RNA editing of AZIN1 coding sites is catalyzed by ADAR1 p150 after splicing

Adenosine-to-inosine RNA editing is catalyzed by nuclear adenosine deaminase acting on RNA 1 (ADAR1) p110 and ADAR2, and cytoplasmic ADAR1 p150 in mammals, all of which recognize dsRNAs as targets. RNA editing occurs in some coding regions, which alters protein functions by exchanging amino acid sequences, and is therefore physiologically significant. In general, such coding sites are edited by ADAR1 p110 and ADAR2 before splicing, given that the corresponding exon forms a dsRNA structure with an adjacent intron. We previously found that RNA editing at two coding sites of antizyme inhibitor 1 (AZIN1) is sustained in Adar1 p110/Aadr2 double KO mice. However, the molecular mechanisms underlying RNA editing of AZIN1 remain unknown. Here, we showed that Azin1 editing levels were increased upon type I interferon treatment, which activated Adar1 p150 transcription, in mouse Raw 264.7 cells. Azin1 RNA editing was observed in mature mRNA but not precursor mRNA. Furthermore, we revealed that the two coding sites were editable only by ADAR1 p150 in both mouse Raw 264.7 and human embryonic kidney 293T cells. This unique editing was achieved by forming a dsRNA structure with a downstream exon after splicing, and the intervening intron suppressed RNA editing. Therefore, deletion of a nuclear export signal from ADAR1 p150, shifting its localization to the nucleus, decreased Azin1 editing levels. Finally, we demonstrated that Azin1 RNA editing was completely absent in Adar1 p150 KO mice. Thus, these findings indicate that RNA editing of AZIN1 coding sites is exceptionally catalyzed by ADAR1 p150 after splicing.

Development of a desktop mask charger

Polypropylene mesh, integrated in N95 respirators and surgical masks that are widely used in the current crisis of COVID-19, filters aerosols via electrostatics in addition to the physical block. However, any contact to water such as storage under high humidity, exposure to exhaling breath, and washing in water removes its charges and thus compromises its filtering efficiency. We developed a desk top device based on a Cockcroft-Walton's voltage multiplier that can restore the electrostatic charge of surgical masks within 1 min and recover the filtering efficiency of the polypropylene mesh from 87% to 97%. The device is easy to operate and safe, thus may be applied for the reuse of surgical masks towards reducing the plastic wastes.

An Aicardi-Goutières Syndrome-Causative Point Mutation in Adar1 Gene Invokes Multiorgan Inflammation and Late-Onset Encephalopathy in Mice

Aicardi-Goutières syndrome (AGS) is a congenital inflammatory disorder accompanied by overactivated type I IFN signaling and encephalopathy with leukodystrophy and intracranial calcification. To date, none of the mouse models carrying an AGS-causative mutation has mimicked such brain pathology. Here, we established a mutant mouse model carrying a K948N point mutation, corresponding to an AGS-causative K999N mutation, located in a deaminase domain of the Adar1 gene that encodes an RNA editing enzyme. Adar1^K948N/K948N mice displayed postnatal growth retardation. Hyperplasia of splenic white pulps with germinal centers and hepatic focal inflammation were observed from 2 mo of age. Inflammation developed in the lungs and heart with lymphocyte infiltration in an age-dependent manner. Furthermore, white matter abnormalities with astrocytosis and microgliosis were detected at 1 y of age. The increased expression of IFN-stimulated genes was detected in multiple organs, including the brain, from birth. In addition, single-nucleus RNA sequencing revealed that this elevated expression of IFN-stimulated genes was commonly observed in all neuronal subtypes, including neurons, oligodendrocytes, and astrocytes. We further showed that a K948N point mutation reduced the RNA editing activity of ADAR1 in vivo. The pathological abnormalities found in Adar1^K948N/K948N mice were ameliorated by either the concurrent deletion of MDA5, a cytosolic sensor of unedited transcripts, or the sole expression of active ADAR1 p150, an isoform of ADAR1. Collectively, such data suggest that although the degree is mild, Adar1^K948N/K948N mice mimic multiple AGS phenotypes, including encephalopathy, which is caused by reduced RNA editing activity of the ADAR1 p150 isoform.

RNA editing at a limited number of sites is sufficient to prevent MDA5 activation in the mouse brain

Adenosine deaminase acting on RNA 1 (ADAR1), an enzyme responsible for adenosine-to-inosine RNA editing, is composed of two isoforms: nuclear p110 and cytoplasmic p150. Deletion of Adar1 or Adar1 p150 genes in mice results in embryonic lethality with overexpression of interferon-stimulating genes (ISGs), caused by the aberrant recognition of unedited endogenous transcripts by melanoma differentiation-associated protein 5 (MDA5). However, among numerous RNA editing sites, how many RNA sites require editing, especially by ADAR1 p150, to avoid MDA5 activation and whether ADAR1 p110 contributes to this function remains elusive. In particular, ADAR1 p110 is abundant in the mouse brain where a subtle amount of ADAR1 p150 is expressed, whereas ADAR1 mutations cause Aicardi-Goutières syndrome, in which the brain is one of the most affected organs accompanied by the elevated expression of ISGs. Therefore, understanding RNA editing-mediated prevention of MDA5 activation in the brain is especially important. Here, we established Adar1 p110-specific knockout mice, in which the upregulated expression of ISGs was not observed. This result suggests that ADAR1 p150-mediated RNA editing is enough to suppress MDA5 activation. Therefore, we further created Adar1 p110/Adar2 double knockout mice to identify ADAR1 p150-mediated editing sites. This analysis demonstrated that although the elevated expression of ISGs was not observed, only less than 2% of editing sites were preserved in the brains of Adar1 p110/Adar2 double knockout mice. Of note, we found that some sites were highly edited, which was comparable to those found in wild-type mice, indicating the presence of ADAR1 p150-specific sites. These data suggest that RNA editing at a very limited sites, which is mediated by a subtle amount of ADAR1 p150, is sufficient to prevents MDA5 activation, at least in the mouse brain.

The identified clinical features of Parkinson's disease in homo-, heterozygous and digenic variants of PINK1

To investigate the prevalence and genotype-phenotype correlations of phosphatase and tensin homolog induced putative kinase 1 (PINK1) variants in Parkinson's disease (PD) patients, we analyzed 1700 patients (842 familial PD and 858 sporadic PD patients from Japanese origin). We screened the entire exon and exon-intron boundaries of PINK1 using Sanger sequencing and target sequencing by Ion torrent system. We identified 30 patients with heterozygous variants, 3 with homozygous variants, and 3 with digenic variants of PINK1-PRKN. Patients with homozygous variants presented a significantly younger age at onset than those with heterozygous variants. The allele frequency of heterozygous variants in patients with age at onset at 50 years and younger with familial PD and sporadic PD showed no differences. [¹²³I]meta-iodobenzylguanidine (MIBG) myocardial scintigraphy indicated that half of patients harboring PINK1 heterozygous variants showed a decreased heart to mediastinum ratio (12/23). Our findings emphasize the importance of PINK1 variants for the onset of PD in patients with age at onset at 50 years and younger and the broad spectrum of clinical symptoms in patients with PINK1 variants.

Count of Fasciculation in Ultrasound Can Predict the Prognosis of Amyotrophic Lateral Sclerosis

Background:

Although muscle ultrasound (MUS) is known to facilitate the diagnosis and evaluation of the severity of amyotrophic lateral sclerosis (ALS), the number of fasciculation has been scarcely examined as a predictive marker of the prognosis in ALS.

Objective:

The objective of this study was to examine the predictive value of fasciculation number for the prognosis of ALS.

Materials and Methods:

We examined fasciculation count (FasC), defined as the number of fasciculation per unit of time and area in MUS, of 11 patients with clinically probable or definite ALS. Thereafter, they were observed for maximally 2 years, unless they reached the endpoint of decease or receiving tracheostomy.

Results:

Six patients, who thereafter reached the endpoint within 2 years, had significantly higher FasC (223 [49.3] vs. 34 [13], P = 0.0043) and shorter disease duration (7 [2.3] vs. 33 [17], P = 0.0022) at MUS than the remaining five patients without reaching the endpoint.

Discussion and Conclusion:

Our study suggested that high FasC in MUS can predict rapid progression in ALS. Due to the limitations such as small sample size, suboptimal length of the observational period, and confounding factor of disease duration, further investigations are required.

Continuous glucose monitoring can disclose glucose fluctuation in advanced Parkinsonian syndromes

Continuous glucose monitoring (CGM) is a method to examine glucose concentration in subcutaneous interstitial fluid sequentially. CGM can disclose glucose fluctuation (GF), which can be unrecognized in routine blood tests. A limited number of studies suggest advanced Parkinsonian syndromes (PS) is at risk of GF, however, the report of CGM in PS is scarce. We performed CGM for 72 h in 11 nondiabetic patients with advanced PS. The etiology was Parkinson’s disease, multiple system atrophy, progressive supranuclear palsy, or dementia with Lewy bodies. All participants were bedridden, elderly (≥65 year-old), and receiving enteral nutrition. The retrospective data was obtained after the removal of CGM device. In the glucose concentration, 9 (81.8%) participants showed nocturnal decline (≤70 mg/dL; 4 of them reached recordable limit of 40 mg/dL), and 6 (54.5%) participants showed remarkable elevation (≥200 mg/dL) postprandially. In the majority, these abnormalities were difficult to predict from routine blood tests. Standard deviation and mean of sequential glucose concentration were higher than those in precedent reports of young or middle-aged healthy controls. CGM in nondiabetic and elderly patients with advanced PS can disclose GF, with features of nocturnal decline and/or postprandial remarkable elevation of glucose concentration. Owing to limitations such as small sample size, heterogeneity of etiology, and retrospectivity of CGM data, further investigations are required.

Injection of Onabotulinum Toxin A into the Bilateral External Oblique Muscle Attenuated Camptocormia: A Prospective Open-Label Study in Six Patients with Parkinson's Disease

INTRODUCTION

Camptocormia (severe bending of the spine) is a debilitating complication of Parkinson's disease (PD) without established treatment. Botulinum toxin (BT) may be beneficial, but data is scarce regarding the efficacy of administration of BT into the bilateral external oblique (EO) muscle for treatment of camptocormia in PD.

METHODS

Six patients with PD and camptocormia, with flexion of the thoracic spine, were enrolled in the study. BT (75 or 90 units, onabotulinum toxin A) were injected into each EO bilaterally under sonographic guidance. Camptocormia angle (CA) was defined as the angle between the acromion-greater trochanter line and a vertical line. CA and disabling symptoms were evaluated during the treatment course.

RESULTS

Two weeks after the injection of BT, the mean CA showed significant attenuation [median (interquartile range); 38° (23.5°) vs. 18° (21°), p = 0.028]. Subjective relief was present in cases 1-3 and 6, and absent in cases 4 and 5. Cases 1-3 received repeated injections to maintain the amelioration; in cases 1 and 2, this was for 1 year or longer, while falls of case 3 limited the amelioration.

CONCLUSION

Botulinum therapy into bilateral EO attenuated the angle of thoracic-level camptocormia in six patients with PD over the observation period of 2 weeks. The reproducibility of the results, long-term efficacy, and subjective relief of symptoms require further examination.

Effect of famotidine on recurrent bleeding after successful endoscopic treatment of bleeding peptic ulcer

AIM

We investigated the effect of acid suppression therapy on recurrent bleeding after successful endoscopic treatment of bleeding peptic ulcer.

METHODS

A total of 400 patients with bleeding peptic ulcer received either intravenous infusion of famotidine (40 mg/day) (n = 207, 163 males, 44 females, mean age 61.5 years) or drip infusion of omeprazole (40 mg/day; n = 193, 134 males, 59 females, mean age 59.8 years) after successful endoscopic treatment. The fasting duration, hospital stay, volume of transfused blood, incidence of rebleeding and mortality were compared between the two groups.

RESULTS

The incidence of rebleeding did not differ significantly between the famotidine group (9%) and the omeprazole group (8%). The mean hospital stay was significantly shorter in the omeprazole group (18.4 days) than in the famotidine group (21.5 days, P = 0.009). However, there was no statistically significant difference in fasting duration, volume of transfused blood or mortality.

CONCLUSION

Our findings indicate that intravenous infusion of famotidine after successful endoscopic treatment is equivalent to drip infusion of omeprazole for prevention of recurrent bleeding.

Effect of additives on insulin absorption from intratracheally administered dry powders in rats

The lungs are useful for administration of macromolecules, which are poorly absorbed from the intestine. In the present study, we prepared several dry powder formulations of insulin using a spray drying technique to examine the effect of additives on insulin absorption. The bioavailability of insulin was estimated from the change in the plasma glucose level. The bioavailability of insulin from dry powder with no additive exceeded that obtained from pH 7.4 solution. The absolute bioavailability of insulin administered as a solution with 1.4 mg/dose of bacitracin or 1.0 mg/dose of Span 85 was almost 100%. The bioavailability of dry powder with 0.42 mg/dose of bacitracin was 20% that of the solution with 1.4 mg/dose of bacitracin. The insulin dry powder with 0.21 mg/dose of Span 85 showed a bioavailability less than that for the insulin solution with 0.1 mg/dose of Span 85. Bacitracin and Span 85 were not as effective in dry powder as in solution in the present study. While citric acid was more effective in dry powder that in solution to increase the hypoglycemic effect. The pH 5.0 and pH 3.0 solutions containing 0.19 mg of citric acid in 0.1 ml showed absolute bioavailabilities of 43% and 57%, respectively, while the bioavailabilities for dry powders containing 0.025 and 0.036 mg/dose citric acid were 42% and 53%, respectively. In addition, the hypoglycemic effect of dry powders continued for a longer period and remained at 240 min with the dry powders, while it disappeared at 180 min with the solutions. When the insulin dry powder containing 0.036 mg/dose of citric acid was administered, the lactate dehydrogenase activity, a sensitive indicator of acute toxicity to lung cells, in bronchoalveolar lavage was as low as that for saline administration, suggesting citric acid is a safe additive. Thus, citric acid appears to be a safe and potent absorption enhancer for insulin in dry powder.

Impairment in biochemical level of arterial dilative capability of a cyclic nucleotides-dependent pathway by induced vasospasm in the canine basilar artery

The authors investigated the changes and the potential of cyclic nucleotide-dependent signal transduction, which induces smooth muscle relaxation, in the basilar artery with severe vasospasm in dogs with double experimental subarachnoid hemorrhage (SAH) to explore at which biochemical level the arterial dilative capability was impaired. The amount of cyclic adenosine and guanosine monophosphates (cAMP and cGMP) decreased significantly in the basilar artery after SAH. The activities of adenylate and guanylate cyclases also were decreased significantly in the smooth muscle cells of the basilar artery 4 days after SAH. In addition to the failure of the pathways to produce cyclic nucleotides, the activities of cAMP- and cGMP-dependent protein kinases, which are representative actual enzymes that amplify the signal for vascular dilation, also significantly decreased together with the almost total loss of activation by cyclic nucleotides in the same basilar artery after SAH. It was revealed that the system for smooth muscle relaxation was impaired severely in the cerebral arteries with severe vasospasm after SAH, on the biochemical basis of significantly less vasodilative capability and in several of the steps to produce the cyclic nucleotides of intracellular signal transduction.

Protein synthesis and immunoreactivities of contraction-related proteins in smooth muscle cells of canine basilar artery after experimental subarachnoid hemorrhage

We examined time-dependent changes in protein synthesis and in the immunoreactivities of representative contraction-related structural proteins in smooth muscle cells of canine basilar arteries after experimental subarachnoid hemorrhage (SAH). Protein synthesis was assessed by the percentage of polyribosome-forming ribosomes to total ribosomes (aggregation rate), a morphological index of the activity of protein synthesis. The aggregation rates in prostaglandin F2 alpha-(PGF 2 alpha) and 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced contracted basilar arteries were 70.0 +/- 7.0% and 71.4 +/- 8.7%, respectively, quite similar to the value in normal basilar artery (73.0 +/- 8.0%). In the single-SAH group with little delayed histological changes in the basilar arteries, the aggregation rate was significantly decreased to 30.5 +/- 6.4% by 24 h after the SAH, and recovered to 52.3 +/- 9.0% and 70.2 +/- 7.6% at 7 and 14 days postSAH, respectively, when the vasospasm was moderately and completely ameliorated. In contrast, in the double-SAH group in which the basilar arteries developed delayed smooth muscle cell death and long-lasting arterial contraction, a significant decrease in the aggregation rate (25.0 +/- 5.0% on day 4) persisted for 14 days. The in vitro incorporation of [3H]-leucine in the basilar arterial cells was also significantly suppressed 4 and 7 days after the initial SAH (1.2 +/- 0.4 and 1.4 +/- 0.3 x 10(3) dpm/mg protein) in the double-SAH group, as opposed to no significant decrease in the basilar artery at 7 days postSAH in the single-SAH group (1.9 +/- 0.6 x 10(3) dpm/mg protein). The immunoreactivity of alpha-smooth muscle actin, a contractile protein, demonstrated by immunohistochemistry and immunoblots, was not altered for up to 14 days even in the double-SAH group, but that of calponin and of h-caldesmon, contraction-inhibiting proteins, was markedly reduced 4-14 days after the initial SAH. Persistent impairment of protein synthesis and relative reduction of immunoreactivities of the contraction-inhibiting proteins were observed in arteries with severe vasospasm and loss of smooth muscle cells, as noted in the double-SAH subjects. These abnormalities may cooperate to cause cerebral arterial narrowing accompanied by degeneration of smooth muscle cells after SAH.

Possible mechanism to induce protein kinase C-dependent arterial smooth muscle contraction after subarachnoid haemorrhage

A possible mechanism for the induction of protein kinase C (PKC)-dependent vascular contraction independent to the increase of intracellular Ca++ was investigated in the pathogenesis of cerebral vasospasm in the double subarachnoid haemorrhage (SAH) model. The level of 1,2-diacylglycerol (DAG), which is an intrinsic PKC activator, significantly increased from days 4 to 7 in the basilar artery after the initial SAH, and the continuous administration of 1,2-bis(nicotinamido)-propane (AVS), a novel free radical scavenger, not only lowered the concentration of lipid peroxides in the CSF but also successfully suppressed the basilar arterial wall in the same model. It was suggested that lipid peroxides generated in the subarachnoid clot affect the DAG content of the cerebral artery. Analysis of hydroxy-eicosatetraenoic acids (HETEs) with high performance liquid chromatography (HPLC) revealed the production of relatively large amount of 12-HETE in the subarachnoid clot. To examine the potential effect of exogenous 12-HETE on the DAG content of the cerebral artery, the basilar artery was incubated with 12-HETE in vitro. 12-HETE induced a concentration-dependent slow increase in DAG content in the arterial wall after 6 hours of incubation. Under conditions in which DAG formation was facilitated by the Ca(++)-ionophore, DAG accumulation in the basilar artery was enhanced in the presence of 12-HETE. It was suggested that 12-HETE generated in the subarachnoid clot, induced DAG accumulation in the arterial wall by inhibition of DAG metabolism, resulting in the induction of prolonged PKC-dependent smooth muscle contraction in the pathogenesis of cerebral vasospasm.

Primary spinal chondrosarcoma localized in the cervical spinal canal and intervertebral foramen--case report

A 48-year-old male presented with a very rare case of spinal chondrosarcoma localized in the cervical spinal canal and intervertebral foramen, but without marked destruction of the vertebral column. Spinal chondrosarcoma is characterized by radiological evidence of destruction of the surrounding bone structure and mottled calcification. Magnetic resonance imaging was useful in the diagnosis and determination of the extent of this spinal chondrosarcoma. However, preoperative differential diagnosis of the tumor was not possible based on neuroimaging evidence.

Usefulness of nucleolar organizer region staining in gastric myogenic tumors: correlation with ploidy by DNA flow cytometry

A silver-staining technique to identify nucleolar organizer region-associated proteins (Ag-NOR) was applied to 55 gastric myogenic tumors. The mean numbers of Ag-NOR in the nucleus were: leiomyoma (30 cases), 2.0 +/- 0.6 (mean +/- SD); low-grade leiomyosarcoma (11 cases), 3.0 +/- 0.7; and high-grade leiomyosarcoma (14 cases), 3.9 +/- 0.7. The Ag-NOR counts were compared with DNA ploidy as determined by flow cytometry in 46 tumors. The Ag-NOR counts were significantly different in the aneuploid leiomyosarcomas (4.1 +/- 0.6: mean +/- SD) and diploid leiomyosarcomas (2.9 +/- 0.6: mean +/- SD). Thus, this parameter may serve as an objective histological discriminant for malignancy.

p53 point mutations in primary human gastric carcinomas

p53 point mutations in primary gastric carcinomas were analyzed by performing cDNA deoxynucleotide sequencing of the gene. Out of 16, 9 (56.3%) primary gastric carcinoma cases, including early cancer, showed one or more p53 point mutations in their open-reading frame, and 4 out of 9 cases had a p53 point mutation within highly conserved domains. The characteristics of the p53 mutation spectrum observed in primary tumors were (a) frequent mutation at an A:T pair (50%, 7 out of 14 mutations), (b) high transversion incidence (29%, 4 out of 14 mutations), (c) no transition at CpG, and (d) no G:C to T:A transversion. Our results suggest that p53 mutation is a common event in gastric carcinoma occurring from the early stage of progression with its specific mutation spectrum.

Histochemical observations of phosphatases in the ulcerative region due to topical traumatic stress in rats given cortisone

SYNOPSIS IN INTERLINGUA

OBSERVATIONES HISTOCHIMIC DE PHOSPHATASES IN LE REGION ULCERATE IN CONSEQUENTIA DE TOPIC STRESS TRAUMATIC IN CORTISONATE RATTOS.—Un noma-oide formation ulceric e alterationes proliferative de osso alveolar in le region del incisor inferior esseva producite in cortisonate rattos per le application topic de stress consistente in secieaturas effectuate con cisorios-pincette al nivello del margine gingival. Observationes histochimic del phosphatases alcalin e acide in ille alterationes proliferative esseva executate le decime e le cinquantesime die del experimento a base de serial sectiones cryostatic. Proliferation ossee esseva trovate al lateres labial e lingual del osso alveolar. Un forte activitate de phosphatase alcalin esseva constatate in un extense area circumjacente le osso proliferante. Intense activitate de phosphatase acide esseva incontrate in un relativemente restringite area circum le osso proliferante. Un leve activitate de phosphatase acide esseva incontrate intra le osso proliferante mesme. Le portiones cave resultante del resorption de osso contineva grados marcate de activitate de ambe le enzymas studiate.