Teodoro Bottiglieri Ph.D.

McKenna Iii, J., D. Kapfhamer, J. M. Kinchen, B. Wasek, M. Dunworth, T. Murray-Stewart, T. Bottiglieri, R. A. Casero, Jr. and M. J. Gambello (2018). “Metabolomic studies identify changes in transmethylation and polyamine metabolism in a brain-specific mouse model of tuberous sclerosis complex.” Hum Mol Genet. Apr 9. [Epub ahead of print].

Full text of this article.

Tuberous sclerosis complex (TSC) is an autosomal dominant neurodevelopmental disorder and the quintessential disorder of mTORC1 dysregulation. Loss of either causative gene, TSC1 or TSC2, leads to constitutive mTORC1 kinase activation and a pathologically anabolic state of macromolecular biosynthesis. Little is known about the organ-specific metabolic reprogramming that occurs in TSC-affected organs. Using a mouse model of TSC in which Tsc2 is disrupted in radial glial precursors and their neuronal and glial descendants, we performed an unbiased metabolomic analysis of hippocampi to identify Tsc2-dependent metabolic changes. Significant metabolic reprogramming was found in well-established pathways associated with mTORC1 activation, including redox homeostasis, glutamine/TCA cycle, pentose and nucleotide metabolism. Changes in two novel pathways were identified: transmethylation and polyamine metabolism. Changes in transmethylation included reduced methionine, cystathionine, S-adenosylmethionine (SAM – the major methyl donor), reduced SAM/SAH ratio (cellular methylation potential), and elevated betaine, an alternative methyl donor. These changes were associated with alterations in SAM-dependent methylation pathways and expression of the enzymes methionine adenosyltransferase 2A (MAT2A) and cystathionine beta synthase (CBS). We also found increased levels of the polyamine putrescine due to increased activity of ornithine decarboxylase, the rate-determining enzyme in polyamine synthesis. Treatment of Tsc2+/- mice with the ornithine decarboxylase (ODC) inhibitor 2-difluoromethylornithine (DFMO), to reduce putrescine synthesis dose-dependently reduced hippocampal astrogliosis. These data establish roles for SAM-dependent methylation reactions and polyamine metabolism in TSC neuropathology. Importantly, both pathways are amenable to nutritional or pharmacologic therapy.

Majtan, T., E. M. Bublil, I. Park, E. Arning, T. Bottiglieri, F. Glavin and J. P. Kraus (2018). “Pharmacokinetics and pharmacodynamics of PEGylated truncated human cystathionine beta-synthase for treatment of homocystinuria.” Life Sci 200: 15-25. May 1.

Full text of this article.

AIMS: PEGylated human truncated cystathionine beta-synthase, lacking the C-terminal regulatory domain (PEG-CBS), is a promising preclinical candidate for enzyme replacement therapy in homocystinuria (HCU). It was designed to function as a metabolic sink to decrease the severely elevated plasma and tissue homocysteine concentrations. In this communication, we evaluated pharmacokinetics (PK), pharmacodynamics (PD) and sub-chronic toxicity of PEG-CBS in homocystinuric mice, wild type rats and monkeys to estimate the minimum human efficacious dose for clinical trials. MAIN METHODS: Animal models received single or multiple doses of PEG-CBS. Activity of PEG-CBS and sulfur amino acid metabolites were determined in plasma and used to determine PK and PD. KEY FINDINGS: The plasma half-lives of PEG-CBS after a single subcutaneous (SC) injection were approximately 20, 44 and 73h in mouse, rat and monkey, respectively. The SC administration of PEG-CBS resulted in a significant improvement or full correction of metabolic imbalance in both blood and tissues of homocystinuric mice. The PD of PEG-CBS in mouse was dose-dependent, but less than dose-proportional, with the maximal efficacy achieved at 8mg/kg. PEG-CBS was well-tolerated in mice and monkeys, but resulted in dose-dependent minimal-to-moderate inflammation at the injection sites and vacuolated macrophages in rats. Allometric scaling of animal data was linear and the estimated human efficacious dose was determined as 0.66mg/kg administered once a week. SIGNIFICANCE: These results provide critical preclinical data for the design of first-in-human PEG-CBS clinical trial.

Majtan, T., E. M. Bublil, I. Park, E. Arning, T. Bottiglieri, F. Glavin and J. P. Kraus (2018). “Pharmacokinetics and pharmacodynamics of PEGylated truncated human cystathionine beta-synthase for treatment of homocystinuria.” Life Sci 200: 15-25.

Full text of this article.

AIMS: PEGylated human truncated cystathionine beta-synthase, lacking the C-terminal regulatory domain (PEG-CBS), is a promising preclinical candidate for enzyme replacement therapy in homocystinuria (HCU). It was designed to function as a metabolic sink to decrease the severely elevated plasma and tissue homocysteine concentrations. In this communication, we evaluated pharmacokinetics (PK), pharmacodynamics (PD) and sub-chronic toxicity of PEG-CBS in homocystinuric mice, wild type rats and monkeys to estimate the minimum human efficacious dose for clinical trials. MAIN METHODS: Animal models received single or multiple doses of PEG-CBS. Activity of PEG-CBS and sulfur amino acid metabolites were determined in plasma and used to determine PK and PD. KEY FINDINGS: The plasma half-lives of PEG-CBS after a single subcutaneous (SC) injection were approximately 20, 44 and 73h in mouse, rat and monkey, respectively. The SC administration of PEG-CBS resulted in a significant improvement or full correction of metabolic imbalance in both blood and tissues of homocystinuric mice. The PD of PEG-CBS in mouse was dose-dependent, but less than dose-proportional, with the maximal efficacy achieved at 8mg/kg. PEG-CBS was well-tolerated in mice and monkeys, but resulted in dose-dependent minimal-to-moderate inflammation at the injection sites and vacuolated macrophages in rats. Allometric scaling of animal data was linear and the estimated human efficacious dose was determined as 0.66mg/kg administered once a week. SIGNIFICANCE: These results provide critical preclinical data for the design of first-in-human PEG-CBS clinical trial.

Shiao, S. P. K., J. Grayson, C. H. Yu, B. Wasek and T. Bottiglieri (2018). “Gene Environment Interactions and Predictors of Colorectal Cancer in Family-Based, Multi-Ethnic Groups.” J Pers Med 8(1).

Full text of this article.

For the personalization of polygenic/omics-based health care, the purpose of this study was to examine the gene-environment interactions and predictors of colorectal cancer (CRC) by including five key genes in the one-carbon metabolism pathways. In this proof-of-concept study, we included a total of 54 families and 108 participants, 54 CRC cases and 54 matched family friends representing four major racial ethnic groups in southern California (White, Asian, Hispanics, and Black). We used three phases of data analytics, including exploratory, family-based analyses adjusting for the dependence within the family for sharing genetic heritage, the ensemble method, and generalized regression models for predictive modeling with a machine learning validation procedure to validate the results for enhanced prediction and reproducibility. The results revealed that despite the family members sharing genetic heritage, the CRC group had greater combined gene polymorphism rates than the family controls (p < 0.05), on MTHFR C677T, MTR A2756G, MTRR A66G, and DHFR 19 bp except MTHFR A1298C. Four racial groups presented different polymorphism rates for four genes (all p < 0.05) except MTHFR A1298C. Following the ensemble method, the most influential factors were identified, and the best predictive models were generated by using the generalized regression models, with Akaike's information criterion and leave-one-out cross validation methods. Body mass index (BMI) and gender were consistent predictors of CRC for both models when individual genes versus total polymorphism counts were used, and alcohol use was interactive with BMI status. Body mass index status was also interactive with both gender and MTHFR C677T gene polymorphism, and the exposure to environmental pollutants was an additional predictor. These results point to the important roles of environmental and modifiable factors in relation to gene-environment interactions in the prevention of CRC.

Ross, R. D., R. C. Shah, S. Leurgans, T. Bottligieri, R. S. Wilson and D. R. Sumner (2018). “Circulating Dkk1 and TRAIL are Associated with Cognitive Decline in Community-Dwelling, Older Adults with Cognitive Concerns.” J Gerontol A Biol Sci Med Sci. Feb 8. [Epub ahead of print].

Full text of this article.

Background: Osteoporosis and Alzheimer’s disease (AD) are common diseases of aging that would seem to be unrelated, but may be linked through the influence of bone-derived signals on brain function. The current study aimed to investigate the relationship between circulating levels of bone-related biomarkers and cognition. Methods: The population included 103 community-dwelling older individuals with memory concerns but without cognitive impairment. A global cognition summary measure was collected at baseline and 6, 12, and 18-months post-enrollment by converting raw scores from 19 cognitive function tests to z-scores and averaging. Baseline plasma concentrations of bone-related biomarkers, including undercarboxylated, carboxylated, and total osteocalcin, parathyroid hormone (PTH), C-terminal telopeptide of collagen 1 (CTX-1), procollagen type 1 amino-terminal propeptide (PINP), osteoprotegrin (OPG), osteopontin (OPN), Dickkopf WNT signaling pathway inhibitor 1 (Dkk1), sclerostin, and amyloid beta peptides (Abeta40 and Abeta42) were measured. Results: Using sex, age, and education-adjusted mixed-effects models, we found that baseline levels of TRAIL (p<0.001), Dkk1 (p=0.014), and CTX-1 (p=0.046) were related to the annual rate of change of global cognition over the 18-month follow-up. In cognitive domain-specific analysis, baseline TRAIL was found to be positively related to the annual rate of change in episodic (p<0.001) and working memory (p=0.016) and baseline Dkk1 was positively related to semantic memory (p=0.027) and negatively related to working memory (p=0.016). Conclusions: These results further confirm the link between bone and brain health and suggest that circulating levels of bone-related biomarkers may have diagnostic potential to predict worsening cognition.