Bile salt hydrolase acyltransferase activity expands bile acid diversity.

Bile acids (BAs) are steroid detergents in bile that contribute to the absorption of fats and fat-soluble vitamins while shaping the gut microbiome because of their antimicrobial properties1-4. Here we identify the enzyme responsible for a mechanism of BA metabolism by the gut microbiota involving amino acid conjugation to the acyl-site of BAs, thus producing a diverse suite of microbially conjugated bile acids (MCBAs). We show that this transformation is mediated by acyltransferase activity of bile salt hydrolase (bile salt hydrolase/transferase, BSH/T). Clostridium perfringens BSH/T rapidly performed acyl transfer when provided various amino acids and taurocholate, glycocholate or cholate, with an optimum at pH 5.3. Amino acid conjugation by C. perfringens BSH/T was diverse, including all proteinaceous amino acids except proline and aspartate. MCBA production was widespread among gut bacteria, with strain-specific amino acid use. Species with similar BSH/T amino acid sequences had similar conjugation profiles and several bsh/t alleles correlated with increased conjugation diversity. Tertiary structure mapping of BSH/T followed by mutagenesis experiments showed that active site structure affects amino acid selectivity. These MCBA products had antimicrobial properties, where greater amino acid hydrophobicity showed greater antimicrobial activity. Inhibitory concentrations of MCBAs reached those measured natively in the mammalian gut. MCBAs fed to mice entered enterohepatic circulation, in which liver and gallbladder concentrations varied depending on the conjugated amino acid. Quantifying MCBAs in human faecal samples showed that they reach concentrations equal to or greater than secondary and primary BAs and were reduced after bariatric surgery, thus supporting MCBAs as a significant component of the BA pool that can be altered by changes in gastrointestinal physiology. In conclusion, the inherent acyltransferase activity of BSH/T greatly diversifies BA chemistry, creating a set of previously underappreciated metabolites with the potential to affect the microbiome and human health.

Persistent Hiccups after Subthalamic Nucleus Deep Brain Stimulator Implantation for Parkinson's Disease: Case Report and Literature Review.

Hiccups are mediated by a reflex arc that consists of afferent, central, and efferent components. The structures involved in the central component have not been fully elucidated, although several brainstem structures have been implicated, including the subthalamic nucleus (STN). Accordingly, Parkinson's disease (PD), a disease defined by the loss of dopaminergic neurons in the STN, has an interesting, although unspecified, relationship to hiccups. Hiccups have been described in association with PD and the use of dopaminergic medications. Interestingly, deep brain stimulation (DBS) of the STN appears to be implicated in the pathogenesis of hiccups as well. There have been sporadic reports of hiccups occurring in conjunction with STN-DBS. We present a case of hiccups occurring after STN-DBS for PD in a 65-year-old man. STN-DBS significantly improved his PD symptoms; however, he developed persistent and daily hiccups. As of writing, 24 months after surgery, the patient experiences hiccups several times per day with no associated gastrointestinal complaints and with significant improvement in his PD symptoms. This report describes the case details and summarizes the existing literature describing hiccups in patients undergoing surgical treatment for PD.

Association of Metabolomic Biomarkers with Sleeve Gastrectomy Weight Loss Outcomes.

This prospective observational study aimed to evaluate the association of metabolomic alterations with weight loss outcomes following sleeve gastrectomy (SG). We evaluated the metabolomic profile of serum and feces prior to SG and three months post-SG, along with weight loss outcomes in 45 adults with obesity. The percent total weight loss for the highest versus the lowest weight loss tertiles (T3 vs. T1) was 17.0 ± 1.3% and 11.1 ± 0.8%, p < 0.001. Serum metabolite alterations specific to T3 at three months included a decrease in methionine sulfoxide concentration as well as alterations to tryptophan and methionine metabolism (p < 0.03). Fecal metabolite changes specific to T3 included a decrease in taurine concentration and perturbations to arachidonic acid metabolism, and taurine and hypotaurine metabolism (p < 0.002). Preoperative metabolites were found to be highly predictive of weight loss outcomes in machine learning algorithms, with an average area under the curve of 94.6% for serum and 93.4% for feces. This comprehensive metabolomics analysis of weight loss outcome differences post-SG highlights specific metabolic alterations as well as machine learning algorithms predictive of weight loss. These findings could contribute to the development of novel therapeutic targets to enhance weight loss outcomes after SG.

Dementia with Lewy bodies post-mortem brains reveal differentially methylated CpG sites with biomarker potential.

Dementia with Lewy bodies (DLB) is a common form of dementia with known genetic and environmental interactions. However, the underlying epigenetic mechanisms which reflect these gene-environment interactions are poorly studied. Herein, we measure genome-wide DNA methylation profiles of post-mortem brain tissue (Broadmann area 7) from 15 pathologically confirmed DLB brains and compare them with 16 cognitively normal controls using Illumina MethylationEPIC arrays. We identify 17 significantly differentially methylated CpGs (DMCs) and 17 differentially methylated regions (DMRs) between the groups. The DMCs are mainly located at the CpG islands, promoter and first exon regions. Genes associated with the DMCs are linked to "Parkinson's disease" and "metabolic pathway", as well as the diseases of "severe intellectual disability" and "mood disorders". Overall, our study highlights previously unreported DMCs offering insights into DLB pathogenesis with the possibility that some of these could be used as biomarkers of DLB in the future.

Lipid Profiling of Alzheimer's Disease Brain Highlights Enrichment in Glycerol(phospho)lipid, and Sphingolipid Metabolism.

Alzheimer's disease (AD) is reported to be closely linked with abnormal lipid metabolism. To gain a more comprehensive understanding of what causes AD and its subsequent development, we profiled the lipidome of postmortem (PM) human brains (neocortex) of people with a range of AD pathology (Braak 0-6). Using high-resolution mass spectrometry, we employed a semi-targeted, fully quantitative lipidomics profiling method (Lipidyzer) to compare the biochemical profiles of brain tissues from persons with mild AD (n = 15) and severe AD (AD; n = 16), and compared them with age-matched, cognitively normal controls (n = 16). Univariate analysis revealed that the concentrations of 420 lipid metabolites significantly (p < 0.05; q < 0.05) differed between AD and controls. A total of 49 lipid metabolites differed between mild AD and controls, and 439 differed between severe AD and mild AD. Interestingly, 13 different subclasses of lipids were significantly perturbed, including neutral lipids, glycerolipids, glycerophospholipids, and sphingolipids. Diacylglycerol (DAG) (14:0/14:0), triacylglycerol (TAG) (58:10/FA20:5), and TAG (48:4/FA18:3) were the most notably altered lipids when AD and control brains were compared (p < 0.05). When we compare mild AD and control brains, phosphatidylethanolamine (PE) (p-18:0/18:1), phosphatidylserine (PS) (18:1/18:2), and PS (14:0/22:6) differed the most (p < 0.05). PE (p-18:0/18:1), DAG (14:0/14:0), and PS (18:1/20:4) were identified as the most significantly perturbed lipids when AD and mild AD brains were compared (p < 0.05). Our analysis provides the most extensive lipid profiling yet undertaken in AD brain tissue and reveals the cumulative perturbation of several lipid pathways with progressive disease pathology. Lipidomics has considerable potential for studying AD etiology and identifying early diagnostic biomarkers.

Targeted Metabolic Profiling of Urine Highlights a Potential Biomarker Panel for the Diagnosis of Alzheimer's Disease and Mild Cognitive Impairment: A Pilot Study.

The lack of sensitive and specific biomarkers for the early detection of mild cognitive impairment (MCI) and Alzheimer's disease (AD) is a major hurdle to improving patient management. A targeted, quantitative metabolomics approach using both 1H NMR and mass spectrometry was employed to investigate the performance of urine metabolites as potential biomarkers for MCI and AD. Correlation-based feature selection (CFS) and least absolute shrinkage and selection operator (LASSO) methods were used to develop biomarker panels tested using support vector machine (SVM) and logistic regression models for diagnosis of each disease state. Metabolic changes were investigated to identify which biochemical pathways were perturbed as a direct result of MCI and AD in urine. Using SVM, we developed a model with 94% sensitivity, 78% specificity, and 78% AUC to distinguish healthy controls from AD sufferers. Using logistic regression, we developed a model with 85% sensitivity, 86% specificity, and an AUC of 82% for AD diagnosis as compared to cognitively healthy controls. Further, we identified 11 urinary metabolites that were significantly altered to include glucose, guanidinoacetate, urocanate, hippuric acid, cytosine, 2- and 3-hydroxyisovalerate, 2-ketoisovalerate, tryptophan, trimethylamine N oxide, and malonate in AD patients, which are also capable of diagnosing MCI, with a sensitivity value of 76%, specificity of 75%, and accuracy of 81% as compared to healthy controls. This pilot study suggests that urine metabolomics may be useful for developing a test capable of diagnosing and distinguishing MCI and AD from cognitively healthy controls.

Low Dose Brain Irradiation Reduces Amyloid-ß and Tau in 3xTg-AD Mice.

We have previously reported that low doses of external beam ionizing irradiation reduced amyloid-ß (Aß) plaques and improved cognition in APP/PS1 mice. In this study we investigated the effects of radiation in an age-matched series of 3xTg-AD mice. Mice were hemibrain-irradiated with 5 fractions of 2 Gy and sacrificed 8 weeks after the end of treatment. Aß and tau were assessed using immunohistochemistry and quantified using image analysis with Definiens Tissue Studio. We observed a significant reduction in Aß plaque burden and tau staining; these two parameters were significantly correlated. This preliminary data is further support that low doses of radiation may be beneficial in Alzheimer's disease.

Effect of Group-Administered Behavioral Treatment on Urinary Incontinence in Older Women: A Randomized Clinical Trial.

Importance: Urinary incontinence (UI) guidelines recommend behavioral interventions as first-line treatment using individualized approaches. A one-time, group-administered behavioral treatment (GBT) could enhance access to behavioral treatment. Objective: To compare the effectiveness, cost, and cost-effectiveness of GBT with no treatment for UI in older women. Design, Setting, and Participants: Multisite randomized clinical trial (the Group Learning Achieves Decreased Incidents of Lower Urinary Symptoms [GLADIOLUS] study), conducted from July 7, 2014, to December 31, 2016. The setting was outpatient practices at 3 academic medical centers. Community-dwelling women 55 years or older with UI were recruited by mail and screened for eligibility, including a score of 3 or higher on the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF), symptoms of at least 3 months' duration, and absence of medical conditions or treatments that could affect continence status. Of 2171 mail respondents, 1125 were invited for clinical screening; 463 were eligible and randomized; 398 completed the 12-month study. Interventions: The GBT group received a one-time 2-hour bladder health class, supported by written materials and an audio CD. Main Outcomes and Measures: Outcomes were measured at in-person visits (at 3 and 12 months) and by mail or telephone (at 6 and 9 months). The primary outcome was the change in the ICIQ-SF score. Secondary outcome measures assessed UI severity, quality of life, perceptions of improvement, pelvic floor muscle strength, and costs. Evaluators were masked to group assignment. Results: Participants (232 in the GBT group and 231 in the control group) were aged 55 to 91 years (mean [SD] age, 64 [7] years), and 46.2% (214 of 463) were African American. In intent-to-treat analyses, the ICIQ-SF scores for GBT were consistently lower than control across all time points but did not achieve the projected 3-point difference. At 3 months, the difference in differences was 0.96 points (95% CI, -1.51 to -0.41 points), which was statistically significant but clinically modest. The mean (SE) treatment effects at 6, 9, and 12 months were 1.36 (0.32), 2.13 (0.33), and 1.77 (0.31), respectively. Significant group differences were found at all time points in favor of GBT on all secondary outcomes except pelvic floor muscle strength. The incremental cost to achieve a treatment success was $723 at 3 months; GBT dominated at 12 months. Conclusions and Relevance: The GLADIOLUS study shows that a novel one-time GBT program is modestly effective and cost-effective for reducing UI frequency, severity, and bother and improving quality of life. Group-administered behavioral treatment is a promising first-line approach to enhancing access to noninvasive behavioral treatment for older women with UI. Trial Registration: ClinicalTrials.gov identifier: NCT02001714.

Cranial irradiation significantly reduces beta amyloid plaques in the brain and improves cognition in a murine model of Alzheimer's Disease (AD).

BACKGROUND AND PURPOSE: To investigate if cranial X-irradiation reduces amyloid-ß (Aß) plaques and influences cognitive function in a transgenic mouse model of AD. METHODS AND MATERIALS: B6.Cg-Tg (APPswePSEN1dE9)85Dbo/J AD-prone mice were given cranial X-irradiation. The number of Aß plaques, along with expression of AD specific genes (84 genes: Mouse Alzheimer's Disease RT(2) Profiler), radiation-associated cytokines (Milliplex MAP Mouse Cytokine Chemokine Immunoassay) and immunohistochemistry (IL10, IL-1ß, Iba1 CD45) was assessed. Behavioral testing was performed to relate changes in Aß burden to cognitive function using a Morris water-maze task. RESULTS: Single X-ray doses reduced the number (p=0.002) and size (p=0.01) of Aß plaques. Low-dose fractionation produced greater 50.6% (1 Gy × 10), 72% (2 Gy × 5) and 78% (2 Gy × 10) reductions. Irradiation was associated with gene (Pkp4, 1.5-fold, p=0.004) and proteomic (MIP-2, 8-fold, p=0.0024) changes at 24-48 h. Microglia increased at 4 weeks post-irradiation (p=0.001). The reduction in Aß burden (2 Gy × 5) was associated with cognitive improvement (p=0.012). CONCLUSION: This is the first report that a clinically relevant course of external beam irradiation (2 Gy × 5) produces a significant reduction in AD-associated amyloid-ß plaques with a subsequent improvement in cognitive function. However, longer-term studies are needed to define the precise underlying mechanism and longevity of this response.

Low bone mass and postfall fracture risk among elderly nursing home men.

OBJECTIVE: To study postfall fracture risk in relation to bone mineral density. SETTING: The study was conducted in men residing in nursing homes. PARTICIPANTS: A total of 212 men above the age of 65 years were recruited, and of these, 172 satisfied the inclusion criteria of the study. Among them, 82 were less than 85 years old, and 90 were at least 85 years old. INTERVENTION: Bone mineral density (BMD) of the calcaneus was measured, using the Lunar PIXI Bone Densitometer (version 1.43) and charts were reviewed for age, falls, and fractures. MEASUREMENTS: The values of BMD were expressed as T-scores, and the Lunar criteria equivalents of T-scores were used (T-scores more than -0.6 for normal BMD, -0.6 to -1.6 for osteopenia, and below -1.6 for osteoporosis). RESULTS: The median age of all participants was 84 years (range 65 to 102 years), and their mean T-score at the calcaneus was -1.51. In about 51% of them, the T-score was in the osteoporotic range. For subjects less than 85 years old, the mean T-score was -1.19, and for those 85 years and older, the mean T-score was -1.81; the mean bone density of those in the older old group was significantly lower than those in the younger old group if there was a history of a fracture. Analysis by age quartiles showed a progressive decline in BMD with advancing age. About 53% of the subjects who fell (37.2%) sustained a nontraumatic fracture. Among them, 67.6% had osteoporosis. CONCLUSION: At any given age after age 65, men who sustained a postfall fracture had a significantly lower BMD than those who did not sustain a postfall fracture.