Eva González-Roca

Waves of early transcriptional activation and pluripotency program initiation during human preimplantation development.

The events regulating human preimplantation development are still largely unknown owing to a scarcity of material, ethical and legal limitations and a lack of reliable techniques to faithfully amplify the transcriptome of a single cell. Nonetheless, human embryology is gathering renewed interest due to its close relationship with both stem cell biology and epigenetic reprogramming to pluripotency and their importance in regenerative medicine. Carefully timed genome-wide transcript analyses of single oocytes and embryos uncovered a series of successive waves of embryonic transcriptional initiation that start as early as the 2-cell stage. In addition, we identified the hierarchical activation of genes involved in the regulation of pluripotency. Finally, we developed HumER, a database of human preimplantation gene expression, to serve the scientific community. Importantly, our work links early transcription in the human embryo with the correct execution of the pluripotency program later in development and paves the way for the identification of factors to improve epigenetic reprogramming.

Somatic NLRP3 mosaicism in Muckle-Wells syndrome. A genetic mechanism shared by different phenotypes of cryopyrin-associated periodic syndromes

UNLABELLED : Familial cold autoinflammatory syndrome, Muckle-Wells syndrome (MWS), and chronic, infantile, neurological, cutaneous and articular (CINCA) syndrome are dominantly inherited autoinflammatory diseases associated to gain-of-function NLRP3 mutations and included in the cryopyrin-associated periodic syndromes (CAPS). A variable degree of somatic NLRP3 mosaicism has been detected in ≈35% of patients with CINCA. However, no data are currently available regarding the relevance of this mechanism in other CAPS phenotypes. OBJECTIVE To evaluate somatic NLRP3 mosaicism as the disease-causing mechanism in patients with clinical CAPS phenotypes other than CINCA and NLRP3 mutation-negative. METHODS NLRP3 analyses were performed by Sanger sequencing and by massively parallel sequencing. Apoptosis-associated Speck-like protein containing a CARD (ASC)-dependent nuclear factor kappa-light chain-enhancer of activated B cells (NF-κB) activation and transfection-induced THP-1 cell death assays determined the functional consequences of the detected variants. RESULTS A variable degree (5.5-34.9%) of somatic NLRP3 mosaicism was detected in 12.5% of enrolled patients, all of them with a MWS phenotype. Six different missense variants, three novel (p.D303A, p.K355T and p.L411F), were identified. Bioinformatics and functional analyses confirmed that they were disease-causing, gain-of-function NLRP3 mutations. All patients treated with anti-interleukin1 drugs showed long-lasting positive responses. CONCLUSIONS We herein show somatic NLRP3 mosaicism underlying MWS, probably representing a shared genetic mechanism in CAPS not restricted to CINCA syndrome. The data here described allowed definitive diagnoses of these patients, which had serious implications for gaining access to anti-interleukin 1 treatments under legal indication and for genetic counselling. The detection of somatic mosaicism is difficult when using conventional methods. Potential candidates should benefit from the use of modern genetic tools.

Accurate Expression Profiling of Very Small Cell Populations

Background Expression profiling, the measurement of all transcripts of a cell or tissue type, is currently the most comprehensive method to describe their physiological states. Given that accurate profiling methods currently available require RNA amounts found in thousands to millions of cells, many fields of biology working with specialized cell types cannot use these techniques because available cell numbers are limited. Currently available alternative methods for expression profiling from nanograms of RNA or from very small cell populations lack a broad validation of results to provide accurate information about the measured transcripts. Methods and Findings We provide evidence that currently available methods for expression profiling of very small cell populations are prone to technical noise and therefore cannot be used efficiently as discovery tools. Furthermore, we present Pico Profiling, a new expression profiling method from as few as ten cells, and we show that this approach is as informative as standard techniques from thousands to millions of cells. The central component of Pico Profiling is Whole Transcriptome Amplification (WTA), which generates expression profiles that are highly comparable to those produced by others, at different times, by standard protocols or by Real-time PCR. We provide a complete workflow from RNA isolation to analysis of expression profiles. Conclusions Pico Profiling, as presented here, allows generating an accurate expression profile from cell populations as small as ten cells.

Calcific periarthritis as the only clinical manifestation of hypophosphatasia in middle-aged sisters.

Hypophosphatasia (HPP) is the inborn error of metabolism that features low serum alkaline phosphatase (ALP) activity caused by loss‐of‐function mutation(s) within the gene for the tissue nonspecific isoenzyme of ALP (TNSALP). In HPP, extracellular accumulation of inorganic pyrophosphate (PPi), a TNSALP substrate and inhibitor of mineralization, leads frequently to premature tooth loss and often to rickets or osteomalacia. In affected adults, the excess PPi sometimes also causes calcium pyrophosphate dihydrate (CPPD) deposition, PPi arthropathy, or pseudogout, or seemingly paradoxical deposition of hydroxyapatite crystals in ligaments or around joints when the condition is called calcific periarthritis (CP). We report three middle‐aged sisters with CP as the only clinical manifestation of HPP. Each presented during early adult life with recurrent episodes of pain principally around the shoulders, elbows, wrists, hips, or Achilles tendon. Otherwise, they were in good health, including no history of unusual dental disease, fractures, or pseudofractures. Calcific deposits were identified in symptomatic areas principally by ultrasonographic assessment but also confirmed radiographically. All three sisters had low serum levels of total and bone‐specific ALP, hyperphosphatemia, and increased serum concentrations of the TNSALP substrate pyridoxal 5′‐phosphate together characteristic of HPP. Mutation analysis revealed that each carried a single unique 18‐bp duplication within TNSALP (c.188_205dup18, p.Gly63_Thr68dup) as did two of their healthy sons and their mother, who was without signs of CPPD deposition or CP but had knee osteoarthritis. We find that CP can be the only complication of HPP in adults. Thus, multiple juxta‐articular deposits of hydroxyapatite causing CP may be a useful sign of HPP, especially when the CP is familial.

Clinical and genetic characterization of the autoinflammatory diseases diagnosed in an adult reference center

INTRODUCTION Autoinflammatory diseases (AID) are usually diagnosed during the pediatric age. However, adult-onset disease or diagnosis during adulthood has been occasionally described. OBJECTIVES To assess the clinical and genetic characteristics of adult patients diagnosed with an AID in an adult referral center for AID. METHODS We retrospectively evaluated clinical and genetic features of adult patients (≥16 years) diagnosed with an AID or referred after AID diagnosis to the Clinical Unit of AID, at the Department of Autoimmune Diseases, Hospital Clínic of Barcelona, from 2008 to 2014. RESULTS During the study period, a genetic study for suspected AID was requested to 90 patients at the Department of Autoimmune Diseases. A final diagnosis of monogenic AID was achieved in 17 patients (19% of patients tested). Five additional cases were diagnosed with periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome and 10 patients with AID were referred from other adult departments. Finally, a total of 32 patients with AID were finally diagnosed or monitored in our Clinical Unit. These included 12 (37.5%) familial Mediterranean fever, 6 (18.8%) tumour necrosis factor-receptor associated periodic syndrome, 8 (25%) cryopirin-associated periodic syndromes (Muckle-Wells syndrome [MWS] or overlap familial cold-associated periodic syndrome/MWS), 1 (3.1%) mevalonate kinase deficiency, and 5 (15.6%) PFAPA. Clinical evidence of disease-onset during childhood and adulthood was observed in 15 (47%) and 17 (53%) patients, respectively. Overall, the final diagnosis was obtained after a delay of a mean of 12 years (range 0-47 years). Compared to children, adult patients with AID in our series presented more frequently with non-severe manifestations and none of them developed amyloidosis during follow-up. Adult patients also carried higher proportion of low-penetrance mutations or polymorphisms and all genetic variants were presented in heterozygosis or as heterozygous compounds. CONCLUSIONS Adult disease-onset or delayed diagnosis of AID during adulthood is associated with milder disease phenotypes, and seem to be driven by mild genotypes, with predominant presence of low-penetrance mutations or polymorphisms.

Brief Report: First Identification of Intrafamilial Recurrence of Blau Syndrome due to Gonosomal NOD2 Mosaicism

Blau syndrome is characterized by noncaseating granulomatous arthritis, dermatitis, and uveitis, and results from gain‐of‐function NOD2 mutations. This study was undertaken to identify the genetic cause of the disease in a family with 3 members with Blau syndrome.

Brief Report: Late-Onset Cryopyrin-Associated Periodic Syndrome Due to Myeloid-Restricted Somatic NLRP3 Mosaicism.

Gain‐of‐function NLRP3 mutations cause cryopyrin‐associated periodic syndrome (CAPS), with gene mosaicism playing a relevant role in the pathogenesis. This study was undertaken to characterize the genetic cause underlying late‐onset but otherwise typical CAPS.

First report of intrafamilial recurrence of Blau syndrome due to gonosomal NOD2 mosaicism

Blau syndrome is characterized by noncaseating granulomatous arthritis, dermatitis, and uveitis, and results from gain‐of‐function NOD2 mutations. This study was undertaken to identify the genetic cause of the disease in a family with 3 members with Blau syndrome.

Late onset cryopyrin‐associated periodic syndrome due to myeloid‐restricted somatic NLRP3 mosaicism

Gain‐of‐function NLRP3 mutations cause cryopyrin‐associated periodic syndrome (CAPS), with gene mosaicism playing a relevant role in the pathogenesis. This study was undertaken to characterize the genetic cause underlying late‐onset but otherwise typical CAPS.

First report of vertical transmission of a somatic NLRP3 mutation in cryopyrin-associated periodic syndromes

Cryopyrin-associated periodic syndromes (CAPS) are rare autoinflammatory diseases caused by dominantly inherited or de novo gain-of-function NLRP3 mutations. They include familial cold autoinflammatory syndrome, Muckle-Wells syndrome and chronic infantile neurological, cutaneous and articular syndrome.1 The NLRP3 gene encodes cryopyrin, a key component of the cytosolic complex termed inflammasome, which generates the active form of interleukin (IL)-1s. Previous studies showed an uncontrolled IL-1s overproduction in CAPS, representing the basis from which to treat these patients with IL-1 blockade.1–3 The important role of somatic NLRP3 mutations in CAPS has been recently shown.4 However, as occurs in most Mendelian diseases, no data are available concerning the presence of low-level somatic NLRP3 mosaicism in parents of CAPS patients. To address this issue we performed massively parallel DNA …