Incidence of re-amputation following partial first ray amputation associated with diabetes mellitus and peripheral sensory neuropathy: a systematic review.

Diabetes mellitus with peripheral sensory neuropathy frequently results in forefoot ulceration. Ulceration at the first ray level tends to be recalcitrant to local wound care modalities and off-loading techniques. If healing does occur, ulcer recurrence is common. When infection develops, partial first ray amputation in an effort to preserve maximum foot length is often performed. However, the survivorship of partial first ray amputations in this patient population and associated re-amputation rate remain unknown. Therefore, in an effort to determine the actual re-amputation rate following any form of partial first ray amputation in patients with diabetes mellitus and peripheral neuropathy, the authors conducted a systematic review. Only studies involving any form of partial first ray amputation associated with diabetes mellitus and peripheral sensory neuropathy but without critical limb ischemia were included. Our search yielded a total of 24 references with 5 (20.8%) meeting our inclusion criteria involving 435 partial first ray amputations. The weighted mean age of patients was 59 years and the weighted mean follow-up was 26 months. The initial amputation level included the proximal phalanx base 167 (38.4%) times; first metatarsal head resection 96 (22.1%) times; first metatarsal-phalangeal joint disarticulation 53 (12.2%) times; first metatarsal mid-shaft 39 (9%) times; hallux fillet flap 32 (7.4%) times; first metatarsal base 29 (6.7%) times; and partial hallux 19 (4.4%) times. The incidence of re-amputation was 19.8% (86/435). The end stage, most proximal level, following re-amputation was an additional digit 32 (37.2%) times; transmetatarsal 28 (32.6%) times; below-knee 25 (29.1%) times; and LisFranc 1 (1.2%) time. The results of our systematic review reveal that one out of every five patients undergoing any version of a partial first ray amputation will eventually require more proximal re-amputation. These results reveal that partial first ray amputation for patients with diabetes and peripheral sensory neuropathy may not represent a durable, functional, or predictable foot-sparing amputation and that a more proximal amputation, such as a balanced transmetatarsal amputation, as the index amputation may be more beneficial to the patient. However, this remains a matter for conjecture due to the limited data available and, therefore, additional prospective investigations are warranted

Comparison of Ga-68-DOTA-Siglec-9 and F-18-Fluorodeoxyribose-Siglec-9: Inflammation Imaging and Radiation Dosimetry

Sialic acid-binding immunoglobulin-like lectin 9 (Siglec-9) is a ligand of inflammation-inducible vascular adhesion protein-1 (VAP1). We compared Ga-68-DOTA-and F-18-fluorodeoxyribose-(FDR) labeled Siglec-9motif peptides for PET imaging of inflammation. Methods. Firstly, we examined Ga-68-DOTA-Siglec-9 and F-18-FDR-Siglec-9 in rats with skin/muscle inflammation. We then studied F-18-FDR-Siglec-9 for the detection of inflamed atherosclerotic plaques in mice and compared it with previous Ga-68-DOTA-Siglec-9 results. Lastly, we estimated human radiation dosimetry fromthe rat data. Results. In rats, Ga-68-DOTA-Siglec-9 (SUV, 0.88 +/- 0.087) and F-18-FDR-Siglec-9 (SUV, 0.77 +/- 0.22) showed comparable (P = 0.29) imaging of inflammation. In atherosclerotic mice, 18 FFDR- Siglec-9 detected inflamed plaques with a target-to-background ratio (1.6 1/8 0.078) similar to previously tested Ga-68-DOTASiglec- 9 (P = 0.35). Humaneffectivedose estimates for Ga-68-DOTA-Siglec-9 and (18) F-FDR-Siglec-9were 0.024 and 0.022 mSv/MBq, respectively. Conclusion. Both tracers are suitable for PET imaging of inflammation. The easier production and lower cost of (68)GaDOTA-Siglec-9 present advantages over F-18-FDR-Siglec-9, indicating it as a primary choice for clinical studies

Autoimmunity, hypogammaglobulinemia, lymphoproliferation and mycobacterial disease in patients with dominant activating mutations in STAT3

The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.The signal transducer and activator of transcription (STAT) family of transcription factors orchestrate hematopoietic cell differentiation. Recently, mutations in STAT1, STAT5B, and STAT3 have been linked to development of IPEX-like syndrome. Here, we immunologically characterized three patients with de novo activating mutations in the DNA binding or dimerization domains of STAT3 (p.K392R, p.M394T and p.K658N, respectively). The patients displayed multi-organ autoimmunity, lymphoproliferation, and delayed-onset mycobacterial disease. Immunologically, we noted hypogammaglobulinemia with terminal B cell maturation arrest, dendritic cell deficiency, peripheral eosinopenia, increased double-negative (CD4-CD8-) T cells, and decreased NK, Th17, and regulatory T cell numbers. Notably, the patient harboring the K392R mutation developed T cell LGL leukemia at age 14. Our results broaden the spectrum of phenotypes caused by activating STAT3 mutations, highlight the role of STAT3 in the development and differentiation of multiple immune cell lineages, and strengthen the link between the STAT family of transcription factors and autoimmunity.</p

An expression signature of syndecan-1 (CD138), E-cadherin and c-met is associated with factors of angiogenesis and lymphangiogenesis in ductal breast carcinoma in situ

INTRODUCTION: Heparan sulphate proteoglycan syndecan-1 modulates cell proliferation, adhesion, migration and angiogenesis. It is a coreceptor for the hepatocyte growth factor receptor c-met, and its coexpression with E-cadherin is synchronously regulated during epithelial-mesenchymal transition. In breast cancer, changes in the expression of syndecan-1, E-cadherin and c-met correlate with poor prognosis. In this study we evaluated whether coexpression of these functionally linked prognostic markers constitutes an expression signature in ductal carcinoma in situ (DCIS) of the breast that may promote cell proliferation and (lymph)angiogenesis. METHODS: Expression of syndecan-1, E-cadherin and c-met was detected immunohistochemically using a tissue microarray in tumour specimens from 200 DCIS patients. Results were correlated with the expression patterns of angiogenic and lymphangiogenic markers. Coexpression of the three prognostic markers was evaluated in human breast cancer cells by confocal immunofluorescence microscopy and RT-PCR. RESULTS: Coexpression and membrane colocalization of the three markers was confirmed in MCF-7 cells. E-cadherin expression decreased, and c-met expression increased progressively in more aggressive cell lines. Tissue microarray analysis revealed strong positive staining of tumour cells for syndecan-1 in 72%, E-cadherin in 67.8% and c-met in 48.6% of DCIS. E-cadherin expression was significantly associated with c-met and syndecan-1. Expression of c-met and syndecan-1 was significantly more frequent in the subgroup of patients with pure DCIS than in those with DCIS and a coexisting invasive carcinoma. Levels of c-met and syndecan-1 expression were associated with HER2 expression. Expression of c-met significantly correlated with expression of endothelin A and B receptors, vascular endothelial growth factor (VEGF)-A and fibroblast growth factor receptor-1, whereas E-cadherin expression correlated significantly with endothelin A receptor, VEGF-A and VEGF-C staining. CONCLUSION: Syndecan-1, E-cadherin and c-met constitute a marker signature associated with angiogenic and lymphangiogenic factors in DCIS. This coexpression may reflect a state of parallel activation of different signal transduction pathways, promoting tumour cell proliferation and angiogenesis. Our findings have implications for future therapeutic approaches in terms of a multiple target approach, which may be useful early in breast cancer progression

Identification of novel risk loci, causal insights, and heritable risk for Parkinson's disease: a meta-analysis of genome-wide association studies

Background: Genome-wide association studies (GWAS) in Parkinson's disease have increased the scope of biological knowledge about the disease over the past decade. We aimed to use the largest aggregate of GWAS data to identify novel risk loci and gain further insight into the causes of Parkinson's disease. / Methods: We did a meta-analysis of 17 datasets from Parkinson's disease GWAS available from European ancestry samples to nominate novel loci for disease risk. These datasets incorporated all available data. We then used these data to estimate heritable risk and develop predictive models of this heritability. We also used large gene expression and methylation resources to examine possible functional consequences as well as tissue, cell type, and biological pathway enrichments for the identified risk factors. Additionally, we examined shared genetic risk between Parkinson's disease and other phenotypes of interest via genetic correlations followed by Mendelian randomisation. / Findings: Between Oct 1, 2017, and Aug 9, 2018, we analysed 7·8 million single nucleotide polymorphisms in 37 688 cases, 18 618 UK Biobank proxy-cases (ie, individuals who do not have Parkinson's disease but have a first degree relative that does), and 1·4 million controls. We identified 90 independent genome-wide significant risk signals across 78 genomic regions, including 38 novel independent risk signals in 37 loci. These 90 variants explained 16–36% of the heritable risk of Parkinson's disease depending on prevalence. Integrating methylation and expression data within a Mendelian randomisation framework identified putatively associated genes at 70 risk signals underlying GWAS loci for follow-up functional studies. Tissue-specific expression enrichment analyses suggested Parkinson's disease loci were heavily brain-enriched, with specific neuronal cell types being implicated from single cell data. We found significant genetic correlations with brain volumes (false discovery rate-adjusted p=0·0035 for intracranial volume, p=0·024 for putamen volume), smoking status (p=0·024), and educational attainment (p=0·038). Mendelian randomisation between cognitive performance and Parkinson's disease risk showed a robust association (p=8·00 × 10−7). / Interpretation: These data provide the most comprehensive survey of genetic risk within Parkinson's disease to date, to the best of our knowledge, by revealing many additional Parkinson's disease risk loci, providing a biological context for these risk factors, and showing that a considerable genetic component of this disease remains unidentified. These associations derived from European ancestry datasets will need to be followed-up with more diverse data. / Funding: The National Institute on Aging at the National Institutes of Health (USA), The Michael J Fox Foundation, and The Parkinson's Foundation (see appendix for full list of funding sources)

Moving beyond neurons: the role of cell type-specific gene regulation in Parkinson's disease heritability

Parkinson’s disease (PD), with its characteristic loss of nigrostriatal dopaminergic neurons and deposition of α-synuclein in neurons, is often considered a neuronal disorder. However, in recent years substantial evidence has emerged to implicate glial cell types, such as astrocytes and microglia. In this study, we used stratified LD score regression and expression-weighted cell-type enrichment together with several brain-related and cell-type-specific genomic annotations to connect human genomic PD findings to specific brain cell types. We found that PD heritability attributable to common variation does not enrich in global and regional brain annotations or brain-related cell-type-specific annotations. Likewise, we found no enrichment of PD susceptibility genes in brain-related cell types. In contrast, we demonstrated a significant enrichment of PD heritability in a curated lysosomal gene set highly expressed in astrocytic, microglial, and oligodendrocyte subtypes, and in LoF-intolerant genes, which were found highly expressed in almost all tested cellular subtypes. Our results suggest that PD risk loci do not lie in specific cell types or individual brain regions, but rather in global cellular processes detectable across several cell types

Identification of sixteen novel candidate genes for late onset Parkinson’s disease

Background Parkinson’s disease (PD) is a neurodegenerative movement disorder affecting 1–5% of the general population for which neither effective cure nor early diagnostic tools are available that could tackle the pathology in the early phase. Here we report a multi-stage procedure to identify candidate genes likely involved in the etiopathogenesis of PD. Methods The study includes a discovery stage based on the analysis of whole exome data from 26 dominant late onset PD families, a validation analysis performed on 1542 independent PD patients and 706 controls from different cohorts and the assessment of polygenic variants load in the Italian cohort (394 unrelated patients and 203 controls). Results Family-based approach identified 28 disrupting variants in 26 candidate genes for PD including PARK2, PINK1, DJ-1(PARK7), LRRK2, HTRA2, FBXO7, EIF4G1, DNAJC6, DNAJC13, SNCAIP, AIMP2, CHMP1A, GIPC1, HMOX2, HSPA8, IMMT, KIF21B, KIF24, MAN2C1, RHOT2, SLC25A39, SPTBN1, TMEM175, TOMM22, TVP23A and ZSCAN21. Sixteen of them have not been associated to PD before, were expressed in mesencephalon and were involved in pathways potentially deregulated in PD. Mutation analysis in independent cohorts disclosed a significant excess of highly deleterious variants in cases (p = 0.0001), supporting their role in PD. Moreover, we demonstrated that the co-inheritance of multiple rare variants (≥ 2) in the 26 genes may predict PD occurrence in about 20% of patients, both familial and sporadic cases, with high specificity (> 93%; p = 4.4 × 10− 5). Moreover, our data highlight the fact that the genetic landmarks of late onset PD does not systematically differ between sporadic and familial forms, especially in the case of small nuclear families and underline the importance of rare variants in the genetics of sporadic PD. Furthermore, patients carrying multiple rare variants showed higher risk of manifesting dyskinesia induced by levodopa treatment. Conclusions Besides confirming the extreme genetic heterogeneity of PD, these data provide novel insights into the genetic of the disease and may be relevant for its prediction, diagnosis and treatment

A Genome-Wide Association Study of Diabetic Kidney Disease in Subjects With Type 2 Diabetes

dentification of sequence variants robustly associated with predisposition to diabetic kidney disease (DKD) has the potential to provide insights into the pathophysiological mechanisms responsible. We conducted a genome-wide association study (GWAS) of DKD in type 2 diabetes (T2D) using eight complementary dichotomous and quantitative DKD phenotypes: the principal dichotomous analysis involved 5,717 T2D subjects, 3,345 with DKD. Promising association signals were evaluated in up to 26,827 subjects with T2D (12,710 with DKD). A combined T1D+T2D GWAS was performed using complementary data available for subjects with T1D, which, with replication samples, involved up to 40,340 subjects with diabetes (18,582 with DKD). Analysis of specific DKD phenotypes identified a novel signal near GABRR1 (rs9942471, P = 4.5 x 10(-8)) associated with microalbuminuria in European T2D case subjects. However, no replication of this signal was observed in Asian subjects with T2D or in the equivalent T1D analysis. There was only limited support, in this substantially enlarged analysis, for association at previously reported DKD signals, except for those at UMOD and PRKAG2, both associated with estimated glomerular filtration rate. We conclude that, despite challenges in addressing phenotypic heterogeneity, access to increased sample sizes will continue to provide more robust inference regarding risk variant discovery for DKD.Peer reviewe