Further characterization of clinical and laboratory features in VEXAS syndrome: large-scale analysis of a multicentre case series of 116 French patients.

BACKGROUND: A new autoinflammatory syndrome related to somatic mutations of UBA1 was recently described and called VEXAS syndrome ('Vacuoles, E1 Enzyme, X-linked, Autoinflammatory, Somatic syndrome'). OBJECTIVES: To describe clinical characteristics, laboratory findings and outcomes of VEXAS syndrome. METHODS: One hundred and sixteen patients with VEXAS syndrome were referred to a French multicentre registry between November 2020 and May 2021. The frequency and median of parameters and vital status, from diagnosis to the end of the follow-up, were recorded. RESULTS: The main clinical features of VEXAS syndrome were found to be skin lesions (83%), noninfectious fever (64%), weight loss (62%), lung involvement (50%), ocular symptoms (39%), relapsing chondritis (36%), venous thrombosis (35%), lymph nodes (34%) and arthralgia (27%). Haematological disease was present in 58 cases (50%): myelodysplastic syndrome (MDS; n = 58) and monoclonal gammopathy of unknown significance (n = 12; all patients with MGUS also have a MDS). UBA1 mutations included p.M41T (45%), p.M41V (30%), p.M41L (18%) and splice mutations (7%). After a median follow-up of 3 years, 18 patients died (15·5%; nine of infection and three due to MDS progression). Unsupervised analysis identified three clusters: cluster 1 (47%; mild-to-moderate disease); cluster 2 (16%; underlying MDS and higher mortality rates); and cluster 3 (37%; constitutional manifestations, higher C-reactive protein levels and less frequent chondritis). The 5-year probability of survival was 84·2% in cluster 1, 50·5% in cluster 2 and 89·6% in cluster 3. The UBA1 p.Met41Leu mutation was associated with a better prognosis. CONCLUSIONS: VEXAS syndrome has a large spectrum of organ manifestations and shows different clinical and prognostic profiles. It also raises a potential impact of the identified UBA1 mutation.

Equivalent outcomes using reduced intensity or conventional myeloablative conditioning transplantation for patients aged 35 years and over with AML.

Allogeneic hematopoietic stem cell transplantation provides the best chance of long-term survival for patients with AML, but is associated with an unpredictable risk of treatment-related mortality. From January 2000 to December 2010, we compared the outcomes for patients with AML aged 35 and over using reduced-intensity conditioning (RIC, N=60) or conventional myeloablative conditioning (MAC) regimen (N=72) transplantation. The median follow-up was 47 months (10-134). The 4-year cumulative incidence of non-relapse mortality was 21%. After adjusting for cytogenetic risk, gender donor/recipient mismatch and CD34+ cells, non-relapse mortality was significantly lower with the RIC regimen (P=0.027). The 4-year cumulative incidence of relapse was 38% and no difference was observed in the adjusted relapse rate between the two groups. The 4-year OS rate was 46%. Using both Cox regression and inverse probability-of-treatment weighted (IPTW) method, a similar OS rate was found with both regimens (adjusted hazard ratios for conventional vs reduced of 1.14 (95% CI 0.67-1.93, P=0.64) with Cox regression, and 1.14 (95% CI 0.55-2.34, P=0.73) with IPTW). Until prospective trials are completed, this study supports the use of a reduced-intensity regimen prior to transplantation for patients with AML aged 35 and over.

Gonadotrophin-releasing hormone release into the hypophyseal portal blood of the ewe mirrors both pulsatile and continuous intravenous infusion of kisspeptin: an insight into kisspeptin's mechanism of action.

Recent studies have demonstrated that kisspeptin (Kp) administration, given as a slow constant infusion of Kp10 (the shortest endogenous form of the Kp molecules which carries biological activity), is able to stimulate gonadotrophin secretion and induce ovulation in anoestrus acyclic ewes. Detailed analysis of peripheral luteinising hormone (LH) concentrations, obtained at 10-min intervals, suggested that this Kp10 treatment induced the continuous release of gonadotrophins. Whether this apparent constant secretion of LH resulted from a continuous elevation of GnRH or discrete high-frequency pulses could not be determined. In the present study, we monitored the patterns of gonadotrophin-releasing homrone (GnRH) secreted into hypophyseal portal blood (HPB) and LH in the peripheral circulation when Kp10 was administered either as discrete pulses or by means of a continuous infusion. Samples of HPB and peripheral blood were obtained at 2 and 10-min intervals, respectively, over a 6-h period, from anoestrous acyclic ewes that received an i.v. bolus injection of Kp10 at 1 h and an infusion of Kp10 between hours 2 and 6. GnRH release following Kp10 administration appeared to be dose-dependent, with larger responses being seen to the 20 µg bolus and 20 µg/h infusion than to the 10 µg bolus and 10 µg/h infusion, with the latter being marginally effective in inducing LH release. Bolus injections of Kp10 (either 20 or 10 µg) induced a sharp GnRH pulse in HPB and a discrete LH pulse in peripheral blood. By contrast, constant infusion of Kp10 (either 20 or 10 µg/h for 4 h) induced a sustained increase in baseline GnRH secretion with no convincing evidence of strictly episodic release. Values remained continuously elevated in HPB. No sign of pituitary desensitisation was observed at either concentration. Finally, i.v. injection of a large bolus (500 µg) of Kp10 produced immediate pharmacological concentrations of Kp10 in the peripheral circulation but were not associated with detectable levels of the peptide in the cerebrospinal fluid. In summary, our results demonstrate that the mode of Kp10 administration (pulsatile versus continuous) is important in shaping the pattern of GnRH secretion and suggests that this regulatory effect is most likely exerted at the level of the terminals of GnRH neurones. Moreover our data also suggest that Kp is involved in, rather than having a permissive role in, the control of endogenous GnRH pulsatility.

[Diagnosis of sleep disordered breathing using portable methods]. / Diagnostik schlafbezogener Atmungsstörungen mittels portabler Verfahren.

Portable monitoring of sleep disordered breathing is the first diagnostic method not only in Germany but today in other countries as well. The conditions under which portable monitoring can be done with reliable results are now well defined. The limitations for the use of portable monitoring are specified as well. The devices used for portable monitoring are classified in four categories according to the number and the kind of signals recorded. New technical developments in the field of portable monitoring (polygraphy) use an indirect assessment of sleep disordered breathing based on signals not directly recording respiration. The recording of ECG and deriving respiration, the analysis of the plethysmographically recorded pulse wave, the recording of jaw movements using magnets, and advanced analysis of respiratory sounds are recent approaches. These new methods are presented with few studies until now. More and larger clinical studies are needed in order to show which of these systems is useful in the diagnosis of sleep disordered breathing and which are the specific strengths and weaknesses.

Antineoplastic activity of ouabain and pyrithione zinc in acute myeloid leukemia.

Despite recent progress in the treatment of acute myeloid leukemia (AML), the prognosis of this rather heterogeneous disease remains poor and novel chemotherapeutics that specifically target leukemic cells must be developed. To address this need at the preclinical level, we implemented a high content imaging-based screen for the identification of small agents that induce AML cell death in vitro. Among a panel of 1040 Food and Drug Administration-approved agents, we identified pyrithione zinc (PZ) and ouabain (OUA) as potential antileukemic compounds. Both PZ and OUA efficiently induced cell death associated with apoptotic chromatin condensation and inhibition of nuclear factor-κB survival signaling, leading to reduced expression of antiapoptotic proteins, in several AML cell lines. PZ- and OUA-induced cell death was associated with the permeabilization of the outer mitochondrial membrane and led to the release of cytochrome c followed by caspase activation. Both PZ and OUA exerted significant anticancer effects in vivo, on human AML cells xenografts as well as ex vivo, on CD34(+) (but not CD34(-)) malignant myeloblasts from AML patients. Altogether, our results suggest that PZ and OUA may exhibit antileukemic effects by inducing the apoptotic demise of AML cells.

Neuroendocrine control by dopamine of teleost reproduction.

While gonadotropin-releasing hormone (GnRH) is considered as the major hypothalamic factor controlling pituitary gonadotrophins in mammals and most other vertebrates, its stimulatory actions may be opposed by the potent inhibitory actions of dopamine (DA) in teleosts. This dual neuroendocrine control of reproduction by GnRH and DA has been demonstrated in various, but not all, adult teleosts, where DA participates in an inhibitory role in the neuroendocrine regulation of the last steps of gametogenesis (final oocyte maturation and ovulation in females and spermiation in males). This has major implications for inducing spawning in aquaculture. In addition, DA may also play an inhibitory role during the early steps of gametogenesis in some teleost species, and thus interact with GnRH in the control of puberty. Various neuroanatomical investigations have shown that DA neurones responsible for the inhibitory control of reproduction originate in a specific nucleus of the preoptic area (NPOav) and project directly to the region of the pituitary where gonadotrophic cells are located. Pharmacological studies showed that the inhibitory effects of DA on pituitary gonadotrophin production are mediated by DA-D2 type receptors. DA-D2 receptors have now been sequenced in several teleosts, and the coexistence of several DA-D2 subtypes has been demonstrated in a few species. Hypophysiotropic DA activity varies with development and reproductive cycle and probably is controlled by environmental cues as well as endogenous signals. Sex steroids have been shown to regulate dopaminergic systems in several teleost species, affecting both DA synthesis and DA-D2 receptor expression. This demonstrates that sex steroid feedbacks target DA hypophysiotropic system, as well as the other components of the brain-pituitary gonadotrophic axis, GnRH and gonadotrophins. Recent studies have revealed that melatonin modulates the activity of DA systems in some teleosts, making the melatonin-DA pathway a prominent relay between environmental cues and control of reproduction. The recruitment of DA neurons for the neuroendocrine control of reproduction provides an additional brain pathway for the integration of various internal and environmental cues. The plasticity of the DA neuroendocrine role observed in teleosts may have contributed to their large diversity of reproductive cycles.

Insights into the mechanism by which kisspeptin stimulates a preovulatory LH surge and ovulation in seasonally acyclic ewes: potential role of estradiol.

We have previously demonstrated that a constant intravenous infusion of kisspeptin (Kp) for 48 h in anestrous ewes induces a preovulatory luteinizing hormone (LH) surge followed by ovulation in approximately 75% of animals. The mechanisms underlying this effect are unknown. In this study, we investigated whether Kp-induced preovulatory LH surges in anestrous ewes were the result of the general activation of the whole gonadotropic axis or of the direct activation of central GnRH neurons required for the GnRH/LH surge. In the first experiment, a constant iv infusion of ovine kisspeptin 10 (Kp; 15.2 nmol/h) was given to 11 seasonally acyclic ewes over 43 h. Blood samples were taken every 10 min for 15 h, starting 5h before the infusion, and then hourly until the end of the infusion. We found that the infusion of Kp induced a well-synchronized LH surge (around 22 h after the start of the Kp infusion) in 82% of the animals. In all ewes with an LH surge, there was an immediate but transient increase in the plasma concentrations of LH, follicle-stimulating hormone (FSH), and growth hormone (GH) at the start of the Kp infusion. Mean (+/- SEM) concentrations for the 5-h periods preceding and following the start of the Kp infusion were, respectively, 0.33 +/- 0.09 vs 2.83 +/- 0.49 ng/mL (P = 0.004) for LH, 0.43 +/- 0.05 vs 0.55 +/- 0.03 ng/mL (P = 0.015) for FSH, and 9.34 +/- 1.01 vs 11.51 +/- 0.92 ng/mL (P = 0.004) for GH. In the first experiment, surges of LH were observed only in ewes that also had a sustained rise in plasma concentrations of estradiol (E(2)) in response to Kp. Therefore, a second experiment was undertaken to determine the minimum duration of Kp infusion necessary to induce such a pronounced and prolonged increase in plasma E(2) concentration. Kisspeptin (15.2 nmol/h) was infused for 6, 12, or 24h in seasonally acyclic ewes (N = 8), and blood samples were collected hourly for 28 h (beginning 5h before the start of infusion), then every 2h for the following 22 h. Kisspeptin infused for 24h induced LH surges in 75% of animals, and this percentage decreased with the duration of the infusion (12h = 50%; 6h = 12.5%). The plasma concentration of E(2) was greater in ewes with an LH surge compared to those without LH surges; mean (+/- SEM) concentrations for the 5-h period following the Kp infusion were, respectively, 2.23 +/- 0.16 vs 1.27 +/- 0.13 pg/mL (P < 0.001). Collectively, our results strongly suggest that the systemic delivery of Kp induced LH surges by activating E(2)-positive feedback on gonadotropin secretion in acyclic ewes.

Melatonin activates brain dopaminergic systems in the eel with an inhibitory impact on reproductive function.

In the eel, a deficit in gonadotrophin-releasing hormone (GnRH) and a strong dopaminergic (DA) inhibition are responsible for the blockade of gonad development if silver eels are prevented from their reproductive migration. Environmental factors that eels encounter during their oceanic reproductive migration are thought to play an important role in the stimulation of eel pubertal development. We investigated the potential role of melatonin, a known mediator of the effects of external factors on reproductive function in vertebrates. We demonstrated that a long-term melatonin treatment increased brain tyrosine hydroxylase (TH, the rate limiting enzyme of DA synthesis) mRNA expression in a region-dependent way. Melatonin stimulated the dopaminergic system of the preoptic area, which is involved in the inhibitory control of gonadotrophin [luteinising hormone (LH) and follicle-stimulating hormone (FSH)] synthesis and release. Moreover, we showed that the increased TH expression appeared to be consistent with melatonin binding site distribution as shown by 2[(125)I]-melatonin labelling studies. On the other hand, melatonin had no effects on the two eel native forms of GnRH (mGnRH and cGnRH-II) mRNA expression. Concerning the pituitary-gonad axis, we showed that melatonin treatment decreased both gonadotrophin beta-subunit (LHbeta, FSHbeta) mRNA expression and reduced sexual steroid (11-ketotestosterone, oestradiol) plasma levels. This indicates that melatonin treatment had a negative effect on eel reproductive function. To our knowledge, the results of the present study provide the first evidence that melatonin enhances TH expression in specific brain regions in a non-mammalian species. By this mechanism melatonin could represent one pathway by which environmental factors could modulate reproductive function in the eel.

The Streptococcus pneumoniae competence regulatory system influences respiratory tract colonization.

The Streptococcus pneumoniae ComDE two-component signaling system controls the development of genetic competence in the bacterium and affects virulence in models of pneumonia and bacteremia. We have investigated the impact of the competence pathway during colonization of the nasopharynx, the principal ecological niche of the pneumococcus. Previous work showed that deletion of the pneumococcal CiaRH signaling system inhibited colonization and increased expression of genes required for competence. We anticipated that signaling by the competence pathway might similarly reduce carriage. Consistent with this expectation, a comE deletion that blocked transformation increased colonization fitness such that the mutant outcompeted the wild type in an infant rat model of asymptomatic carriage. Deletion of comD-immediately upstream of comE and likewise required for competence-similarly increased colonization fitness if the orientation of the antibiotic resistance cassette inserted into the comD locus was such that it reduced transcription of comE. However, an alternative comD deletion mutation that caused an increase in comE transcription impaired colonization instead. Activation of the competence system through a comE(D143Y) mutation did not affect colonization, but an inability to secrete the competence-stimulating peptide due to deletion of comAB produced a density-dependent reduction in colonization fitness. These results suggest a model in which signaling by the unactivated form of ComE reduces colonization fitness compared to that of bacteria in which it is either activated or absent entirely, with the most substantial fitness gain accompanying deletion of comE. This observation demonstrates that the pneumococcus incurs a substantial fitness cost in order to retain a functional competence regulatory system.

Pneumococcal HtrA protease mediates inhibition of competence by the CiaRH two-component signaling system.

Activation of the CiaRH two-component signaling system prevents the development of competence for genetic transformation in Streptococcus pneumoniae through a previously unknown mechanism. Earlier studies have shown that CiaRH controls the expression of htrA, which we show encodes a surface-expressed serine protease. We found that mutagenesis of the putative catalytic serine of HtrA, while not impacting the competence of a ciaRH+ strain, restored a normal competence profile to a strain having a mutation that constitutively activates the CiaH histidine kinase. This result implies that activity of HtrA is necessary for the CiaRH system to inhibit competence. Consistent with this finding, recombinant HtrA (rHtrA) decreased the competence of pneumococcal cultures. The rHtrA-mediated decline in transformation efficiency could not be corrected with excess competence-stimulating peptide (CSP), suggesting that HtrA does not act through degradation of this signaling molecule. The inhibitory effects of rHtrA and activated CiaH, however, were largely overcome in a strain having constitutive activation of the competence pathway through a mutation in the cytoplasmic domain of the ComD histidine kinase. Although these results suggested that HtrA might act through degradation of the extracellular portion of the ComD receptor, Western immunoblots for ComD did not reveal changes in protein levels attributable to HtrA. We therefore postulate that HtrA may act on an unknown protein target that potentiates the activation of the ComDE system by CSP. These findings suggest a novel regulatory role for pneumococcal HtrA in modulating the activity of a two-component signaling system that controls the development of genetic competence.

Dopaminergic inhibition of reproduction in teleost fishes: ecophysiological and evolutionary implications.

In many teleosts, dopamine (DA) exerts direct inhibitory control on gonadotropes, counteracting the stimulatory effect of gonadotropin-releasing hormone (GnRH) on gonadotropin release. This dual control by GnRH and DA has been demonstrated in various adult teleosts and has major implications for aquaculture. Because of its unique life cycle, the European eel has provided a powerful model for demonstrating the key role of DA in the control of puberty. Data from tetrapods suggest that the inhibitory role of DA on reproduction is not restricted to the teleosts. Thus, DA inhibitory control could represent an ancient evolutionary component in the neuroendocrine regulation of reproduction that may have been differentially maintained throughout vertebrate evolution. The intensity of DA inhibition, its main site of action, and its involvement in the control of puberty, seasonal reproduction, ovulation, spermiation, or even sex change may differ among classes of vertebrates, as well as within smaller phylogenetic units such as teleosts or mammals. An inhibitory role for DA has been reported also in some invertebrates, indicating that neuronal DA pathways may have been recruited in various groups of metazoa to participate in the control of reproduction. In addition to the incontestable GnRH neurons, the recruitment of DA neurons for the neuroendocrine control of reproduction provides an additional brain pathway for the integration of various species-specific, internal, and environmental cues. In teleosts, the plasticity of the DA neuroendocrine role may have contributed to their large diversity of biological cycles and to their successful adaptation to various environments.

Microarray-based identification of htrA, a Streptococcus pneumoniae gene that is regulated by the CiaRH two-component system and contributes to nasopharyngeal colonization.

Nasopharyngeal carriage is the reservoir from which most disease with Streptococcus pneumoniae arises. Survival as a commensal in this environment is likely to require a set of adaptations distinct from those needed to cause disease, some of which may be mediated by two-component signal transduction systems (TCSTS). We examined the contributions of nine pneumococcal TCSTS to the process of nasopharyngeal colonization by using an infant rat model. Whereas deletions in all but one of these systems have been associated previously with a high degree of attenuation in a murine model of pneumonia, only the CiaRH system was necessary for efficient carriage. Transcriptional analysis by using microarray hybridization identified a locus consisting of two adjacent genes, htrA and spoJ, that was specifically and strongly downregulated in a DeltaciaRH-null mutant. A S. pneumoniae strain lacking the htrA gene encoding a putative serine protease, but not one lacking spoJ, showed decreased fitness in a competitive model of colonization, a finding consistent with this gene mediating a portion of the carriage deficit observed with the DeltaciaRH strain.

Expression of mRNA for neurotrophic factors and their receptors in the rat dorsal root ganglion and sciatic nerve following nerve injury.

The adult rat dorsal root ganglion (DRG) produces mRNA for the neurotrophic factors nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and contains large populations of neurons responsive to these factors. We report that following a focal crush injury of the sciatic nerve, NGF mRNA expression increases threefold and BDNF mRNA two-fold, in the ipsilateral L4 and L5 DRGs. The mRNAs encoding the cognate neurotrophin receptors, p75NGFR, trkA, and trkB were expressed in the DRG throughout the post-injury time course, suggesting that DRG neurons remain responsive to both NGF and BDNF. p75NGFR mRNA levels became transiently depressed in the DRG during the first several days after the lesion but returned to normal within 1 week. trkB mRNA was expressed in the normal sciatic nerve and levels were not altered by nerve crush. RNase protection assays detected both full-length and truncated trkB transcripts in the DRG, but only truncated trkB mRNA, lacking the tyrosine kinase domain, was detected in the sciatic nerve. Likewise, trkA transcripts were not detected by RNase protection in normal sciatic nerve or in a segment of nerve distal to the crush site. These results are consistent with a model in which regenerating sensory neurons are supported by neurotrophic factors synthesized within the DRG.