Three classes of epigenomic regulators converge to hyperactivate the essential maternal gene deadhead within a heterochromatin mini-domain.

The formation of a diploid zygote is a highly complex cellular process that is entirely controlled by maternal gene products stored in the egg cytoplasm. This highly specialized transcriptional program is tightly controlled at the chromatin level in the female germline. As an extreme case in point, the massive and specific ovarian expression of the essential thioredoxin Deadhead (DHD) is critically regulated in Drosophila by the histone demethylase Lid and its partner, the histone deacetylase complex Sin3A/Rpd3, via yet unknown mechanisms. Here, we identified Snr1 and Mod(mdg4) as essential for dhd expression and investigated how these epigenomic effectors act with Lid and Sin3A to hyperactivate dhd. Using Cut&Run chromatin profiling with a dedicated data analysis procedure, we found that dhd is intriguingly embedded in an H3K27me3/H3K9me3-enriched mini-domain flanked by DNA regulatory elements, including a dhd promoter-proximal element essential for its expression. Surprisingly, Lid, Sin3a, Snr1 and Mod(mdg4) impact H3K27me3 and this regulatory element in distinct manners. However, we show that these effectors activate dhd independently of H3K27me3/H3K9me3, and that dhd remains silent in the absence of these marks. Together, our study demonstrates an atypical and critical role for chromatin regulators Lid, Sin3A, Snr1 and Mod(mdg4) to trigger tissue-specific hyperactivation within a unique heterochromatin mini-domain.

One model fits all: Combining inference and simulation of gene regulatory networks.

The rise of single-cell data highlights the need for a nondeterministic view of gene expression, while offering new opportunities regarding gene regulatory network inference. We recently introduced two strategies that specifically exploit time-course data, where single-cell profiling is performed after a stimulus: HARISSA, a mechanistic network model with a highly efficient simulation procedure, and CARDAMOM, a scalable inference method seen as model calibration. Here, we combine the two approaches and show that the same model driven by transcriptional bursting can be used simultaneously as an inference tool, to reconstruct biologically relevant networks, and as a simulation tool, to generate realistic transcriptional profiles emerging from gene interactions. We verify that CARDAMOM quantitatively reconstructs causal links when the data is simulated from HARISSA, and demonstrate its performance on experimental data collected on in vitro differentiating mouse embryonic stem cells. Overall, this integrated strategy largely overcomes the limitations of disconnected inference and simulation.

The Lid/KDM5 histone demethylase complex activates a critical effector of the oocyte-to-zygote transition.

Following fertilization of a mature oocyte, the formation of a diploid zygote involves a series of coordinated cellular events that ends with the first embryonic mitosis. In animals, this complex developmental transition is almost entirely controlled by maternal gene products. How such a crucial transcriptional program is established during oogenesis remains poorly understood. Here, we have performed an shRNA-based genetic screen in Drosophila to identify genes required to form a diploid zygote. We found that the Lid/KDM5 histone demethylase and its partner, the Sin3A-HDAC1 deacetylase complex, are necessary for sperm nuclear decompaction and karyogamy. Surprisingly, transcriptomic analyses revealed that these histone modifiers are required for the massive transcriptional activation of deadhead (dhd), which encodes a maternal thioredoxin involved in sperm chromatin remodeling. Unexpectedly, while lid knock-down tends to slightly favor the accumulation of its target, H3K4me3, on the genome, this mark was lost at the dhd locus. We propose that Lid/KDM5 and Sin3A cooperate to establish a local chromatin environment facilitating the unusually high expression of dhd, a key effector of the oocyte-to-zygote transition.

The male external urethral sphincter is autonomically innervated.

INTRODUCTION: The aim of the present study was to describe autonomic urethral sphincter (US) innervation using specific muscular and neuronal antibody markers and 3D reconstruction. MATERIAL AND METHODS: We performed en-bloc removal of the entire pelvis of three male human fetuses between 18 and 40 weeks. Serial whole mount sections (5 µm intervals) were stained and investigated. The sections were stained with Masson's trichrome and Eosin Hematoxylin, and immunostained with: anti-SMA antibody for smooth muscle; anti-S100 antibody for all nerves; and anti-PMP22 antibody, anti-TH antibody, anti-CGRP antibody, anti-NOS antibody for somatic, adrenergic, sensory and nitrergic nerve fibers, respectively. The slides were digitized for 3D reconstruction to improve topographical understanding. An animated reconstruction of the autonomic innervation of the US was generated. RESULTS: The external and internal US are innervated by autonomic nerves of the inferior hypogastric plexus (IHP). These nerves are sympathetic (positive anti-TH antibody), sensory (positive anti-CGRP antibody), and nitrergic (positive anti-NOS antibody). Some autonomic fibers run within the neurovascular bundles, posterolaterally. Others run from the IHP to the posteromedial aspect of the prostate apex, above an through the rectourethral muscle. The external US is also innervated by somatic nerves (positive anti-PMP22 antibody) arising from the pudendal nerve, joining the midline but remaining below the rectourethral. CONCLUSIONS: This study provides anatomical evidence of an autonomic component in the innervation of the external US that travels in the neurovascular bundle. During radical prostatectomy, the rectourethral muscle and the neurovascular bundles are to be preserved, particularly during apical dissection.

Detailed muscular structure and neural control anatomy of the levator ani muscle: a study based on female human fetuses.

BACKGROUND: Injury to the levator ani muscle or pelvic nerves during pregnancy and vaginal delivery is responsible for pelvic floor dysfunction. OBJECTIVE: We sought to demonstrate the presence of smooth muscular cell areas within the levator ani muscle and describe their localization and innervation. STUDY DESIGN: Five female human fetuses were studied after approval from the French Biomedicine Agency. Specimens were serially sectioned and stained by Masson trichrome and immunostained for striated and smooth muscle, as well as for somatic, adrenergic, cholinergic, and nitriergic nerve fibers. Slides were digitized for 3-dimensional reconstruction. One fetus was reserved for electron microscopy. We explored the structure and innervation of the levator ani muscle. RESULTS: Smooth muscular cell beams were connected externally to the anococcygeal raphe and the levator ani muscle and with the longitudinal anal muscle sphincter. The caudalmost part of the pubovaginal muscle was found to bulge between the rectum and the vagina. This bulging was a smooth muscular interface between the levator ani muscle and the longitudinal anal muscle sphincter. The medial (visceral) part of the levator ani muscle contained smooth muscle cells, in relation to the autonomic nerve fibers of the inferior hypogastric plexus. The lateral (parietal) part of the levator ani muscle contained striated muscle cells only and was innervated by the somatic nerve fibers of levator ani and pudendal nerves. The presence of smooth muscle cells within the medial part of the levator ani muscle was confirmed under electron microscopy in 1 fetus. CONCLUSION: We characterized the muscular structure and neural control of the levator ani muscle. The muscle consists of a medial part containing smooth muscle cells under autonomic nerve influence and a lateral part containing striated muscle cells under somatic nerve control. These findings could result in new postpartum rehabilitation techniques.

Retinoic Acid Receptors Control Spermatogonia Cell-Fate and Induce Expression of the SALL4A Transcription Factor.

All-trans retinoic acid (ATRA) is instrumental to male germ cell differentiation, but its mechanism of action remains elusive. To address this question, we have analyzed the phenotypes of mice lacking, in spermatogonia, all rexinoid receptors (RXRA, RXRB and RXRG) or all ATRA receptors (RARA, RARB and RARG). We demonstrate that the combined ablation of RXRA and RXRB in spermatogonia recapitulates the set of defects observed both upon ablation of RAR in spermatogonia. We also show that ATRA activates RAR and RXR bound to a conserved regulatory region to increase expression of the SALL4A transcription factor in spermatogonia. Our results reveal that this major pluripotency gene is a target of ATRA signaling and that RAR/RXR heterodimers are the functional units driving its expression in spermatogonia. They add to the mechanisms through which ATRA promote expression of the KIT tyrosine kinase receptor to trigger a critical step in spermatogonia differentiation. Importantly, they indicate also that meiosis eventually occurs in the absence of a RAR/RXR pathway within germ cells and suggest that instructing this process is either ATRA-independent or requires an ATRA signal originating from Sertoli cells.

Functional and structural microanatomy of the fetal sciatic nerve.

INTRODUCTION: The ultrastructure of a nerve has implications for surgical nerve repair. The aim of our study was to characterize the fascicular versus fibrillar anatomy and the autonomic versus somatic nature of the fetal sciatic nerve (SN). METHODS: Immunohistochemistry for vesicular acetylcholine transporter, tyrosine hydroxylase, and peripheral myelin protein 22 was performed to identify cholinergic, adrenergic, and somatic axons, respectively, in the human fetal SN. Two-dimensional (2D) analysis and 3D reconstructions were performed. RESULTS: The fetal SN is composed of one-third stromal tissue and two-thirds neural tissue. Autonomic fibers are predominant over somatic fibers within the neural tissue. The distribution of somatic fibers is initially random, but then become topographically organized after intra- and interfascicular rearrangements have occurred within the nerve. CONCLUSIONS: The fetal model presents limitations but enables illustration of the nature of the nerve fibers and the 3D fascicular anatomy of the SN. Muscle Nerve 56: 787-796, 2017.

Origin and nature of pelvic ureter innervation.

AIMS: Innervation of the pelvic ureter traditionally comes from the pelvic plexus. This innervation is independent: adrenergic and cholinergic. The purpose of this study was to describe more precisely the origin and nature of its innervation (adrenergic, cholinergic, nitrergic, and somatic). METHODS: Six specimens of normal human fetal pelvis (four male and two female) from 20 to 30 weeks gestation were studied. The sections of these fetuses, carried out every 5 µm without interval, were treated with Hematoxylin Eosin (HE), with Masson's trichrome (TriM), immunolabeling of smooth muscle cells with smooth anti-actin, of nerves with anti-S100 protein, anti-tyrosine hydroxylase, anti-VAChT, anti-nNOS, and with anti- peripheral myelin protein 22 (PMP 22). The slides were scanned and two-dimensional images reconstructed in 3D, and analyzed. RESULTS: The terminal pelvic ureter travels above and inside the inferior hypogastric plexus (IHP). The nerve fibers that innervate the ureterovesical junction come mainly from the superior hypogastric plexus (SHP) which gives off the hypogastric nerves and pelvic branches of the sacral plexus that form the IHP. Most nerve fibers meet below the ureter, behind the bladder to form an ascending bundle, which innervates the pelvic ureter. Immunohistochemical analysis shows that the nerves of the pelvic ureter consist of adrenergic, cholinergic, and nitrergic fibers. CONCLUSION: The innervation of the distal ureter depends mainly on the SHP. This innervation is adrenergic, cholinergic, and nitrergic. It innervates the pelvic ureter in an ascending manner. This anatomical information can change rectal resection and ureteral reimplantation techniques and drug treatments for pelvic ureter stones. Neurourol. Urodynam. 36:271-279, 2017. © 2015 Wiley Periodicals, Inc.

Levator ani muscle innervation: Anatomical study in human fetus.

AIMS: To characterize the nature and function of the levator ani muscle innervation pathways and to perform a comprehensive three-dimensional reconstruction of female pelvic innervation. METHODS: A computer-assisted anatomical dissection protocol was applied to seven female human fetuses, after approval from the national biomedicine agency. Specimens were serially sectioned and immunostained for overall (antibody against protein S100), somatic (antibody against peripheral myelin protein 22), adrenergic (antibody against tyrosine hydroxylase), cholinergic (antibody against vesicular acetylcholine transferase), and nitrergic (antibody against the neural isoform of nitric oxide synthase) nerve fibers. Slides were digitized for three-dimensional reconstructions using WinSurf®. RESULTS: Three main nerve pathways to the levator ani muscle were observed: the levator ani nerve, the pudendal nerve, and the inferior hypogastric plexus. The pudendal nerve was both somatic and autonomic, located below the levator ani muscle (infralevator pathway), supplying innervation to the inferior aspect of the levator ani muscle. The levator ani nerve was solely somatic, located above the levator ani muscle (supralevator pathway), supplying innervation to the superior aspect of the levator ani muscle. The inferior hypogastric plexus nerve fibers were solely autonomic, located in between the levator ani muscle and pelvic organs (endolevator pathway), supplying innervation to the medial portion of the levator ani muscle. CONCLUSIONS: Our study provides a new representation of levator ani muscle innervation with three nerve pathways, and the levator ani muscle itself as an anatomical landmark.

RAR/RXR binding dynamics distinguish pluripotency from differentiation associated cis-regulatory elements.

In mouse embryonic cells, ligand-activated retinoic acid receptors (RARs) play a key role in inhibiting pluripotency-maintaining genes and activating some major actors of cell differentiation. To investigate the mechanism underlying this dual regulation, we performed joint RAR/RXR ChIP-seq and mRNA-seq time series during the first 48 h of the RA-induced Primitive Endoderm (PrE) differentiation process in F9 embryonal carcinoma (EC) cells. We show here that this dual regulation is associated with RAR/RXR genomic redistribution during the differentiation process. In-depth analysis of RAR/RXR binding sites occupancy dynamics and composition show that in undifferentiated cells, RAR/RXR interact with genomic regions characterized by binding of pluripotency-associated factors and high prevalence of the non-canonical DR0-containing RA response element. By contrast, in differentiated cells, RAR/RXR bound regions are enriched in functional Sox17 binding sites and are characterized with a higher frequency of the canonical DR5 motif. Our data offer an unprecedentedly detailed view on the action of RA in triggering pluripotent cell differentiation and demonstrate that RAR/RXR action is mediated via two different sets of regulatory regions tightly associated with cell differentiation status.

Burned-Out Testis Tumors in Asymptomatic Infertile Men: Multiparametric Sonography and MRI Findings.

Multiparametric testicular ultrasound and magnetic resonance imaging (MRI) findings were analyzed in a series of 10 infertile asymptomatic men presenting with pathologically confirmed burned-out testicular tumors. Color/power Doppler ultrasound (CDUS), shear wave elastography (SWE), contrast-enhanced ultrasonography (CEUS), and MRI were performed on 10, 5, 6, and 7 patients, respectively. All lesions appeared as a hypoechoic and hypovascular nodular area at CDUS, SWE, CEUS CDUS, and CEUS (if performed). Shear wave elastography showed a stiffer nodular area compared with the surrounding/contralateral tissues (13 versus 2 kPa); MRI revealed a well-delineated nodular area in hypointense signal on T2, a high apparent diffusion coefficient value, and a lack of enhancement.

Genome-wide analysis of thyroid hormone receptors shared and specific functions in neural cells.

TRα1 and TRß1, the two main thyroid hormone receptors in mammals, are transcription factors that share similar properties. However, their respective functions are very different. This functional divergence might be explained in two ways: it can reflect different expression patterns or result from different intrinsic properties of the receptors. We tested this second hypothesis by comparing the repertoires of 3,3',5-triiodo-L-thyronine (T3)-responsive genes of two neural cell lines, expressing either TRα1 or TRß1. Using transcriptome analysis, we found that a substantial fraction of the T3 target genes display a marked preference for one of the two receptors. So when placed alone in identical situations, the two receptors have different repertoires of target genes. Chromatin occupancy analysis, performed at a genome-wide scale, revealed that TRα1 and TRß1 cistromes were also different. However, receptor-selective regulation of T3 target genes did not result from receptor-selective chromatin occupancy of their promoter regions. We conclude that modification of TRα1 and TRß1 intrinsic properties contributes in a large part to the divergent evolution of the receptors' function, at least during neurodevelopment.

The visceromotor and somatic afferent nerves of the penis.

INTRODUCTION: Innervation of the penis supports erectile and sensory functions. AIM: This article aims to study the efferent autonomic (visceromotor) and afferent somatic (sensory) nervous systems of the penis and to investigate how these systems relate to vascular pathways. METHODS: Penises obtained from five adult cadavers were studied via computer-assisted anatomic dissection (CAAD). MAIN OUTCOME MEASURES: The number of autonomic and somatic nerve fibers was compared using the Kruskal-Wallis test. RESULTS: Proximally, penile innervation was mainly somatic in the extra-albugineal sector and mainly autonomic in the intracavernosal sector. Distally, both sectors were almost exclusively supplied by somatic nerve fibers, except the intrapenile vascular anastomoses that accompanied both somatic and autonomic (nitrergic) fibers. From this point, the neural immunolabeling within perivascular nerve fibers was mixed (somatic labeling and autonomic labeling). Accessory afferent, extra-albugineal pathways supplied the outer layers of the penis. CONCLUSIONS: There is a major change in the functional type of innervation between the proximal and distal parts of the intracavernosal sector of the penis. In addition to the pelvis and the hilum of the penis, the intrapenile neurovascular routes are the third level where the efferent autonomic (visceromotor) and the afferent somatic (sensory) penile nerve fibers are close. Intrapenile neurovascular pathways define a proximal penile segment, which guarantees erectile rigidity, and a sensory distal segment.

Retinoic acid induces Sertoli cell paracrine signals for spermatogonia differentiation but cell autonomously drives spermatocyte meiosis.

Direct evidence for a role of endogenous retinoic acid (RA), the active metabolite of vitamin A in the initial differentiation and meiotic entry of spermatogonia, and thus in the initiation of spermatogenesis is still lacking. RA is synthesized by dedicated enzymes, the retinaldehyde dehydrogenases (RALDH), and binds to and activates nuclear RA receptors (RARA, RARB, and RARG) either within the RA-synthesizing cells or in the neighboring cells. In the present study, we have used a combination of somatic genetic ablations and pharmacological approaches in vivo to show that during the first, prepubertal, spermatogenic cycle (i) RALDH-dependent synthesis of RA by Sertoli cells (SC), the supporting cells of the germ cell (GC) lineage, is indispensable to initiate differentiation of A aligned into A1 spermatogonia; (ii) RARA in SC mediates the effects of RA, possibly through activating Mafb expression, a gene whose Drosophila homolog is mandatory to GC differentiation; (iii) RA synthesized by premeiotic spermatocytes cell autonomously induces meiotic initiation through controlling the RAR-dependent expression of Stra8. Furthermore, we show that RA of SC origin is no longer necessary for the subsequent spermatogenic cycles but essential to spermiation. Altogether, our data establish that the effects of RA in vivo on spermatogonia differentiation are indirect, via SC, but direct on meiotic initiation in spermatocytes, supporting thereby the notion that, contrary to the situation in the female, RA is necessary to induce meiosis in the male.

Testicular-sparing surgery for bilateral or monorchide testicular tumours: a multicenter study of long-term oncological and functional results.

OBJECTIVE: To review long-term oncological and functional outcomes of testicular-sparing surgery (TSS) in men presenting with bilateral or monorchide testicular tumours at one of five reference centres for testicular neoplasm and infertility. PATIENTS AND METHODS: We review 25 cases of bilateral synchrone and metachrone testicular tumours treated in five academic centres between 1984 and 2013. Clinical, biological, ultrasonography and pathological tumour findings, overall survival (OS) times, local or metastatic recurrence, pre- and postoperative hormonal profile, paternity and the need for androgen substitution were assessed. RESULTS: Eleven patients with a bilateral synchrone tumour and 14 patients with a testicular tumour on a solitary testicle underwent a tumorectomy. The mean (sem) patient age was 31.9 (1.04) years, total testosterone level was 4.5 (0.57) ng.mL and tumour size was 11.66 (1.49) mm. Tumour types were as follows: 11 seminoma, nine non-seminomatous or mixed germ cell tumours, four Leydig tumours, and one hamartoma. Frozen-section examination was performed in 14 patients, and matched the final pathological analysis in 11 patients. There was an OS rate of 100% and three patients (12%) presented with a local recurrence after a mean follow-up of 42.7 months. Radical orchiectomy was performed for six patients. No patient with a preserved testicle required androgen therapy; the mean postoperative total testosterone level was 4.0 ng/mL. No patient remained fertile after radiation therapy. CONCLUSIONS: TSS for bilateral testicular tumour is safe and effective in selected patients, and should be considered to avoid definitive androgen therapy. Adjuvant radiotherapy remains poorly described in the literature, leading to adjuvant treatment heterogeneity for testicular tumours.

Retinoic acid receptors recognize the mouse genome through binding elements with diverse spacing and topology.

Retinoic acid receptors (RARs) heterodimerize with retinoid X receptors (RXRs) and bind to RA response elements (RAREs) in the regulatory regions of their target genes. Although previous studies on limited sets of RA-regulated genes have defined canonical RAREs as direct repeats of the consensus RGKTCA separated by 1, 2, or 5 nucleotides (DR1, DR2, DR5), we show that in mouse embryoid bodies or F9 embryonal carcinoma cells, RARs occupy a large repertoire of sites with DR0, DR8, and IR0 (inverted repeat 0) elements. Recombinant RAR-RXR binds these non-canonical spacings in vitro with comparable affinities to DR2 and DR5. Most DR8 elements comprise three half-sites with DR2 and DR0 spacings. This specific half-site organization constitutes a previously unrecognized but frequent signature of RAR binding elements. In functional assays, DR8 and IR0 elements act as independent RAREs, whereas DR0 does not. Our results reveal an unexpected diversity in the spacing and topology of binding elements for the RAR-RXR heterodimer. The differential ability of RAR-RXR bound to DR0 compared to DR2, DR5, and DR8 to mediate RA-dependent transcriptional activation indicates that half-site spacing allosterically regulates RAR function.

Identification of the origin of adrenergic and cholinergic nerve fibers within the superior hypogastric plexus of the human fetus.

Nerve fibers contributing to the superior hypogastric plexus (SHP) and the hypogastric nerves (HN) are currently considered to comprise an adrenergic part of the autonomic nervous system located between vertebrae (T1 and L2), with cholinergic aspects originating from the second to fourth sacral spinal segments (S2, S3 and S4). The aim of this study was to identify the origin and the nature of the nerve fibers within the SHP and the HN, especially the cholinergic fibers, using computer-assisted anatomic dissection (CAAD). Serial histological sections were performed at the level of the lumbar spine and pelvis in five human fetuses between 14 and 30 weeks of gestation. Sections were treated with histological staining [hematoxylin-eosin (HE) and Masson's trichrome (TriM)] and with immunohistochemical methods to detect nerve fibers (anti-S100), adrenergic fibers (anti-TH), cholinergic fibers (anti-VAChT) and nitrergic fibers (anti-nNOS). The sections were then digitalized using a high-resolution scanner and the 3D images were reconstructed using winsurf software. These experiments revealed the coexistence of adrenergic and cholinergic fibers within the SHP and the HNs. One-third of these cholinergic fibers were nitrergic fibers [anti-VACHT (+)/anti-NOS (+)] and potentially pro-erectile, while the others were non-nitrergic [anti-VACHT (+)/anti-NOS (-)]. We found these cholinergic fibers arose from the lumbar nerve roots. This study described the nature of the SHP nerve fibers which gives a better understanding of the urinary and sexual dysfunctions after surgical injuries.

What is the origin of the arterial vascularization of the corpora cavernosa? A computer-assisted anatomic dissection study.

The purpose of this study was to identify the microscopic arterial vascularization of the corpora cavernosa (CC) of the penis using computer-assisted anatomic dissection (CAAD), determine the contribution of the different penile arteries towards this vascularization, detail the nature of cavernospongiosum shunts, and locate the anastomoses between these different arteries. Tissue specimens were taken from five donors who donated their bodies to science. The specimens were fixed in 10% formalin and sliced into a series of five 5-µm sections at intervals of 200 µm. The first section was stained with hematoxylin-eosin or Masson's trichrome and the second with anti-protein S100. The cavernous artery of the penis is not the only source of arterial vascularization of the CC. In four of the five cases studied, we found two to four perforating branches arising from the dorsal arteries of the penis that join up with the cavernous artery of the penis or that are solely responsible for the vascularization of the distal third of the penis. The bulbo-urethral and urethral arteries are situated outside of the tunica albuginea of the corpus spongiosum on their lateral and dorsal sides. The anastomoses do not occur between the cavernous artery of the penis and the corpus spongiosum but between the cavernous artery of the penis and the urethral artery on the surface of the tunica albuginea. All of these arteries are accompanied by nerve branches. The CC were found to be vascularized by both cavernous and dorsal arteries of the penis. Intrapenile vascularization is organized around four arterial axes, which are anastomosed by multiple neurovascular shunts.

Genome-wide in silico identification of new conserved and functional retinoic acid receptor response elements (direct repeats separated by 5 bp).

The nuclear retinoic acid receptors interact with specific retinoic acid (RA) response elements (RAREs) located in the promoters of target genes to orchestrate transcriptional networks involved in cell growth and differentiation. Here we describe a genome-wide in silico analysis of consensus DR5 RAREs based on the recurrent RGKTSA motifs. More than 15,000 DR5 RAREs were identified and analyzed for their localization and conservation in vertebrates. We selected 138 elements located ±10 kb from transcription start sites and gene ends and conserved across more than 6 species. We also validated the functionality of these RAREs by analyzing their ability to bind retinoic acid receptors (ChIP sequencing experiments) as well as the RA regulation of the corresponding genes (RNA sequencing and quantitative real time PCR experiments). Such a strategy provided a global set of high confidence RAREs expanding the known experimentally validated RAREs repertoire associated to a series of new genes involved in cell signaling, development, and tumor suppression. Finally, the present work provides a valuable knowledge base for the analysis of a wider range of RA-target genes in different species.

Decrease in and management of urolithiasis after kidney transplantation.

PURPOSE: Urolithiasis after kidney transplantation can involve several contributing factors and the treatment strategy is open to question. We determined the incidence and management of urolithiasis in kidney recipients. MATERIALS AND METHODS: We retrospectively reviewed a single center series of 3,000 kidney graft recipients during 32 years to identify those with urolithiasis. We analyzed data by the prevalence per decade, including perioperative procedures (preoperative assessment, anastomosis type and urinary drainage) and long-term followup (urinary stenosis, time to presentation, size, site, treatment type, renal function and survival). RESULTS: We identified 31 cases and noted a significant decrease in incidence from 2.1% to 0.6% during the 3 decades. Excluding 4 cases of donor in situ stones the mean time to diagnosis was 8.5 years. Surgical risk factors were ureteral obstruction in 41% of cases, infravesical obstruction in 14% and urinary-digestive anastomosis in 14%. A total of 12 cases (38%) were observed exclusively with 2 of spontaneous passage. With minor adaptations all mini-invasive procedures, including extracorporeal shock wave lithotripsy, endoscopy and percutaneous nephrolithotomy, were feasible in graft recipients. Antegrade procedures were facilitated by the ventral position of the graft. Eight patients (25%) were treated with open surgical ureteroureteral anastomosis. CONCLUSIONS: Prevention with a perioperative Double-J® stent and early treatment of ureteral obstruction have decreased and stabilized the urolithiasis rate at around 0.6%. Careful surveillance or any currently available instrumental treatments of urinary stones can be valid options.