Gender differences on preoperative psychologic factors affecting acute postoperative pain in patients with lumbar spinal disorders.

BACKGROUND: Psychosexual factors are one of the preoperative factors influencing acute postoperative pain. Because of gender differences in pain, the preoperative factors that influence acute postoperative pain may also differ between males and females. However, there have been no reports on such factors in patients with spinal disorders that focused on gender differences. Therefore, the purpose of this study was to examine the preoperative factors that influence acute postoperative pain, focusing on gender differences. METHODS: The subjects were 75 males and 60 females admitted for surgery for lumbar spinal disorders. Preoperatively, the following were assessed: low back pain using the Numeric Rating Scale (NRS); anxiety and depression using the Japanese version of the Hospital Anxiety and Depression Scale (HADS); catastrophic thinking using the Pain Catastrophizing Scale (PCS); psychiatric problems using the Brief Scale for Psychiatric Problems in Orthopaedic Patients (BS-POP); and neurological assessments. Acute postoperative pain was also assessed using the NRS within 48 h, postoperatively. Based on these data, we analyzed gender differences in preoperative factors affecting acute postoperative pain in patients with lumbar spinal disorders. RESULTS: Postoperative NRS and preoperative PCS scores were higher in females compared to males. In the males, the coefficient of determination of the multiple regression equation was 0.088, and PCS (ß = 0.323, p = 0.015) was extracted as a significant factor. In the females, the coefficient of determination of the multiple regression equation was 0.075, and BS-POP (ß = 0.300, p = 0.019) was extracted as a significant factor. CONCLUSION: Preoperative factors influencing acute postoperative pain for patients with lumbar spinal disorders vary by gender. It was suggested that males should be screened using PCS. In females, on the other hand, PCS alone is not sufficient for evaluation. It was suggested that evaluation using BS-POP should be considered in addition to PCS.

Cloning and characterization of DPPL1 and DPPL2, representatives of a novel type of mammalian phosphatidate phosphatase.

Phosphatidate phosphatase (PAP) enzymes are classified as either Mg(2+)-dependent (PAP1) or Mg(2+)-independent (PAP2) with respect to their Mg(2+) cofactor requirement for catalytic activity. Sensitivity to the thioreactive compound N-ethylmaleimide (NEM) has also been used to differentiate PAP1 (NEM-sensitive) from PAP2 (NEM-insensitive) activity in mammalian cells. We report here the cloning and initial characterization of DPPL1 and DPPL2, representatives of a novel type of mammalian phosphatidate phosphatase. Both DPPL1 and DPPL2 show greater homology to a yeast diacylglycerol pyrophosphate (DGPP) phosphatase, DPP1, than to known phosphatidate phosphatases of mammals. Like the yeast DPP1 protein, both DPPL1 and DPPL2 proteins show broad substrate specificity, but DGPP is the preferred substrate compared with LPA and PA. These reactions are Mg(2+)-independent, but unlike DPP1 and mammalian PAP2, they are sensitive to NEM. DPPL1 mRNA is ubiquitously expressed in various tissues and cells, but DPPL2 mRNA is restricted to several tissues including the brain, kidney and testis, and it is preferentially expressed in endothelial cells. Immunohistological staining of synovium containing vessels, plasma cells and lymphocytes revealed specific expression of DPPL2 protein in the endothelium. Collectively, our work indicates that DPPL1 and DPPL2 represent a novel type of mammalian phosphatidate phosphatase.

Absence of Activation-induced Cytidine Deaminase, a Regulator of Class Switch Recombination and Hypermutation in B Cells, Suppresses Aorta Allograft Vasculopathy in Mice.

BACKGROUND: Antibody-mediated rejection is caused in part by increasing circulation/production of donor-specific antibody (DSA). Activation-induced cytidine deaminase (AID) is a key regulator of class switch recombination and somatic hypermutation of immunoglobulin in B cells, yet its role in antibody-mediated transplant rejection remains unclear. We show here that AID deficiency in mice enables suppression of allograft vasculopathy (AV) after aorta transplantation, a DSA-mediated process. METHODS: Splenocytes from C57BL/6 J (B6) AID(−/−) mice were used for determining in vitro proliferation responses, alloreactivity, cell surface marker expression, and antibody production. BALB/c mouse aortas were transplanted into B6 AID(−/−) mice with or without FK506 treatment. Blood and aorta grafts were harvested on day 30 after transplantation and were subjected to DSA, histological, and immunohistological analyses. RESULTS: The AID(−/−) splenocytes were comparable to wild type splenocytes in proliferation responses, alloreactivity, and expression of cell surface markers in vitro. However, they completely failed to produce immunoglobulin G, although they were not impaired in immunoglobulin M production relative to controls. Furthermore, BALB/c aorta grafts from B6 AID(−/−) recipient mice on day 30 after transplantation showed reduced signs of AV compared to the grafts from B6 wild type recipient mice which had severe vascular intimal hyperplasia, interstitial fibrosis, and inflammation. Treatment with FK506 produced a synergistic effect in the grafts from AID(−/−) recipients with further reduction of intimal hyperplasia and fibrosis scores. CONCLUSIONS: The AID deficiency inhibits DSA-mediated AV after aorta transplantation in mice. We propose that AID could be a novel molecular target for controlling antibody-mediated rejection in organ transplantation.

Lung surfactant levels are regulated by Ig-Hepta/GPR116 by monitoring surfactant protein D.

Lung surfactant is a complex mixture of lipids and proteins, which is secreted from the alveolar type II epithelial cell and coats the surface of alveoli as a thin layer. It plays a crucial role in the prevention of alveolar collapse through its ability to reduce surface tension. Under normal conditions, surfactant homeostasis is maintained by balancing its release and the uptake by the type II cell for recycling and the internalization by alveolar macrophages for degradation. Little is known about how the surfactant pool is monitored and regulated. Here we show, by an analysis of gene-targeted mice exhibiting massive accumulation of surfactant, that Ig-Hepta/GPR116, an orphan receptor, is expressed on the type II cell and sensing the amount of surfactant by monitoring one of its protein components, surfactant protein D, and its deletion results in a pulmonary alveolar proteinosis and emphysema-like pathology. By a coexpression experiment with Sp-D and the extracellular region of Ig-Hepta/GPR116 followed by immunoprecipitation, we identified Sp-D as the ligand of Ig-Hepta/GPR116. Analyses of surfactant metabolism in Ig-Hepta(+/+) and Ig-Hepta(-/-) mice by using radioactive tracers indicated that the Ig-Hepta/GPR116 signaling system exerts attenuating effects on (i) balanced synthesis of surfactant lipids and proteins and (ii) surfactant secretion, and (iii) a stimulating effect on recycling (uptake) in response to elevated levels of Sp-D in alveolar space.

Cleavage of Ig-Hepta at a "SEA" module and at a conserved G protein-coupled receptor proteolytic site.

Ig-Hepta is a member of a new subfamily of the heptahelical receptors and has an unusually long N terminus extending toward the extracellular side of the plasma membrane. Pulse-chase experiments in 293T cells using antisera specifically recognizing its N- and C-terminal regions demonstrated that Ig-Hepta is core-glycosylated cotranslationally and proteolytically processed into a two-chain form in the endoplasmic reticulum, followed by maturation of oligosaccharide chains and dimerization. The cleavage occurs at two highly conserved sites: one in a "SEA" module (a module first identified in sperm protein, enterokinase, and agrin) near the N terminus and the other in the stalk region preceding the first transmembrane span, generating approximately 20-, 130-, and 32-kDa fragments. The latter two remain tightly associated non-covalently even after cleavage as revealed by immunoprecipitation of native and myc-tagged Ig-Hepta constructs that were transiently expressed in 293T cells. The dimer consisting of four chains, (130 kDa + 32 kDa)(2), is linked by disulfide bonds. A fusion protein of the extracellular domain of Ig-Hepta and the Fc domain of immunoglobulin was found to be a good substrate of the processing enzymes and used for determining the exact cleavage sites in the SEA module and juxtamembrane stalk region.

[Heterogeneity of G protein-coupled receptor generated by post-translational mechanisms and its clinical meanings].

G protein-coupled receptors (GPCRs) are the most famous target proteins for medicinal drugs. So far, heterogeneity of GPCRs is mainly focused on genetic variation. However, it has been reported that the structure and function of GPCRs are modified by several mechanisms after translation. RNA editing introduces the amino acid different from that encoded in genome by changing the nucleotide. Dimer formation is another example of how heterogeneity is produced. Many receptors form homo- or hetero-dimers, and obtain different function from original receptors. Receptors are regulated by several means to modulate stimulation strength. Receptor subtype is often differentially regulated by receptor kinases and/or second messenger-regulated kinases. There is a new type of receptor that shows a novel structural feature, a long amino terminal region belonging to class B seven transmembrane receptors. The physiological function of this class of receptor is assumed to play a role in cell-cell communication. This novel structural feature may directly link GPCR to the cytoskeleton. These mechanisms to produce functional and structural heterogeneity may explain how cells evoke different responses in different tissues or cells upon the same stimulation. Thus, the post-translational mechanism to produce heterogeneity provides additional flexibility when cells respond to one extracellular stimulus.