal differentiation of invertebrate multipotent cells.

Etodolac, a cyclooxygenase-2 inhibitor, attenuates paclitaxel-induced peripheral neuropathy in a mouse model of mechanical allodynia.

The effect of the cyclooxygenase-2 (COX-2) inhibitor etodolac on the mechanical allodynia induced by paclitaxel was investigated in mice and compared with the effects of the nonselective COX inhibitors indomethacin and diclofenac, the selective COX-2 inhibitor celecoxib, the calcium channel α(2)δ subunit inhibitor pregabalin, the sodium channel blocker mexiletine, and the serotonin-norepinephrine reuptake inhibitor duloxetine. The decrease in the paw-withdrawal threshold induced by paclitaxel was reversed by oral administration of etodolac at 10 mg/kg but was not affected by indomethacin, diclofenac, or celecoxib. The antiallodynic effect of etodolac gradually increased during repeated administration, and after 2 weeks the paw-withdrawal threshold at the preadministration point was significantly increased. Pregabalin, duloxetine, and mexiletine also showed an antiallodynic effect in this model. Whereas pregabalin had a preadministration effect similar to that of etodolac during repeated administration, mexiletine or duloxetine had no such effect. There was almost no difference in the distribution of etodolac and diclofenac in nervous tissue, indicating that COX inhibition is unlikely to be involved in the antiallodynic effect of etodolac. Etodolac did not show a neuroprotective effect against morphological transformations such as the axonal degeneration induced by paclitaxel. Instead, etodolac probably acts at the level of functional changes accompanying paclitaxel treatment, such as alterations in the activation state of components of the pain transmission pathway. Our findings suggest that etodolac attenuates paclitaxel-induced peripheral neuropathy by a COX-independent pathway and that it might be useful for the treatment of paclitaxel-induced peripheral neuropathy.

Modulation of 11ß-hydroxysteroid dehydrogenase 1 by ß2-adrenoceptor in the ischaemia-reperfused rat kidney.

BACKGROUND: 11ß-Hydroxysteroid dehydrogenase Type 1 (11ßHSD-1) amplifies intracellular levels of active glucocorticoids which possess protective effects against organ ischaemia and reperfusion (I/R). However, the mechanisms by which 11ßHSD-1 is modified after a renal I/R challenge remain unclear. This study investigated the effect of ß(2)-adrenoceptor (ß(2)-AR) activation and the subsequent signalling pathways on renal 11ßHSD-1 gene expression following renal I/R. METHODS: Renal I/R was induced using 25 min of bilateral renal artery occlusion in 4-week-old Wistar rats followed by an intraperitoneal injection of various doses of adeno-ß(2)-AR gene. Following renal I/R, kidneys, plasma and urine were collected to assay 11ßHSD messenger RNA (mRNA) levels, ß(2)-AR signalling cascades and renal function. RESULTS: On the second day after the renal I/R challenge, there was a reduction in renal 11ßHSD-1 mRNA levels associated with a decrease in stimulatory G protein α (Gsα) and adenylate cyclase-1 (ACY-1) in the kidney. The addition of the adeno-ß(2)-AR gene resulted in greater increases in 11ßHSD-1 mRNA and ß(2)-AR-Gsα-ACY-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) activity in the kidney but had no effect on 11ßHSD-2 mRNA or protein kinase C levels in the kidney. CONCLUSIONS: Over-expression of ß(2)-AR resulting from the gene delivery improved renal function and 11ßHSD-1 production following renal I/R, which were actions exerted through the cAMP-PKA pathway. The stimulatory effect of functional ß(2)-AR activation on renal 11ßHSD-1 expression may offer a means of protection from renal I/R injury.

Down-regulation of myosin light chain kinase expression in vascular smooth muscle cells accelerates cell proliferation: requirement of its actin-binding domain for reversion to normal rates.

Myosin light-chain kinase (MLCK) is a multi-domain protein with kinase and actin-binding domains, among others. Deficiency of MLCK expression in GBaSM-4 vascular smooth muscle cells enhanced cell proliferation rate and shortened cell doubling time. Transient transfection of the MLCK-deficient cells with cDNA constructs of either wild-type MLCK or its mutant lacking the kinase activity reverted the cell proliferation rate to that of wild-type cells, whereas that of MLCK lacking the actin-binding domain maintained cell proliferation at an elevated rate similar to the MLCK-deficient cells. Thus, the actin-binding domain of MLCK seems to play a role in regulating cell proliferation.

The actions of Shiga toxin-2 administration into the brain on renal sympathetic nerve activity.

BACKGROUND: It remains unclear whether Shiga toxin-2 (Stx-2)-induced acute encephalopathy contributes to an inappropriate activation of the renal sympathetic outflow. This investigation set out to examine the impact of Stx-2 administered into the brain on the neural control of the kidney. METHODS: Using acutely anaesthetised male Wistar rats (300-350 g), saline, Stx-2 (10 µg/kg) or lipopolysaccharide (LPS 50 µg/kg) was administered intracerebroventricularly (icv) and measurements of renal haemodynamic and excretory function or renal nerve activity were made over the following 4 h. RESULTS: There were minimal changes in renal blood flow, glomerular filtration rate, urine flow or sodium excretion, irrespective of whether saline, Stx-2 or LPS was administered into the brain. The renal nerve recordings showed that whereas saline and LPS caused small inconsistent changes in renal nerve activity over the 4-h period, there was a significant (P < 0.05) doubling of renal nerve activity in the rats which were administered Stx-2 icv. Immunocytochemical examination demonstrated that Stx-2 induced globotriaosylceramide receptors, the proposed functional receptors for Stx-2, on the blood vessel walls around the hypothalamus and hippocampus, and histological evaluations showed that changes in the kidney were beginning to occur to the renal tubular epithelial cells, consistent with developing lesions. CONCLUSION: Stx-2 crosses either the blood-brain barrier or the blood-cerebrospinal fluid barrier where it can alter neuronal function and trigger neuronal derangements. These structural changes could contribute, at least in part, to the raised renal sympathetic nerve activity.

Effects of artificial intelligence aibo intervention on alleviating distress and fear in children.

BACKGROUND: Procedures and actions such as injections and immobilization cause distress to children. In the pediatric field, there is a need for interventions and support to alleviate the pain and distress caused by such medical procedures. In recent years, the introduction of robots as a means of distraction has begun to be attempted. METHODS: In this study, we conducted a non-randomized controlled trial to examine the effect of intervention using 'aibo', a dog-like robot which has artificial intelligence (AI), to promote distraction in children after vaccination. Children between the ages of 3 and 12 years old eligible for the Japanese encephalitis vaccine, and their caregivers were assigned to intervention group or control group. Then, children evaluated their pain and children's behavior were observed by observer. The mean values of Faces pain rating scale scores and observer pain scale scores were compared between groups using an unpaired t-test. RESULTS: Fifty-seven children (32 in the intervention group) participated in the study. Results of a t-test with the control group showed that the intervention group using aibo had significantly less pain following the post-vaccination intervention than the control group using stuffed dog (Face Scale, t(55) = 2.582, p = .0125; Behavioral Observation Scale, t(55) = 2.772, p = .00759). The results support the hypothesis that the aibo intervention group will be less distressed and able to calm down more quickly after vaccination than the control group. CONCLUSION: Interactive communicative play intervention by an artificially intelligent aibo before and after painful and frightening medical procedures may alleviate fear and anxiety and prevent medical trauma in children.

Effect of cigarette smoke components on vascular smooth muscle cell migration toward platelet-derived growth factor BB.

Cigarette smoking is one of the factors causing accumulation of vascular smooth muscle cells (VSMCs) in atherosclerotic plaques. Changes in cell migration toward platelet-derived growth factor BB were investigated using a Boyden chamber after 48-h preincubation of GBaSM-4 VSMCs with nicotine or nicotine-free cigarette smoke extract (CSE). A nicotine concentration of 0.1 µM maximally promoted cell migration; 0.1% CSE also promoted cell migration, while high CSE concentrations damaged GBaSM-4 cells. Fetal bovine serum (FBS) long-depletion induced decrease in migration of GBaSM-4 cells. Our results suggest that nicotine and some CSE components can induce GBaSM-4 cell migration.

Myosin light chain kinase/actin interaction in phorbol dibutyrate-stimulated smooth muscle cells.

Previous work has suggested that in addition to its kinase activity, myosin light chain kinase (MLCK) exhibits non-kinase properties within its N-terminus that could influence cytoskeletal organization of smooth muscle cells (A. Nakamura et al. Biochem Biophys Res Commun. 2008;369:135-143). Myosin ATPase activity measurements indicate that the 26-41 peptide of MLCK significantly decreases ATPase activity as the concentration of this peptide increases. Sliding velocity of actin-filaments on myosin and stress responses in skinned smooth muscle tissue are also inhibited. Peptide-mediated uptake and the microinjection technique in cells indicate that the peptide was necessary for actin-filament stabilization. Fluorescence resonance energy transfer analysis indicated that in the presence of MLCK, α-actin but not ß-actin remodeled during phorbol 12,13-dibutyrate (PDBu)-induced contractions. PDBu also induced podosomes in the cell. When MLCK expression was down-regulated by introduction of RNAi for MLCK by lentivirus vector into the cells, we failed to observe the podosome induction upon PDBu stimulation. Rescue experiments indicate that the non-kinase activity of MLCK plays an important role in maintaining actin stress fibers and in the PDBu-induced reorganization of actin-filaments in smooth muscle cells.