Alopecia areata: Recent advances and emerging therapies.

Alopecia areata is an acquired, chronic, non-scarring hair disorder of the skin affecting 0.5-2% of the general population worldwide. Multiple mechanisms are involved in the disease, namely genetic predisposition, environmental triggers, impaired hair growth, and altered inflammatory and immune responses. Recent progress in the understanding of immune pathophysiological mechanisms has opened interesting perspectives for innovative treatment strategies. Several strategies have been tested, with debated results. However, proof of concept in humans of targeting of the Interferon (IFN)γ/Th1 pathway and of the Janus Kinase (JAK) signaling pathway has led to the development of several topical and oral JAK inhibitors in this disease with high unmet needs. Our review covers novel immune mechanisms of the disease and promising therapeutic approaches already tested in clinical trials and/or under development.

[What follow-up after pediatric cancer ? The SALTO consultation experience]. / Quel suivi après un cancer pédiatrique ? L'expérience de la consultation SALTO.

During the past 50 years, the mortality due to childhood cancers decreased dramatically thanks to improvements in supportive care and the use of multimodal approaches. In this context, the long-term follow up after childhood cancer has become a main concern for pediatric oncologists. The SALTO programme was developed in 2012 at the CHR Citadelle in Liège in order to organize a multidisciplinary long-term follow-up for the patients previously treated in our department for a childhood cancer. The aim of the present study was to review, for the most frequent childhood cancers, the long-term sequellae and the second cancers developed by the patients participating to the SALTO programme in order to define the follow-up needed. Our data confirm the importance of a multidisciplinary long-term follow-up, based on the treatments received and following international guidelines.

Au cours des cinquante dernières années, la mortalité liée aux cancers pédiatriques a fortement diminué grâce à une amélioration des soins de support et à l'utilisation d'approches multimodales. Dans ce contexte, le devenir à long terme des patients guéris d'un cancer pédiatrique est devenu une des préoccupations majeures pour les oncologues pédiatres. Dans cette optique, la consultation SALTO («Suivi À Long Terme en Oncologie¼) a été mise en place en 2012 au CHR de la Citadelle pour assurer le suivi multidisciplinaire des adultes ayant été traités dans notre secteur d'hémato-oncologie pédiatrique. L'objectif de cette étude a été de revoir, pour les cancers pédiatriques les plus fréquents, les séquelles et les tumeurs secondaires présentées par les patients suivis en consultation SALTO afin de préciser les modalités du suivi au long cours après cancer pédiatrique. Nos résultats confirment l'importance d'un suivi multidisciplinaire à long terme adapté aux traitements reçus, sur base de recommandations internationales.

Phenotype and function of circulating memory T cells in human vitiligo.

BACKGROUND: Vitiligo is a chronic inflammatory skin disorder characterized by the loss of melanocytes. While a T helper cell (Th)1/cytotoxic T cell (Tc)1-skewed immune response is now well demonstrated in vitiligo, recent data suggest that the T-cell component could be more complex, involving different combinatorial T-cell subsets. OBJECTIVES: To analyse the phenotype and function of circulating CD4+ and CD8+ memory T-cell subsets in patients with stable and active vitiligo, in comparison with patients with psoriasis and healthy controls. METHODS: This is a monocentric, prospective, descriptive and exploratory study. Multiparametric flow cytometry analyses were performed to evaluate the surface expression of homing and T-cell-subset markers together with intracellular cytokine production in peripheral blood mononuclear cells from 60 patients with vitiligo, 25 patients with psoriasis and 28 healthy donors. RESULTS: Vitiligo peripheral blood circulating effector and central memory T cells expressed similar proportions of skin-homing markers. Decrease in the frequencies of circulating CD4+ and CD8+ Th1/Tc1, Th17/Tc17, and Th1/Th17 or Tc1/Tc17 effector memory T-cell subsets were observed in patients with vitiligo compared with healthy donors. Similar observations were made in psoriasis. In contrast, vitiligo circulating T cells showed a similar capacity for proinflammatory cytokine production compared with those in psoriasis and healthy controls. CONCLUSIONS: The decreased frequencies of circulating Th1/Tc1, Th17/Tc17 and Th1/Th17-Tc1/Tc17 cells suggest a possible migration of these T-cell subsets into the skin of patients with vitiligo. These could be targeted to prevent flares of the disease. What is already known about this topic? Vitiligo is a chronic inflammatory skin disorder associated with the loss of melanocytes. Vitiligo is characterized by a T helper cell (Th)1/cytotoxic T cell (Tc)1-skewed immune response in the skin. What does this study add? A thorough analysis of the phenotype and function of circulating memory T cells suggests the migration of Th1/Tc1, Th17/Tc17 and Th1/Th17-Tc1/Tc17 cell subsets in the skin. What is the translational message? A better understanding of the different immune T-cell subsets involved in vitiligo could lead to better therapeutic options. Linked Comment: Matos. Br J Dermatol 2020; 183:803.

Heat shock protein 70 potentiates interferon alpha production by plasmacytoid dendritic cells: relevance for cutaneous lupus and vitiligo pathogenesis.

BACKGROUND: Plasmacytoid dendritic cells (pDCs) are a subset of dendritic cells specialized in the production of type I interferon (IFN-α/ß) and involved in various cutaneous inflammatory and autoimmune disorders, such as cutaneous lupus erythematosus (CLE) and vitiligo. Heat shock proteins (HSPs) are molecular chaperones essential for maintaining cellular functions, but they can act as a danger signal during inflammation. OBJECTIVES: To decipher the role of HSP70 in the production of IFN-α by pDCs in CLE and vitiligo. METHODS: Expression of HSP70 and CD123+ pDCs was analysed by immunohistochemistry or immunofluorescence in CLE and vitiligo skin samples. Flow cytometry was performed to analyse expression of HSP70 receptors, activation markers on pDCs and DNA uptake by pDCs in the presence of HSP70. The impact of HSP70 on DNA-induced IFN-α secretion by pDCs was evaluated by enzyme-linked immunosorbent assay (ELISA). The effect of IFN-α on chemokine (C-X-C motif) ligand 9 (CXCL9)/10 gene and protein expression by keratinocytes was determined by real-time polymerase chain reaction and ELISA. RESULTS: Infiltration of pDCs in CLE and progressive vitiligo was primarily located in the epidermis, close to keratinocytes expressing HSP70. In vitro experiments revealed that the pDCs expressing HSP70 receptor Lox-1 (lectin-like oxidized low-density lipoprotein-receptor-1) were able to aggregate HSP70. Exogenous HSP70 induced activation of pDCs and increased the uptake of exogenous DNA. Furthermore, HSP70 potentiated DNA-induced IFN-α production by pDCs. Finally, IFN-α induced expression of CXCL9 and CXCL10 by keratinocytes. CONCLUSIONS: These data demonstrate that interaction between HSP70 and pDCs in CLE and vitiligo is a prerequisite for the enhancement of IFN-α production, and could be an interesting target.

Waved aCGH: to smooth or not to smooth.

Array-based comparative genomic hybridization (aCGH) is a powerful tool to detect genomic imbalances in the human genome. The analysis of aCGH data sets has revealed the existence of a widespread technical artifact termed as 'waves', characterized by an undulating data profile along the chromosome. Here, we describe the development of a novel noise-reduction algorithm, waves aCGH correction algorithm (WACA), based on GC content and fragment size correction. WACA efficiently removes the wave artifact, thereby greatly improving the accuracy of aCGH data analysis. We describe the application of WACA to both real and simulated aCGH data sets, and demonstrate that our algorithm, by systematically correcting for all known sources of bias, is a significant improvement on existing aCGH noise reduction algorithms. WACA and associated files are freely available as Supplementary Data.

[Glucocorticoid sensitive bilateral leg swelling in an 85-year-old woman presenting with polymyalgia rheumatica: A case report]. / Œdèmes des membres inférieurs cortico-sensibles chez une patiente âgée de 85 ans présentant une pseudopolyarthrite rhizomélique.

INTRODUCTION: Polymyalgia rheumatica (PMR) can be associated with distal swelling indicating an associated RS3PE syndrome. We report a case of PMR associated with oedema of the lower limbs, which resolved rapidly under glucocorticoid therapy. CASE REPORT: A 85-year-old woman presented with a 4 month history of PMR responding to the 2012 EULAR/ACR classification criteria. Examination of the lower limbs revealed pitting oedema bilaterally up to the knees, with mild erythema and warmth. Hypoalbuminemia (30g/L) was present. There was no cardiac, renal or hepatic cause to explain leg swelling. FDG-PET/CT demonstrated increased metabolism in the periarticular area of shoulders and hips. There was no sign of aortitis or neoplasia. Under treatment with prednisone 10mg/day leg swelling disappeared concomitantly to a weight loss of 8kg within 8days. CONCLUSION: This case, the first to report leg swelling of inflammatory origin in the context of PMR, could indicate an increased vascular permeability caused by inflammation in the elderly.

Use-dependent inhibition of hHCN4 by ivabradine and relationship with reduction in pacemaker activity.

BACKGROUND AND PURPOSE: Ivabradine, a specific and use-dependent I(f) inhibitor, exerts anti-ischaemic activity purely by reducing heart rate. The aim of this work was to characterize its effect on the predominant HCN channel isoform expressed in human sino-atrial nodes (hSAN), to determine its kinetics in HCN channels from multicellular preparations and rate-dependency of its action. EXPERIMENTAL APPROACH: RT-PCR analysis of the four HCN channel isoforms was carried out on RNAs from hSAN. Patch-clamp and intracellular recordings were obtained from CHO cells stably expressing hHCN4 and isolated SAN, respectively. Beating rate of rat isolated atria was followed using a transducer. KEY RESULTS: hHCN4 mRNAs were predominant in hSAN. Ivabradine induced a time-dependent inhibition of hHCN4 with an IC(50) of 0.5 microM. In rabbit SAN, ivabradine progressively reduced the frequency of action potentials: by 10% after 3 h at 0.1 microM, by 14% after 2 h at 0.3 microM and by 17% after 1.5 h at 1 microM. After 3h, ivabradine reduced the beating rate of rat right atria with an IC(30) of 0.2 microM. The onset of action of ivabradine was use-dependent rather than time-dependent with slower effects than caesium, an extracellular I (f) blocker. Ivabradine 3 microM decreased the frequency of action potentials in SAN from guinea-pig, rabbit and pig by 33%, 21% and 15% at 40 min, respectively. CONCLUSIONS AND IMPLICATIONS: The use-dependent inhibition of hHCN4 current by ivabradine probably contributes to its slow developing effect in isolated SAN and right atria and to its increased effectiveness in species with rapid SAN activity.

Incorporation of [14c] arachidonate in pig thyroid lipids and prostaglandins.

In pig and sheep thyroid, the arachidonate content of phosphatidylinositol (14.3--17.5%) is much higher than in the other phospholipids. In the thyroid, phosphatidylinositol seems to play an important role in the biosynthesis of prostaglandins. In neutral thyroid lipids, the arachidonate content is much higher in diacylglycerols (15.8%) than in monoacylglycerols (2.9%) or triacylglycerols (4.2%). However, the most important pool of esterified arachidonate is triacylglycerols (1030 nmol of arachidonate/g tissue). Arachidonate represents a very small part of total free fatty acids measured in the presence of albumin and indomethacin (0.65% or 16.4 nmol/g tissue). Thyrotropin (50 munits/ml) causes after 1 h a 2-fold increase in the level of free arachidonate (37.3 nmol/g tissue). Pig thyroid slices rapidly take up [14C]arachidonate and incorporate it into neutral lipids and phospholipids. Specific activity of phosphatidylinositol is 3-fold higher than that of phosphatidylcholine after an hour incubation. Specific activity of diacylglycerols is 8-fold higher than that of triacylglycerols. Thyrotropin (50 munits/ml) causes a significant decrease (32--33%) of incorporation of radioactivity in lipids as compared with standard incubation. This result is compatible with the isotopic dilution of the labeled [14C]arachidonate by nonradioactive arachidonate liberated in the incubation medium under thyrotropin action. Slices and homogenates of pig thyroid weakly convert [14C]arachidonate to prostaglandins E2 and F2alpha (1--2%. Thyrotropin (50 munits/ml) always diminishes the conversion of radioactivity to prostaglandins as compared with standard incubation. This result is compatible with the above-mentioned hypothesis.

Relationship between prostaglandin biosynthesis and the effect of insulin on hormone-stimulated lipolysis in rat adipose tissue.

Lipolysis in rat fat pads was studied by determination of free fatty acid and glycerol production in various experimental conditions (in the absence or presence of glucose, adrenalin and insulin). These results were compared to the accumulation of endogenous prostaglandins E2 and F2alpha during lipolysis. In the absence of glucose the prostaglandin production followed the adrenalin-induced fluctuations in released free fatty acids both in the presence or absence of insulin. In the presence of glucose and insulin, a drop in prostaglandin accumulation was observed whereas free fatty acids production was strongly stimulated. These results suggest that either free fatty acid composition is modified, influencing the activity of prostaglandin synthetase, or that there exists a specific mechanism controlling prostaglandin synthesis.

Chronic and acute effects of thyrotropin on phosphatidylinositol turnover in cultured porcine thyroid cells.

The 32P incorporation into phospholipids of isolated porcine thyroid cells, cultured for 1-4 days, has been studied in subsequent 2-h incubations. Along with culture ageing, decreased 32P incorporation into total phospholipid of control cells was observed. The presence of 40 munits/ml TSH during the 2 h incubation yielded a relative increase in labelling of phosphatidylinositol, named 'acute phospholipid effect'. A chronic treatment of the cells with TSH concentration ranging from 0.1 to 10 munits/ml ensured the maintenance of a high turnover rate of total phospholipids. The analysis of individual phospholipids revealed that 1-day culture cells in the presence of 0.1 munits/ml TSH presented a strong increase of phosphatidylinositol labelling. This 'chronic phospholipid effect' of TSH can be reproduced by a chronic treatment with dibutyryl cyclic AMP (10(-3)M) or prostaglandin E2 (10(-6)M), which did not evoke a classical phospholipid effect in a 2 h incubation. If TSH (40 munits/ml) is added to the cells in a 2 h incubation, control cells show the classical phospholipid effect whereas cells chronically treated with TSH, dibutyryl cyclic AMP or prostaglandin E2 presented a 'reverse phospholipid effect' i.e. a relative decrease in phosphatidylinositol labelling. 10(-4)M cycloheximide presence during the last 12 h of culture prevented the establishment of the 'chronic phospholipid effect' and of its consequence, 'the reverse phospholipid effect'. On the basis of these results a scheme is proposed in keeping with current hypotheses concerning phosphatidylinositol metabolism.

1-O-alkyl-2-acyl-sn-glycero-3-phosphorylcholine is the precursor of platelet-activating factor in stimulated rabbit platelets. Evidence for an alkylacetyl-glycerophosphorylcholine cycle.

The metabolism of [3H]PAF-acether ([1',2'-3H]alkyl-2-acetyl-sn-glycero-3-phosphorylcholine ([3H]alkylacetyl-GPC)) by rabbit platelets was investigated using thin-layer chromatography and high-performance liquid chromatography followed by radioactivity detection. After 2 h of incubation at 37 degrees C, 90 +/- 5.3% of [3H]PAF-acether taken up by the platelets were converted into a product identified as sn-2 long-chain acyl analogue ([3H]alkylacyl-GPC) which was incorporated in the membranes. This conversion was independent from extracellular calcium and was completely inhibited by platelet pre-exposure to 2 mM phenylmethylsulfonyl fluoride, a serine hydrolase inhibitor, which failed to inhibit the uptake of [3H]PAF-acether by the cells. The 2-deacetylated derivative, lyso-[3H]PAF-acether was found to be an intermediate of the conversion of [3H]PAF-acether into [3H]alkylacyl-GPC in platelet homogenates. Platelet stimulation with 2.5 U/ml of thrombin induced a reduction (16.5 +/- 2.2%) of its content of [3H]alkylacyl-GPC, accompanied by the release of [3H]PAF-acether and lyso-[3H]PAF-acether to the medium. These effects were suppressed by the phospholipase A2 inhibitor, p-bromophenacyl bromide. Our results demonstrate that intact platelets convert exogenous PAF-acether into alkylacyl-GPC, which can serve as the precursor of PAF-acether released during stimulation. The existence of a metabolic cycle for the uptake, the release and the inactivation of PAF-acether by platelets is suggested.

Control by thyrotropin of the production by thyroid cells of an inositol phosphate-glycan.

The increased turnover of phosphatidylinositol promoted by thyrotropin (TSH) in pig thyroid tissue does not seem to be caused by an increased production of inositol tris-phosphate. We have explored another possibility, the synthesis of an inositol phosphate-glycan (IP-gly). Our results show that thyroid cells in culture produced this substance from a precursor phosphatidylinositol-glycan (Gly-PI). The obtained IP-gly seemed, by its analytical and biological properties, to be identical, or similar, to the previously described insulin mediator.

Autocrine biological effects of glycosyl inositol phosphate produced by reconstituted pig thyroid follicles: role of pertussis toxin sensitive G proteins.

We examine the autocrine activity of glycosyl inositol phosphate (InP-gly) on thyroid metabolism. The cAMP accumulation promoted by thyrotropin (TSH) or forskolin was modulated by InP-gly, stimulated by the lowest tested concentration (10(-8) M) and progressively inhibited by higher concentrations. Iodide uptake and iodine organification were decreased in a concentration-dependent manner by InP-gly alone, or in the presence of TSH. The IAP component of pertussis toxin blocked the inhibitory action of InP-gly on cAMP accumulation by reconstituted thyroid follicles (RTF), suggesting the participation of Gi protein. But the same treatment with IAP was without effect on iodine metabolism, suggesting that there is a second target for InP-gly, more distal than Gi protein, or coupled to another G protein which is insensitive to the toxin.

Induction of type II 5'-deiodinase activity in cultured rat astroglial cells by 12-O-tetradecanoylphorbol-13-acetate: dependence on glucocorticoids.

The effect of an activator of protein kinase C, 12-O-tetradecanoylphorbol-13-acetate (TPA), on the 5'-deiodinase (5'D) activity was studied in rat astroglial cells cultured in chemically defined medium. TPA promoted a large increase in the type II 5'D activity, which was maximal 5-10 h after addition of TPA and then declined to the basal level at 24 h. The optimal TPA concentration was 10(-7) M. TPA and 8-Br-cAMP, an other inducer of 5'D activity were antagonist. Otherwise, TPA stimulated 5'D activity only in the presence of glucocorticoids at concentrations from 10(-8) M to 10(-4) M. Glucocorticoids alone induced a slight increase in 5'D activity. These data indicate that protein kinase C contributes to the control of 5'D activity in astroglial cells and that its action is dependent on glucocorticoids.

The expression of thyrotropin receptor in the brain.

The regulation of the thyroid gland by TSH is mediated by a heterotrimeric G protein-coupled receptor. Nonthyroid effects of TSH have been reported, and expression of its receptor has been described in adipocytes and lymphocytes. We have previously reported the existence of specific and saturable binding sites of TSH and specific TSH effects in primary cultured rat brain astroglial cells. We now report expression of the TSH receptor gene in these cells; the coding sequence of the corresponding complementary DNA is identical to that previously established in thyroid. Using specific antisense RNA probe, expression of this gene was detected in some isolated or clustered glial fibrillary acidic protein-positive primary cultured cells by in situ hybridization. With this technique, we further detected TSH receptor messenger RNA (mRNA) expression in rat brain cryoslices in both neuronal cells and astrocytes. Its presence predominated in neuron-rich areas (pyriform and postcingulate cortex, hippocampus, and hypothalamic nuclei) and was mostly colocalized with neuron-specific enolase. In astrocytes, this mRNA was detected in the ependymal cell layer and the subependymal zone, and several isolated cells were also found in the brain parenchyma. We also detected TSH receptor mRNA and protein in primary cultured human astrocytes. The protein was detected as well in both rat and human brain cryoslices. Together, these findings clearly demonstrate the expression of the TSH receptor gene in the brain in both neuronal cells and astrocytes.

Restoration by insulin of the responsiveness of stimulated adipocytes to adenosine.

The stimulation of adipocyte-cyclase by isoproterenol decreases its sensitivity to adenosine, with, as a consequence, a decrease in its antilipolytic effect. The presence of insulin under conditions where its action on the phosphodiesterase activity is impaired, restores the responsiveness of adenylate-cyclase and of lipolysis to adenosine.

Effects of eicosatetraynoic acid (ETYA) on cultured pig thyroid cells. Relationships between the inhibition of the phosphatidate-phosphatidyl inositol cycle, the iodination and the cyclic AMP responsiveness to thyrotropin.

The arachidonate inhibition of the adenylate-cyclase system of cultured pig thyroid cells was not mediated by cyclooxygenase, lipoxygenase or peroxidase metabolites. Indeed ETYA, an inhibitor of cyclooxygenase and lipoxygenase, and methimazole, an inhibitor of peroxidase and iodination were without effect on the arachidonate inhibition. Moreover the effect of arachidonate was amplified by a combination with ETYA. In 32P incorporation experiments we observed a modification of the labelling of individual phospholipids of cultured pig thyroid cells resulting in a decrease into phosphatidylinositol (PI) and an increase into phosphatidate (PA) of arachidonate and ETYA-treated cells. These results may be explained by an inhibition of CDP-diacylglycerol: inositol transferase and conversely a stimulation of PI specific phospholipase C yielding a decrease in PI and an increase in PA, which inhibits in turn adenylate cyclase activity possibly by Ca2+ translocation.