Distal Vessel Imaging via Intra-arterial Flat Panel Detector CTA during Mechanical Thrombectomy.

BACKGROUND AND PURPOSE: Obtaining information on invisible vasculature distal to the occlusion site helps to deploy a stent retriever safely during mechanical thrombectomy for large-vessel occlusion. It is essential to reduce the amount of contrast used for detecting the vessels distal to the occlusion site because acute ischemic stroke patients tend to have chronic kidney disease and patients with severe chronic kidney disease are at an increased risk of contrast-associated acute kidney injury. We assessed whether vessels distal to the occlusion site during acute ischemic stroke with large-vessel occlusion could be visualized on angiographic images using flat panel detector CT acquired following intra-arterial diluted contrast injection, compared with MRA findings. MATERIALS AND METHODS: Between May 2019 and January 2020, we enrolled 28 consecutive patients with large-vessel occlusions of the anterior circulation eligible for mechanical thrombectomy following MR imaging. The patients underwent CBV imaging using flat panel detector CT with an intra-arterial diluted contrast injection instead of intravenous injection. Flat panel detector CT angiographic images reconstructed from the same dataset were evaluated for image quality, collateral status of the MCA territory, and visualization of the vessels distal to the occlusion site. These findings were compared with MRA findings. RESULTS: Twenty-two patients were retrospectively examined. Flat panel detector CT angiographic image quality in 20 patients (91%) was excellent or good. The distal portion of the occluded vessel segment was visualized in 14 patients (70%), while the proximal portion of the segment adjacent to the occluded vessel in 3 (15%) was visualized. No visualization was observed in only 1 patient (5%) with no collateral supply. Flat panel detector CT angiographic images were shown to evaluate vessels distal to the occlusion site more accurately than MRA. CONCLUSIONS: In acute ischemic stroke with large-vessel occlusion, flat panel detector CT angiographic images could successfully visualize vessels distal to the occlusion site with a small amount of contrast material.

The suppressive effect on CD4 T cell alloresponse against endothelial HLA-DR via PD-L1 induced by anti-A/B ligation.

While donor-specific human leukocyte antigen (HLA) antibodies are a frequent cause for chronic antibody-mediated rejection in organ transplantation, this is not the case for antibodies targeting blood group antigens, as ABO-incompatible (ABO-I) organ transplantation has been associated with a favorable graft outcome. Here, we explored the role of CD4 T cell-mediated alloresponses against endothelial HLA-D-related (DR) in the presence of anti-HLA class I or anti-A/B antibodies. CD4 T cells, notably CD45RA-memory CD4 T cells, undergo extensive proliferation in response to endothelial HLA-DR. The CD4 T cell proliferative response was enhanced in the presence of anti-HLA class I, but attenuated in the presence of anti-A/B antibodies. Microarray analysis and molecular profiling demonstrated that the expression of CD274 programmed cell death ligand 1 (PD-L1) increased in response to anti-A/B ligation-mediated extracellular signal-regulated kinase (ERK) inactivation in endothelial cells that were detected even in the presence of interferon-γ stimulation. Anti-PD-1 antibody enhanced CD4 T cell proliferation, and blocked the suppressive effect of the anti-A/B antibodies. Educated CD25+ CD127- regulatory T cells (edu.Tregs ) were more effective at preventing CD4 T cell alloresponses to endothelial cells compared with naive Treg ; anti-A/B antibodies were not involved in the Treg -mediated events. Finally, amplified expression of transcript encoding PD-L1 was observed in biopsy samples from ABO-I renal transplants when compared with those from ABO-identical/compatible transplants. Taken together, our findings identified a possible factor that might prevent graft rejection and thus contribute to a favorable outcome in ABO-I renal transplantation.

Functional modulation of caecal fermentation and microbiota in rat by feeding bean husk as a dietary fibre supplement.

A feeding study using rats was conducted to evaluate the utility of lablab bean husk and soya bean husk as sources of potential prebiotic fibre. Twenty 5-week-old Sprague Dawley rats were divided into 4 groups and fed one of the following diets for 3 weeks: purified diet (AIN93 G) containing 5% cellulose (CEL), or the same diet in which cellulose was replaced by corn starch (STA), lablab bean husk (LBH), or soya bean husk (SBH). Rats were sacrificed at 8 weeks of age and caecal digesta were collected. Feed intake, body weight, anatomical parameters, and caecal ammonia level did not differ significantly among diets. Rats on LBH and SBH showed higher concentrations of caecal short-chain fatty acid and lactate than those on CEL. Rats on CEL, SBH, and LBH exhibited lower caecal indole and skatole levels. LBH yielded increased caecal abundance of Akkermansia muciniphila and Oscillibacter relatives, as demonstrated by either qPCR, MiSeq, or clone library analysis. SBH favoured the growth of lactobacilli as assessed by both qPCR and MiSeq, and favoured the growth of bifidobacteria as assessed by MiSeq. In comparison with STA, LBH and SBH yielded lower caecal abundance of bacteria related to Dorea massiliensis, as demonstrated by qPCR, MiSeq, and clone library analysis. Both types of bean husk were found to contain oligosaccharides that might selectively stimulate the growth of beneficial bacteria. Based on these results, the two species of bean husk tested are considered potentially functional for promoting the gut health of monogastric animals.

Risk factors for advanced duodenal and ampullary adenomatosis in familial adenomatous polyposis: a prospective, single-center study.

BACKGROUND AND STUDY AIMS: To determine the clinical features associated with advanced duodenal and ampullary adenomas in familial adenomatous polyposis. Secondarily, we describe the prevalence and clinical significance of jejunal polyposis. PATIENTS AND METHODS: This is a single center, prospective study of 62 patients with familial adenomatous polyposis. Duodenal polyposis was classified according to Spigelman and ampullary adenomas were identified. Patients with Spigelman III and IV duodenal polyposis underwent balloon assisted enteroscopy. Predefined groups according to Spigelman and presence or not of ampullary adenomas were related to the clinical variables: gender, age, family history of familial adenomatous polyposis, type of colorectal surgery, and type of colorectal polyposis. RESULTS: Advanced duodenal polyposis was present in 13 patients (21 %; 9 male) at a mean age of 37.61 ±â€Š13.9 years. There was a statistically significant association between family history of the disease and groups according to Spigelman ( P  = 0.03). Seven unrelated patients (6 male) presented ampullary adenomas at a mean age of 36.14 ±â€Š14.2 years. The association between ampullary adenomas and extraintestinal manifestations was statistically significant in multivariate analysis ( P  = 0.009). Five endoscopic types of non-ampullary adenoma were identified, showing that lesions larger than 10 mm or with a central depression presented foci of high grade dysplasia. Among 28 patients in 12 different families, a similar Spigelman score was identified; 10/12 patients (83.3 %) who underwent enteroscopy presented small tubular adenomas with low grade dysplasia in the proximal jejunum. CONCLUSIONS: Advanced duodenal polyposis phenotype may be predictable from disease severity in a first-degree relative. Ampullary adenomas were independently associated with the presence of extraintestinal manifestations.

Quantitative evaluation of oral function in acute and recovery phase of idiopathic facial palsy; a preliminary controlled study.

OBJECTIVES: Patients with peripheral facial palsy frequently complain of fluid leakage and food retention during meals. We investigated oral function during eating in adults with peripheral facial palsy. DESIGN: A prospective two-phase controlled observational study. SETTING: Data were collected at the ENT clinic in Nihon University Itabashi Hospital (patients) and Nihon University Dental Hospital (controls) between September 2009 and August 2011 and analysed at the Department of Oral Diagnostic Sciences in Nihon University School of Dentistry. PARTICIPANTS: Fourteen patients with acute idiopathic facial palsy and 14 controls completed Study 1. Sixteen patients with acute idiopathic facial palsy and 16 controls completed Study 2. MAIN OUTCOME MEASURES: In Study 1, oral vestibular cleansing capability was assessed by measuring the amount of rice remaining in the oral vestibule after mastication. In Study 2, masticatory efficiency was evaluated by measuring glucose eluted from gummy jelly during chewing. These oral functions were observed at the first visit and final visit (after patients with facial palsy had recovered). RESULTS: Oral vestibular cleansing capability at the first visit was significantly decreased by facial palsy (P < 0.001 versus healthy volunteers and P < 0.001 versus contralateral side) but recovered as facial muscular function improved (P = 0.034). There was a significant correlation between improvement in paralysis and decreased food retention (r = -0.528, P = 0.010). At the first visit, masticatory efficiency on the affected side was significantly lower than that of controls (P = 0.002) but had mostly recovered after resolution of facial palsy (P = 0.033). CONCLUSIONS: Oral functions were decreased by peripheral facial palsy. Oral vestibular cleansing capability was more significantly associated than masticatory efficiency with facial muscle function. Our data suggest that peripheral facial palsy impairs eating and worsens oral hygiene, which may result in oral disease.

[Hyperplastic polyp with neoplastic transformation in a patient with atrophic gastritis and multiple gastric neuroendocrine tumors]. / Pólipo hiperplásico con transformación neoplásica en paciente con gastritis atrófica y múltiples tumores neuroendocrinos.

Hyperplastic gastric polyps are often found at GI endoscopy and are not considered premalignant lesions, although some cases of malignancy have been reported. Neuroendocrine tumors, conversely, are rare and account for approximately 1% to 2% of gastric polyps. Both hyperplastic gastric polyps and neuroendocrine tumors are related to gastric atrophy. The case of a hyperplastic polyp with multifocal areas of adenocarcinoma within the polyp associated to multiple gastric neuroendocrine tumors is reported.

NO dissociation on Cu(111) and Cu2O(111) surfaces: a density functional theory based study.

NO dissociation on Cu(111) and Cu(2)O(111) surfaces is investigated using spin-polarized density functional theory. This is to verify the possibility of using Cu-based catalyst for NO dissociation which is the rate limiting step for the NO(x) reduction process. The dissociation of molecularly adsorbed NO on the surface is activated for both cases. However, from the reaction path of the NO-Cu(2)O(111) system, the calculated transition state lies below the reference energy which indicates the possibility of dissociation. For the NO-Cu(111) system, the reaction path shows that NO desorption is more likely to occur. The geometric and electronic structure of the Cu(2)O(111) surface indicates that the surface Cu atoms stabilize themselves with reference to the O atom in the subsurface. The interaction results in modification of the electronic structure of the surface Cu atoms of Cu(2)O(111) which greatly affects the adsorption and dissociation of NO. This phenomenon further explains the obtained differences in the dissociation pathways of NO on the surfaces.

Synchronous phosphorylation of CPI-17 and MYPT1 is essential for inducing Ca(2+) sensitization in intestinal smooth muscle.

BACKGROUND: Myosin phosphatase activity is regulated by mechanisms involving the phosphorylation of CPI-17 and MYPT1, primarily based on studies with tonic-type vascular smooth muscles. This study examined how these mechanisms contribute to the regulation of contraction of a phasic-type intestinal smooth muscle. METHODS: Phosphorylation levels, tension, and Ca(2+) sensitization was detected in rat ileal smooth muscle. Key Results In rat ileal smooth muscle, phosphorylation level of CPI-17 at Thr(38) and MYPT1 at Thr(853) , but not MYPT1 at Thr(696) , were increased with carbachol (1µmolL(-1) ) accompanied with muscle contraction. The PKC inhibitor Go6976 (1µmol L(-1) ) inhibited the carbachol-induced phosphorylation of CPI-17, whereas the Rho-associated kinase (ROCK) inhibitor, Y-27632 (10µmol L(-1) ) inhibited the carbachol-induced phosphorylation of both CPI-17 and MYPT1. Application of Go6976 or Y-27632 alone inhibited the carbachol-induced contraction; however, the combined application of these inhibitors did not inhibit the contraction in an additive manner. In ß-escin-permeabilized ileal strip, treatment with antiphosphorylated antibodies for CPI-17 at Thr(38) and MYPT1 at Thr(853) and Thr(696) alone almost completely abolished the Ca(2+) sensitization due to carbachol with GTP. CONCLUSIONS & INFERENCES: In conclusion, receptor stimulation increases the Ca(2+) sensitivity of contractile elements through CPI-17 phosphorylation via the PKC/ROCK pathways and MYPT1 phosphorylation via the ROCK pathway, when these mechanisms operate cooperatively and/or synchronously in intestinal smooth muscle.

Permanent cerebral bypass approach for lung cancer resection with aortic arch invasion.

We report a case of a 54-year-old man with T4N0M0 non-small cell lung cancer directly invading the thoracic wall and aortic arch. He underwent neoadjuvant chemotherapy followed by en bloc resection of the tumor, lung, chest wall and aortic arch. Perfusion was maintained through femoral-femoral cardiopulmonary bypass, with permanent bypass to the arch vessels to avoid separate extracorporeal cerebral circulation. Total reconstructions of the chest wall and aortic arch were completed without the need for cardiac arrest. The final pathological diagnosis was squamous cell carcinoma, T4N0M0. The patient was discharged without major complications and has been free of disease for 20 months postoperatively.

Use of multiple channel pH monitoring for evaluation of ultra-distal reflux in patients after fundoplication for treatment of Barrett's esophagus.

Dysplasia and esophageal adenocarcinoma may arise in patients with Barrett's esophagus after fundoplication esophageal pH monitoring showing no acid in esophagus. This suggests the need to develop methodology to evaluate the occurrence of ultra-distal reflux (1cm above the LES). The objective of the study was to compare acid exposition in three different levels: 5cm above the upper border of the LES, 1cm above the LES and in the intrasphincteric region. Eleven patients with Barrett's esophagus after Nissen fundoplication with no clinical, endoscopic and radiologic evidence of reflux were selected. Four-channel pH monitoring took place: channel A, 5cm above the upper border of the LES; channel B, 1cm above the LES; channel C, intrasphincteric; channel D, intragastric. The results of channels A, B and C were compared. There was significant increase in number of reflux episodes and a higher fraction of time with pH <4.0 in channel B compared to channel A. There was significant decrease in fraction of time with pH <4.0 in channel B compared to channel C. Two cases of esophageal adenocarcinoma were diagnosed in the studied patients. The region 1cm above the upper border of the LES is more exposed to acid than the region 5cm above the upper border of the LES, although this exposure occurred in reduced levels. The region 1cm above the upper border of the LES is less exposed to acid than the intrasphincteric region.

A case of middle-ear cavernous lymphangioma with facial palsy.

OBJECTIVE: Only a few benign tumours of the middle ear have been reported to lead to the development of facial palsy. Here, we describe a patient with middle-ear cavernous lymphangioma and facial palsy. STUDY DESIGN: Single case study. PATIENT: A 61-year-old man presented with left-sided hearing impairment and incomplete left facial palsy. A tumour was confirmed to be occupying the epi- to mesotympanum and to be joined to the facial nerve. The tumour was removed along with facial nerve tissue, which was resected at its horizontal portion, and the remaining facial nerve was fixed by end-to-end anastomosis. Complete facial paralysis occurred after the operation, but the patient's House-Brackmann grade gradually improved to grade III. Post-operative histopathological examination revealed infiltration of the lymphangioma into the facial nerve tissue, together with mild neural atrophy of the facial nerve. CONCLUSION: These findings suggested that tumour invasion was the cause of facial palsy in this patient.

MAC-CCD system: a novel lymphocyte microwell-array chip system equipped with CCD scanner to generate human monoclonal antibodies against influenza virus.

We previously developed a lymphocyte microwell-array system, which effectively detects antigen-specific B-cells by monitoring intracellular Ca(2+) mobilization at the single-cell level with a fluorescent Ca(2+) indicator, fluo-4. However, it is difficult for the system to perform time-lapse monitoring. Here, we developed a novel method, a lymphocyte microwell-array chip system equipped with a charge-coupled device (CCD) time-lapse scanner (MAC-CCD system), for monitoring intracellular Ca(2+) mobilization. The MAC-CCD system is able to monitor intracellular Ca(2+) mobilization of more than 15,000-20,000 individual live B-cells every 10 s. In addition, we adopted a correlation method in a MAC-CCD system, which enabled us to detect B-cells with a frequency of as few as 0.046%. Furthermore, we succeeded in obtaining six influenza nucleoprotein-specific human monoclonal antibodies from the peripheral blood of influenza-vaccinated volunteers. These results demonstrate that the MAC-CCD system with a correlation method could detect very rare antigen-specific B-cells.

Analysis of recessive lethality on swine chromosome 6 in a Göttingen miniature resource family.

Previously, we reported recessive gene(s) that terminate fetal development on swine chromosome (SSC) 6 between SW855 and SW122. The affected alleles originated from a Göttingen miniature pig used for construction of a Göttingen miniature pig x Meishan resource population. However, it is not known when the gene(s) are activated during fetal development, which is one of the important factors in selecting candidate genes responsible for fetal death. In the present study, a second swine population consisting of 159 progeny was produced by mating pigs carrying the deleterious allele(s). This population allowed us to narrow the genetic region harbouring the affected gene(s) and to demonstrate that the region was confined between RYR1 and SW782 (5.7 cM on the National Institute of Animal Industry (NIAI) map and 100 cR on the INRA/University of Minnesota porcine radiation hybrid panel map). In order to determine when the affected gene(s) are activated and in turn terminate fetal development, embryos produced in the second population were collected at several development stages and genotyped for markers in the region. Genes in the homozygous state affected embryo development between 9 and 11 days post-coitus.

Orbital emphysema following nose blowing as a sequel of a snowboard related head injury.

A case of orbital emphysema as a sequel of a snowboard related head injury is reported. It is believed that a fracture of the medial orbital wall was caused by the increased intraorbital pressure when the patient hit his forehead on the snowy ground, allowing air to enter the orbit when he blew his nose. Wearing goggles may prevent this type of sports related injury.

Transrectal colour Doppler ultrasonography for quantifying angiogenesis in prostate cancer.

OBJECTIVE: To assess the correlation between angiogenesis and Doppler signal intensity using transrectal colour Doppler ultrasonography (CDUS) in patients with prostate cancer. PATIENTS AND METHODS: The study comprised 56 patients who underwent radical prostatectomy and had untreated tumours with a volume of> 0.1 mL in the peripheral zone. CDUS images were recorded on videotape before surgery. The Doppler signal intensity in tumours was evaluated using the colour pixel intensity (PI). Microvessel density (MVD) and vascular endothelial growth factor (VEGF) immunoreactivity were determined in the prostatectomy specimens. Microvessels were identified by immunohistochemical staining of endothelial cells for CD31. RESULTS: The PI in the tumour correlated with MVD (P < 0.001) and increased with higher levels of VEGF immunoreactivity (P = 0.004). There was no correlation between Gleason score and MVD or PI in the tumour. CONCLUSION: Blood flow assessed by CDUS may reflect the state of angiogenesis in prostate cancer. CDUS may be a useful technique for predicting tumour progression or prognosis, and may be useful for monitoring the effects of anti-angiogenic agents in the future.

Secretory pattern of inhibin A, inhibin B and inhibin pro-alpha C during induced follicular atresia and subsequent follicular development in the golden hamster (Mesocricetus auratus).

The changes in plasma concentrations of inhibins A, B and pro-alpha C were determined in the cyclic golden hamster during follicular atresia induced with antiserum against luteinizing hormone releasing hormone (LHRH-AS) at 1100 h on day 4 (day 1=day of ovulation). Follicular status in the ovary was also studied by determining the number of follicles ovulating in response to human chorionic gonadotrophin (hCG) injection. The time-courses of changes in plasma concentrations of inhibins A, B and pro-alpha C were different from each other during induced follicular atresia and subsequent follicular development. Plasma concentrations of inhibin A decreased to 58.6% of initial values by 24 h after LHRH-AS treatment, and then remained relatively low until at least 60 h later. Plasma concentrations of inhibin B decreased to 64.2% of the initial values by 18 h after LHRH-AS treatment and remained at basal values for 36 h, but increased abruptly to greater than initial values at 42 h after the treatment. Plasma concentrations of inhibin pro-alpha C increased at 6 and 12 h, decreased suddenly to 21.9% of the initial values by 24 h after LHRH-AS treatment, and then gradually increased until 60 h after LHRH-AS. The number of follicles responding to hCG decreased gradually between 0 and 30 h after LHRH-AS, when no ovulations were observed, and then gradually increased until 60 h. The changes in follicular ovulatory responses to hCG correlated with the plasma profile of inhibin A throughout the experiment. These results suggest that inhibin A is mainly secreted by large antral follicles. In contrast, during the subsequent follicular development, the plasma concentration of inhibin B increased earlier than that of inhibin A. These results suggest that inhibin B is secreted by small and large antral follicles. Plasma concentrations of inhibin pro-alpha C were high at a time when plasma concentrations of oestradiol-17 beta had already decreased, indicating that inhibin pro-alpha C is secreted not only from healthy follicles but also from early atretic antral follicles.

Potential role of activin A in follicular development during the second half of pregnancy in the golden hamster: utero-placental source of activin A.

Numerous antral follicles develop during the second half of pregnancy in the golden hamster. However, mechanisms regulating follicular development during this period are unknown. Because inhibin and activin are related to follicular development, these hormones were studied to gain insight into any potential roles in follicular development. Plasma inhibin A and B suddenly increased from day 8 of pregnancy, reached peak levels on day 10 and gradually declined to term. Plasma activin A gradually increased from day 8 to day 15 of pregnancy, and this was followed by an abrupt decrease at day one of lactation. Ovariectomy on day 12 of pregnancy rapidly reduced plasma inhibin A and B, but not activin A levels. Hysterectomy or placentectomy on day 12 of pregnancy caused an abrupt decrease in the levels of plasma activin A and FSH, but not inhibin A and B at 6 h after surgery. Hysterectomy also induced atresia of large antral follicles at 24 h after surgery. These results indicate that antral follicles are the main source of circulating inhibin A and B, whereas uteri and placentae are the main source of circulating activin A. These results suggest that increased levels of activin A may be involved in folliculogenesis in the ovary during the second half of pregnancy in the golden hamster.

Expression of C-C chemokine TARC in human nasal mucosa and its regulation by cytokines.

BACKGROUND: Although interleukin (IL)-4 and IL-5 have been demonstrated to play a critical role in the pathophysiology of allergic diseases such as allergic rhinitis, the mechanism that causes the predominance of Th2 lymphocytes has yet to be clarified. Thymus and activation-regulated chemokine (TARC) has been known to facilitate the recruitment, activation and development of Th2 polarized cells, leading investigators to suggest a role for TARC in the development of Th2 responses. OBJECTIVE: To gain a better understanding of the role of TARC in the pathogenesis of allergic rhinitis we investigated the cellular sources of this chemokine in nasal mucosa. In addition, the effect of cytokines on TARC production has been investigated. METHODS: The expression of TARC in human nasal mucosa was assessed by immunohistochemistry. To study the effect of cytokines on TARC production, epithelial cells, endothelial cells and fibroblasts, isolated from inferior nasal mucosa samples, were stimulated by a variety of cytokines including IL-4, IL-13, tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma. RESULTS: Epithelial cells in nasal mucosa in subjects with allergic rhinitis expressed higher signal level than those in non-allergy patients. Combined stimulation with IL-4 and TNF-alpha, as well as IL-13 and TNF-alpha, synergistically induced TARC expression in epithelial cells. Furthermore, the amount of TARC induced by these cytokines was higher in epithelial cells obtained from patients with allergic rhinitis than in those from non-allergic patients. CONCLUSION: These results demonstrate a crucial role of nasal epithelial cells in the expression of TARC, and that Th2 cytokine IL-4 and IL-13 may promote Th2 responses by inducing TARC production from epithelial cells.

Differential involvement of p38 MAP kinase pathway and Bax translocation in the mitochondria-mediated cell death in TCR- and dexamethasone-stimulated thymocytes.

Mitochondria play a central role in many apoptotic reactions. Although mitochondrial apoptotic changes and caspase activation have been demonstrated in the apoptotic thymocytes, cell death signal through mitochondria in TCR-stimulated thymocytes has not been fully understood. In this study, we show that TCR stimulation induced disruption of mitochondrial transmembrane potential (Delta Psi(m)), the cytochrome c release from mitochondira, capase-3 activation, and the cell death of thymocytes. Bongkrekic acid, an inhibitor of Delta Psi(m) disruption, blocked the cytochrome c release from mitochondria and the following caspase-3-mediated cell death. Furthermore, a pro-apoptotic Bcl-2 family protein, Bax, but not Bad or Bid, was translocated from cytosol to mitochondria in TCR-stimulated thymocytes. This translocation and the following apoptotic changes were inhibited by SB203580, a p38 kinase inhibitor, in a specific manner. These results suggest that activated p38 kinase pathway by TCR stimulation induces translocation of Bax to mitochondria, causing Delta Psi(m) disruption, and the release of cytochrome c, which finally induces caspase-3-mediated apoptosis in thymocytes.

Osmotic shock induces G1 arrest through p53 phosphorylation at Ser33 by activated p38MAPK without phosphorylation at Ser15 and Ser20.

Osmotic shock induced transient stabilization of p53, possibly due to increased degradation of Mdm2. Stabilized p53 was activated by p38(MAPK), resulting in G(1) arrest through induction of p21(WAF1). Among the postulated phosphorylation sites involved in p53 stabilization or activation (Ser(15), Ser(20), Ser(33), and Ser(46)), only Ser(33) was phosphorylated. Furthermore, interaction of p53 with the transcriptional coactivator p300 was induced, and Lys(382) of p53 was acetylated. Although inhibition of p38(MAPK) did not prevent nuclear accumulation of p53, phosphorylation of Ser(33) was markedly suppressed by SB203580, a specific inhibitor of p38(MAPK). Under these conditions, acetylation of Lys(382) and induction of p21(WAF1) were also inhibited, and cells with elevated levels of p53 showed normal cell cycle progression. Activated p38(MAPK) phosphorylated endogenous p53 at Ser(33) in living cells. In stable transformants expressing dominant negative MKK6, an upstream protein kinase of p38(MAPK), p53 stabilization was induced normally following osmotic shock, but phosphorylation of Ser(33), acetylation of Lys(382), and induction of p21(WAF1) were almost completely inhibited. These results suggest that phosphorylation at Ser(33) by p38(MAPK) is critical for activation of p53 following osmotic shock. Phosphorylation of neither Ser(15) nor Ser(20) was needed in this activation.