Medical Economic Effect of Pharmaceutical Interventions by Board-Certified Pharmacists in Palliative Pharmacy for Patients with Cancer Using Medical Narcotics in Japan: A Multicenter, Retrospective Study.

BACKGROUND: The Japanese Society for Pharmaceutical Palliative Care and Sciences specializes in pharmacology in the field of palliative medicine. More than 700 board-certified pharmacists in palliative pharmacy (BCPPP) are actively involved in palliative pharmacotherapy at various hospitals and pharmacies. The purpose of this study was to determine the economic effect of pharmaceutical interventions by BCPPPs. METHODS: This multicenter retrospective study included 27 medical centers and analyzed the medical economic effect of interventions by BCPPPs (17 pharmacists) and non-BCPPPs (24 pharmacists) on patients using medical narcotics for cancer pain in September 2021. RESULTS: The percentage of patients who received a pharmaceutical intervention and whose drug costs were reduced by pharmacist intervention was significantly higher in the BCPPP group than in the non-BCPPP group. Although there was no significant difference between the two groups in drug cost reduction per patient per month (BCPPP group: $0.89 [-$64.91 to $106.76] vs. non-BCPPP group $0.00 [-$1,828.95 to $25.82]; P = 0.730), the medical economic benefit of pharmacist intervention in avoiding or reducing adverse drug reactions was higher in the BCPPP group ($103.18 [$0.00 to $628.03]) than in the non-BCPPP group ($0.00 [$0.00 to $628.03]) (P = 0.070). The total medical economic benefit-the sum of these-was significantly higher in the BCPPP group ($88.82 [-$14.62 to $705.37]) than in the non-BCPPP group ($0.66 [-$1,200.93 to $269.61]) (P = 0.006). CONCLUSION: Pharmacological intervention for patients with cancer using medical narcotics may have a greater medical economic benefit when managed by BCPPPs than by non-certified pharmacists in Japan.

Multicenter prospective observational study on hospital pharmacist interventions to reduce inappropriate medications.

Background: In Japan, the involvement of hospital pharmacists in inappropriate medications (IMs) practices has not been sufficiently reported. Therefore, this prospective study described the interventions of hospital pharmacists in discontinuing inappropriate drugs or reducing drug doses. Methods: We conducted a prospective, multicenter, observational study to investigate the intervention of hospital pharmacists in inappropriate prescriptions for inpatients in September 2018. Fifty pharmacists from 45 hospitals in Japan participated in this study. IMs were defined as medications that pharmacists deemed inappropriate for patient treatment. The subjects of the study were patients who interacted with the participating pharmacists. Results: During the study period, the median number of beds in hospitals where the 50 participating pharmacists worked was 380, and the average number of beds for which the pharmacists were responsible was 49. The enrolled hospital pharmacists recommended that doctors discontinue or reduce the doses of their regular drugs for 347 out of 1,415 (24.5%) patients. Among the 391 pharmacists' recommendations to reduce IMs for 347 patients, physicians accepted 368 (94.1%) recommendations, and 523 drugs were discontinued as a result. Pharmacist intervention also led to improvements in hypnotic sedation, delirium, and hypotension. The most common reasons for IMs identified by pharmacists were "long-term administration of irresponsible or aimless medications" (44.5%), "adverse effects caused by medications" (31.5%), and "medications-mediated duplication of the pharmacological effect" (15.3%). Approximately 90% of pharmacists' suggestions to reduce medications were accepted for each reason. The average number of regular medications used by patients involved in drug reduction was 8.2, and the average number of medications reduced was 1.7. A sub-analysis showed that patients using opioids tended to take more medications, and these patients were able to reduce the amount of medications taken. Interventions by pharmacists certified in palliative pharmacies tended to reduce adverse drug events. Conclusion: This was the first multicenter prospective observational study conducted in Japan to demonstrate hospital pharmacist intervention's effectiveness in promoting appropriate prescription and, consequently, a reduction in the number of medications in use and polypharmacy.

Opioid-Related Respiratory Depression in Non-Cancer Patients, as Reported in the Japanese Adverse Drug Event Report Database.

BACKGROUND: Opioid-induced respiratory depression (RD) is a potentially life-threatening adverse drug event. This study used the Japanese Adverse Drug Event Report (JADER) database to investigate the profile of opioid-related RD in non-cancer patients. METHODS: We analyzed data recorded in the JADER database between April 2004 and February 2020, which were downloaded from the Pharmaceutical and Medical Devices Agency website. Reporting odds ratios for RD were calculated for the 20 opioids approved in Japan, and daily dose and onset time were further analyzed for opioids used in chronic non-cancer pain (CNCP). RESULTS: Among the opioids, RD adverse event signals were detected for 22 combinations of opioids and administration routes in non-cancer patients. Of these combinations, transdermal buprenorphine and oral tramadol/acetaminophen were approved for CNCP and tended to be reported more frequently in elderly patients. The median daily doses of transdermal buprenorphine and oral tramadol/acetaminophen were 10.0 and 22.5 mg of daily oral morphine equivalent doses, respectively, which are within the standard range for starting dosage. The median time-to-onset of transdermal buprenorphine and oral tramadol/acetaminophen was 6.5 and 4.0 days, respectively, and 75% of cases were reported within 20 to 40 days after the start of treatment. The hazard type for both opioids was classified as early failure. CONCLUSIONS: Our findings suggest that elderly CNCP patients should be closely monitored after the start of opioid treatment, especially during the first week and, if possible, for 1 month, even if starting doses are within ranges recommended by the manufacturer and guidelines.

Multicentre prospective observational study on community pharmacist interventions to reduce inappropriate medications.

OBJECTIVES: The status of community pharmacists' involvement in inappropriate prescription practices among outpatients who visit community pharmacies has not been reported in Japan. Therefore, this study described community pharmacists' interventions aimed at the discontinuation of inappropriate drugs or the reduction of drug doses. METHODS: We conducted a multicentre prospective observational study of pharmacists' interventions on inappropriate prescriptions for outpatients during a 1-month period in September 2018. A total of 28 pharmacists from 28 community pharmacies in Japan participated in this study. We analysed cases in which pharmacists discontinued drugs or changed the doses due to drugs being inappropriate, adverse effects, duplication of pharmacological effects and drug-drug interactions. KEY FINDINGS: Community pharmacists provided interventions for 736 patients at an average of 26.2 patients per day during the study period. The pharmacists recommended that doctors discontinue inappropriate drugs or reduce the doses of regular drugs for 103 patients (13.9%). Among the 107 pharmacist recommendations to decrease inappropriate prescriptions, 83 (77.6%) were accepted, including 62 cases of discontinuation (57.9%) and 21 of drug dose reduction (19.6%). A total of 122 drugs were discontinued according to pharmacists' recommendations. In addition, pharmacists' intervention improved sleepiness, sedation and cognitive function. CONCLUSIONS: This study shows the active involvement of community pharmacists in polypharmacy by discontinuing inappropriate drugs or reducing the dose of regular drugs, which may contribute to the improvement of adverse effects among outpatients.

High-Trough Plasma Concentration of Afatinib Is Associated with Dose Reduction.

Afatinib is used to treat non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutation as a second-generation EGFR-tyrosine kinase inhibitor (TKI). Early prediction of adverse effects based on the pharmacokinetics of afatinib enables support for quality of life (QOL) in patients with no change in efficacy. We examined the pharmacokinetic relationship between trough plasma concentration and adverse effects and evaluated the utility of measuring the trough plasma concentration of afatinib as the first EGFR-TKI treatment for NSCLC in a prospective multicenter study. Twenty-four patients treated with afatinib were enrolled in this study. All blood samples were collected at the trough point, and plasma concentrations were measured using high-performance liquid chromatography-tandem mass spectrometry. Logistic regression analysis for the dose reduction of afatinib was performed, and the receiver operating characteristic (ROC) curve was plotted. Although all patients started afatinib at 40 mg/day, plasma concentrations were variable, and mean and median trough plasma concentrations were 32.9 ng/mL and 32.5 ng/mL in this study, respectively. Minimum and maximum trough plasma concentrations were 10.4 ng/mL and 72.7 ng/mL, respectively. This variability was speculated to involve personal parameters such as laboratory data. However, no patient characteristics or laboratory data examined correlated with the trough plasma concentration of afatinib, except albumin. Albumin showed a weak correlation with plasma concentration (r = 0.60, p = 0.009). The trough plasma concentration of afatinib was significantly associated with the dose reduction of afatinib (p = 0.047). The area under the ROC curve (AUC) for the trough plasma concentration of afatinib was 0.81. The cut-off value was 21.4 ng/mL. The sensitivity and specificity of the cut-off as a risk factor were 0.80 and 0.75. In summary, the trough plasma concentration of afatinib was associated with continued or reduced dosage because of the onset of several adverse effects, and a threshold was seen. Adverse effects not only lower QOL but also hinder continued treatment. Measuring plasma concentrations of afatinib appears valuable to predict adverse effects and continue effective therapy.

[Evaluation of Capturing Accurate HbA1c Value Using Medical Information and Communication Technology by Pharmacist].

The medical information and communication technology "Kibitan Health Net" was introduced as a part of the medical reconstruction assistance national project in Fukushima. However, its effect on the performance of the pharmacists has not yet been validated in community pharmacy. In this study, we investigated the usefulness of acquisition and utilization of precise medical information from diabetic patients using Kibitan Health Net. The subjects of this study were 18 patients having type 2 diabetes mellitus with a mean HbA1c level of 7.4±1.0 (%). We compared the HbA1c level captured by the pharmacists from the patients (total 72 times) with that updated on Kibitan Health Net (41 times correctly captured by the pharmacists). We next compared the HbA1c levels between the "group that could listen to accurate laboratory data" and the "group that could not listen to accurate laboratory data" using intergroup analysis. After factor analysis between the two groups, we demonstrated that the proportion of patients who could not precisely communicate laboratory results was significantly higher among the elderly population (p<0.05). Recent studies have reported that elderly diabetic patients have a higher risk of cognitive decline and Alzheimer-type dementia resulting in higher brain dysfunction. The utilization of Kibitan Health Net enabled the capturing of precise patient information. These data could make it possible to provide instruction for proper compliance and guidance for recuperation among the elderly diabetic patients, and prevent their cognitive decline due to poor glycemic control, as well as set future therapeutic goals and improve adherence.

A nationwide survey of hospital pharmacist interventions to improve polypharmacy for patients with cancer in palliative care in Japan.

BACKGROUND: There is no nationwide data on polypharmacy in palliative care in Japan. In this study, the research committee of the Japanese Society for Pharmaceutical Palliative Care and Sciences conducted an online survey on polypharmacy and inappropriate prescriptions involving its members who worked as hospital pharmacists. METHODS: The online questionnaire included questions about hospital pharmacist interventions for cancer patients who regularly used six or more drugs during a two-month period from October to November 2017. RESULTS: Of 2618 hospital pharmacists, 359 responded (13.7%). With regard to cancer patients receiving opioids, 40.9 and 22.3% of the respondents replied that percentages of patients prescribed six or more regular medications were "40-69%" and "70-99%," respectively. Regarding patients on polypharmacy, 73.0% of the respondents reported a low or moderate rate of inappropriate prescriptions, with responses such as "long-term administration of irresponsible or aimless medications", "adverse drug reactions," and "duplication of the pharmacological effect". Furthermore, 24.2, 46.8, and 23.4% of respondents replied that the rates of drug reduction due to pharmacist recommendations were "0", "1-39%", and "more than 40%," respectively. Pharmacist interventions decreased the use of inappropriate medications, including antiemetics, gastrointestinal medications, and hypnotic sedatives, and reduced or prevented adverse drug reactions such as extrapyramidal symptoms, delirium, and sleepiness. Similar results were obtained for cancer patients who did not use opioids. However, the rates of cancer patients on polypharmacy and with reduction of inappropriate medications by pharmacist interventions were significantly higher in cancer patients receiving opioids. Finally, recommendations of board-certified pharmacists in palliative pharmacy contributed to a decrease in the use of inappropriate medications in cancer patients on polypharmacy (p = 0.06). CONCLUSION: This nationwide survey clarified pharmacist interventions for polypharmacy in palliative care in Japan. Our data showed frequent polypharmacy in cancer patients receiving opioids, and benefits of pharmacist interventions, especially by board-certified pharmacists in palliative pharmacy, for reducing inappropriate medications and improving adverse drug reactions. TRIAL REGISTRATION: The study approval numbers in the institution; 0046. Registered November 6, 2017.

Analyses of Respiratory Depression Associated with Opioids in Cancer Patients Based on the Japanese Adverse Drug Event Report Database.

Opioid-induced respiratory depression is a potentially life-threatening adverse drug event. The purpose of this study was to evaluate the incidence of respiratory depression using the Japanese Adverse Drug Event Report (JADER) Database to obtain data to promote proper use of opioids. The JADER database from April 2004 to March 2017 was obtained from the Pharmaceuticals and Medical Devices Agency. We calculated the reporting odds ratios (RORs) of suspected opioids (morphine, fentanyl, oxycodone, tapentadol, methadone, tramadol, pentazocine, buprenorphine, and codeine phosphate hydrate), analyzed the daily dose at first appearance and the time-to-onset profile, and assessed the hazard type using the Weibull shape parameter. ROR analysis detected adverse event signals for all opioids. Morphine showed a large ROR value with statistical significance in elderly (≥70 years old) patients. The median daily doses of oral morphine and oxycodone for inducing respiratory depression were comparably low (30 mg/d as oral morphine equivalent dose), while that of transdermal fentanyl was 120 mg/d (oral morphine equivalent dose). On time-to-onset analysis using the Weibull distribution, those opioids were classified as the early failure type. The median time-to-onset of oral morphine, oral oxycodone and transdermal fentanyl was 5.5, 11 and 12.5 d, respectively, and almost 50% of cases were reported within 30 d. Taken together, our results suggest that it is important to monitor patients carefully for at least the first one week to one month, even if opioids are administered at a relatively low dose, especially in elderly patients administered morphine.

Current Status of Adverse Events Related with Opioid Analgesics in Japan: Assessment Based on Japanese Adverse Drug Event Report Database.

Opioid analgesics have greatly contributed to the advancement of pain management. However, although opioids have been appropriately used in Japan, they rarely induce serious adverse events, such as respiratory depression. The present study aimed to investigate the temporal changes in the occurrence of opioid-related adverse events and deaths between 2004 and 2017 in Japan using the Japanese Adverse Drug Event Report (JADER) database. We analyzed the following points using data extracted from JADER website: 1) temporal changes in the number and proportion of opioid-related adverse event reports; 2) temporal changes in the number of morphine-, oxycodone-, and fentanyl-related adverse event reports per annual consumption; and 3) cases in which the reported outcome following opioid-related adverse events was death. Our results showed no dramatic changes in the overall incidence of opioid-related adverse events, despite the temporal changes in the annual consumption and shared component of each opioid during the survey period. However, the number and rate of fentanyl-related adverse events and their outcome "death" increased since 2010, being the highest among all adverse event including those related to morphine and oxycodone. Outcome "death" by fentanyl-related adverse events was caused mainly due to respiratory depression. These findings suggest that, although opioid-related adverse events can be controlled through proper monitoring and management by medical personnel in Japan, extra caution should be continuously paid for the rare but serious fentanyl-induced adverse events.

A Nationwide Survey of Community Pharmacist Contributions to Polypharmacy in Opioid-Using and Non-using Cancer Patients in Japan.

No nationwide study on polypharmacy in palliative care among Japanese community pharmacies has yet been conducted. We conducted an online questionnaire survey for community pharmacist members of The Japanese Society for Pharmaceutical Palliative Care and Sciences regarding their contributions to cancer patients who regularly used six or more drugs, including opioids, in service during the two-month period from October to November 2017. Of 579 community pharmacists, 83 responded to the survey (14.3%). Among them, 47.0 and 27.7% of respondents replied that more than 40% of opioid-using and non-using cancer patients were prescribed six or more regular medications, respectively. The proportion of patients with polypharmacy was marginally higher among opioid-using than non-using patients. Additionally, 31.3 and 22.9% of respondents replied that a low or moderate rate of opioid-using and non-using patients with polypharmacy received inappropriate prescriptions, respectively, including "unnecessary medications," "adverse drug reactions" and "duplication of pharmacological effect." The proportion of patients who received inappropriate prescriptions was significantly higher among opioid-using than non-using patients. Furthermore, 37.3 and 19.3% of respondents replied that pharmacist's recommendations contributed to drug reduction in opioid-using and non-using patients with polypharmacy who received inappropriate prescriptions, respectively. The responders with higher confidence in palliative care showed more success rate for reducing inappropriate medications. Our findings suggest that opioid use can be associated with an increased risk of polypharmacy in cancer patients, and that recommendations by a population of community pharmacists can reduce inappropriate medications and improve adverse drug reactions in both opioid-using and non-using cancer patients with polypharmacy.

One-year intranasal application of growth hormone releasing peptide-2 improves body weight and hypoglycemia in a severely emaciated anorexia nervosa patient.

BACKGROUND: In Japan, growth hormone releasing peptide-2 (GHRP-2) is clinically used as a diagnostic agent for growth hormone secretion deficiency, but the therapeutic application of GHRP-2 has not been studied in anorexia nervosa. GHRP-2 reportedly exhibits agonistic action for ghrelin receptor and increases food intake. METHODS: We administered GHRP-2 to a patient with a 20-year history of anorexia nervosa to determine whether GHRP-2 treatment increases food intake and body weight. GHRP-2 was administered before every meal by an intranasal approach for 1 year. RESULTS: Although the patient reported a decreased fear of eating and decreased desire to be thin by our previous treatment, she was unable to increase food intake or body weight because of digestive tract dysfunction. Vomiting after meals caused by delayed gastric emptying and incurable constipation were prolonged, and sub-ileus and hypoglycemia were observed. GHRP-2 increased the feeling of hunger and food intake, decreased early satiety and improved hypoglycemia. The patient's body weight gradually increased by 6.7 kg (from 21.1 kg to 27.8 kg) in 14 months after starting GHRP-2 administration. The fatigability and muscle strength improved, and the physical and mental activities were also increased. No obvious side effects were observed after long-term intranasal administration of GHRP-2. CONCLUSIONS: Patients with a long-term history of eating disorder occasionally recover from the psychological problems such as fear for obesity but remain emaciated. We believe that ghrelin agonists such as GHRP-2 may be promising agents for the effective treatments of severe anorexia nervosa in a chronic condition.

Functional characterization of neural-restrictive silencer element in mouse pituitary adenylate cyclase-activating polypeptide (PACAP) gene expression.

Pituitary adenylate cyclase-activating polypeptide (PACAP) is predominantly localized in the nervous system, but the underlying mechanism in its neuron-specific expression remains unclear. In addition to two neural-restrictive silencer-like element (NRSLE1 and 2), as reported previously, we have identified the third element in -1,601 to -1,581 bp from the translational initiation site of mouse PACAP gene and termed it as NRSLE3, of which, the sequence and location were highly conserved among mouse, rat, and human PACAP genes. In luciferase reporter assay, the deletion or site-directed mutagenesis of NRSLE3 in the reporter gene construct, driven by heterologous SV40 promoter, cancelled the repression of luciferase activity in non-neuronal Swiss-3T3 cells. Furthermore, its promoter activity was significantly repressed in Swiss-3T3 cells, but not in neuronal-differentiated PC12 cells. The electrophoretic mobility shift assay (EMSA) with nuclear extracts of Swiss-3T3 cells demonstrated a specific complex with NRSLE3 probe that exhibited the same migration with the neural-restrictive silencer element (NRSE) probe of rat type II sodium channel gene. During neuronal differentiation of PC12 cells, the increment of PACAP mRNA exhibited the correlation with that of REST4 mRNA, which is a neuron-specific variant form of neural-restrictive silencer factor (NRSF). In undifferentiated PC12 cells, trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, which indirectly inhibits NRSF-mediated gene silencing, increased PACAP mRNA level and attenuated the repression of promoter activity of 5' flanking region of mouse PACAP gene containing NRSLEs. These suggest that the NRSE-NRSF system implicates in the regulatory mechanism of neuron-specific expression of PACAP gene.

Characterization of the testis-specific promoter region in the human pituitary adenylate cyclase-activating polypeptide (PACAP) gene.

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a pleiotropic neuropeptide localized in the testis at concentration comparable to that found in the brain, suggesting involvement in spermatogenesis. In this study, we identified the human PACAP testis-specific exon (TSE) 10.9 kb upstream from the translational start site and found that the testis-specific transcript of the human PACAP gene was found to be spliced from the TSE into a region of intron 2 without a frameshift. The resulting PACAP precursor has no signal peptide, suggesting that PACAP functions physiologically in an intracrine manner in the testis. The 5'-flanking region of the TSE contains an 80-bp fragment with potent promoter activity in testicular F9 cell. Electrophoresis mobility shift assays showed that proteins from the F9 nuclear extract interacted specifically with the 80-bp fragment. DNA affinity chromatography allowed isolation of the specific proteins bound to the 80-bp fragment, two of which were identified as Poly (ADP-ribose) polymerase-1 (PARP-1) and TIA-1-related protein (TIAR) by mass spectrometry. By using their siRNAs, the depletion of their proteins in F9 cells affected the potent promoter activity of the 80-bp fragment, suggesting that they might be involved in the testis-specific gene expression of PACAP.

Alternative splicing of the pituitary adenylate cyclase-activating polypetide (PACAP) receptor contributes to function of PACAP-27.

Pituitary adenylate cyclase-activating polypeptide (PACAP)-27 and PACAP-38 are neuropeptides performing a variety of physiological functions. The PACAP-specific receptor PAC1 has several variants that result mainly from alternative splicing in the mRNA region encoding the first extracellular (EC1) domain and the third intracellular cytoplasmic (IC3) loop. To characterize the molecular forms of alternative splicing variants of PAC1, we examined the binding affinity and activation of two major second messenger pathways (cAMP production and changes in [Ca(2+)]( i )) by PACAP-27. Activation of cAMP was influenced by the variant in both of the EC1 domain and IC3 loops. In the N form in the EC1 domain, the suppressive effect of the HOP1 form in the IC3 loop was enhanced. Regarding the intracellular calcium mobilization assay, the rank order of the potency of PACAP-27 for the different PAC1 isoforms was S/HOP1>>N/R~S/R>>N/HOP1. In particular, PACAP-27 exhibited remarkable potency of calcium mobilization in the S/HOP1-expressing cells at sub-picomolar concentrations even though the affinities of PACAP-27 to the four PAC1 isoforms were not significantly different. This suggests the specific functions of PACAP-27 due to PACAP-27 preferring PAC1 activation, and leads in clarification of the pleiotoropic function of PACAP.

Implication of pituitary adenylate cyclase-activating polypeptide (PACAP) for neuroprotection of nicotinic acetylcholine receptor signaling in PC12 cells.

Pituitary adenylate cyclase-activating polypeptide (PACAP) functions as a neurotrophic factor through PAC1-R, PACAP-specific receptor, in the central nervous system. On the other hand, by interacting with nicotinic acetylcholine receptor (nAChR), nicotine exhibits several neuroprotective effects. Since the relevance of PACAP and nAChR signaling has not been reported so far, we attempted to investigate their relevance in terms of neuroprotection in PC12 cells. Regarding the effect of nicotine on PACAP gene expression, nicotine increased its mRNA level in time-dependent and dose-dependent manners in the PC12 cells differentiated with nerve growth factor (NGF). In addition, luciferase reporter assay demonstrated that nicotine treatment significantly augments the promoter activity of PACAP gene. Since PAC1-R mRNA expression was induced by NGF, PACAP exhibited neuroprotective effect against tunicamycin-induced cell death in the differentiated PC12 cells. Nicotine also exhibited the neuroprotective effect, which was significantly attenuated by Max.d.4 (PAC1-R specific antagonist). These results suggest that the increment of PACAP gene expression due to nicotine treatment might be involved in the neuroprotection by nicotine.

Differential intracellular signaling through PAC1 isoforms as a result of alternative splicing in the first extracellular domain and the third intracellular loop.

Pituitary adenylate cyclase-activating polypeptide (PACAP), a pleiotropic neuropeptide, performs a variety of physiological functions. The PACAP-specific receptor PAC1 has several variants that result mainly from alternative splicing in the mRNA regions encoding the first extracellular (EC1) domain and the third intracellular cytoplasmic (IC3) loop. The effects on downstream signaling produced by combinations of alternative splicing events in the EC1 domain and IC3 loop have not yet been clarified. In this study, we have used semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) to examine the tissue distributions of four PAC1 isoforms in mice. We then established cell lines constitutively expressing each of the PAC1 isoforms and characterized the binding properties of each isoform to PACAP-38, vasoactive intestinal polypeptide (VIP), and the PAC1-specific agonist maxadilan, as well as the resulting effects on two major intracellular signaling pathways: cAMP production and changes in the intracellular calcium concentration. The results demonstrate that the variants of the IC3 loop affect the binding affinity of the ligands for the receptor, whereas the variants of the EC1 domain primarily affect the intracellular signaling downstream of PAC1. Accordingly, this study indicates that the combination of alternative splicing events in the EC1 domain and the IC3 loop create a variety of PAC1 isoforms, which in turn may contribute to the functional pleiotropism of PACAP. This study not only contributes to the understanding of the multiple functions of PACAP but also helps to elucidate the relationship between the structures and functions of G-protein-coupled receptors.

Characterization of the PAC1 variants expressed in the mouse heart.

Pituitary adenylate cyclase-activating polypeptide (PACAP), a pleiotropic neuropeptide, exerts a variety of physiological functions through three types of G protein-coupled receptors, PAC1, VPAC1, and VAPC2. Characterization of the molecular forms of PAC1 in mouse heart revealed the presence of four types of variant receptors harboring the N or S variant in the first extracellular domain (EC1 domain) with or without the HOP1 insert in the third intracellular cytoplasmic loop (IC3 loop). Then, we assessed the binding affinity and ability to stimulate adenylyl cyclase of the PCA1 variant-expressing cells for PACAP. Adenylyl cyclase activation by PACAP was markedly influenced with the variant in the EC1 domain as well as that in the IC3 loop, in spite of a little difference in their binding properties. These data suggest that the combination of EC1 domain variants and IC3 loop variants might account for the diversity of intracellular signaling, which might contribute to multiple functions of PACAP including a role in the cardiovascular system.

Neural-restrictive silencers in the regulatory mechanism of pituitary adenylate cyclase-activating polypeptide gene expression.

Pituitary adenylate cyclase-activating polypeptide (PACAP) is known as a pleiotropic neuropeptide and is present abundantly in central nervous system. During a detailed analysis of the 5'-flanking region of the mouse PACAP gene, we found and characterized two negative regulatory elements, which are homologous to the neural-restrictive silencer element, and are termed neural-restrictive silencer-like elements 1 and 2 (NRSLE1 and NRSLE2). Their sequence and position were significantly conserved among mouse, human, and rat PACAP genes. In the electrophoretic mobility shift assay (EMSA) with nuclear extracts of Swiss-3T3 cells and individual oligonucleotide probes for NRSLE1 and NRSLE2, a specific complex was observed to have the same migration as compared with the NRSE probe of rat type II sodium channel gene (NaII). Furthermore, these complexes were efficiently competed by the unlabeled NaII probe. In the luciferase reporter assay, the reporter gene constructs containing NRSLEs, driven by heterologous SV40 promoter, exhibited repression of luciferase activity almost equal to basal level in Swiss-3T3 cells. In contrast, the repression was not observed in differentiated PC12 cells with NGF. These results suggested that the neural-restrictive silencer system might be involved in the regulatory mechanism of neuron-specific PACAP gene expression.

Diverse effects of intrathecal pituitary adenylate cyclase-activating polypeptide on nociceptive transmission in mice spinal cord.

Pituitary adenylate cyclase-activating polypeptide (PACAP) immunoreactive neural elements have been detected in the mouse spinal cord. The discrepancy of PACAP actions in the role of sensory transmission has been proposed to have potentiation and inhibition on nociceptive responses after intrathecal application of PACAP. The aim of the present study was to assess nociceptive transmission of PACAP in the mouse spinal cord by comparison with that of substance P (SP). The intrathecal injection of PACAP induced licking or scratching behavior similar to that of SP. These PACAP-induced aversive behaviors showed different manner from SP-induced responses in point of time course. SP-induced aversive responses quickly increased and suddenly disappeared almost within 1 min. Meanwhile, following a long latency after the injection, PACAP-induced aversive responses gradually appeared, and then persisted more than 60 min. In the early phase, PACAP produced an increase of tail flick latency. Pretreatment with 6-hydroxydopamine (6-OHDA) which destroys noradrenaline neuron of descending pain inhibitory systems in the spinal cord markedly abridged the latency and augmented the duration of PACAP-induced aversive responses. In this way, PACAP exhibits diverse effects on nociception, such as an analgesic role in early phase of the injection and subsequently lasting algesia. These results suggest that PACAP as a neurotransmitter or neuromodulator might have crucial role in nociceptive transmission system.

[The regulatory mechanism for neuron specific expression of PACAP gene].

Pituitary adenylate cyclase-activating polypeptide (PACAP), a pleiotropic neuropeptide, is present abundantly in the central nervous system. In the 5'-flanking region of the PACAP gene, we found and characterized two negative regulatory elements, which are homologous to the neural-restrictive silencer element (NRSE). Their sequence and position were significantly conserved among mouse, human, and rat PACAP genes. NRSE is a crucial negative-acting DNA regulatory element for neuron-specific gene expression. NRSE acts through the transcription factor known as neural-restrictive silencer factor (NRSF). In non-neuronal cells, NRSF suppresses the expression of neuron-specific genes. On the other hand, in neuronal cells, NRnV, a NRSF truncated form, repress their expressions in a dominant negative manner. The electrophoretic mobility shift assay with 3T3 cells extract demonstrated the identical complexes among NRSLE-1, NRSLE2, and the NRSE of rat type II sodium channel gene. In the luciferase reporter assay, NRSLEs suppressed SV40 promoter activity in 3T3 cells, but not in PC12 cells. RT-PCR analysis revealed that PACAP and NRnV mRNAs are expressed in neuronal cells (differentiated PC12), but not in non-neuronal cells (3T3 or C6). These results suggested that the NRSE-NRSF system might be involved in the regulatory mechanism of neuron-specific expression of the PACAP gene.