Insights into the Genetics and Signaling Pathways in Maturity-Onset Diabetes of the Young.

Diabetes Mellitus (DM) is a complex disease with a significant impact in today's world. Studies have emphasized the crucial role of genetics in DM, unraveling the distinction of monogenic diabetes from the most common types that have been recognized over the years, such as type 1 diabetes (T1DM) and type 2 diabetes (T2DM). A literature search was carried out to scrutinize the subtypes of maturity-onset diabetes of the young (MODY), as well as the connection between the recognized genetic and molecular mechanisms responsible for such phenotypes. Thus far, 14 subtypes of MODY have been identified. Here, the authors review the pathophysiological and molecular pathways in which monogenic diabetes genes are involved. Despite being estimated to affect approximately 2% of all T2DM patients in Europe, the exact prevalence of MODY is still unknown, enhancing the need for research focused on biomarkers. Due to its impact in personalized medicine, a follow-up of associated complications, and genetic implications for siblings and offspring of affected individuals, it is imperative to diagnose the monogenic forms of DM accurately. Currently, advances in the genetics field has allowed for the recognition of new DM subtypes, which until now were considered to be slight variations of the typical forms. New molecular insights can define therapeutic strategies, aiming for the prevention, correction, or at least delay of ß-cell dysfunction. Thus, it is imperative to act in the close interaction between genetics and clinical manifestations to improve diagnosis and individualize treatment.

Diffuse Idiopathic Skeletal Hyperostosis (DISH) and a Possible Inflammatory Component.

PURPOSE OF REVIEW: Diffuse Idiopathic Skeletal Hyperostosis (DISH) is considered a metabolic condition, characterized by new bone formation affecting mainly at entheseal sites. Enthesitis and enthesopathies occur not only in the axial skeleton but also at some peripheral sites, and they resemble to some extent the enthesitis that is a cardinal feature in spondyloarthritis (SpA), which is an inflammatory disease. RECENT FINDINGS: We review the possible non-metabolic mechanism such as inflammation that may also be involved at some stage and help promote new bone formation in DISH. We discuss supporting pathogenic mechanisms for a local inflammation at sites typically affected by this disease, and that is also supported by imaging studies that report some similarities between DISH and SpA. Local inflammation, either primary or secondary to metabolic derangements, may contribute to new bone formation in DISH. This new hypothesis is expected to stimulate further research in both the metabolic and inflammatory pathways in order to better understand the mechanisms that lead to new bone formation. This may lead to development of measures that will help in earlier detection and effective management before damage occurs.

Combined approach for finding susceptibility genes in DISH/chondrocalcinosis families: whole-genome-wide linkage and IBS/IBD studies.

Twelve families with exuberant and early-onset calcium pyrophosphate dehydrate chondrocalcinosis (CC) and diffuse idiopathic skeletal hyperostosis (DISH), hereafter designated DISH/CC, were identified in Terceira Island, the Azores, Portugal. Ninety-two (92) individuals from these families were selected for whole-genome-wide linkage analysis. An identity-by-descent (IBD) analysis was performed in 10 individuals from 5 of the investigated pedigrees. The chromosome area with the maximal logarithm of the odds score (1.32; P=0.007) was not identified using the IBD/identity-by-state (IBS) analysis; therefore, it was not investigated further. From the IBD/IBS analysis, two candidate genes, LEMD3 and RSPO4, were identified and sequenced. Nine genetic variants were identified in the RSPO4 gene; one regulatory variant (rs146447064) was significantly more frequent in control individuals than in DISH/CC patients (P=0.03). Four variants were identified in LEMD3, and the rs201930700 variant was further investigated using segregation analysis. None of the genetic variants in RSPO4 or LEMD3 segregated within the studied families. Therefore, although a major genetic effect was shown to determine DISH/CC occurrence within these families, the specific genetic variants involved were not identified.

Anti-inflammatory guaiane-type sesquiterpenes from the fruits of Pittosporum undulatum.

Two unprecedented guaiane-type sesquiterpene glycosides (undulatumosides A and B) were isolated by bioassay-guided fractionation from the MeOH extract of Pittosporum undulatum fruits, along with six known compounds, including the guaiane isomers 5-guaien-11-ol and 4-guaien-11-ol. The structures of the compounds were established as 4-guaiene-11-O-ß-d-(3'-angeloxy-6'-deoxy)-glucopyranoside and 1(5)-guaiene-11-O-ß-d-(3'-angeloxy-6'-deoxy)-glucopyranoside by spectroscopic methods, including 1D and 2D homo- and heteronuclear NMR experiments (COSY, HSQC, HMBC and NOESY), and HR-mass spectrometry. P. undulatum is a highly invasive weed that often outcompetes other plants, yet its fruits have become a traditional anti-inflammatory medicine in Azores. Therefore, aiming to investigate the claimed properties, the in vitro anti-inflammatory activity of guaiane-type sesquiterpenes was evaluated by analyzing their inhibitory effects on chemical mediators released by the LPS activated RAW 264.7 murine macrophages cell line. In addition, the cytotoxicity of these compounds was also evaluated in this cell line. Undulatumoside A, 5-guaien-11-ol and 4-guaien-11-ol displayed anti-inflammatory activity with IC50 values of 16.4, 8.1 and 7.2µM, respectively, comparable to that of the positive control, indomethacin (IC50=18.2 µM), with no cytotoxic effects (IC50 ≥ 198 µM). Furthermore, the same set of compounds was also assessed for anti-proliferative activity in lung large cell carcinoma COR-L23 and amelanotic melanoma C32 cells.

Novel ANKH amino terminus mutation (Pro5Ser) associated with early-onset calcium pyrophosphate disease with associated phosphaturia.

This report describes a 32-year-old woman presenting since childhood with progressive calcium pyrophosphate disease (CPPD), characterized by severe arthropathy and chondrocalcinosis involving multiple peripheral joints and intervertebral disks. Because ANKH mutations have been previously described in familial CPPD, the proband's DNA was assessed at this locus by direct sequencing of promoter and coding regions and revealed 3 sequence variants in ANKH. Sequences of exon 1 revealed a novel isolated nonsynonymous mutation (c.13 C>T), altering amino acid in codon 5 from proline to serine (CCG>TCG). Sequencing of parental DNA revealed an identical mutation in the proband's father but not the mother. Subsequent clinical evaluation demonstrated extensive chondrocalcinosis and degenerative arthropathy in the proband's father. In summary, we report a novel mutation, not previously described, in ANKH exon 1, wherein serine replaces proline, in a case of early-onset severe CPPD associated with metabolic abnormalities, with similar findings in the proband's father.

Large-scale analysis of association between polymorphisms in the transforming growth factor beta 1 gene (TGFB1) and osteoporosis: the GENOMOS study.

INTRODUCTION: The TGFB1 gene which encodes transforming growth factor beta 1, is a strong candidate for susceptibility to osteoporosis and several studies have reported associations between bone mineral density (BMD), osteoporotic fractures and polymorphisms of TGFB1, although these studies have yielded conflicting results. METHODS: We investigated associations between TGFB1 polymorphisms and BMD and fracture in the GENOMOS study: a prospective multicenter study involving 10 European research studies including a total of 28,924 participants. Genotyping was conducted for known TGFB1 polymorphisms at the following sites: G-1639-A (G-800-A, rs1800468), C-1348-T (C-509-T, rs1800469), T29-C (Leu10Pro, rs1982073), G74-C (Arg25Pro, rs1800471) and C788-T (Thr263Ile, rs1800472). These polymorphisms were genotyped prospectively and methodology was standardized across research centers. Genotypes and haplotypes were related to BMD at the lumbar sine and femoral neck and fractures. RESULTS: There were no significant differences in either women or men at either skeletal site for any of the examined polymorphisms with the possible exception of a weak association with reduced BMD (-12 mg/cm2) in men with the T-1348 allele (p<0.05). None of the haplotypes was associated with BMD and none of the polymorphisms or haplotypes significantly affected overall risk of fractures, however, the odds ratio for incident vertebral fracture in carriers of the rare T788 allele was 1.64 (95% CI: 1.09-2.64), p<0.05. CONCLUSIONS: This study indicates that polymorphic variation in the TGFB1 gene does not play a major role in regulating BMD or susceptibility to fractures. The weak associations we observed between the C-1348-T and lumbar spine BMD in men and between C788-T and risk of incident vertebral fractures are of interest but could be chance findings and will need replication in future studies.

The role of HLA-DRB1 alleles on susceptibility and outcome of a Portuguese Multiple Sclerosis population.

BACKGROUND: The association between susceptibility to multiple sclerosis (MS) and HLA-DRB1*15 has been reported in various European populations. OBJECTIVE: To investigate the relationship between MS, HLA-DRB1*15 and other DRB1 alleles in a Portuguese population and their association with clinical course of MS. METHODS: The HLA-DRB1 alleles were analyzed by PCR-SSP in 248 MS patients and 282 healthy controls. In order to relate HLA-DRB1 alleles to disease aggressiveness, patients with relapsing remitting MS and secondary progressive MS were subdivided into 3 groups: 'benign' MS patients who maintain an Extended Disability Status Scale (EDSS) score of 3 after the same period and 'aggressive' MS those with EDSS>or=6 within 15 years of disease onset. RESULTS: As expected, a higher frequency of HLA-DRB1*15 was found in MS patients (29.8% vs 19.9%, odds ratio (OR)=1.72, 95% CI=1.15-2.56, p=0.008). The HLA-DRB1*03 allele was positively associated with MS in the overall patient population (22.6% vs 15.6%, OR=1.58, 95% CI=1.02-2.45). Concerning disease aggressiveness, HLA-DRB1*15 occurred more frequently in the group with benign disease (42.6% vs 19.9%, OR=2.99, 95% CI=1.56-5.72) and in the group with non-benign disease (34.1% vs 19.9%, OR=2.09, 95% CI=1.05-4.16) compared with controls. When time to reach an EDSS=3 or EDSS=6 was considered as end point, HLA-DRB1*15 negative patients were found to have a worse prognosis. CONCLUSIONS: In this population of Portuguese MS patients, the HLA-DRB1*15 allele is established as a genetic marker for susceptibility to MS and is also associated with a better outcome.

Linkage disequilibrium between S65C HFE mutation and HLA A29-B44 haplotype in Terceira Island, Azores.

Our objective was to investigate the frequency of HFE gene mutations and to study linkage disequilibrium (LD) between HLA-Class I alleles and these mutations in the population of Terceira Island, Azores, Portugal. A total of 218 unrelated individuals were investigated. Three HFE mutations--C282Y, H63D, and S65C--were identified by restriction endonuclease digestion of polymerase chain reaction (PCR)-amplified genomic DNA. HLA-Class I alleles were typed by PCR-single-strand polymorphism. Gene frequencies and LD were estimated using Arlequin V 1.1. Six genotypes were found in the population: WT/WT (58.3%), H63D/WT (31.2%), H63D/H63D (2.3%), H63D/C282Y (0.9%), S65C/WT (4.1%), and C282Y/WT (3.2%). No cases of C282Y or S65C homozygosity were identified. HLA haplotype A3-B7 was in LD with C282Y; HLA alleles A29, B44, and HLA haplotype A29-B44 were in LD with S65C mutation. HFE gene frequencies in this population are similar to those in other European populations; HFE S65C mutation was found in LD with the alleles A29, B44, and with A29-B44 HLA haplotype.