Mogrol stimulates G-protein-coupled bile acid receptor 1 (GPBAR1/TGR5) and insulin secretion from pancreatic ß-cells and alleviates hyperglycemia in mice.

Target identification is a crucial step in elucidating the mechanisms by which functional food components exert their functions. Here, we identified the G-protein-coupled bile acid receptor 1 (GPBAR1, also known as TGR5) as a target of the triterpenoid mogrol, a class of aglycone mogroside derivative from Siraitia grosvenorii. Mogrol, but not mogrosides, activated cAMP-response element-mediated transcription in a TGR5-dependent manner. Additionally, mogrol selectively activated TGR5 but not the other bile acid-responsive receptors (i.e., farnesoid X receptor, vitamin D receptor, or muscarinic acetylcholine receptor M3). Several amino acids in TGR5 (L71A2.60, W75AECL1, Q77AECL1, R80AECL1, Y89A3.29, F161AECL2, L166A5.39, Y240A6.51, S247A6.58, Y251A6.62, L262A7.35, and L266A7.39) were found to be important for mogrol-induced activation. Mogrol activated insulin secretion under low-glucose conditions in INS-1 pancreatic ß-cells, which can be inhibited by a TGR5 inhibitor. Similar effects of mogrol on insulin secretion were observed in the isolated mouse islets. Mogrol administration partially but significantly alleviated hyperglycemia in KKAy diabetic mice by increasing the insulin levels without affecting the ß-cell mass or pancreatic insulin content. These results suggest that mogrol stimulates insulin secretion and alleviates hyperglycemia by acting as a TGR5 agonist.

Decreased Interoceptive Awareness as a Risk Factor for Moderate to Severe Pain in Japanese Full-Time Workers: A Longitudinal Cohort Study.

Interoceptive awareness, the conscious perception of internal bodily states, is a key construct of mind-body interaction. Decreases in interoceptive awareness, as measured by the Multidimensional Assessment of Interoceptive Awareness (MAIA), are found in chronic pain patients. In this study, we explored whether a specific aspect of interoceptive awareness is a risk for the onset and chronicity of pain. A longitudinal cohort study was conducted in 2018 and 2020 among a sample of full-time workers in an industrial manufacturing company in Japan. Participants completed a questionnaire on pain intensity, MAIA, exercise habits, kinesiophobia, psychological distress and work stress. Principal component analyses using the MAIA identified two principal components: self-control and emotional stability. Low emotional stability was associated with the prevalence of moderate to severe pain in 2020 among people with mild or no pain in 2018 (p < 0.01). Lack of exercise habits were associated with the prevalence of moderate to severe pain in 2020 among people with pain in 2018 (p < 0.01). Furthermore, exercise habits were associated with reduction in kinesiophobia among people with moderate to severe pain in 2018 (p = 0.047). Overall, these findings indicate that low emotional stability may be a risk for the onset of moderate to severe pain; lack of exercise habits may sustain kinesiophobia and be a risk for the chronicity of pain.

Buccal fat pad flap for transoral repair of radiation-induced necrosis in the lateral oropharyngeal wall.

Soft tissue necrosis (STN) is a late toxicity after radiotherapy. Extensive tissue defects due to STN near the carotid artery, such as in the lateral oropharyngeal wall, may lead to infectious pseudoaneurysms associated with fatal bleeding. Such defects are usually treated with transcervical reconstructive surgeries, which are highly invasive and technically difficult. We report a case in which a buccal fat pad (BFP) flap was used for minimally invasive transoral repair of tissue defects due to radiation-induced STN in the lateral oropharyngeal wall. The BFP flap covered the tissue defect, and the wound epithelialized completely. The patient had no dysfunctional mouth opening, speech, or swallowing. The BFP flap can be easily harvested via a minimally invasive transoral approach and is expected to be further utilized for radiation-induced STN in the lateral oropharyngeal wall.

Long-Term Outcomes of End-Flexible-Rigidscopic Transoral Surgery for Pharyngolaryngeal Cancer.

OBJECTIVE: End-flexible-rigidscopic transoral surgery (E-TOS) is a new and minimally invasive transoral surgery for resection of Tis-selected T3 pharyngolaryngeal cancers. We evaluated long-term oncological outcomes and whether postoperative voice and swallowing function were preserved following E-TOS. METHODS: In this retrospective single-center study, 154 patients treated with E-TOS using a curved retractor, flexible-tip rigid endoscope, and thin curved instruments were included. Their survival rate, larynx preservation rate, and disease control rate were estimated using the Kaplan-Meier method. Postoperative voice function was evaluated using both objective and subjective tests. Postoperative swallowing function was assessed using the Hyodo score and the functional outcome swallowing scale. RESULTS: The 3-year and 5-year overall survival, disease-specific survival, disease-free survival, laryngectomy-free survival, local control, and loco-regional control rates post E-TOS were 89.8% and 82.2%, 95.6% and 92.3%, 78.5% and 70.3%, 87.2% and 80.9%, 93.9% and 92.5%, and 87.2% and 85.7%, respectively. Both objective and subjective postoperative voice and swallowing function tests were within normal limits in more than 90% of the patients. CONCLUSION: E-TOS is an effective, safe, low-cost, and minimally invasive transoral surgery for Tis-selected T3 pharyngolaryngeal cancer; it also preserves postoperative voice, larynx, and swallowing function. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:1415-1424, 2023.

Improvement in Disability Mediates the Effect of Self-Efficacy on Pain Relief in Chronic Low Back Pain Patients with Exercise Therapy.

Background: The biopsychosocial mechanism by which exercise leads to improvement in chronic low back pain (CLBP) remains unstudied. This prospective cohort study was performed to examine the effectiveness of exercise on pain, disability, and psychological status for CLBP. We also tested path analytic models in which changes in these variables were included. Methods: CLBP patients who visited the Interdisciplinary Pain Center of Keio University Hospital from July 2018 to April 2020 were included. The propensity score matching was performed between patients who underwent exercise (the exercise group) and those who did not (the control group). At the first visit and at the 3-month follow-up, pain (Numerical Rating Scale (NRS)), disability (Pain Disability Assessment Scale (PDAS)), and psychological status (Pain Self-Efficacy Questionnaire (PSEQ), and Pain Catastrophizing Scale (PCS)) were assessed. Changes in pain and disability at the follow-up were compared between the groups. The relationships between changes in pain, disability, and psychological variables were examined using Pearson's correlation and mediation analysis. Results: A significantly larger decrease in the PDAS was observed in the exercise group (N = 49) than in the control (N = 49) (p < 0.05). Increased PSEQ scores were significantly correlated with decreased NRS scores in both groups. In the exercise group, decreased PDAS fully mediated the relationship between increased PSEQ and decreased NRS (P < 0.05). Conclusion: Exercise improved disability, and the improved disability by exercise mediated the effect of increased self-efficacy on pain relief in CLBP patients.

B cell-activating factor is involved in thrombocytopenia in patients with liver cirrhosis.

Liver cirrhosis (LC) involves B cells that produce anti-glycoprotein (GP) IIb/IIIa antibodies, found in primary immune thrombocytopenia (ITP). The role of autoimmunity in the pathology of thrombocytopenia in LC was investigated using 25 LC patients with thrombocytopenia, 18 ITP patients, and 30 healthy controls. Anti-GPIIb/IIIa antibody-producing B cells were quantified using enzyme-linked immunospot assay. Platelet-associated and plasma anti-GPIIb/IIIa antibody, plasma B cell-activating factor (BAFF), and a proliferation-inducing ligand (APRIL) levels were measured using enzyme-linked immunosorbent assay. B cell subset fractions and regulatory T cells (Tregs) were quantified using flow cytometry.The number of anti-GPIIb/IIIa antibody-producing B cells was significantly higher in LC patients than in ITP patients and healthy controls (both p < 0.001). Platelet-associated anti-GPIIb/IIIa antibodies were significantly higher in LC patients than in ITP patients and healthy controls (p = 0.002, p < 0.001, respectively). BAFF levels were significantly higher in LC patients than in ITP patients and healthy controls (p = 0.001 and p < 0.001, respectively), and APRIL levels were significantly higher in LC patients than in healthy controls (p < 0.001). Anti-GPIIb/IIIa antibody-producing B cells and platelet-associated anti-GPIIb/IIIa antibodies were positively correlated with BAFF levels in LC patients. LC patients had more naïve B cells and plasmablasts than healthy controls (p = 0.005, p = 0.03, respectively); plasmablasts were positively correlated with BAFF levels. LC patients had similar Tregs levels as ITP patients and healthy controls. Therefore, excessive BAFF production in LC patients with thrombocytopenia is likely associated with autoimmune B cell response, inducing anti-GPIIb/IIIa antibody production.

A Cross-Sectional Study of the Impact of Pain Severity on Absenteeism and Presenteeism Among Japanese Full-Time Workers.

INTRODUCTION: Pain is known to have a high impact on work performance, but there are several confounding factors, such as stress and mental issues. Little is known about the impact of pain severity on work performance when adjusted for such confounding factors. The aim of this study was to identify the effect of pain severity on absence from work (absenteeism) and reduced performance (presenteeism). METHODS: A cross-sectional study was conducted among full-time workers at an industrial manufacturing company in Japan. Participants were assessed using a self-reported questionnaire, including work performance evaluations, pain characteristics, pain-related fear, psychological distress, stress at the workplace and home, workaholism, and self-awareness. Principal component analysis was utilized to decrease the dimensions of the measures, and orthogonal rotation was performed on identified components with an eigenvalue > 1.0. Multivariable logistic regression analyses were performed to determine the association between pain severity and absenteeism and presenteeism, and were adjusted for confounding factors. We also analyzed the association between pain intensity and presenteeism using multivariable logistic regression analyses. RESULTS: A total of 349 workers participated in the study. Six principal components were identified as confounding factors: work stress, regulation, mental instability, less support, home stress, and life dissatisfaction. Multivariable logistic regression analyses showed significant associations of moderate to severe pain with absenteeism (p = 0.02) and low and high presenteeism (p = 0.004 and 0.009, respectively), adjusted for age, sex, body mass index, short sleep, and the six principal components. Pain intensity was also significantly associated with low and high presenteeism (p = 0.002 and 0.014, respectively) in people with pain. CONCLUSIONS: Pain severity is a risk factor for absenteeism and presenteeism, even if workers have comorbid psychological stress or mental health problems.

Association of work performance and interoceptive awareness of 'body trusting' in an occupational setting: a cross-sectional study.

OBJECTIVES: Work performance has been known to be influenced by both psychological stress (mind) and physical conditions (body). The aim of this study was to investigate the association between work performance and 'body trusting', which is a dimension of interoceptive awareness representing mind-body interactions. METHODS: A cross-sectional study was conducted among a sample of workers in an industrial manufacturing company in Japan. Participants were assessed with a self-reported questionnaire including evaluations of work performance, body trusting, psychological distress, pain persistence, workplace and home stressors, and workaholism. Participants' sociodemographic, health and lifestyle characteristics were collected from their annual health check data. The association between work performance and body trusting was examined using multivariable regression analyses in the overall sample and in a subsample of people with pain. RESULTS: A total of 349 workers participated in the study. A significant association between work performance and body trusting was observed, with higher body trusting representing higher work performance. The association was significant after controlling for psychological distress, workplace and home stress, workaholism and participants' characteristics (p<0.001). Compared with people without pain (n=126, 36.1%), people with pain (n=223, 63.9%) showed less body trusting, which was associated with decreased work performance after controlling for pain-related variables (p<0.001). CONCLUSIONS: Workers with higher body trusting showed higher work performance, even after controlling for various influencing factors. Body trusting may be an important target to promote work performance and to prevent loss of performance induced by health problems.

Endoscopic Endonasal Surgery of a Large Vidian Nerve Schwannoma With Preparation for Avoiding Major Vascular Injury.

Vidian nerve schwannomas are extremely rare, and their surgical management requires an awareness of the surrounding vascular and nervous systems, including the internal carotid artery. Herein, we report a case of a vidian nerve schwannoma that was successfully removed using an endoscopic endonasal approach in a 21-year-old patient who presented with lacrimal hyposecretion. Imaging revealed a large mass extending to the middle cranial fossa posteriorly, to the pterygopalatine fossa laterally, and to the sphenoid sinus medially. The paraclival and petrosal portions of the internal carotid artery were displaced posteriorly. Endoscopic observation of the right nose demonstrated anterior displacement of the inferior portion of the middle turbinate. Based on the above, we suspected a vidian nerve schwannoma, and endoscopic endonasal surgery was performed with particular attention to avoid vascular injuries. An endoscopic transmaxillary approach was used to expose the anterior surface of the tumor. After confirming the pathological diagnosis intraoperatively, intracapsular resection of the tumor was completed using an ultrasonic surgical aspirator with Doppler monitoring of the location of the internal carotid artery. Endoscopic management of the surgical field and preparation to avoid vascular injury are essential for safe and efficient tumor resection.

Utility of Microcrystalline Cellulose for Improving Drug Content Uniformity in Tablet Manufacturing Using Direct Powder Compression.

Direct powder compression is the simplest tablet manufacturing method. However, segregation occurs when the drug content is low. It is difficult to assure drug content uniformity in these cases. In this study, we evaluated microcrystalline cellulose (MCC) as a segregation inhibitor in pharmaceutical powders. We assessed the influence of MCC concentration and mixing time on the physical properties of tablets. The tablet formulation comprised acetaminophen, lactose hydrate, cornstarch, MCC (0%, 10%, or 20%), croscarmellose sodium, and magnesium stearate (Mg-St). All powders except Mg-St were premixed for 5, 15, or 25 min. Mg-St was then added and mixed for 5 min to prepare nine pharmaceutical powders. Flowability index and practical angle of internal friction were measured. Tablets were also prepared, and their weight variation, hardness, friability, disintegration time, and drug content variation were evaluated. MCC slightly decreased pharmaceutical powder flowability. Tablet hardness increased and disintegration time decreased with increasing MCC concentration. MCC mixed for ≥ 15 min also significantly lowered drug content variation. A contour plot was prepared to assess the effect of MCC concentration and mixing time on the physical properties of tablets. It was determined that tablets with 50-80 N hardness, ≤ 3.5 min disintegration time, and ≤ 3% drug content variation can be prepared when MCC concentration is 6.5-8.5% and the mixing time is 19-24 min. Therefore, MCC is effective as a segregation inhibitor, and the addition of MCC to tablet formulation improves drug content uniformity.

Rab27a is essential for the formation of neutrophil extracellular traps (NETs) in neutrophil-like differentiated HL60 cells.

Neutrophils play a crucial role in host defence. In response to a variety of inflammatory stimulation, they form neutrophil extracellular traps (NETs). NETs are extracellular structures composed of chromatin fibers decorated with antimicrobial proteins and developing studies indicate that NETs contribute to extracellular microbial killing. While the intracellular signaling pathways that regulate NET formation remain largely unknown, there is growing evidence that generation of reactive oxygen species (ROS) is a key event for NET formation. The Rab family small GTPase Rab27a is an important component of the secretory machinery of azurophilic granules in neutrophils. However, the precise mechanism of NET formation and whether or not Rab27a contributes to this process are unknown. Using neutrophil-like differentiated HL60 cells, we show here that Rab27a plays an essential role in both phorbol myristate acetate (PMA)- and Candida albicans-induced NET formation by regulating ROS production. Rab27a-knockdown inhibited ROS-positive phagosome formation during complement-mediated phagocytosis. To investigate the role of Rab27a in neutrophil function in detail, both primary human neutrophils and neutrophil-like differentiated HL60 cells were treated with PMA, and NET formation process was assessed by measurement of release of histone H3 into the medium, citrullination of the arginine in position 3 of histone H4 and chase of the nuclear change of the living cells in the co-existence of both cell-permeable and -impermeable nuclear indicators. PMA-induced NET formation occured sequentially in both neutrophil-like differentiated HL60 cells and primary neutrophils, and Rab27a-knockdown clearly inhibited NET formation in association with reduced ROS production. We also found that serum-treated Candida albicans triggers NET formation in a ROS-dependent manner, and that Rab27a-knockdown inhibits this process as well. Our findings demonstrate that Rab27a plays an important role in NET formation induced by both Candida albicans infection and PMA treatment by regulating ROS production.

Rab27b regulates c-kit expression by controlling the secretion of stem cell factor.

Rab27b, a subfamily of Rab27 small GTPases, was originally identified in platelets. However, the role of Rab27b in megakaryocytic lineage cells remains unknown. Here, using a human megakaryoblastic cell line, CMK, we show that Rab27b negatively regulates c-kit-expression. We found that transfection of shRNA-Rab27b into CMK cells led to specific increase in the amount of the receptor-type tyrosine kinase c-kit. To elucidate the molecular mechanisms by which Rab27b regulates c-kit expression, we analyzed the dynamics of c-kit by the stimulation with its ligand, stem cell factor (SCF). We found that cell surface expression of c-kit was promptly reduced and rapidly degraded in both CMK and Rab27b-knockdown CMK cells. Pretreatment with a lysosome inhibitor bafilomycin suppressed the degradation of c-kit, indicating that c-kit expression is controlled by SCF-induced endolysosomal degradation system. We therefore focused on the potential involvement of SCF in Rab27b-mediated effects on c-kit expression levels. We found that autocrine secretion of SCF was downregulated in Rab27b-knockdown cells as compared with parental CMK cells. These results suggest that Rab27b negatively regulates the cell surface expression of c-kit via secretion of SCF and that ligation of SCF leads to the endolysosomal degradation system of c-kit.

Rab27a negatively regulates phagocytosis by prolongation of the actin-coating stage around phagosomes.

Rab27a, a Rab family small GTPase, is involved in the exocytosis of secretory granules in melanocytes and cytotoxic T-cells. Rab27a mutations cause type 2 Griscelli syndrome, which is characterized by immunodeficiency, including uncontrolled macrophage activation known as hemophagocytic syndrome. However, the role of Rab27a in phagocytosis remains elusive. Here, using macrophage-like differentiated HL-60 cells and C3bi-opsonized zymosan as a pathogen-phagocyte model, we show that Rab27a negatively regulates complement-mediated phagocytic activity in association with F-actin remodeling. We found that transfection of Rab27a shRNA into HL-60 cells enhances complement-mediated phagocytosis. To clarify the mechanisms underlying the elevated phagocytosis in Rab27a knockdown cells, we analyzed the process of phagosome formation focusing on F-actin dynamics: F-actin assembly, followed by F-actin extension around the particles and the subsequent degradation of F-actin, leading to internalization of the particles enclosed in phagosomes. Microscopic analysis revealed that these actin-related processes, including F-actin coating and F-actin degradation, proceed more rapidly in Rab27a knockdown cells than in control HL-60 cells. Both elevated phagocytosis and accelerated F-actin remodeling were restored by expression of rescue-Rab27a and Rab27a-Q78L (GTP-bound form), but not by Rab27a-T23N (GDP-bound form). Furthermore, an increased accumulation of Coronin 1A surrounding F-actin coats was observed in Rab27a knockdown cells, suggesting that the function of Coronin 1A is related to the regulation of the F-actin coating. Our findings demonstrate that Rab27a plays a direct regulatory role in the nascent process of phagocytosis by prolongation of the stage of actin coating via suppression of Coronin 1A. This study may contribute to an explanation of the underlying mechanisms of excessive phagocytosis observed in Griscelli syndrome.

ATP-induced osteoclast function: the formation of sealing-zone like structure and the secretion of lytic granules via microtubule-deacetylation under the control of Syk.

Osteoclasts are bone-resorbing cells which play an exclusive role in bone remodeling, but the molecular mechanisms of osteolysis, how osteoclasts are activated and how the lytic granules are finally released towards the bone matrix are poorly understood. Here we show that an energy molecule ATP induces osteolysis via P2X(7)-nucleotide receptor and that deacetylation of alpha-tubulin is essential for the whole process of osteolysis under the control of a tyrosine kinase Syk. By developing a traceable and reproducible in vitro analyzing system for osteoclast function, we found that ATP-signaling gives rise to two events simultaneously (i) cytoskeletal reorganization for the formation of sealing zones, ring-like adhesion structures which delimit the contact surface, and (ii) the delivery and secretion of lytic granules towards the delimited site on the matrix. We further found that deacetylation of alpha-tubulin is a critical reaction for osteoclast function. Pharmacological inhibition of alpha-tubulin deacetylation resulted in (i) failure of the sealing-zone like structure formation and (ii) ceased secretion of lytic granules. Additionally, kinetics of deacetylation was found to be regulated by Syk. These data suggest a novel P2X(7) microtubular regulation pathway related to Syk for a therapeutic target in osteolytic diseases.

Induction of apoptosis by epigallocatechin-3-gallate in human lymphoblastoid B cells.

(-)-Epigallocatechin-3-gallate (EGCG), a major constituent of green tea polyphenols, has been shown to suppress cancer cell proliferation and induce apoptosis. In this study we investigated its efficacy and the mechanism underlying its effect using human B lymphoblastoid cell line Ramos, and effect of co-treatment with EGCG and a chemotherapeutic agent on apoptotic cell death. EGCG induced dose- and time-dependent apoptotic cell death accompanied by loss of mitochondrial transmembrane potential, release of cytochrome c into the cytosol, and cleavage of pro-caspase-9 to its active form. EGCG also enhanced production of intracellular reactive oxygen species (ROS). Pretreatment with diphenylene iodonium chloride, an inhibitor of NAD(P)H oxidase and an antioxidant, partially suppressed both EGCG-induced apoptosis and production of ROS, implying that oxidative stress is involved in the apoptotic response. Furthermore, we showed that combined-treatment with EGCG and a chemotherapeutic agent, etoposide, synergistically induced apoptosis in Ramos cells.

Protein kinase A-regulated membrane trafficking of a green fluorescent protein-aquaporin 5 chimera in MDCK cells.

The green fluorescent protein (GFP) of the jellyfish, Aeqorea victoria, was used as an autofluorescent tag to track the trafficking of aquaporin 5 (AQP5), an exocrine gland-type water channel. Two groups of chimeric proteins were constructed; one in which GFP was fused to the amino-terminus of AQP5 (GFP-AQP5) and the other, in which it was fused to the carboxyl terminus of it (AQP5-GFP). In each group, 2 chimeras were produced, a wild-type AQP5 with its normal sequence and a mutant AQP5 having a mutated amino acid at 259, i.e., GFP-AQP5-T259A and AQP5-GFP-T259A. They were used to transfect Madin-Darby canine kidney (MDCK) cells. The GFP-AQP5 chimera was localized in the intracellular vesicles, which trafficked to the plasma membrane in response to N(6), 2'-O-dibutyryladenosine 3', 5'-cyclic monophosphate (dbcAMP). Membrane trafficking was inhibited by N-[2-(p-bromocinnamylamino)ethyl]-5-isoquimolinesulfonamide (H-89) but not by palmitoyl-dl-carnitine chloride (PCC). In contrast, the AQP5-GFP chimera expressed in MDCK cells was localized constitutively on the plasma membrane. The cellular localization of the latter chimera was not affected by stimulation with dbcAMP in the presence or absence of H-89 or PCC. Replacement of Thr-259 with Ala-259 did not affect the dbcAMP-induced translocation of the chimeric protein, suggesting that phosphorylation of Thr-259 was not necessary for AQP5 trafficking under the present experimental conditions. Thus, the GFP-AQP5 chimera will be a useful tool to study AQP5 trafficking in vitro, whereas the constitutive membrane localization of the AQP5-GFP chimera suggests the importance of the carboxyl terminus of the AQP5 protein for its sorting, whether it is translocated to intracellular vesicles or to the plasma membrane.

Protein-tyrosine kinase Syk is required for pathogen engulfment in complement-mediated phagocytosis.

The protein tyrosine kinase Syk plays a central role in Fcgamma receptor-mediated phagocytosis in the adaptive immune system. We show here that Syk also plays an essential role in complement-mediated phagocytosis in innate immunity. Macrophage-like differentiated HL60 cells and C3bi-opsonized zymosan comprised the pathogen-phagocyte system. C3bi-opsonized zymosan particles promptly attached to the cells and were subsequently engulfed via complement receptor 3. During this process, Syk became tyrosine phosphorylated and accumulated around the nascent phagosomes. The transfer of Syk-siRNA or dominant-negative Syk (DN-Syk) into HL60 cells resulted in impaired phagocytosis. Quenching assays using fluorescent zymosan revealed that most of the attached zymosan particles were located inside parental HL60 cells, whereas few were ingested by the mutant cells. These data indicated that Syk is required for the engulfment of C3bi-opsonized zymosan. During C3bi-zymosan-induced phagocytosis, actin accumulation occurred around phagosomes and was followed by depolymerization, and further RhoA was activated together with tyrosine phosphorylation of Vav. These responses including the actin remodeling were suppressed in Syk-siRNA- or DN-Syk-expressing cells. Our results demonstrated that Syk plays an indispensable role in complement-mediated phagocytosis by regulating both actin dynamics and the RhoA activation pathway and that these functions of Syk lead to phagosome formation and pathogen engulfment.

Lipopolysaccharide-induced elevation and secretion of interleukin-1beta in the submandibular gland of male mice.

The intraperitoneal injection of lipopolysaccharide (LPS) (400 microg/kg body weight) induced the expression of mRNAs of inflammatory cytokines such as interleukin (IL)-1beta, IL-6 and tumour necrosis factor (TNF)-alpha in the submandibular gland (SMG) of C3H/HeN mice but not that of C3H/HeJ mice, a mutant strain for Toll-like receptor-4 (TLR-4(-) mutant). The mRNA levels of these cytokines in the SMG of the wild-type mice increased as early as 3 hr after injection, peaked at 3-6 hr, and had decreased again by 24 hr. In this study, we particularly focused on IL-1beta, and induction by this endotoxin was investigated in detail. Denervation of the superior cervical trunk and chorda tympani nerve did not diminish the LPS-induced elevation of IL-1beta mRNA in the SMG, indicating the irrelevance of the central nervous system in this induction. TLR-4 mRNA and protein were shown to be strongly expressed in the SMG, suggesting the direct action of LPS on this gland. IL-1beta proteins were localized in the secretory granules of granular convoluted tubular (GCT) cells, and their molecular weights in the gland were 17.5 and 20 kDa. IL-1beta of the same size appeared in the saliva 6 hr after LPS injection in C3H/HeN but not in C3H/HeJ mice. The present study thus suggests that IL-1beta, an inflammation cytokine, is induced and secreted into the saliva in response to endotoxin injected intraperitoneally.

Subcellular redistribution of AQP5 by vasoactive intestinal polypeptide in the Brunner's gland of the rat duodenum.

Aquaporin (AQP)5, an exocrine-type water channel, was detected in the rat duodenum by Western blot analysis, and was localized by immunohistochemistry in the secretory granule membranes as well as in the apical and lateral aspects of the plasma membrane of Brunner's gland cells. Incubation of duodenal slices with vasoactive intestinal polypeptide (VIP) in vitro significantly increased the amount of AQP5 in the apical membrane fraction in a dose- and time-dependent manner with the amount reaching a plateau at 100 nM VIP and becoming near maximal after a 30-s incubation. Protein kinase inhibitors, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7, 50 muM), and N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide (H-89; PKA-specific, 1 muM) blocked this increase, but PKC-specific inhibitor calphostin C did not, implying the involvement of PKA but not PKC in this cellular event. Intravenous injection with VIP (40 mug/kg body wt) provoked dilation of the lumen of the Brunner's gland at 2 and 7 min and increased the staining intensity of AQP5 in the apical and lateral membranes. AQP1 (both nonglycosylated and glycosylated forms) was also found to localize in the apical and basolateral membranes of cells of Brunner's gland. VIP, however, did not provoke any significant change in the AQP1 level in the apical membrane, as judged from the results of the above in vitro and in vivo experiments. These results suggest that VIP induced the exocytosis of granule contents and simultaneously caused translocation of AQP5 but not of AQP1 to the apical membrane in Brunner's gland cells.

LAD-III, a leukocyte adhesion deficiency syndrome associated with defective Rap1 activation and impaired stabilization of integrin bonds.

Recently, we reported a rare leukocyte adhesion deficiency (LAD) associated with severe defects in integrin activation by chemokine signals, despite normal ligand binding of leukocyte integrins.(1) We now report that the small GTPase, Rap1, a key regulator of inside-out integrin activation is abnormally regulated in LAD Epstein-Barr virus (EBV) lymphocyte cells. Both constitutive and chemokine-triggered activation of Rap1 were abolished in LAD lymphocytes despite normal chemokine signaling. Nevertheless, Rap1 expression and activation by phorbol esters were intact, ruling out an LAD defect in Rap1 guanosine triphosphate (GTP) loading. The very late antigen 4 (VLA-4) integrin abnormally tethered LAD EBV lymphocytes to its ligand vascular cell adhesion molecule 1 (VCAM-1) under shear flow due to impaired generation of high-avidity contacts despite normal ligand binding and intact avidity to surface-bound anti-VLA-4 monoclonal antibody (mAb). Thus, a defect in constitutive Rap1 activation results in an inability of ligand-occupied integrins to generate high-avidity binding to ligand under shear flow. This is a first report of an inherited Rap1 activation defect associated with a pathologic disorder in leukocyte integrin function, we herein term it "LAD-III."