Geographic characteristics of HTLV-1 molecular subgroups and genetic substitutions in East Asia: Insights from complete genome sequencing of HTLV-1 strains isolated in Taiwan and Japan.

BACKGROUND: Although Japan is a major endemic area for human T-lymphotropic virus type 1 (HTLV-1) and the virus has been well-studied in this region, there is limited research on HTLV-1 in surrounding regions. In this study, we determined the complete genome sequences of HTLV-1 strains isolated from Taiwan and Japan and investigated the geographic characteristics of molecular subgroups and substitution mutations to understand the spread of HTLV-1 and its correlation with human migration. METHODOLOGY/PRINCIPAL FINDINGS: The complete genome sequences of 26 HTLV-1 isolates from Taiwan were determined using next-generation sequencing and were compared with those of 211 isolates from Japan in terms of subgroup and genetic mutations. In total, 15/26 (58%) isolates from Taiwan belonged to the transcontinental subgroup and 11/26 (42%) isolates belonged to the Japanese subgroup. The transcontinental subgroup was significantly more prevalent among Taiwanese isolates than Japanese isolates (58% vs 18%, P < 0.0001). The mutation rate for the complete HTLV-1 sequence was as low as 0.2%. On examining individual base substitutions, the G-to-A mutation was predominant. Bayesian phylogenetic tree analysis estimated the time to the most recent common ancestor for the transcontinental and Japanese subgroups to be 28447 years. The transcontinental subgroups from Taiwan and Japan appeared to form clusters according to their respective regions. CONCLUSIONS/SIGNIFICANCE: The transcontinental subgroup of HTLV-1 is predominant in Taiwan, while the Japanese subgroup is common in Japan. The difference in subgroup distribution may be attributed to the initial spread of the transcontinental subgroup in East Asia, followed by the influx of the Japanese subgroup.

Stereocontrolled synthesis of α-d-allulofuranosides using α-selective d-fructofuranosidation reaction.

Stereocontrolled synthesis of rare sugar derivatives, namely α-d-allulofuranosides, was achieved using d-fructose, one of the most abundant carbohydrates in nature. The following are the key steps of the α-d-allulofuranosides' synthesis. (1) An α-selective glycosidation reaction of 1,3,4,6-tetra-O-benzoylated d-fructofuranosyl donor to obtain α-d-fructofuranosides with 98 %-75 % isolated yields. (2) A regioselective 1,4,6-tri-O-pivaloylation reaction of the tetraol of α-d-fructofuranosides with the C3-hydroxy group remaining intact. (3) The oxidation of the C3-hydroxy group followed by the stereoselective reduction of the C3-carbonyl group. Primary and secondary alcohols and sugars can be used as glycosyl acceptors and aglycones for the following pivaloylation and stereoinversion reactions to obtain α-d-allulofuranosides.

Effect of helicity and hydrophobicity on cell-penetrating ability of arginine-rich peptides.

Arginine (Arg)-rich peptides are one of the typical cell-penetrating peptides (CPPs), which can deliver membrane-impermeable compounds into intracellular compartments. Guanidino groups in Arg-rich peptides are critical for their high cell-penetrating ability, although it remains unclear whether peptide secondary structures contribute to this ability. In the current study, we designed four Arg-rich peptides containing α,α-disubstituted α-amino acids (dAAs), which prefer to adopt a helical structure. The four dAA-containing peptides adopted slightly different peptide secondary structures, from a random structure to a helical structure, with different hydrophobicities. In these peptides, dipropylglycine-containing peptide exhibited the highest helicity and hydrophobicity, and showed the best cell-penetrating ability. These findings suggested that the helicity and hydrophobicity of Arg-rich peptides contributes to their high cell-penetrating ability.

HTLV-1-associated myelopathy/tropical spastic paraplegia with sporadic late-onset nemaline myopathy: a case report.

BACKGROUND: Sporadic late onset nemaline myopathy (SLONM) is a muscle disorder characterized by the presence of nemaline rods in muscle fibers. SLONM has no known genetic cause but has been associated with monoclonal gammopathy of undetermined significance and with human immunodeficiency virus (HIV) infection. Human T-cell leukemia virus-1 (HTLV-1) is a known causative agent of adult T-cell leukemia/lymphoma and HTLV-1 associated myelopathy/tropical spastic paraplegia (HAM/TSP), a chronic inflammatory neurological disease. HTLV-1 has been reported to be implicated in inflammatory myopathies, as well as in HIV infection.; however, there have been no reports of an association between HTLV-1 infection and SLONM to date. CASE PRESENTATION: A 70-year-old Japanese woman presented with gait disturbance, lumbar kyphosis, and respiratory dysfunction. The diagnosis of HAM/TSP with SLONM was made based on characteristic clinical symptoms of HAM/TSP, such as spasticity in the lower extremities, and cerebrospinal fluid test results; and of SLONM, such as generalized head drooping, respiratory failure, and muscle biopsy results. Steroid treatment was initiated and improvement in her stooped posture was observed after 3 days of treatment. CONCLUSION: This is the first case report of SLONM combined with HTLV-1 infection. Further studies are needed to elucidate the relationship between retroviruses and muscle diseases.

Polymorphism of genes encoding drug-metabolizing and inflammation-related enzymes for susceptibility to cholangiocarcinoma in Thailand.

BACKGROUND: Cholangiocarcinoma (CCA) is an intractable cancer, and its incidence in northeastern Thailand is the highest worldwide. Infection with the liver fluke Opisthorchis viverrini (OV) has been associated with CCA risk. However, animal experiments have suggested that OV alone does not induce CCA, but its combination with a chemical carcinogen like nitrosamine can cause experimentally induced CCA in hamsters. Therefore, in humans, other environmental and genetic factors may also be involved. AIM: To examine relations between risk for CCA and genetic polymorphisms in carcinogen-metabolizing and inflammation-related genes. METHODS: This hospital-based case-control study enrolled 95 case-control pairs matched by age (± 5 years) and sex. We examined relations between risk for CCA and genetic polymorphisms in carcinogen-metabolizing and inflammation-related genes, serum anti-OV, alcohol consumption, and smoking. Polymorphisms of CYP2E1, IL-6 (-174 and -634), IL-10 (-819), and NF-κB (-94) and their co-occurrence with polymorphisms in the drug-metabolizing enzyme gene GSTT1 or GSTM1 were also analyzed. RESULTS: Although CCA risk was not significantly associated with any single polymorphism, persons with the GSTT1 wild-type and CYP2E1 c1/c2 + c2/c2 genotype had an increased risk (OR = 3.33, 95%CI: 1.23-9.00) as compared with persons having the GSTT1 wild-type and CYP2E1 c1/c1 wild genotype. The presence of anti-OV in serum was associated with a 7- to 11-fold increased risk, and smoking level was related to an OR of 1.5-1.8 in multivariable analyses adjusted for each of the seven genetic polymorphisms. CONCLUSION: In addition to infection with OV, gene-gene interactions may be considered as one of the risk factors for CCA development.

Identification and tracking of HTLV-1-infected T cell clones in virus-associated neurologic disease.

Human T lymphotropic virus type 1-assoicated (HTLV-1-associated) myelopathy/tropical spastic paraparesis (HAM/TSP) is a neuroinflammatory disease caused by the persistent proliferation of HTLV-1-infected T cells. Here, we performed a T cell receptor (TCR) repertoire analysis focused on HTLV-1-infected cells to identify and track the infected T cell clones that are preserved in patients with HAM/TSP and migrate to the CNS. TCRß repertoire analysis revealed higher clonal expansion in HTLV-1-infected cells compared with noninfected cells from patients with HAM/TSP and asymptomatic carriers (ACs). TCR clonality in HTLV-1-infected cells was similar in patients with HAM/TSP and ACs. Longitudinal analysis showed that the TCR repertoire signature in HTLV-1-infected cells remained stable, and highly expanded infected clones were preserved within each patient with HAM/TSP over years. Expanded HTLV-1-infected clones revealed different distributions between cerebrospinal fluid (CSF) and peripheral blood and were enriched in the CSF of patients with HAM/TSP. Cluster analysis showed similarity in TCRß sequences in HTLV-1-infected cells, suggesting that they proliferate after common antigen stimulation. Our results indicate that exploring TCR repertoires of HTLV-1-infected cells can elucidate individual clonal dynamics and identify potential pathogenic clones expanded in the CNS.

Iliopsoas Muscle Weakness as a Key Diagnostic Marker in HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP).

Human T-cell leukemia virus-1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a slowly progressive neurological disease that arises from HTLV-1 infection. Pathologically, the condition is characterized by diffuse myelitis, which is most evident in the thoracic spinal cord. Clinical manifestations of the infectious disease, HAM/TSP, are empirically known to include weakness of the proximal muscles of the lower extremities and atrophy of the paraspinal muscles, which is characteristic of the distribution of disturbed muscles usually seen in muscular diseases, except that the upper extremities are almost normal. This unique clinical presentation is useful information for physicians and physical therapists involved in diagnosing and rehabilitating patients with HAM/TSP, as well as critical information for understanding the pathogenesis of HAM/TSP. However, the precise pattern of muscle involvement in this condition has yet to be reported. The purpose of this study was to identify the muscles affected by HAM/TSP in order to understand the pathogenesis of HAM/TSP as well as to aid in the diagnosis and rehabilitation of HAM/TSP. A retrospective review of medical records was conducted on 101 consecutively admitted patients with HAM/TSP at Kagoshima University Hospital. Among 101 patients with HAM/TSP, all but three had muscle weakness in the lower extremities. Specifically, the hamstrings and iliopsoas muscle were the most frequently affected in over 90% of the patients. Manual muscle testing (MMT) revealed that the iliopsoas was the weakest of the muscles assessed, a consistent feature from the early to advanced stages of the disease. Our findings demonstrate a unique distribution of muscle weakness in HAM/TSP, with the proximal muscles of the lower extremities, particularly the iliopsoas muscle, being the most frequently and severely affected.

Diffusion coefficient of cationic liposomes during lipoplex formation determines transfection efficiency in HepG2 cells.

Cationic lipid-based lipoplexes are well-known for gene delivery. To determine the relationship between physicochemical characteristics and transfection efficiency, cationic liposomes of different sizes were prepared and incubated with plasmid DNA at different temperatures to form lipoplexes. We found that the liposome diffusion coefficient during lipoplex formation strongly correlated with the physicochemical characteristics of lipoplexes, accessibility of plasmid DNA in lipoplexes, and logarithm of gene expression per metabolic activity. Clathrin-mediated endocytosis was the major route for lipoplexes comprising 100 nm-liposomes, as reported previously. As liposome size increased, the major route shifted to lipid raft-mediated endocytosis. In addition, macropinocytosis was observed for all liposome sizes. The role of reactive oxygen species might depend on liposome size and endocytosis. Information from this study would be useful for understanding cationic lipoplex-mediated transfection.

Anti-ganglionic acetylcholine receptor antibodies in functional neurological symptom disorder/conversion disorder.

Objective: Autoimmune autonomic ganglionopathy (AAG) is a rare disorder characterized by autonomic failure associated with the presence of anti-ganglionic acetylcholine receptor (gAChR) antibodies; however, several studies have reported that individuals with anti-gAChR antibodies present with central nervous system (CNS) symptoms such as impaired consciousness and seizures. In the present study, we investigated whether the presence of serum anti-gAChR antibodies correlated with autonomic symptoms in patients with functional neurological symptom disorder/conversion disorder (FNSD/CD). Methods: Clinical data were collected for 59 patients presenting with neurologically unexplained motor and sensory symptoms at the Department of Neurology and Geriatrics between January 2013 and October 2017 and who were ultimately diagnosed with FNSD/CD according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition. Correlations between serum anti-gAChR antibodies and clinical symptoms and laboratory data were analyzed. Data analysis was conducted in 2021. Results: Of the 59 patients with FNSD/CD, 52 (88.1%) exhibited autonomic disturbances and 16 (27.1%) were positive for serum anti-gAChR antibodies. Cardiovascular autonomic dysfunction, including orthostatic hypotension, was significantly more prevalent (75.0 vs. 34.9%, P = 0.008), whereas involuntary movements were significantly less prevalent (31.3 vs. 69.8%, P = 0.007), among anti-gAChR antibody-positive compared with -negative patients. Anti-gAChR antibody serostatus did not correlate significantly with the frequency of other autonomic, sensory, or motor symptoms analyzed. Conclusions: An autoimmune mechanism mediated by anti-gAChR antibodies may be involved in disease etiology in a subgroup of FNSD/CD patients.

An Amphipathic Structure of a Dipropylglycine-Containing Helical Peptide with Sufficient Length Enables Safe and Effective Intracellular siRNA Delivery.

Amphipathic peptides composed of cationic amino acids and hydrophobic amino acids have cell-penetrating ability and are often used as a delivery tool for membrane-impermeable compounds. Small interfering RNA (siRNAs) are one of the delivery targets for such cell-penetrating peptides (CPPs). Cationic CPPs can associate with anionic siRNAs by electrostatic interactions resulting in the formation of nano-sized complexes, which can deliver siRNAs intracellularly. CPPs containing unnatural amino acids offer promising tools to siRNA delivery. However, the detailed structure-activity relationship in siRNA delivery has been rarely studied. In the current study, we designed peptides containing dipropylglycine (Dpg) and explored the cellular uptake and cytotoxicity of peptide/siRNA complexes. The amphipathic structure of the peptides played a key role in complexation with siRNAs and intracellular siRNA delivery. In the amphipathic peptides, cellular uptake of siRNA increased with increasing peptide length, but cytotoxicity was reduced. A peptide containing four Dpg exhibited an effective gene-silencing effect with small amounts of peptides without cytotoxicity in medium containing serum. These findings will be helpful for the design of novel CPPs for siRNA delivery.

Efficacy of l-Arginine treatment in patients with HTLV-1-associated neurological disease.

OBJECTIVE: HTLV-1 infection causes HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), resulting in loss of motor function. In this Phase 2 trial, we assessed the efficacy and safety of l-arginine in patients with HAM/TSP. METHODS: This open-label, single-arm, Phase 2 study enrolled patients diagnosed with HAM/TSP. Patients received l-arginine at a dose of 20 g orally for 1 week and were followed-up for 3 weeks. The primary endpoint was change in walking speed in the 10-m walk test (10MWT). The main secondary endpoints were change in Timed Up and Go Test (TUGT) time, improvement in inflammatory markers in cerebrospinal fluid (CSF), safety, and tolerability. RESULTS: The study enrolled 20 patients (13 [65%] female) with a mean age of 67.8 years (95% CI 62.3 to 73.3). Although the primary endpoint, the changes in 10MWT time between baseline (Day 0) and Day 7, did not reach statistical significance (mean percent change in time -3.5%, 95% CI -10.8% to 3.7%; P = 0.32), a significant improvement was detected between baseline and Day 14 (-9.4%, 95% CI -16.6% to -2.2%; P = 0.01). Significant improvements were also observed in selected secondary endpoints, including in TUGT time (-9.1%, 95% CI -15.5% to -2.7%; P < 0.01), and in neopterin concentration in CSF (-2.1 pmol/mL, 95% CI -3.8 to -0.5; P = 0.01). Adverse events were infrequent, mild, and resolved rapidly. INTERPRETATION: l-arginine therapy improved motor function and decreased CSF inflammatory markers. l-arginine thus represents a promising therapeutic option for patients with HAM/TSP. TRIAL REGISTRATION NUMBER: UMIN000023854.

An Enzyme-Linked Immunosorbent Assay to Quantify Poly (ADP-Ribose) Level In Vivo.

PolyADP-ribosylation is a posttranslational modification of proteins that results from enzymatic synthesis of poly(ADP-ribose) with NAD+ as the substrate. A unique characteristic of polyADP-ribosylation is that the poly(ADP-ribose) chain can have 200 or more ADP-ribose residues in branched patterns, and the presence and variety of these chains can have substantive effects on protein function. To understand how polyADP-ribosylation affects biological processes, it is important to know the physiological level of poly(ADP-ribose) in cells. Under normal cell physiological conditions and in the absence of any exogenous DNA damaging agents, we found that the concentration of poly(ADP-ribose) in HeLa cells is approximately 0.04 pmol (25 pg)/106 cells, as measured with a double-antibody sandwich, enzyme-linked immunosorbent assay protocol that avoids artificial activation of PARP1 during cell lysis. Notably, this system demonstrated that the poly(ADP-ribose) level peaks in S phase and that the average cellular turnover of a single poly(ADP-ribose) is less than 40 s.

Elucidating Differences in Early-Stage Centrosome Amplification in Primary and Immortalized Mouse Cells.

The centrosome is involved in cytoplasmic microtubule organization during interphase and in mitotic spindle assembly during cell division. Centrosome amplification (abnormal proliferation of centrosome number) has been observed in several types of cancer and in precancerous conditions. Therefore, it is important to elucidate the mechanism of centrosome amplification in order to understand the early stage of carcinogenesis. Primary cells could be used to better understand the early stage of carcinogenesis rather than immortalized cells, which tend to have various genetic and epigenetic changes. Previously, we demonstrated that a poly(ADP-ribose) polymerase (PARP) inhibitor, 3-aminobenzamide (3AB), which is known to be nontoxic and nonmutagenic, could induce centrosome amplification and chromosomal aneuploidy in CHO-K1 cells. In this study, we compared primary mouse embryonic fibroblasts (MEF) and immortalized MEF using 3AB. Although centrosome amplification was induced with 3AB treatment in immortalized MEF, a more potent PARP inhibitor, AG14361, was required for primary MEF. However, after centrosome amplification, neither 3AB in immortalized MEF nor AG14361 in primary MEF caused chromosomal aneuploidy, suggesting that further genetic and/or epigenetic change(s) are required to exhibit aneuploidy. The DNA-damaging agents doxorubicin and γ-irradiation can cause cancer and centrosome amplification in experimental animals. Although doxorubicin and γ-irradiation induced centrosome amplification and led to decreased p27Kip protein levels in immortalized MEF and primary MEF, the phosphorylation ratio of nucleophosmin (Thr199) increased in immortalized MEF, whereas it decreased in primary MEF. These results suggest that there exists a yet unidentified pathway, different from the nucleophosmin phosphorylation pathway, which can cause centrosome amplification in primary MEF.

Development of delivery carriers for plasmid DNA by conjugation of a helical template to oligoarginine.

Arginine (Arg)-rich peptides can penetrate the cell membrane and deliver nucleic acid-based therapeutics into cells. In this study, a helical template designed with a repeating sequence composed of two l-leucines (l-Leu) and a 2-aminoisobutyric acid (Aib) (l-Leu-l-Leu-Aib) was conjugated to nona-arginine on either the C- or N- terminus, designated as Block 1 and Block 2. Each terminal modification induced helical structure formation and improved the physicochemical properties of peptide/plasmid DNA (pDNA) complexes, resulting in efficient intracellular pDNA delivery. The introduction of a helical template may be effective for the endosomal escape of pDNA and pDNA release from complexes in cells. These results emphasized the potency of a helical template for the development of novel cell-penetrating peptides for pDNA delivery.

Flavonoids Enhance Lipofection Efficiency and Ameliorate Cytotoxicity in Colon26 and HepG2 Cells via Oxidative Stress Regulation.

The generation of reactive oxygen species (ROS) can affect cationic liposome-mediated transfection. In this study, we focused on a specific class of antioxidants, flavonoids, to investigate the transfection efficiency using cationic liposome/plasmid DNA complexes (lipoplexes) in 2D and 3D cultures of Colon26 and HepG2 cells, respectively. All tested flavonoids enhanced the transfection efficiency in 2D Colon26 and HepG2 cells. Among the tested flavonoids, 25 µM quercetin showed the highest promotion effect of 8.4- and 7.6-folds in 2D Colon26 and HepG2 cells, respectively. Transfection was also performed in 3D cultures of Colon26 and HepG2 cells using lipoplexes with quercetin. Quercetin (12.5 µM) showed the highest transfection efficiency at all transfection timings in 3D Colon26 and HepG2 cells with increased cell viability. Flow cytometry revealed that quercetin treatment reduced the population of gene expression-negative cells with high ROS levels and increased the number of gene expression-positive cells with low ROS levels in HepG2 cells. Information from this study can be valuable to develop strategies to promote transfection efficiency and attenuate cytotoxicity using lipoplexes.

PARP Inhibitor Decreases Akt Phosphorylation and Induces Centrosome Amplification and Chromosomal Aneuploidy in CHO-K1 Cells.

Cancer cells are known to have chromosomal number abnormalities (aneuploidy), a hallmark of malignant tumors. Cancer cells also have an increased number of centrosomes (centrosome amplification). Paradoxically, cancer therapies, including γ-irradiation and some anticancer drugs, are carcinogenic and can induce centrosome amplification and chromosomal aneuploidy. Thus, the processes of carcinogenesis and killing cancer cells might have some mechanisms in common. Previously, we found that the inhibitors of polyADP-ribosylation, a post-translational modification of proteins, caused centrosome amplification. However, the mechanism of action of the inhibitors of polyADP-ribosylation is not fully understood. In this study, we found that an inhibitor of polyADP-ribosylation, 3-aminobenzamide, caused centrosome amplification, as well as aneuploidy of chromosomes in CHO-K1 cells. Moreover, inhibitors of polyADP-ribosylation inhibited AKT phosphorylation, and inhibitors of AKT phosphorylation inhibited polyADP-ribosylation, suggesting the involvement of polyADP-ribosylation in the PI3K/Akt/mTOR signaling pathway for controlling cell proliferation. Our data suggest a possibility for developing drugs that induce centrosome amplification and aneuploidy for therapeutic applications to clinical cancer.

Physiological levels of poly(ADP-ribose) during the cell cycle regulate HeLa cell proliferation.

Protein targets of polyADP-ribosylation undergo covalent modification with high-molecular-weight, branched poly(ADP-ribose) (PAR) of lengths up to 200 or more ADP-ribose residues derived from NAD+. PAR polymerase 1 (PARP1) is the most abundant and well-characterized enzyme involved in PAR biosynthesis. Extensive studies have been carried out to determine how polyADP-ribosylation (PARylation) regulates cell proliferation during cell cycle, with conflicting conclusions. Since significant activation of PARP1 occurs during cell lysis in vitro, we changed the standard method for cell lysis, and using our sensitive ELISA system, quantified without addition of a PAR glycohydrolase inhibitor and clarified that the PAR level is significantly higher in S phase than that in G1. Under normal condition in the absence of exogenous DNA-damaging agent, PAR turns over with a half-life of <40 s; consistent with significant decrease of NAD+ levels in S phase, which is rescued by PARP inhibitors, in line with the observed rapid turnover of PAR. PARP inhibitors delayed cell cycle in S phase and decreased cell proliferation. Our results underscore the importance of a suitable assay system to measure rapid PAR chain dynamics in living cells and aid our understanding of the function of PARylation during the cell cycle.

E-Selective Ring-Closing Metathesis in α-Helical Stapled Peptides Using Carbocyclic α,α-Disubstituted α-Amino Acids.

We present an E-selective ring-closing metathesis reaction in α-helical stapled peptides at positions i and i + 4. The use of two chiral carbocyclic α,α-disubstituted α-amino acids, (1S,3S)-Ac5c3OAll and (1R,3S)-Ac5c3OAll, provides a high E-selectivity of a ≤59:1 E:Z ratio, while mixtures with E:Z ratios of 2.1-0.5:1 were produced with standard acyclic (S)-(4-pentenyl)alanine amino acids. A stapled octapeptide composed of (1S,3S)- and (1R,3S)-Ac5c3OAll amino acids showed a right-handed α-helical crystal structure.

High Prevalence of HTLV-1 Carriers Among the Elderly Population in Kagoshima, a Highly Endemic Area in Japan.

Japan is one of the world's highly endemic areas for human T cell leukemia virus type 1 (HTLV-1), and it is known that the infection rate of HTLV-1 increases with age. The infection rate among the elderly has been estimated based on data from blood donors under the age of 65, and the actual number and rate of infection among the elderly are unknown. Data of 26,090 preoperative HTLV-1 screening tests conducted at Kagoshima University Hospital from 2001 to 2020, including 2726 HTLV-1-positive patients, were used for calculating the decadal infection rates for the year of birth. Estimated infection rates by birth year and demographic tables were used to estimate the current number of infected people in Kagoshima. The estimated total numbers of people infected with HTLV-1 in Kagoshima prefecture were 139,436 in 2005 and 80,975 in 2019. The infection rate increased with age for both men and women, reaching 17.3% for women born before the 1920s. Next, we tried to clarify whether the increase in infection rates with age was due to post-school age infections. The age of birth with the greatest increase in infection rate after 10 years was women born in the 1970s, and the increase in infection rate was only 0.98%, which is not a statistically significant increase. The number of infected people in Kagoshima was >80,000 in 2019. No data were available in this study to point to the involvement of horizontal transmission after school age in the high infection rate among the elderly. The high infection rate among the elderly is thought to have been high even when they were infants.

A helix foldamer oligopeptide improves intracellular stability and prolongs protein expression of the delivered mRNA.

Prolonging the duration of protein expression from mRNA is a major challenge in the development of mRNA nanomedicines. mRNA complexed with helix foldamer oligopeptides consisting of arginine and α-aminoisobutyric acids showed higher intracellular stability than that complexed with oligoarginines, thereby maintaining efficient protein translation for three days.