Idiopathic nephrotic syndrome in children: role of regulatory T cells and gut microbiota.

BACKGROUND: We investigated whether an association exists between regulatory T cells (Tregs) during initial presentation in children with idiopathic nephrotic syndrome (INS) and later development of frequently relapsing INS. METHODS: Blood samples were obtained at onset and at remission from 25 patients (median age, 4.0 years) with INS; eight did not show relapse after initial response (non-relapsing [NR]), whereas 17 showed frequent relapses (frequently relapsing [FR]). Tregs were measured by flow cytometry; increases were compared between groups. Fecal samples were obtained at onset from 20 patients with INS, as well as from 20 age-matched healthy children. Gut microbiota composition was assessed using 16S ribosomal RNA (rRNA) sequencing (ion PGM). RESULTS: The rate of increase in Tregs from onset to remission was significantly lower in the FR group (124.78%) than in the NR group (879.16%; P < 0.001). Additionally, 16S rRNA sequencing of gut microbiota showed that the proportion of butyric acid-producing bacteria was significantly lower in the FR group (7.08%) than in the healthy children (17.45%; P < 0.001). CONCLUSIONS: In children with INS, small increases in Tregs in response to steroid treatment were associated with subsequent increased risk of frequent relapses. In addition, the FR group had a greater degree of dysbiosis at onset. IMPACT: A low rate of Tregs increase is associated with subsequent frequent relapses of INS. The increase in Tregs in response to steroid treatment was small when dysbiosis was present in patients with INS, particularly when the proportion of butyrate-producing bacteria was considerably reduced We presume that improvement of dysbiosis by administration of probiotics and prebiotics may enhance the rate of Tregs' increase, thus preventing frequent relapse.

Impact of Long-Term Low Dose Antibiotic Prophylaxis on Gut Microbiota in Children.

PURPOSE: We evaluated the effect of long-term low dose antibiotic prophylaxis on children's gut microbiota. MATERIALS AND METHODS: We conducted 16S ribosomal RNA gene sequencing using stool samples from 35 patients younger than 3 years old (median age 5.2 months; male-to-female ratio 17:18) who underwent antibiotic treatment during the acute phase of febrile urinary tract infection. Samples were collected at 5 time points, ie before, during and at 1 to 2, 3 to 4, and 5 to 6 months after febrile urinary tract infection onset and antibiotic treatment. Continuous antibiotic prophylaxis using trimethoprim-sulfamethoxazole was initiated in 23 patients with grade III or higher vesicoureteral reflux and was not administered in 12 patients without reflux. RESULTS: Within 2 weeks after initiation of treatment for febrile urinary tract infection almost all enteric bacteria belonged to the order Lactobacillales, and gut microbiota diversity decreased compared to the pretreatment level (average Shannon index 2.9 before treatment, 1.4 during treatment). The diversity recovered within 1 to 2 months after febrile urinary tract infection onset in both groups. Diversity was maintained during the study period in both groups (p=0.43). A smaller proportion of gut microbiota component belonged to the order Enterobacteriales (p=0.002) in the antibiotic prophylaxis group. CONCLUSIONS: Our results revealed that patients receiving continuous antibiotic prophylaxis had normal gut microbiota diversity, indicating that the effect of trimethoprim-sulfamethoxazole on gut microbiota was insignificant. Furthermore, prophylaxis with trimethoprim-sulfamethoxazole might selectively suppress the growth of bacteria belonging to the order Enterobacteriales, such as Escherichia coli and Klebsiella species, which are the main causative bacteria of febrile urinary tract infections.

Effect of Delivery Mode and Nutrition on Gut Microbiota in Neonates.

BACKGROUND/AIMS: The mode of delivery (vaginal or cesarean section) and feeding type (breastfeeding or formula feeding) of neonates are considered the most influential factors in the development of gut microbiota. OBJECTIVES: This study investigated the effect of prebiotic-rich breast milk on overcoming gut microbiota dysbiosis. METHOD: Stool samples from 36 healthy Japanese neonates were obtained at 4 days and 1 month of age, and divided into 4 groups based on mode of delivery and feeding type. The gut microbiota composition and bacterial diversity were assessed using 16S rRNA sequencing. RESULTS: At 4 days old, vaginally delivered neonates had a significantly higher diversity of bacteria than those born by cesarean section. Bacteroidales and Enterobacteriales were overrepresented in vaginally delivered neonates (p = 0.0031 and p = 0.011), while Bacillales and Lactobacillales were overrepresented in caesarean section delivered neonates (p = 0.012 and p = 0.0016). However, there was little difference in bacterial diversity and bacterial relative abundance at 1 month of age between groups. CONCLUSIONS: Cesarean section delivery appeared to reduce the diversity of neonate gut microbiota, resulting in dysbiosis, but this improved to the equivalent level seen in vaginally delivered infants by 1 month of age. Breastfeeding, even for short periods, may therefore improve neonate gut dysbiosis.

Gut Microbiota Dysbiosis in Children with Relapsing Idiopathic Nephrotic Syndrome.

BACKGROUND: While the etiology of idiopathic nephrotic syndrome (idiopathic nephrotic syndrome [INS]; characterized by repeated relapses and comorbid allergic conditions) remains unknown, recent evidence suggests that dysfunction in regulatory T cells (Tregs) plays an important role in the development of INS as well as allergic diseases. We hypothesized that dysbiosis involving decreased butyric acid-producing gut microbiota leads to defective induction and differentiation of peripherally induced Tregs, resulting in INS relapse. METHODS: Study subjects were 12 children with INS, 8 classified as relapsing (R group; median age: 3.0 years) and 4 as non-relapsing (NR group; median age: 4.3 years), and 11 healthy children (HC group; median age: 5.1 years) serving as normal controls. Measurement of microbiota was performed using 16S ribosomal RNA metagenomic analysis, and fecal butyric acid was measured using high performance liquid chromatography. Flow-cytometric analysis of Tregs and CD4-positive (CD4+) cells in peripheral blood was also performed. RESULTS: Metagenomic analysis of gut microbiota using feces showed that the proportion of butyric acid-producing bacteria was significantly lower in R (median 6.36%) than HC (median 18.84%; p = 0.0013), but no different between NR (median 16.71%) and HC (p = 0.29). Fecal organic acid analysis revealed significantly lower butyric acid quantities in R than HC (medians: 0.48 vs. 0.99 mg/g, p = 0.042). Circulating Tregs as a proportion of CD4+ cells were decreased in 75% of R and NR. CONCLUSION: Pediatric relapsing INS patients show gut microbiota dysbiosis, characterized by a decreased proportion of butyric acid-producing bacteria and lower fecal butyric acid quantities, concomitant with reduced circulatory Tregs.

Dysbiosis of the gut microbiota in children with severe motor and intellectual disabilities receiving enteral nutrition: A pilot study.

BACKGROUND: Children with severe motor and intellectual disabilities (SMIDs) frequently and continuously receive enteral nutrition and medications and lack adequate exercise, which may lead to dysbiosis, an imbalance in the composition of the gut microbiota. However, studies on the composition of gut microbiota in children with SMIDs are limited. Therefore, we aimed to examine the characteristics of the gut microbiota in children with SMIDs. METHODS: 16S rRNA gene sequencing was performed using fecal samples of 10 children with SMIDs, who received enteral nutrition through a gastric fistula or gastric tube (SMID group: median age, 10.0 years), and 19 healthy children (healthy control [HC] group: median age, 9.0 years). Microbial diversity, microbial composition, and abundance of butyric acid-producing bacteria were compared between the groups. Daily dietary fiber intake in the SMID group was evaluated using questionnaires. RESULTS: The Shannon and Simpson indices (alpha diversity indices) were significantly lower in the SMID group than those in the HC group. Beta diversity analysis identified different clusters. Compared with the HC group, Clostridiales and butyric acid-producing bacteria were less abundant and Bacteroidales were more abundant in the SMID group. Dietary fiber intake in the SMID group was approximately two-thirds of the estimated average requirement for healthy Japanese children. CONCLUSION: Children with SMIDs showed dysbiosis with alteration in the microbial diversity, which could partly be attributed to their low dietary fiber intake. Further studies, with the intervention of prebiotics, probiotics, and synbiotics, are warranted to improve dysbiosis in children with SMIDs.

Dysbiosis in Gut Microbiota in Children Born Preterm Who Developed Autism Spectrum Disorder: A Pilot Study.

The gut microbiota was reported to differ between children with autism spectrum disorder (ASD) and typically developing (TD) children, and dysbiosis of the gut microbiota in preterm infants is common. Here, we explored the characteristics of gut microbiota in children born preterm with ASD. We performed 16S rRNA gene sequencing using stool samples from ASD children born preterm and TD children born preterm. Alpha diversity was significantly greater in the ASD group. A comparison of beta diversity showed different clusters. Linear discriminant analysis effect size analysis revealed significantly more Firmicutes in the ASD group compared with the TD group. In conclusion, the gut microbiota in children born preterm differs between children with ASD and TD.

Characterization of cytoskeletal and structural effects of INF2 variants causing glomerulopathy and neuropathy.

Focal segmental glomerulosclerosis (FSGS) is a common glomerular injury leading to end-stage renal disease. Monogenic FSGS is primarily ascribed to decreased podocyte integrity. Variants between residues 184 and 245 of INF2, an actin assembly factor, produce the monogenic FSGS phenotype. Meanwhile, variants between residues 57 and 184 cause a dual-faceted disease involving peripheral neurons and podocytes (Charcot-Marie-Tooth CMT/FSGS). To understand the molecular basis for INF2 disorders, we compared structural and cytoskeletal effects of INF2 variants classified into two subgroups: One (G73D, V108D) causes the CMT/FSGS phenotype, and the other (T161N, N202S) produces monogenic FSGS. Molecular dynamics analysis revealed that all INF2 variants show distinct flexibility compared to the wild-type INF2 and could affect stability of an intramolecular interaction between their N- and C-terminal segments. Immunocytochemistry of cells expressing INF2 variants showed fewer actin stress fibers, and disorganization of cytoplasmic microtubule arrays. Notably, CMT/FSGS variants caused more prominent changes in mitochondrial distribution and fragmentation than FSGS variants and these changes correlated with the severity of cytoskeletal disruption. Our results indicate that CMT/FSGS variants are associated with more severe global cellular defects caused by disrupted cytoskeleton-organelle interactions than are FSGS variants. Further study is needed to clarify tissue-specific pathways and/or cellular functions implicated in FSGS and CMT phenotypes.

Removal effect of DNA contamination by hydrogen peroxide plasma compared to ethylene-oxide gas.

We examined the ability of hydrogen peroxide plasma (HPP) to remove DNA contamination, to evaluate whether it is a suitable forensic-grade treatment under ISO 18385. HPP treatment was compared to ethylene-oxide gas (EOG) treatment, which is required by ISO 18385. For the evaluation, commercial control DNA solution and cultured cells sprinkled on Petri dishes were used, and the DNA fragments (214 and 80 bp autosomal DNA fragments and 75 bp Y chromosome fragment) were quantified. HPP treatment was performed up to four times and EOG treatment was performed once. Performing HPP treatment three times was as effective as EOG treatment, with all fragments decreasing to below 1/1,000 in DNA solution. With STR and Y-STR typing, no alleles were detected for three HPP treatments of control DNA using the original amount, i.e., 1 ng. Therefore, HPP appears useful for removing DNA contamination. For cells sprinkled on Petri dishes, the DNA degradation abilities of the HPP and EOG were comparable. However, less DNA was degraded with the HPP and EOG and neither met the ISO criteria. Although the current version of ISO 18385 recommends an evaluation method using cultured cells sprinkled on Petri dishes, it needs to be revised. These findings should be considered when revising ISO 18385.

Allele frequencies of 31 autosomal short tandem repeat (auSTR) loci obtained using the Precision ID GlobalFiler™ NGS STR Panel v2 in 322 individuals from the Japanese population.

In human identification methods that target short tandem repeats (STRs), massively parallel sequencing (MPS) technology has made it possible to genotype at the level of the specific sequence itself. This allows for the detection of repeat unit variants and single nucleotide polymorphisms (SNPs) adjacent to the STRs. Using the GlobalFiler™ NGS STR Panel v2, Ion S5, and Converge software, this study constructed a Japanese database of 31 autosomal STRs (auSTRs) and two sex markers from 322 individuals. After excluding some sequence errors and stutters, a total of 31 novel alleles were identified. Additionally, using the allele frequencies of 31 auSTR loci, the match probabilities for the length-based and sequence-based data were calculated to be 1.433 × 10-34 and 9.163 × 10-38, respectively. These values are at least nine orders of magnitude higher than that obtained from 21 auSTR loci in the Japanese population using the conventional capillary electrophoresis method. The database generated in this study is expected to be implemented in forensic practice and used to solve difficult casework.

Clinical Significance of Probiotics for Children with Idiopathic Nephrotic Syndrome.

We previously reported that a decrease in butyrate-producing bacteria in the gut is a potential cause of regulatory T cell (Treg) abnormalities in children with idiopathic nephrotic syndrome (INS). Therefore, we hypothesized that administration of butyrate-producing bacteria might reduce INS relapse and the need for immunosuppressants in these patients. Twenty patients in remission from INS (median age 5.3 years, 15 boys) were enrolled in the study and assigned to receive either daily oral treatment with a preparation of 3 g Clostridium butyricum or no probiotic treatment. The number of relapses and requirement for immunosuppressive agents were compared between the two groups. In the probiotic treatment group, analyses of the gut microbiota and Treg measurements were also performed. Probiotic-treated patients experienced fewer INS relapses per year compared with non-probiotic-treated patients (p = 0.016). Further, administration of rituximab in the probiotic treatment group was significantly less frequent compared with the non-probiotic-treated group (p = 0.025). In the probiotic treatment group, analyses before and after probiotic treatment revealed the significant increases in the relative abundance of butyrate-producing bacteria (p = 0.017) and blood Treg counts (p = 0.0065). Thus, oral administration of butyrate-producing bacteria during INS remission may reduce the frequency of relapse and the need for immunosuppressive agents.

Evaluation of probability distribution models for stutter ratios in the typing system of GlobalFiler and 3500xL Genetic Analyzer.

As DNA typing systems have become increasingly sensitive in recent years, probability distribution models for back, forward, double-back, and minus 2-nt stutter ratios have been desired to be considered in DNA evidence interpretation using specific software programs. However, experimental investigations have been insufficient, especially for forward, double-back, and minus 2-nt stutters. In this study, we experimentally reevaluated the probability distribution models for each stutter ratio in the typing systems of GlobalFiler™ PCR Amplification Kit and 3500xL Genetic Analyzer from Thermo Fisher Scientific. In addition, to enhance the reliability of longest uninterrupted stretch (LUS) values and corrected allele numbers used in previously developed models for stutter ratios using sequence information (i.e., LUS model and multi-seq model), we propose the weighted average of LUS values and corrected allele numbers based on the number of observations in sequence-based population data. Back stutter ratios demonstrated a positive correlation with allele numbers (allele model) in eight loci, LUS values (LUS model) in eight loci, and corrected allele numbers (multi-seq model) in five loci. The forward stutter ratios (FSRs) of D22S1045 followed the LUS model. FSRs other than D22S1045 and double-back stutter ratios followed the LUS model by considering multiple loci together. Minus 2-nt stutter ratios observed in SE33 and D1S1656 did not increase with the increase in the allele numbers. The adopted models for each stutter ratio can be implemented in software programs for DNA evidence interpretation and enable a reliable interpretation of crime stain profiles in forensic caseworks.

Fiber-Rich Barley Increases Butyric Acid-Producing Bacteria in the Human Gut Microbiota.

Butyric acid produced in the intestine by butyric acid-producing bacteria (BAPB) is known to suppress excessive inflammatory response and may prevent chronic disease development. We evaluated whether fiber-rich barley intake increases BAPB in the gut and concomitantly butyric acid in feces. Eighteen healthy adults received granola containing functional barley (BARLEYmax®) once daily for four weeks. Fecal DNA before intake, after intake, and one month after intake was analyzed using 16S rRNA gene sequencing to assess microbial diversity, microbial composition at the order level, and the proportion of BAPB. Fecal butyric acid concentration was also measured. There were no significant differences in diversities and microbial composition between samples. The proportion of BAPB increased significantly after the intake (from 5.9% to 8.2%). However, one month after stopping the intake, the proportion of BAPB returned to the original value (5.4%). Fecal butyric acid concentration increased significantly from 0.99 mg/g feces before intake to 1.43 mg/g after intake (p = 0.028), which decreased significantly to 0.87 mg/g after stopping intake (p = 0.008). As BAPB produce butyric acid by degrading dietary fiber, functional barley may act as a prebiotic, increasing BAPB and consequently butyric acid in the intestine.

Association of Neonatal Jaundice with Gut Dysbiosis Characterized by Decreased Bifidobacteriales.

Neonatal jaundice, caused by excess serum bilirubin levels, is a common condition in neonates. Imbalance in the gut microbiota is believed to play a role in the development of neonatal jaundice. Thus, we aimed to reveal the gut microbiota characteristics in neonates with jaundice. 16S rRNA gene sequencing was performed on stool samples collected on day 4 from 26 neonates with jaundice (serum total bilirubin > 15.0 mg/dL) and 17 neonates without jaundice (total serum bilirubin < 10.0 mg/dL). All neonates were born full term, with normal weight, by vaginal delivery, and were breastfed. Neonates who were administered antibiotics, had serum direct bilirubin levels above 1 mg/dL, or had conditions possibly leading to hemolytic anemia were excluded. The median serum bilirubin was 16.0 mg/dL (interquartile range: 15.5-16.8) and 7.4 mg/dL (interquartile range: 6.8-8.3) for the jaundice and non-jaundice groups, respectively. There was no difference in the alpha diversity indices. Meanwhile, in the jaundice group, linear discriminant analysis effect size revealed that Bifidobacteriales were decreased at the order level, while Enterococcaceae were increased and Bifidobacteriaceae were decreased at the family level. Bifidobacteriaceae may act preventatively because of their suppressive effect on beta-glucuronidase, leading to accelerated deconjugation of conjugated bilirubin in the intestine. In summary, neonates with jaundice had dysbiosis characterized by a decreased abundance of Bifidobacteriales.

A Japanese SPG4 Patient with a Confirmed De Novo Mutation of the SPAST Gene.

Spastic paraplegia type 4 (SPG4) is caused by mutations of the SPAST gene and is the most common form of autosomal-dominantly inherited pure hereditary spastic paraplegia (HSP). We herein report a Japanese patient with SPG4 with a confirmed de novo mutation of SPAST. On exome sequencing and Sanger sequencing, we identified the heterozygous missense mutation p.R460L in the SPAST gene. This mutation was absent in the parents, and the paternity and maternity of the parents were both confirmed. The patient showed a pure SPG4 phenotype with an infantile onset. This study may expand the clinical and genetic findings for SPG4.

Epigenetic mechanism controls PDK4 gene activation before and after exercise therapy following artificial knee arthroplasty.

PURPOSE: DNA methylation is thought to play a role in exercise-induced gene expression. We aimed to examine changes in muscular strength and body composition in elderly patients with end-stage knee osteoarthritis before and after artificial knee arthroplasty and exercise therapy. We aimed to confirm the relationship between DNA methylation and body composition, using the methylation rate of the pyruvate dehydrogenase kinase 4 (PDK4) gene that regulates skeletal muscle and fat metabolism. PATIENTS AND METHODS: Patients underwent artificial knee arthroplasty between April 2017 and June 2017 at Kansai Medical University Hospital. Six patients (seven knees) were included in the analysis (four males/two females; average age, 75.7 years; body mass index, 25.1 kg/m2). Body composition and knee extension muscle strength were measured before surgery and 5 months after surgery. Rehabilitation was performed for 3 months after surgery. In the remaining 2 months, patients performed resistance training and aerobic exercise using an ergometer for 20 mins, twice a week. A biopsy of the vastus medialis was taken during surgery and 5 months post-surgery. Biopsy samples were treated with bisulfite after DNA extraction, and DNA methylation rate was calculated. RESULTS: Body weight (P=0.046), total weight (P=0.027), and total fat mass (P=0.028) were significantly lower 5 months postoperatively than preoperatively. Five months post-surgery, the PDK4 gene was significantly more hypomethylated at eight sites in the CpG island, compared to pre-surgery. There was a significant correlation (r=0.88, P=0.02) between promoter region hypomethylation and weight loss. Total methylation rate and weight loss were significantly correlated (r=0.829, P=0.042). Total methylation rate and decrease in total fat mass showed a positive trending relationship (r=0.812, P=0.05). CONCLUSION: Rehabilitative exercise resulted in significant decreases in weight and body fat. Hypomethylation of the PDK4 gene promoter region signified the effect of postoperative management focus on exercise therapy on weight and fat loss.

Two small linear marks on a mandible: collaborative networking between forensic experts.

A human male mandible was found under the eaves of a house. There were no associated items that allowed for personal identification. An anthropologist, who voluntarily joined our forensics team to give an expert opinion, found two small linear marks of 0.6 cm on the surface of the right condylar process. He thought these marks had been produced by a sharp object, and at the very least were not the result of bite marks by rodents or other animals. At first, the police did not appreciate the significance of the marks. One month later, however, other remains with similar marks were found near the scene, strongly suggesting that the case was a mutilation murder with a sharp weapon. After a vigorous search, the police obtained information that a young man in his twenties had gone missing in the area one year previously. After checking up on his relationships, a suspect was identified and arrested. The suspect subsequently confessed and was convicted as guilty of the crime. There are only a few forensic anthropologists in Japan. Consequently, almost all cases requiring bone examination have been handled by forensic pathologists, but it is hard for forensic pathologists to cover all fields comprehensively. The present case might have been solved without help from the anthropologist. However, we believe that forensic pathologists, especially less experienced ones, should seek advice from an expert in the field of forensic anthropology in order to carry a multidisciplinary forensic investigation. Given the current situation in, it is difficult in many institutes of forensics to obtain direct help from forensic anthropologists. The authors believe that collaborative networking via the Internet between forensic experts in each field cannot only obtain further information on complicated cases, but would also be helpful in training young forensic pathologists.

12 Y-chromosomal STR haplotypes in Japanese.

Haplotypes and allele frequencies of 12 Y-STRs were examined in a population sample of 381 Japanese male volunteers. A total of 315 haplotypes were identified, of which 288 haplotypes were unique, and 18, three, three, two, one and one were found in two, three, four, five, eight and 18 individuals, respectively. Total gene diversity was 0.997.

Acute Physical Stress Increases Serum Levels of Specific microRNAs.

INTRODUCTION: MicroRNA (miR) is non-coding small RNA that regulate mRNA at the post-transcriptional level by degradation or inhibition. To find physical stress markers, we developed a rat model involving a simple and complicated stress and measured serum miR levels. MATERIALS AND METHODS: To demonstrate changes in serum miR levels when physical stress is applied, we constructed three stress modalities using rats: alcohol intake, treadmill running and restraint. After alcohol administration, the rats were made to run on a treadmill and some of the rats were further stressed by restraining with a 2 kg water bag immediately after the treadmill run. The rats were grouped as follows: control, run for 20 min, run for 90 min, run and restrained for 20 min, run and restrained for 90 min. Using total RNA extracted from sera, expression levels of eight miRs were measured by real-time PCR. RESULTS: The level of miR-199a was increased by 20 min stress procedures and the levels of miR-1, miR-24a and miR-133a/b were increased by 90 min stress procedures. No change in the levels of miR-208, miR-212 or miR-296-5p was seen under any stress conditions. There was no significant difference between a treadmill run only and a combination of treadmill run and being restrained by a 2 kg water bag. DISCUSSION: We demonstrated that a combination of these serum miRs might indicate the intensity of stress experienced.