The stem cells that safeguard synovial joints in adulthood are undefined. Studies on mesenchymal stromal/stem cells (MSCs) have mainly focused on bone marrow. Here we show that lineage tracing of Gdf5-expressing joint interzone cells identifies in adult mouse synovium an MSC population largely negative for the skeletal stem cell markers Nestin-GFP, Leptin receptor and Gremlin1. Following cartilage injury, Gdf5-lineage cells underpin synovial hyperplasia through proliferation, are recruited to a Nestin-GFPhigh perivascular population, and contribute to cartilage repair. The transcriptional co-factor Yap is upregulated after injury, and its conditional ablation in Gdf5-lineage cells prevents synovial lining hyperplasia and decreases contribution of Gdf5-lineage cells to cartilage repair. Cultured Gdf5-lineage cells exhibit progenitor activity for stable chondrocytes and are able to self-organize three-dimensionally to form a synovial lining-like layer. Finally, human synovial MSCs transduced with Bmp7 display morphogenetic properties by patterning a joint-like organ in vivo. Our findings further the understanding of the skeletal stem/progenitor cells in adult life.
COBISS.SI-ID: 4337009
To identify genetic determinants of susceptibility to clinical vertebral fractures, which is an important complication of osteoporosis. Here we conduct a genome-wide association study in 1553 postmenopausal women with clinical vertebral fractures and 4340 controls, with a two-stage replication involving 1028 cases and 3762 controls. Potentially causal variants were identified using expression quantitative trait loci (eQTL) data from transiliac bone biopsies and bioinformatic studies. A locus tagged by rs10190845 was identified on chromosome 2q13, which was significantly associated with clinical vertebral fracture (P=1.04%10%9) with a large effect size (OR 1.74, 95%%CI 1.06 to 2.6). Bioinformatic analysis of this locus identified several potentially functional SNPs that are associated with expression of the positional candidate genes TTL (tubulin tyrosine ligase) and SLC20A1 (solute carrier family 20 member 1). Three other suggestive loci were identified on chromosomes 1p31, 11q12 and 15q11. All these loci were novel and had not previously been associated with bone mineral density or clinical fractures. We have identified a novel genetic variant that is associated with clinical vertebral fractures by mechanisms that are independent of BMD. Further studies are now in progress to validate this association and evaluate the underlying mechanism.
COBISS.SI-ID: 4456049
Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip cir- cumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures ( P , 5 3 10 2 8 ). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms.
COBISS.SI-ID: 4045937
Bone mineral density (BMD) is the most widely used predictor of fracture risk.We performed the largest meta-analysis to date on lumbar spine and femoral neck BMD, including 1 17 genome-wide association studies and 32,961 1 individuals of European and east Asian ancestry. We tested the top BMD-associated markers for replication in 50,933 independent subjects and for association with risk of low-trauma fracture in 31,016 individuals with a history of fracture (cases) and 1 102,444 controls. We identified 56 loci (32 new) associated with BMD at genome-wide significance (P ( 5 x 10(-8). Several of these factors cluster within the RANK-RANKL-OPG, mesenchymal stem cell differentiation, endochondral ossification and Wnt signaling pathways. However, we also discovered loci that were localized to genes not known to have a role in bone biology. Fourteen BMD-associated loci were also associated with fracture risk (P ( 5 x 10(-4), Bonferroni corrected), of which six reached P ( 5 x 10(-8), including at 1 18p1111.21 (FAM210A), 7q21.3 (SLC25A13), 11 11 11q13.2 (LRP5), 4q22.1 1 (MEPE), 2p16.2 (SPTBN1) and 1 10q21.1 1 (DKK1). These findings shed light on the genetic architecture and pathophysiological mechanisms underlying BMD variation and fracture susceptibility.
COBISS.SI-ID: 3233137
Adrenergic stimulation is important for osteoclast differentiation and bone resorption. Previous research shows that this happens through [alpha]2-adrenergic receptor (AR), but there are conflicting evidence on presence and role of [alpha]2A-AR in bone. The aim of this study was to investigate the presence of [alpha]2A-AR and its involvement in neuro-endocrine signalling of bone remodelling in humans. Real-time polymerase chain reaction (PCR) and immunohistochemistry were used to investigate [alpha]2A-AR receptor presence and localization in bone cells. Functionality of rs553668 and rs1800544 single nucleotide polymorphism SNPs located in [alpha]2A-AR gene was analysed by qPCR expression on bone samples and luciferase reporter assay in human osteosarcoma HOS cells. Using real-timePCR, genetic association study between rs553668 A)G and rs1800544 C)GSNPs and major bone markers was performed on 661 Slovenian patients with osteoporosis. [alpha2A-AR is expressed in osteoblasts and lining cells but not in osteocytes. SNP rs553668 has a significant influence on [alpha]2A-AR mRNA level in human bone samples through the stability of mRNA. [alpha]2A-AR gene locus associates with important bone remodelling markers (BMD, CTX, Cathepsin K and pOC). The results of this study are providing comprehensive new evidence that [alpha]2A-AR is involved in neuro-endocrine signalling of bone turnover and development of osteoporosis. As shown by our results the neurological signalling is mediated through osteoblasts and result in bone resorption. Genetic study showed association of SNPs in [alpha]2A-AR gene locus with bone remodelling markers, identifying the individuals with higher risk of development of osteoporosis.
COBISS.SI-ID: 3887217
Background Although unilateral primary aldosteronism is the most common surgically correctable cause of hypertension, no standard criteria exist to classify surgical outcomes. We aimed to create consensus criteria for clinical and biochemical outcomes and follow-up of adrenalectomy for unilateral primary aldosteronism and apply these criteria to an international cohort to analyse the frequency of remission and identify preoperative determinants of successful outcome. Methods The Primary Aldosteronism Surgical Outcome (PASO) study was an international project to develop consensus criteria for outcomes and follow-up of adrenalectomy for unilateral primary aldosteronism. An international panel of 31 experts from 28 centres, including six endocrine surgeons, used the Delphi method to reach consensus. We then retrospectively analysed follow-up data from prospective cohorts for outcome assessment of patients diagnosed with unilateral primary aldosteronism by adrenal venous sampling who had undergone a total adrenalectomy, consecutively included from 12 referral centres in nine countries. On the basis of standardised criteria, we determined the proportions of patients achieving complete, partial, or absent clinical and biochemical success in accordance with the consensus. We then used logistic regression analyses to identify preoperative factors associated with clinical and biochemical outcomes. Findings Consensus was reached for criteria for six outcomes (complete, partial, and absent success of clinical and biochemical outcomes) based on blood pressure, use of antihypertensive drugs, plasma potassium and aldosterone concentrations, and plasma renin concentrations or activities. Consensus was also reached for two recommendations for the timing of follow-up assessment. For the international cohort analysis, we analysed clinical data from 705 patients recruited between 1994 and 2015, of whom 699 also had biochemical data. Complete clinical success was achieved in 259 (37%) of 705 patients, with a wide variance (range 17-62), and partial clinical success in an additional 334 (47%, range 35%66); complete biochemical success was seen in 656 (94%, 83%100) of 699 patients. Female patients had a higher likelihood of complete clinical success (odds ratio [OR] 2.25, 95% CI 1.40-3.62; p=0.001) and clinical benefit (complete plus partial clinical success; OR 2.89, 1.49-5.59; p=0.002) than male patients. Younger patients had a higher likelihood of complete clinical success (OR 0.95 per extra year, 0.93-0.98; p(0.001) and clinical benefit (OR 0.95 per extra year, 0.92-0.98; p=0.004). Higher levels of preoperative medication were associated with lower levels of complete clinical success (OR 0.80 per unit increase, 0.70-0.90; p(0.001). Interpretation These standardised outcome criteria are relevant for the assessment of the success of surgical treatment in individual patients and will allow the comparison of outcome data in future studies. The variable baseline clinical characteristics of our international cohort contributed to wide variation in clinical outcomes. Most patients derive clinical benefit from adrenalectomy, with younger patients and female patients more likely to have a favourable surgical outcome. Screening for primary aldosteronism should nonetheless be done in every individual fulfilling US Endocrine Society guideline criteria because biochemical success without clinical success is by itself clinically important and older women and men can also derive post-operative clinical benefit.
COBISS.SI-ID: 33291737
Aims These recommendations aim to improve care for patients with type 2 diabetes (T2D) at high cardiovascular (CV) risk in Central and Eastern Europe. Cardiovascular disease (CVD) and/or chronic kidney disease (CKD) are major interdependent comorbidities in patients with T2D, accounting for 50% of mortality. Following recent CV outcomes trial (CVOT) results, including those from EMPA-REG OUTCOME, LEADER, SUSTAIN-6 and, most recently, the CANVAS study, it is essential to develop regional expert consensus recommendations to aid physicians in interpreting these newest data to clinical practice. Methods The Central and Eastern European Diabetes Expert Group (CEEDEG) followed a Delphi method to develop treatment algorithms to aid physicians in the clinical management of patients with T2D at high CV risk. Results In light of the latest CVOT results, and in particular the EMPA-REG OUTCOME and LEADER trials, the diagnosis, assessment, treatment choice and monitoring of patients with T2D and established CVD and/or CKD have been considered together with existing guidelines and presented in two reference algorithms. In addition, adherence, special prescribing considerations and a proposed multidisciplinary management approach have been discussed and are presented with the proposed algorithms. Conclusions The latest available high-level evidence on glucose-lowering drugs has enabled CEEDEG to develop practical consensus recommendations for patients with established CVD and/or CKD. These recommendations represent an update to international and country-level guidelines used for these patients, with the aim of providing a resource not only to endocrinologists, but to cardiologists, nephrologists and primary care physicians in the region.
COBISS.SI-ID: 33466329
Phosphodiesterase (PDE) enzymes, including members of PDE4, have been investigated in the regulation of endocrine and reproductive functions of ovaries. In addition, selective inhibition of PDE4 enzyme has recently been implicated in the regulation of metabolism with positive effects on glucose homeostasis and weight reduction. OBJECTIVE:The aim of this study was to evaluate whether the PDE4 inhibitor roflumilast affects body weight and hormonal and metabolic status in obese women with polycystic ovary syndrome (PCOS). Design/Participants/Main Outcome Measures: A 12-week prospective randomized open-label study was conducted with 36 obese women with PCOS diagnosed by the National Eunice Kennedy Shriver Institute of Child Health and Human Development criteria that had been pretreated with metformin (MET). They were randomized to MET 1000 mg twice a day or combined treatment (COM) with MET 1000 mg twice a day and roflumilast 500 µg every day. The primary outcome was change in anthropometric measures of obesity. RESULTS:Thirty-one patients (aged 33.8 ± 7.4 y, twice a day 36.4 ± 5.1 kg/m(2), mean ± SD) completed the study: 16 on MET and 15 on COM. Subjects treated with COM lost on average 4.2 ± 2.8 kg compared with a 0.9 ± 2.5 kg weight gain in the MET group (P = .025). Body mass index decreased for 1.6 ± 1.1 kg/m(2) in COM arm compared with increase for 0.9 ± 2.4 kg/m(2) in the MET arm (P = .046). Visceral adipose tissue area as assessed by dual-energy x-ray absorptiometry decreased from 136.7 ± 37.8 to 121.2 ± 36.2 cm(2) in the COM arm compared with an increase from 155.3 ± 61.9 to 166.7 ± 67.2 cm(2) in the MET arm (P = .02). From baseline to study end, both treatment interventions resulted in a significant reduction of androstenedione (P = .013), free T (P = .002), and homeostasis model assessment for insulin resistance score (P = .027) and a significant increase in SHBG (P = .024), although the between-treatment differences of the changes have not been statistically significant yet.CONCLUSION:Roflumilast added to metformin reduced body weight in obese women with PCOS, primarily due to a loss of fat mass.
COBISS.SI-ID: 1796780