Advances in the neurosciences have placed the field in the position where it is poised to significantly reduce the burden of nervous system disorders. However, drug discovery, development, and ...translation for nervous system disorders still pose many unique challenges. The key scientific challenges can be summarized as follows: mechanisms of disease, target identification and validation, predictive models, biomarkers for patient stratification and as endpoints for clinical trials, clear regulatory pathways, reliability and reproducibility of published data, and data sharing and collaboration. To accelerate nervous system drug development, the Institute of Medicine’s Forum on Neuroscience and Nervous System Disorders has hosted a series of public workshops that brought together representatives of industry, government (including both research funding and regulatory agencies), academia, and patient groups to discuss these challenges and offer potential strategies to improve the translational neuroscience.
Pankevich, Altevogt, Dunlop, Gage, and Hyman discuss current challenges to drug discovery, development, and translation for nervous system disorders, overviewing the results of a series of workshops on translational neuroscience hosted by Institute of Medicine’s Forum on Neuroscience and Nervous System Disorders.
Donor‐specific antibodies (DSAs) have a deleterious effect on allografts and remain a major immunologic barrier in transplantation. Current therapies to eliminate DSAs are ineffective in highly ...HLA‐sensitized patients. Proteasome inhibitors have been employed as a strategy to target bone marrow plasma cells (BMPCs), the source of long‐term antibody production; however, their efficacy has been limited by poorly defined drug‐resistance mechanisms. Here, we performed transcriptomic profiling of CD138+ BMPCs that survived in vivo desensitization therapy with the proteasome inhibitor carfilzomib to identify mechanisms of drug resistance. The results revealed a genomic signature that included increased expression of the immunoproteasome, a highly specialized proteasomal variant. Western blotting and functional studies demonstrated that catalytically active immunoproteasomes and the immunoproteasome activator PA28 were upregulated in carfilzomib‐resistant BMPCs. Carfilzomib‐resistant BMPCs displayed reduced sensitivity to the proteasome inhibitors carfilzomib, bortezomib, and ixazomib, but enhanced sensitivity to an immunoproteasome‐specific inhibitor ONX‐0914. Finally, in vitro carfilzomib treatment of BMPCs from HLA‐sensitized patients increased levels of the immunoproteasome β5i (PSMB8) catalytic subunit suggesting that carfilzomib therapy directly induces an adaptive immunoproteasome response. Taken together, our results indicate that carfilzomib induces structural changes in proteasomes and immunoproteasome formation.
Bone marrow plasma cells from patients treated with a carfilzomib‐based desensitization regimen are shown to exhibit increased immunoproteasome expression prior to treatment and also demonstrate increased immunoproteasome‐specific catalytic activity.
Second malignant neoplasms (SMN) are therapy-induced malignancies and a growing problem in cancer survivors, particularly survivors of childhood cancers. The lack of experimental models of SMNs has ...limited understanding of their pathogenesis. It is currently not possible to predict or prevent this devastating late complication. Individuals with neurofibromatosis I (NF1) are at increased risk of developing therapy-induced cancers for unclear reasons. To model SMNs, we replicated clinical radiotherapy and delivered fractionated abdominal irradiation to Nf1(+/-) and wild-type mice. Similar to irradiated cancer survivors, irradiated wild-type and Nf1(+/-) mice developed diverse in-field malignancies. In Nf1(+/-) mice, fractionated irradiation promoted both classical NF1-associated malignancies and malignancies unassociated with the NF1 syndrome but typical of SMNs. Nf1 heterozygosity potentiated the mutagenic effects of irradiation, as evidenced by the significantly reduced survival after irradiation and tumor development that was often characterized by synchronous primary tumors. Interestingly, diverse radiation-induced tumors arising in wild-type and Nf1(+/-) mice shared a genetic signature characterized by monoallelic loss of Nf1 and the adjacent Trp53 allele. These findings implicate Nf1 loss as mediating tumorigenesis in a broad range of cell types and organs extending beyond the classical NF1 tumor histologies. Examining clinical SMN samples, we found LOH of NF1 in SMNs from non-NF1 patients. Nf1 heterozygosity confers broad susceptibility to genotoxin-induced tumorigenesis, and this paradigm serves as an experimental platform for future studies of SMNs.
A critical component to addressing climate change is effective communication with the public and legislators about urgency for action. Health professionals have a vital role to play in climate ...advocacy. However, several key barriers to public advocacy have been identified, including limited communication skills to effectively advocate with others.
We describe the development, implementation, and evaluation of a novel online workshop, whose goal is to teach volunteers to communicate more effectively on climate change with those holding differing views regarding potential solutions (e.g., role of government vs. private sector). The development phase included seeking input from multiple stakeholders about the workshop's focus and creating specific examples and prompts. The workshop was then pilot-tested, and refinements were made based on evaluations. Volunteers within a climate organization then took the workshop and evaluations were collected.
Evaluations from 312 attendees were analyzed, including 14% in healthcare-related fields. On a 10-point scale (10 being highest), volunteers reporting a median score of 8 in their confidence level for setting a constructive tone in conversations with people holding differing views on climate solutions. Qualitative analysis of participants’ responses “Single most important learning?”, “What was most important to share?”, and “What would you like to see changed?” by two independent observers supported almost perfect agreement (kappa of 0.88) in themes that included Learning New Skills, Developing New Ways of Being, Format, and Additional Training/Suggested Enhancements.
Our workshop increased participant confidence in having conversations on climate change solutions, an important part of climate advocacy.
The application of genome-wide expression analysis to a largescale, multicentered program in critically ill patients poses a number of theoretical and technical challenges. We describe here an ...analytical and organizational approach to a systematic evaluation of the variance associated with genome-wide expression analysis specifically tailored to study human disease. We analyzed sources of variance in genome-wide expression analyses performed with commercial oligonucleotide arrays. In addition, variance in gene expression in human blood leukocytes caused by repeated sampling in the same subject, among different healthy subjects, among different leukocyte subpopulations, and the effect of traumatic injury, were also explored. We report that analytical variance caused by sample processing was acceptably small. Blood leukocyte gene expression in the same individual over a 24-h period was remarkably constant. In contrast, genome-wide expression varied significantly among different subjects and leukocyte subpopulations. Expectedly, traumatic injury induced dramatic changes in apparent gene expression that were greater in magnitude than the analytical noise and interindividual variance. We demonstrate that the development of a nation-wide program for gene expression analysis with careful attention to analytical details can reduce the variance in the clinical setting to a level where patterns of gene expression are informative among different healthy human subjects, and can be studied with confidence in human disease.
Levels of low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides and total cholesterol are heritable, modifiable risk factors for coronary artery ...disease. To identify new loci and refine known loci influencing these lipids, we examined 188,577 individuals using genome-wide and custom genotyping arrays. We identify and annotate 157 loci associated with lipid levels at P < 5 × 10(-8), including 62 loci not previously associated with lipid levels in humans. Using dense genotyping in individuals of European, East Asian, South Asian and African ancestry, we narrow association signals in 12 loci. We find that loci associated with blood lipid levels are often associated with cardiovascular and metabolic traits, including coronary artery disease, type 2 diabetes, blood pressure, waist-hip ratio and body mass index. Our results demonstrate the value of using genetic data from individuals of diverse ancestry and provide insights into the biological mechanisms regulating blood lipids to guide future genetic, biological and therapeutic research.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Triglycerides are transported in plasma by specific triglyceride-rich lipoproteins; in epidemiological studies, increased triglyceride levels correlate with higher risk for coronary artery disease ...(CAD). However, it is unclear whether this association reflects causal processes. We used 185 common variants recently mapped for plasma lipids (P < 5 × 10(-8) for each) to examine the role of triglycerides in risk for CAD. First, we highlight loci associated with both low-density lipoprotein cholesterol (LDL-C) and triglyceride levels, and we show that the direction and magnitude of the associations with both traits are factors in determining CAD risk. Second, we consider loci with only a strong association with triglycerides and show that these loci are also associated with CAD. Finally, in a model accounting for effects on LDL-C and/or high-density lipoprotein cholesterol (HDL-C) levels, the strength of a polymorphism's effect on triglyceride levels is correlated with the magnitude of its effect on CAD risk. These results suggest that triglyceride-rich lipoproteins causally influence risk for CAD.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Scavenger receptor BI (SR-BI) is the major receptor for high-density lipoprotein (HDL) cholesterol (HDL-C). In humans, high amounts of HDL-C in plasma are associated with a lower risk of coronary ...heart disease (CHD). Mice that have depleted Scarb1 (SR-BI knockout mice) have markedly elevated HDL-C levels but, paradoxically, increased atherosclerosis. The impact of SR-BI on HDL metabolism and CHD risk in humans remains unclear. Through targeted sequencing of coding regions of lipid-modifying genes in 328 individuals with extremely high plasma HDL-C levels, we identified a homozygote for a loss-of-function variant, in which leucine replaces proline 376 (P376L), in SCARB1, the gene encoding SR-BI. The P376L variant impairs posttranslational processing of SR-BI and abrogates selective HDL cholesterol uptake in transfected cells, in hepatocyte-like cells derived from induced pluripotent stem cells from the homozygous subject, and in mice. Large population-based studies revealed that subjects who are heterozygous carriers of the P376L variant have significantly increased levels of plasma HDL-C. P376L carriers have a profound HDL-related phenotype and an increased risk of CHD (odds ratio = 1.79, which is statistically significant).
Genome-wide association studies (GWASs) have identified many SNPs underlying variations in plasma-lipid levels. We explore whether additional loci associated with plasma-lipid phenotypes, such as ...high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and triglycerides (TGs), can be identified by a dense gene-centric approach. Our meta-analysis of 32 studies in 66,240 individuals of European ancestry was based on the custom ∼50,000 SNP genotyping array (the ITMAT-Broad-CARe array) covering ∼2,000 candidate genes. SNP-lipid associations were replicated either in a cohort comprising an additional 24,736 samples or within the Global Lipid Genetic Consortium. We identified four, six, ten, and four unreported SNPs in established lipid genes for HDL-C, LDL-C, TC, and TGs, respectively. We also identified several lipid-related SNPs in previously unreported genes: DGAT2, HCAR2, GPIHBP1, PPARG, and FTO for HDL-C; SOCS3, APOH, SPTY2D1, BRCA2, and VLDLR for LDL-C; SOCS3, UGT1A1, BRCA2, UBE3B, FCGR2A, CHUK, and INSIG2 for TC; and SERPINF2, C4B, GCK, GATA4, INSR, and LPAL2 for TGs. The proportion of explained phenotypic variance in the subset of studies providing individual-level data was 9.9% for HDL-C, 9.5% for LDL-C, 10.3% for TC, and 8.0% for TGs. This large meta-analysis of lipid phenotypes with the use of a dense gene-centric approach identified multiple SNPs not previously described in established lipid genes and several previously unknown loci. The explained phenotypic variance from this approach was comparable to that from a meta-analysis of GWAS data, suggesting that a focused genotyping approach can further increase the understanding of heritability of plasma lipids.
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