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Background: To evaluate the effect of the type and codetection of respiratory viruses on admission requirements among children with respiratory infections in the post-COVID-19 pandemic era. Methods: In this retrospective study, we analyzed patients with acute respiratory symptoms using FilmArray® Respiratory Panel between December 2020 and March 2024. The viruses were classified into eight groups: adenovirus, seasonal coronavirus, human metapneumovirus, human rhinovirus/enterovirus, influenza virus, parainfluenza virus, respiratory syncytial virus, and severe acute respiratory virus coronavirus-2. The impact of the detected viral groups and viral codetection on hospitalization rates were examined using multivariable regression analysis in three pediatric age groups (

PurposeTo delineate the characteristics of probable antibody-negative pediatric autoimmune encephalitis (probable Ab-negative AE), we compared the clinical features of probable Ab-negative AE to those of major antibody-positive AE.MethodsWe retrospectively reviewed the clinical features of 18 patients with probable Ab-negative AE, 13 with anti-N-methyl-D-aspartate receptor encephalitis (NMDARE), and 13 with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Clinical characteristics, neuroimaging findings, treatments, and outcomes were analyzed.ResultsThe age of onset and length of hospital stay were significantly higher in the NMDARE group than in the other groups (p = 0.02 and p

Abstract Objective The use of folic acid (FA) has been discouraged in cerebral folate deficiency (CFD) because, theoretically, it could inhibit the transport of 5‐methyltetrahydrofolic acid (5MTHF) across the blood–cerebrospinal fluid (CSF) barrier. We present the clinical biochemical data of two cases with CFD to support this hypothesis. Methods We measured CSF and serum 5MTHF concentrations in a patient with Kearns‐Sayre syndrome (KSS) and a patient homozygous for MTHFR C677T polymorphism before and during folate supplementation therapy. To evaluate these 5MTHF concentrations, we also analyzed CSF and serum samples in pediatric patients without folate supplementation. Results Both patients had low CSF 5MTHF before treatment and high‐dose FA therapy did not normalize CSF 5MTHF. There was a dissociation between serum total folate and 5MTHF concentrations during FA therapy, which was considered to be due to the appearance of unmetabolized FA. The addition of folinic acid did not improve low CSF 5MTHF in the KSS patient and the cessation of FA resulted in the normalization of CSF 5MTHF. In the patient homozygous for MTHFR C677T, minimization of the FA dosage resulted in the normalization of CSF 5MTHF and an increased CSF‐to‐serum 5MTHF ratio. Conclusions Our data suggest that excess supplementation of FA impaired 5MTHF transport across the blood–CSF barrier. In the treatment of CFD, supplementation of folinic acid or 5MTHF (in cases of impaired 5MTHF synthesis) is preferred over the use of FA. The reference values of CSF 5MTHF concentration based on 600 pediatric cases were also provided.

Abstract These days, networked control systems (NCSs) in which data is transmitted via communication have been actively studied for many potential applications. In an NCS, data dropout degrades control performance depending on network conditions. For an NCS with data dropout, the authors propose a model‐predictive‐control‐based input optimisation, representing data dropout as both a Bernoulli model and a finite‐order Markov chain. Using the proposed NCS data dropout model, the authors derive an optimal input that provides the estimated error between the expected state of the plant and a given reference. The proposed control problem is formulated as its equivalent quadratic programming, as executed at each online sampling. The authors also demonstrate simulations and experiments to show the effectiveness of the proposed method.

Parechovirus type 3 (PeV-3) presents with sepsis-like syndrome in neonates and young infants. PeV-3 has neurotropism and occasionally causes encephalitis. We evaluated the cytokine/chemokine profile in the cerebrospinal fluid of a young infant with PeV-3 encephalitis. The patient was a 1-month-old boy who developed fever, loss of consciousness, and seizures. On admission (2nd day of illness), no abnormalities were found on MRI. Thereafter, head MRI on the 4th day revealed abnormal intensities in the white matter around the bilateral lateral ventricles, corpus callosum, and bilateral hippocampus and amygdala. Although intravenous thiopental failed to stop the seizures, ketamine and phenobarbital were effective. Bilateral hippocampal lesions were unusual in HPeV-3 encephalitis and considered to be caused by super-refractory status epilepticus, indicating the strength of the disease. PeV-3 was detected in the blood, cerebrospinal fluid, nasal discharge, and fecal samples upon admission. The cytokine and chemokine levels in the cerebrospinal fluid were significantly elevated. Characteristically, neopterin levels in the cerebrospinal fluid increased as the white matter lesions appeared. These results suggested that cytokine/chemokine overproduction may be deeply involved in the pathology of the PeV-3 encephalitis. Although super-refractory status epilepticus and cytokine/chemokine overproduction indicated the strength of the disease, our patient was discharged without neurological sequelae and the combination of immunotherapy as well as seizure control may have contributed to the good outcome.

This study aimed to evaluate the impact of the prolonged COVID-19 pandemic on outpatient antibiotic prescriptions for pediatric respiratory infections at an acute care hospital in Japan in order to direct future pediatric outpatient antibiotic stewardship. The impact of the COVID-19 pandemic and the FilmArray Respiratory Panel (RP) on outpatient antibiotic prescriptions was assessed from January 2019 to December 2021 using an interrupted time series analysis of children

Background: The number of reports on GRIN1 variants associated with neurodevelopmental phenotypes has increased in recent years. However, there are only two detailed reports on electroencephalography findings. Case study: We had a case with severe global developmental delay, and exome sequencing revealed a novel de novo heterozygous variant of GRIN1. The patient's electroencephalography showed unique findings: paroxysmal fast activity—20–30 Hz beta waves, independently in the bilateral occipital regions, sometimes in a continuous manner—and prolonged alpha activity in the bilateral frontal regions, observed mainly during sleep, those findings were observed persistently. Discussion: The electroencephalography findings of our case have not been reported in the past. Receptor hypofunction due to the GRIN1 variant and imbalance in excitatory/inhibitory transmission owing to the dysfunction of the N-methyl-D-aspartate receptors may be the mechanism for the global developmental delay, stereotyped movements, and development of paroxysmal fast activity in our case. Accumulation of additional case reports is needed to confirm the reproducibility of the electroencephalography findings for disease specificity.

Abstract Background Heat shock protein 22 (HSP22) belongs to class I of the small HSP family that displays ubiquitous expression in osteoblasts. We previously demonstrated that prostaglandin F2α (PGF2α), a potent bone remodeling factor, induces the synthesis of interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) via p44/p42 mitogen-activated protein (MAP) kinase and p38 MAP kinase in osteoblast-like MC3T3-E1 cells. In the present study, we investigated whether HSP22 is implicated in the PGF2α-induced synthesis of IL-6 and VEGF and the mechanism of MC3T3-E1 cells. Methods MC3T3-E1 cells were transfected with HSP22-siRNA. IL-6 and VEGF release was assessed by ELISA. Phosphorylation of p44/p42 MAP kinase and p38 MAP kinase was detected by Western blotting. Results The PGF2α-induced release of IL-6 in HSP22 knockdown cells was significantly suppressed compared with that in the control cells. HSP22 knockdown also reduced the VEGF release by PGF2α. Phosphorylation of p44/p42 MAP kinase and p38 MAP kinase was attenuated by HSP22 downregulation. Conclusions Our results strongly suggest that HSP22 acts as a positive regulator in the PGF2α-induced synthesis of IL-6 and VEGF in osteoblasts.

In cell therapy, transplanting an appropriate number of cells to the target site is crucial. One way to achieve this is to transplant cell sheets. Transplantation of cell sheets has already been utilized for various diseases in clinical practice. However, reducing the cost of cell sheet utilization is essential so as to facilitate the spread of regenerative medicine. Several ways to reduce costs are available, one of which is the use of allogenic cells. Another alternative is the use of cell sheets, which necessitates the development of methods for freezing cell sheets. This is the first study to report the use of a 3D Freezer for freezing cells. 3D Freezers have been used in the field of food processing and technology for a long time. The 3D Freezer freezes objects using cold air at a uniform temperature from all directions. In this study, we analyzed the cooling speed of human fibroblast sheets in 11 cell preservation solutions using a 3D Freezer and a Program Freezer. The cooling speed was −2 °C per min in the 3D Freezer. Supercooling in 10 cell preservation solutions was lower in the 3D Freezer than in the Program Freezer. Cell viability after freeze–thaw of the cell sheets using 3D Freezer was more than 70% in five cell preservation solutions. The levels of hepatocyte growth factor and transforming growth factor-β1 were the same not only in the fibroblast sheets frozen using the five cell preservation solutions but also in the non-frozen fibroblast sheets. These results suggest that the 3D Freezer can freeze implantable cell sheets immediately after thawing.

We present a case of drug-resistant focal motor seizures in which separate cortico-cortical epileptic networks within the supplementary motor area (SMA) proper and primary motor area (PMA) were proven by ictal high-frequency oscillation (HFO) and cortico-cortical evoked potential (CCEP). A 12-year-old girl presented with two types seizures: type A, tonic extension and subsequent clonic movements of the right arm; and type B, tonic and clonic movements of the right leg. MRI was normal and karyotype genetic analysis revealed 46,X,t(X;14)(q13;p12). She underwent placement of chronic subdural electrodes over the left hemisphere. We recorded a total of nine seizures during 10 days of epilepsy monitoring. Type A seizures started from the lower part of the left SMA proper and early spread to the hand motor area of the PMA. Type B seizures started from the upper part of the SMA proper and early spread to the leg motor area of the PMA. CCEPs of both SMA proper and PMA activated two identical routes for evoked potentials correlating with separate pathways. Corticectomy of the left SMA proper and PMA achieved seizure-free without hemiparesis. Within a small homunculus of the SMA proper, separate epileptic networks were proven and validated by seizure semiology, ictal HFO, and CCEP.

Heat shock protein 90 (HSP90) that is ubiquitously expressed in various tissues, is recognized to be a major molecular chaperone. We have previously reported that prostaglandin F2α (PGF2α), a potent bone remodeling mediator, stimulates the synthesis of interleukin-6 (IL-6) through p44/p42 mitogen-activated protein (MAP) kinase and p38 MAP kinase in osteoblast-like MC3T3-E1 cells, and that Rho-kinase acts at a point upstream of p38 MAP kinase. In the present study, we investigated the involvement of HSP90 in the PGF2α-stimulated IL-6 synthesis and the underlying mechanism in MC3T3-E1 cells. Geldanamycin, an inhibitor of HSP90, significantly amplified both the PGF2α-stimulated IL-6 release and the mRNA expression levels. In addition, other HSP90 inhibitors, 17-allylamino-17demethoxy-geldanamycin (17-AAG) and 17-dimethylamino-ethylamino-17-demethoxy-geldanamycin (17-DMAG) and onalespib, enhanced the PGF2α-stimulated IL-6 release. Geldanamycin, 17-AAG and onalespib markedly strengthened the PGF2α-induced phosphorylation of p38 MAP kinase. Geldanamycin and 17-AAG did not affect the PGF2α-induced phosphorylation of p44/p42 MAP kinase and myosin phosphatase targeting subunit (MYPT-1), a substrate of Rho-kinase, and the protein levels of RhoA and Rho-kinase. In addition, HSP90-siRNA enhanced the PGF2α-induced phosphorylation of p38 MAP kinase. Furthermore, SB203580, an inhibitor of p38 MAP kinase, significantly suppressed the amplification by geldanamycin, 17-AAG or 17-DMAG of the PGF2α-stimulated IL-6 release. Our results strongly suggest that HSP90 negatively regulates the PGF2α-stimulated IL-6 synthesis in osteoblasts, and that the effect of HSP90 is exerted through regulating p38 MAP kinase activation.

It is firmly established that resveratrol, a natural food compound abundantly found in grape skins and red wine, has beneficial properties for human health. In the present study, we investigated the effect of basic fibroblast growth factor (FGF-2) on osteoprotegerin (OPG) synthesis in osteoblast-like MC3T3-E1 cells and whether resveratrol affects the OPG synthesis. FGF-2 stimulated both the OPG release and the expression of OPG mRNA. Resveratrol significantly suppressed the FGF-2-stimulated OPG release and the mRNA levels of OPG. SRT1720, an activator of SIRT1, reduced the FGF-2-induced OPG release and the OPG mRNA expression. PD98059, an inhibitor of upstream kinase activating p44/p42 mitogen-activated protein (MAP) kinase, had little effect on the FGF-2-stimulated OPG release. On the other hand, SB203580, an inhibitor of p38 MAP kinase, SP600125, an inhibitor of stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), and Akt inhibitor suppressed the OPG release induced by FGF-2. Resveratrol failed to affect the FGF-2-induced phosphorylation of p44/p42 MAP kinase, p38 MAP kinase or SAPK/JNK. The phosphorylation of Akt induced by FGF-2 was significantly suppressed by resveratrol or SRT1720. These findings strongly suggest that resveratrol down-regulates FGF-2-stimulated OPG synthesis through the suppression of the Akt pathway in osteoblasts and that the inhibitory effect of resveratrol is mediated at least in part by SIRT1 activation.

Surgical approaches for traumatic diaphragmatic hernia include transabdominal, transthoracic, and thoracoabdominal. Selection of the optimal approach depends on the timing and organ damage, often minimally invasive approaches with laparoscopy or thoracoscopy are performed. A 47-year-old man with blunt chest trauma was diagnosed with left traumatic diaphragmatic hernia 1 month after the trauma. The prolapsed omentum was detached from the chest wall and around the hernia orifice and returned to the abdominal cavity by coordinated thoracoscopic and laparoscopic manipulations. The 4 x 2 cm herniation in the diaphragm was sutured closed from the thoracic side while preventing re-prolapse of the omentum and abdominal organs from the abdominal side. A combined thoracoscopic and laparoscopic approach can be effective in confirming organ damage, repositioning of prolapsed organs, and safe repair of the diaphragm in latent traumatic diaphragmatic hernia. [ABSTRACT FROM AUTHOR]

Forged composites of raw particulate unsintered hydroxyapatite/poly-L-lactide (F-u-HA/PLLA) devices possess high mechanical strength, bioactivity, and radio-opacity. The aim of this study was to assess the efficacy of F-u-HA/PLLA screws in the treatment of lateral tibial condylar fractures. From January 2005 to December 2010, a total of 7 patients with displaced closed lateral tibial condylar fractures (Schatzker type II) were treated using F-u-HA/PLLA screws. Open reduction and internal fixation was performed using 2 or 3 F-u-HA/PLLA screws. After surgery, weight bearing was not allowed for 6 weeks. Range of motion exercise was initiated after removal of the plaster splint. Radiographs were evaluated for fracture healing, joint depression, and the radioopacity of F-u-HA/PLLA screws. Clinical outcomes and postoperative complications were also assessed. Average follow-up was 44 months. All fractures were successfully healed. Average values for joint depression were 4.7 mm (range, 2-9 mm) preoperatively, 0.4 mm (range, 0-1 mm) postoperatively, and 0.4 mm (range, 0-1 mm) at final follow-up. Whole shadows of F-u-HA/PLLA screws were observed during the follow-up period. Breakage of screws, osteolysis, and a radiolucent zone around the screws were not observed at final follow-up. Average knee flexion and extension were 134° (range, 110° to 150°) and -1° (range, -10° to 0°), respectively. No patient had wound infection, late aseptic tissue response, or foreign body reaction postoperatively. None of the patients reported pain at final follow-up. These results suggest that F-u-HA/PLLA screws could be an alternative option for the treatment of lateral tibial condylar fractures. [Orthopedics. 2018; 41(3):e365-e368.]. [ABSTRACT FROM AUTHOR]

Heat shock protein 90 (HSP90) is an ATP-dependent ubiquitous molecular chaperon which is important in cell homeostasis. The authors previously demonstrated that bone morphogenetic protein (BMP)-4 stimulates osteoprotegerin (OPG) production in osteoblast-like MC3T3-E1 cells, and that p70 S6 kinase positively regulates the OPG synthesis by BMP-4. The present study investigated the involvement of HSP90 in the BMP-4-stimulated OPG synthesis and the mechanism in MC3T3-E1 cells. HSP90 inhibitors, 17-allylamino-17demethoxy-geldanamycin (17-A AG), 17-dimethylamino-ethylamino-17-demethoxy-geldanamycin (17-DMAG) and geldanamycin significantly suppressed the BMP-4-stimulated OPG release. Geldanamycin markedly reduced the BMP-4-induced mRNA expression of OPG. 17-AAG and 17-DMAG significantly attenuated the phosphorylation of p70 S6 kinase induced by BMP-4 without affecting the BMP-4-induced phosphorylation of mothers against decapentaplegic homolog 1/5. The results suggest that HSP90 inhibitors suppress the BMP-4-stimulated OPG synthesis in osteoblasts, and that their suppressive effects are exerted through downregulating p70 S6 kinase. [ABSTRACT FROM AUTHOR]

Resveratrol, a polyphenolic compound that is present in grape skins, berries and red wine, may be beneficial for human health through its anti‑inflammatory and anti‑oxidant effects. It has been previously demonstrated that resveratrol exerts its biological effects primarily via sirtuin 1 (SIRT1) activation. We previously reported that triiodothyronine (T3) induces osteocalcin synthesis in osteoblast‑like MC3T3‑E1 cells, and that p38 mitogen‑activated protein (MAP) kinase mediates the T3‑stimulated synthesis of osteocalcin. The present study investigated the effect of resveratrol on T3‑induced osteocalcin synthesis and its underlying mechanism in MC3T3‑E1 cells. Cultured cells were stimulated with T3, and osteocalcin release from MC3T3‑E1 cells was measured by ELISA and phosphorylation of p38 MAP kinase was analyzed by western blotting. Resveratrol significantly suppressed the release of osteocalcin stimulated by T3, and SRT1720, a SIRT1 activator, significantly reduced T3‑induced osteocalcin release. The expression level of osteocalcin mRNA stimulated by T3 was significantly attenuated by resveratrol and T3‑induced transactivation activity of the thyroid hormone‑responsive element was significantly diminished by resveratrol. However, only limited effects of resveratrol on the T3‑induced phosphorylation of p38 MAP kinase were observed. The results of the present study demonstrated that resveratrol suppresses T3‑stimulated osteocalcin synthesis at a point upstream of transcription in osteoblasts, and that the inhibitory effect of resveratrol is mediated, at least partially, through SIRT1 activation. These results indicate that there may be a novel role for the polyphenol in the modulation of bone metabolism. [ABSTRACT FROM AUTHOR]

Chlorogenic acid (CGA) is a primary phenolic component of coffee and (-)-epigallocatechin gallate (EGCG) is a primary flavonoid component of green tea, both of which have been documented to possess beneficial health properties. A previous study by the present authors demonstrated that p38 mitogen-activated protein kinase (MAPK) may be associated with osteoprotegerin synthesis stimulated by bone morphogenetic protein-4 (BMP-4) in osteoblast-like MC3T3-E1 cells. In the present study, the effects of CGA and EGCG on BMP-4-stimulated osteoprotegerin synthesis in MC3T3-E1 cells were investigated. It was observed that CGA had no effect on osteoprotegerin release stimulated by BMP-4, whereas EGCG significantly enhanced BMP-4-stimulated osteoprotegerin release (P=0.003). Levels of osteoprotegerin mRNA expression induced by BMP-4 were also significantly increased by EGCG (P=0.03). By contrast, EGCG had no significant effect on phosphorylation of Smad1 or p38 MAPK induced by BMP-4. In addition, EGCG had little effect on BMP-induced phosphorylation of p70 S6 kinase; however rapamycin, as an inhibitor of p70 S6 kinase, significantly suppressed osteoprotegerin release (P=0.007). These data suggest that EGCG but not CGA may upregulate the synthesis of osteoprotegerin induced by BMP-4 in osteoblasts. [ABSTRACT FROM AUTHOR]

Mimosine, which is a natural plant amino acid present in the Leucaena genus, is able to induce hypoxia-inducible factors (HIFs). Previous evidence has indicated that HIF regulates angiogenesis-osteogenesis coupling in bone metabolism, and it has previously been reported that mimosine inhibits prostaglandin (PG)F2α-induced osteoprotegerin (OPG) synthesis without affecting interleukin-6 (IL-6) production in osteoblast-like MC3T3-E1 cells. In addition, PGE1 has been demonstrated to induce OPG synthesis via activation of p38 mitogen-activated protein (MAP) kinase and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) in these cells, and PGE1 stimulates IL-6 production via the activation of protein kinase A. In the present study, the effects of mimosine on the PGE1-stimulated synthesis of OPG and IL-6 were investigated in osteoblast-like MC3T3-E1 cells. The concentrations of OPG and IL-6 were measured using relevant ELISA kits. OPG mRNA was measured by semi-quantitative reverse transcription polymerase chain reaction. The phosphorylation of p38 MAP kinase and SAPK/JNK was analyzed by western blotting. Mimosine significantly reduced PGE1-induced release of OPG and OPG mRNA expression levels without affecting the release of IL-6. In addition, deferoxamine, which is also a normoxic HIF inducer, significantly inhibited PGE1-induced OPG release and OPG mRNA expression levels; however, it had little effect on IL-6 release. Furthermore, mimosine and deferoxamine failed to affect PGE1-stimulated phosphorylation of p38 MAP kinase or SAPK/JNK. These results strongly suggest that normoxic HIF inducers attenuate PGE1-stimulated OPG synthesis without affecting IL-6 production in osteoblasts. [ABSTRACT FROM AUTHOR]

We have previously reported that collagen-induced phosphorylation of heat shock protein (HSP) 27 via p44/p42 mitogen-activated protein (MAP) kinase in human platelets is sufficient to induce the secretion of platelet-derived growth factor (PDGF)-AB and the release of soluble cluster of differentiation 40 ligand (sCD40L). Adenosine monophosphate-activated protein kinase (AMPK), which is known to regulate energy homeostasis, has a crucial role as an energy sensor in various eukaryotic cells. The present study investigated the effects of 5-aminoimidazole-4-carbox amide-1-β-d-ribofuranosyl 5'-monophosphate (AICAR), which is an activator of AMPK, on the collagen-induced activation of human platelets. It was demonstrated that AICAR dose-dependently reduced collagen-stimulated platelet aggregation up to 1.0 µM. Analysis of the size of platelet aggregates demonstrated that AICAR decreased the ratio of large aggregates (50-70 µm), whereas the ratio of small aggregates (9-25 µm) was increased by AICAR administration. AICAR markedly attenuated the phosphorylation levels of p44/p42 MAP kinase and HSP27, which are induced by collagen. Furthermore, AICAR significantly decreased the secretion of PDGF-AB and the collagen-induced release of sCD40L. These results indicated that AICAR-activated AMPK may reduce the secretion of PDGF-AB and the collagen-induced release of sCD40L by inhibiting HSP27 phosphorylation via p44/p42 MAP kinase in human platelets. [ABSTRACT FROM AUTHOR]

AMP-activated protein kinase (AMPK) is firmly established as a central regulator of cellular energy homeostasis. We have previously reported that prostaglandin E1 (PGE1) timulates the synthesis of osteoprotegerin through p38 mitogen-activated protein (MAP) kinase and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) in osteoblast-like MC3T3-E1 cells. The present study investigated the involvement of AMPK in PGE1-induced osteoprotegerin synthesis in MC3T3-E1 cells. The levels of osteoprotegerin were measured using an enzyme-linked immunosorbent assay, while the phosphorylation of AMPK, acetyl-CoA carboxylase, p38 MAP kinase and SAPK/JNK were analyzed by western blotting. In addition, the mRNA expression levels of osteoprotegerin were determined by a reverse transcription-quantitative polymerase chain reaction. It was revealed that PGE1 significantly induced the phosphorylation of the α and β subunits of AMPK in a time-dependent manner (P<0.05). In addition, acetyl-CoA carboxylase, a direct substrate of AMPK, was significantly phosphorylated by PGE1 (P<0.05). Compound C, an AMPK inhibitor, was revealed to suppress the phosphorylation of acetyl-CoA carboxylase, which significantly reduced the release and mRNA expression levels of PGE1-stimulated osteoprotegerin (P<0.05). However, the PGE1-induced phosphorylation of p38 MAP kinase and SAPK/JNK were not affected by compound C. The results of the present study indicated that AMPK may positively regulate PGE1-stimulated osteoprotegerin synthesis in osteoblasts; thus providing novel insight into the regulatory mechanisms underlying bone metabolism. [ABSTRACT FROM AUTHOR]

Adenosine monophosphate-activated protein kinase (AMPK) is currently recognized to act as a key sensing enzyme in the regulation of cellular energy homeostasis. It has been previously demonstrated that prostaglandin E2 (PGE2) stimulates the synthesis of osteoprotegerin (OPG) through the activation of p38 mitogen-activated protein (MAP) kinase, p44/p42 MAP kinase and stress-activated protein kinase/ c-Jun N-terminal kinase (SAPK/JNK) in osteoblast-like MC3T3-E1 cells. In the present study, it was investigated whether AMPK is implicated in the PGE2-induced OPG synthesis in MC3T3-E1 cells. PGE2 was observed to induce the phosphorylation of AMPKα (Thr-172) and AMPKβ (Ser-108) in a time-dependent manner. PGE2 additionally induced the phosphorylation of acetyl-coenzyme A (CoA) carboxylase, a direct substrate of AMPK. Compound C, an inhibitor of AMPK, which attenuated the phosphorylation of acetyl-CoA carboxylase, significantly suppressed the PGE2-stimulated OPG release and the mRNA expression level. Compound C failed to affect the PGE2-stimulated phosphorylation of p38 MAP kinase or p44/p42 MAP kinase. On the contrary, the phosphorylation of SAPK/JNK was markedly attenuated by compound C. The results of the current study suggest that AMPK acts as a positive regulator in PGE2-stimulated OPG synthesis via SAPK/JNK signaling in osteoblasts. [ABSTRACT FROM AUTHOR]

Resveratrol is a naturally occurring polyphenol that possesses health-related properties, and is predominantly found in grapes and berries. Bone morphogenetic protein-4 (BMP-4) stimulates osteocalcin synthesis via p38 mitogen-activated protein (MAP) kinase in osteoblast-like MC3T3-E1 cells. The present study aimed to investigate the effects of resveratrol on BMP-4-induced osteoprotegerin (OPG) synthesis in MC3T3-E1 cells. Resveratrol alone had no effect on OPG expression levels, but significantly enhanced BMP-4-induced OPG release. In addition, resveratrol markedly amplified the mRNA expression levels of BMP-4-induced OPG. SB203580 is an inhibitor of p38 MAP kinase, which was shown to suppress BMP-4-stimulated OPG release. BMP-4-induced phosphorylation of p38 MAP kinase was also enhanced by resveratrol. Furthermore, SB203580 significantly reduced the resveratrol-induced amplification of BMP-4-stimulated OPG release. These results suggested that resveratrol was able to upregulate BMP-4-stimulated OPG synthesis via the amplification of p38 MAP kinase activity in osteoblasts. [ABSTRACT FROM AUTHOR]

Our group has previously shown that αB-crystallin (HSPB5), a small heat shock protein, inhibits human platelet aggregation by ristocetin, an activator of glycoprotein Ib/IX/V. In addition, it was demonstrated that glycoprotein Ib/IX/V activation induces soluble CD40 (sCD40) ligand release via thromboxane (TX) A2. In the present study, the effect of αB-crystallin on the ristocetin-induced sCD40 ligand release in human platelets was investigated. The ristocetin-induced release of sCD40 ligand was suppressed by αB-crystallin. In addition, αB-crystallin reduced the ristocetin-stimulated production of 11-dehydro-TX B2, a stable metabolite of TXA2. αB-crystallin did not suppress the platelet aggregation induced by U46619, a TXA2 receptor agonist. αB-crystallin had little effect on the U46619-induced phosphorylation of p38 mitogen-activated protein kinase or sCD40 ligand release. In addition, αB-crystallin failed to reduce the binding of SZ2, a monoclonal antibody against the sulfated sequence in the α-chain of glycoprotein Ib, to the ristocetin-stimulated platelets. These results strongly suggest that αB-crystallin extracellularly suppresses ristocetin-stimulated release of sCD40 ligand by inhibiting the TXA2 production in human platelets. [ABSTRACT FROM AUTHOR]

Resveratrol, which is found in grape and berry skins and red wine, is generally known to be beneficial for human health due to its anti-inflammation and antioxidant effects. We have recently reported that transforming growth factor-β (TGF-β) stimulates vascular endothelial growth factor (VEGF) synthesis through Smad-independent pathways, such as the p38 mitogen-activated protein (MAP) kinase, p44/p42 MAP kinase and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) pathways, in osteoblast-like MC3T3-E1 cells. The aim of the present study was to investigate the effect of resveratrol on the TGF-β-induced VEGF synthesis and the mechanism in osteoblast-like MC3T3-E1 cells. Resveratrol significantly suppressed the TGF-β-stimulated release of VEGF and the VEGF mRNA expression levels. SRT1720, a synthetic sirtuin 1 (SIRT1) activator, also reduced the VEGF release and the mRNA levels. With regard to the intracellular signaling in the TGF-β-stimulated VEGF synthesis, resveratrol and SRT1720 significantly attenuated the phosphorylation of p44/p42 MAP kinase and SAPK/JNK stimulated by TGF-β; however, the TGF-β-induced phosphorylation of Smad2 and p38 MAP kinase was hardly affected by resveratrol or SRT1720. These results strongly suggest that the TGF-β-stimulated VEGF synthesis is suppressed by resveratrol through the inhibition of p44/p42 MAP kinase and SAPK/JNK in osteoblasts, and that the suppressive effect is mediated, at least in part, via SIRT1 activation. [ABSTRACT FROM AUTHOR]

We have previously shown that glycoprotein Ib/IX/V activation stimulates the release of the soluble CD40 ligand (sCD40L) via the generation of thromboxane A2 from human platelets. In the present study, the role of Rac, which is a member of the Rho family, was investigated in the thromboxane A2-stimulated release of platelet-derived growth factor (PDGF)-AB and sCD40L in human platelets. U46619, a thromboxane receptor agonist, stimulated the activation of Rac time-dependently in human platelets, and NSC23766, a selective inhibitor of the Rac-guanine nucleotide exchange factor interaction, reduced the U46619-induced platelet aggregation. NSC23766 markedly suppressed the U46619-induced p38 mitogen-activated protein (MAP) kinase phosphorylation. The thromboxane A2-induced release of PDGF-AB and sCD40L was significantly suppressed by NSC23766 in a dose-dependent manner. In addition, NSC23766 reduced the sCD40L release stimulated by ristocetin, a glycoprotein Ib/IX/V activator. These results indicate that Rac regulates the thromboxane A2-induced stimulation of PDGF-AB secretion and sCD40L release via the p38 MAP kinase in human platelets. [ABSTRACT FROM AUTHOR]