RNA interference-mediated knock-down of transient receptor potential vanilloid 1 prevents forepaw inflammatory hyperalgesia in rat

Transient receptor potential vanilloid (TRPV)1 is a ligand-gated cation channel expressed by primary sensory neurons, including those in the dorsal root ganglia (DRG). TRPV1 plays an essential role in development of inflammatory thermal hyperalgesia after tissue injury and its expression in rat lumbar DRG is increased after hindpaw inflammation. However, the identity of factors mediating forepaw inflammatory hyperalgesia has remained elusive. Here, we examined behavioral responses to noxious thermal stimuli after forepaw inflammation in rats and found that inflammation induced by intraplantar injection of complete Freund's adjuvant significantly reduced hot-plate latency (HPL) at 50 degrees C. TRPV1 expression levels in the ipsilateral cervical DRG were also elevated after forepaw inflammation. By contrast, HPL at 56 degrees C was not shortened after forepaw inflammation and expression of TRPV2, a TRPV1 homolog, in the DRG was not increased. Paratracheal injection of short interfering RNA targeting TRPV1 blocked TRPV1 up-regulation in cervical DRG and abolished inflammation-mediated HPL reductions seen at 50 degrees C. However, thermal hyperalgesia previously established by inflammation was not reversed by short interfering RNA injection. These results indicate that: (i) enhanced TRPV1 expression in cervical DRG is closely associated with development of inflammatory thermal hyperalgesia in the forepaw after tissue injury and (ii) RNA interference targeting TRPV1 prevents inflammatory thermal hyperalgesia after forepaw injuries but does not ameliorate it when already established in a rat model of nociceptive pain representing upper limb injury in humans.     

Inhibition of NMDA-induced protein kinase C translocation by a Zn chelator: Implication of intracellular Zn

The role of intracellular Zn²⁺ in the translocation of protein kinase C from cytosol to membrane fractions was examined by the [³H]phorbol 12,13-dibutyrate (PDBu) binding method in guinea pig cerebral synaptoneurosomes. N-methyl-d-aspartate (NMDA, 100 μM) and calcium ionophore A23187 (0.3–30 μM) decreased the binding activity in the cytosol with a concomitant increase in the membrane fractions. Pretreatment of synaptoneurosomes with a heavy metal chelator, N,N,N′,N′-tetrakis-(2-pyridylmethyl)ethylenediamine (TPEN), inhibited the NMDA- and A23187-induced changes of the distribution of [³H]PDBu binding sites in cytosol and membrane fractions. The inhibitory effect of TPEN was negated by a preincubation of TPEN with equimolar Zn²⁺ but not by that with Ca²⁺. The addition of 500 μM Zn²⁺ to the lysate of synaptoneurosomes induced an increase of [³H]PDBu binding activity in the membrane fraction with a concomitant decrease in the cytosol fraction, as did 100 μM Ca²⁺. Low concentrations of Zn²⁺ (10 μM), which alone had no effect on the distribution of the binding, significantly enhanced the effect of 10 μM Ca²⁺ in the lysate. Under those conditions TPEN inhibited the Zn²⁺-potentiated Ca²⁺-dependent changes in the binding. These results suggest that intracellular Zn²⁺ is essential for the agonist-induced translocation of protein kinase C in guinea pig synaptoneurosomes.     

Nonsense Mutation at Codon 63 of the BRCA1 Gene in Japanese Breast Cancer Patients

The involvement of abnormalities of the BRCA1 gene in breast cancers in Japanese patients without any family history of this cancer was investigated by polymerase chain reaction-based single-strand conformation polymorphism analysis of the DNA sequences corresponding to the zinc finger domain (exons 2, 3 and 5) and the binding domain with Rad51 (exon 11) of the BRCA1 protein. An identical nonsense mutation at codon 63 (TTA to TAA) was found in 2 of 56 (3.5%) breast cancers from independent patients. The nucleotide change was also detected in the DNAs from non-cancerous tissues of both patients and therefore was a germline mutation. One of the patients was a member of a pedigree involving 3 ovarian cancer and 1 gastric cancer patients, while the other patient had no family history of malignancy. The same germline mutation at codon 63 was reported in four other independent Japanese pedigrees with frequent breast cancer, but not in such families in other countries. These observations suggest that the mutation commonly originated from a single Japanese ancestor. No other mutation of the BRCA1 gene was observed in the samples analyzed in this study. A low incidence of germline mutation and the absence of somatic mutation suggest that the aberration of the BRCA1 gene is involved only in a subset of Japanese breast cancers.     

Gerstmann-Sträussler syndrome — A variant type: amyloid plaques and Alzheimer's neurofibrillary tangles in cerebral cortex

Summary This report presents a variant of Gerstmann-Sträussler syndrome (GSS). A 53-year-old female had developed slowly progressive dementia and atactic gait since the age of 45. No myoclonic jerks and periodic synchronous discharges were observed throughout the illness. The neuropathological study revealed that many amyloid plaques and widespread Alzheimer's neurofibrillary tangles (NFTs) appeared in the cerebral cortex. Characteristically, the plaques reacted with anti-prion protein and none of them reacted with anti- protein, and they were made of many components, including amyloid cores, macrophages laden with lipid granules and/or degenerated neurites. Neuropil threads were seen mainly in amyloid plaques. Moreover, plaques appeared which were confluent and laminar in arrangement in the fifth and sixth cortical layers and had a close relationship to the neuronal loss. There was no spongiform change in the cerebral cortex or cerebellum. The cerebellum was almost intact except for a few amyloid plaques. Ultrastructurally, some of the plaques simulated kuru plaques and others had many degenerated neurites possessing paired helical filaments and other accumulated organelles. GSS has been proposed to include cases with progressive ataxia, dementia and massive multifocal plaques in the brain with or without cerebral spongiform changes. The case presented here is a very peculiar case of GSS. Recently, similar cases have been reported in some large families, diagnosed as familial Alzheimer's disease. These cases may be a telencephalic form with numerous NFTs of GSS.     

Neuronal responses in the nucleus accumbens shell during sexual behavior in male rats

Previous behavioral studies have indicated that the nucleus accumbens (NAc) shell of a male rat is involved in its sexual behavior; however, no previous studies have investigated neuronal activities in the male rat NAc shell during sexual behavior. To investigate this issue, we recorded single unit activities in the NAc shell of male rats during sexual behavior. Of 123 NAc shell neurons studied, 53, 47, and 40 neurons exhibited significantly changed firing rates at various times during intromission, genital auto-grooming, and sniffing of females, respectively. The two types of NAc shell neurons [putative fast spiking interneurons (pFSIs) and medium spiny neurons (pMSNs)] responded differently during sexual behavior. First, more pFSIs than pMSNs exhibited inhibitory responses to thrusting with intromission and genital grooming, while pFSIs and pMSNs responded similarly to sniffing of females. Second, both pFSIs and pMSNs responded differently to thrusting with and without intromission. Furthermore, NAc shell neuronal activity was significantly different across the different phases of sexual behavior, and the number of NAc shell neurons with delta oscillation, which is related to behavioral inhibition, and high gamma oscillation, which is related to reward perception, increased after ejaculation. Together, our results suggest that the NAc shell is deeply involved in sexual behavior, and changes in NAc shell neuronal activity are related to performance of sexual behavior, encoding cues or contexts related to sexual behavior, reward-related processing, and the inhibition of sexual behavior after ejaculation.     

Influence of the COVID-19 Pandemic on Overall Physician Visits and Telemedicine Use Among Patients With Type 1 or Type 2 Diabetes in Japan

BackgroundRegular visits with healthcare professionals are important for preventing serious complications in patients with diabetes. The purpose of this retrospective cohort study was to clarify whether there was any suppression of physician visits among patients with diabetes during the spread of the novel coronavirus 2019 (COVID-19) in Japan and to assess whether telemedicine contributed to continued visits.MethodsWe used the JMDC Claims database, which contains the monthly claims reported from July 2018 to May 2020 and included 4,595 (type 1) and 123,686 (type 2) patients with diabetes. Using a difference-in-differences analysis, we estimated the changes in the monthly numbers of physician visits or telemedicine per 100 patients in April and May 2020 compared with the same months in 2019.ResultsFor patients with type 1 diabetes, the estimates for total overall physician visits were −2.53 (95% confidence interval [CI], −4.63 to 0.44) in April and −8.80 (95% CI, −10.85 to −6.74) in May; those for telemedicine visits were 0.71 (95% CI, 0.47–0.96) in April and 0.54 (95% CI, 0.32–0.76) in May. For patients with type 2 diabetes, the estimates for overall physician visits were −2.50 (95% CI, −2.95 to −2.04) in April and −3.74 (95% CI, −4.16 to −3.32) in May; those for telemedicine visits were 1.13 (95% CI, 1.07–1.20) in April and 0.73 (95% CI, 0.68–0.78) in May.ConclusionThe COVID-19 pandemic was associated with suppression of physician visits and a slight increase in the utilization of telemedicine among patients with diabetes during April and May 2020.Key words: COVID-19, telemedicine, outpatient, diabetes     

Overexpression of RGPR-p117 induces the decrease in protein and DNA contents in cloned normal rat kidney proximal tubular epithelial NRK52E cells

A novel protein RGPR-p117 was discovered as a regucalcin gene promoter region-related protein that binds to the TTGGC motif. Regucalcin is known to regulate the intracellular signaling system in many cell types. RGPR-p117 has been shown to enhance the promoter activity of the regucalcin gene in cloned normal rat kidney proximal tubular epithelial NRK52E cells. The role of RGPR-p117 in cell function remains to be elucidated, however. This study was undertaken to determine whether overexpression of RGPR-p117 has an effect on cell proliferation, protein and DNA contents in NRK52E cells. NRK52E cells (wild-type) or stable RGPR-p117/phCMV2-transfected cells (transfectants) were cultured in Dulbecco's minimum essential medium containing 5% bovine serum (BS). RGPR-p117 was markedly expressed in the transfectants. NRK52E cells (wild-type) or transfectants were cultured for 24, 48, or 72 h in a medium containing 5% BS, and after subconfluency the cells were cultured for 24, 48, or 72 h in a medium without BS. Cell proliferation was not significantly changed in the transfectants as compared with that of wild-type cells. Protein and DNA contents in NRK52E cells were significantly decreased in the transfectants with cell proliferation in the presence of BS. When NRK52E cells with subconfluency were cultured for 24, 48, or 72 h in a medium without BS, the number of transfectant cells was not significantly changed compared with that of wild-type cells. Protein and DNA contents in NRK52E cells were significantly decreased in the transfectants cultured in a medium without BS after subconfluency. This study demonstrates that overexpression of RGPR-p117 induces the decrease in protein and DNA contents in NK52E cells, indicating its role in the regulation of cell function.