PARP2 promotes inflammation in psoriasis by modulating estradiol biosynthesis in keratinocytes.

Poly(ADP-ribose) polymerase 2 (PARP2) alongside PARP1 are responsible for the bulk of cellular PARP activity, and they were first described as DNA repair factors. However, research in past decades implicated PARPs in biological functions as diverse as the regulation of cellular energetics, lipid homeostasis, cell death, and inflammation. PARP activation was described in Th2-mediated inflammatory processes, but studies focused on the role of PARP1, while we have little information on PARP2 in inflammatory regulation. In this study, we assessed the role of PARP2 in a Th17-mediated inflammatory skin condition, psoriasis. We found that PARP2 mRNA expression is increased in human psoriatic lesions. Therefore, we studied the functional consequence of decreased PARP2 expression in murine and cellular human models of psoriasis. We observed that the deletion of PARP2 attenuated the imiquimod-induced psoriasis-like dermatitis in mice. Silencing of PARP2 in human keratinocytes prevented their hyperproliferation, maintained their terminal differentiation, and reduced their production of inflammatory mediators after treatment with psoriasis-mimicking cytokines IL17A and TNFα. Underlying these observations, we found that aromatase was induced in the epidermis of PARP2 knock-out mice and in PARP2-deficient human keratinocytes, and the resulting higher estradiol production suppressed NF-κB activation, and hence, inflammation in keratinocytes. Steroidogenic alterations have previously been described in psoriasis, and we extend these observations by showing that aromatase expression is reduced in psoriatic lesions. Collectively, our data identify PARP2 as a modulator of estrogen biosynthesis by epidermal keratinocytes that may be relevant in Th17 type inflammation. KEY MESSAGES : PARP2 mRNA expression is increased in lesional skin of psoriasis patients. PARP2 deletion in mice attenuated IMQ-induced psoriasis-like dermatitis. NF-κB activation is suppressed in PARP2-deficient human keratinocytes. Higher estradiol in PARP2-deficient keratinocytes conveys anti-inflammatory effect.

Pruritogenic molecules in the skin of patients with dermatomyositis.

Introduction: Pruritus is a common excruciating symptom in systemic autoimmune diseases such as dermatomyositis (DM) but the pathogenesis is not fully understood. We intended to investigate the targeted expression analysis of candidate molecules involved in the development of pruritus in lesional vs. non-lesional skin samples of patients affected with active DM. We looked for correlations between the investigated pruriceptive signaling molecules, disease activity, and itching sensation of DM patients. Methods: Interleukins (IL-33 and IL-6), tumor necrosis factor α (TNF-α), peroxisome proliferator-activated receptor γ (PPAR-γ), and ion channels belonging to the transient receptor potential (TRP) family were analyzed. The expression of TNF-α, PPAR-γ, IL-33, IL-6, and TRP channels in lesional DM skin was evaluated by RT-qPCR and immunohistochemistry and was compared with non-lesional DM skin samples. Pruritus, disease activity, and damage of DM were evaluated by the 5-D itch scale and Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI), respectively. Statistical analysis was performed with IBM SPSS 28 software. Results: A total of 17 active DM patients participated in the study. We could show that the itching score was positively correlated with the CDASI activity score (Kendall's tau-b = 0.571; p = 0.003). TNF-α gene expression was significantly higher in lesional DM skin than in non-lesional DM skin (p = 0.009) and differed in the subgroups of patients with different itch intensities (p = 0.038). The mRNA expression of lesional IL-6 correlated positively with 5-D itch and CDASI activity score (Kendall's tau-b = 0.585; p = 0.008 and 0.45; p = 0.013, respectively). TRPV4 expressions were positively correlated with CDASI damage score (Kendall's tau-b = 0.626; p < 0.001), but the mRNA expressions of the TRP family, PPAR-γ, IL-6, and IL-33 were not different in lesional and non-lesional samples. Immunohistochemistry analysis did not find significant alterations in the expressions of TNF-α, PPAR-γ, IL-6, and IL-33 in lesional and non-lesional regions. Discussion: Our results argue that cutaneous disease activity, TNF-α, and IL-6 might play a central role in DM-associated itch, while TRPV4 plays a central role in tissue regeneration.

Zinc Transporter 9 (SLC30A9) Expression Is Decreased in the Vaginal Tissues of Menopausal Women.

Our aim was to compare zinc transporter (ZnT/SLC30A, and ZIP/SLC39A) expression between pre- and postmenopausal women in human vaginal tissues. Zinc transporter families are responsible for the maintenance of intracellular zinc concentrations. Zinc has significant effects on the extracellular matrix composition. Vaginal wall biopsies were obtained from seven premenopausal and seven postmenopausal women. mRNA expression of twenty-four zinc transporters was determined by quantitative real-time PCR. Zinc transporter expression at the protein level was assessed by immunohistochemistry. Student's t test and Mann-Whitney U test were used to compare data. ZnT4 and ZnT9 mRNA expression were significantly lower in postmenopausal women compared with premenopausal women (mean ± SD mRNA expression in relative units, 96.43 ± 140.61 vs. 410.59 ± 304.34, p = 0.03 and 0.62 ± 0.39 vs. 1.13 ± 0.31, p = 0.02). In addition, ZIP2, ZIP3, and ZIP6 mRNA expressions were significantly lower in postmenopausal women compared with premenopausal women (mean ± SD mRNA expression in relative units, 1.11 ± 0.61 vs. 2.29 ± 1.20, p = 0.04; 2.32 ± 1.90 vs. 15.82 ± 12.97, p = 0.02 and 1.10 ± 0.80 vs. 5.73 ± 4.72, p = 0.03). ZnT9 protein expression in the stratum spinosum was significantly lower in postmenopausal women (p = 0.012). Zinc transporters were expressed differentially in the vaginal tissues. ZnT9 expression was significantly lower in postmenopausal women compared with premenopausal women.

GPR119 Is a Potent Regulator of Human Sebocyte Biology.

We have shown previously that endocannabinoids promote sebaceous lipogenesis, and sebocytes are involved in the metabolism of the endocannabinoid-like substance oleoylethanolamide (OEA). OEA is an endogenous activator of GPR119, a recently deorphanized receptor, which currently is being investigated as a promising antidiabetic drug target. In this study, we investigated the effects of OEA as well as the expression and role of GPR119 in human sebocytes. We found that OEA promoted differentiation of human SZ95 sebocytes (elevated lipogenesis, enhanced granulation, and the induction of early apoptotic events), and it switched the cells to a proinflammatory phenotype (increased expression and release of several proinflammatory cytokines). Moreover, we could also demonstrate that GPR119 was expressed in human sebocytes, and its small interfering RNA-mediated gene silencing suppressed OEA-induced sebaceous lipogenesis, which was mediated via c-Jun N-terminal kinase, extracellular signal-regulated kinase 1/2, protein kinase B, and CRE-binding protein activation. Finally, our pilot data demonstrated that GPR119 was downregulated in the sebaceous glands of patients with acne, arguing that GPR119 signaling may indeed be disturbed in acne. Collectively, our findings introduce the OEA/GPR119 signaling as a positive regulator of sebocyte differentiation and highlight the possibility that dysregulation of this pathway may contribute to the development of seborrhea and acne.

Endocannabinoid Tone Regulates Human Sebocyte Biology.

We have previously shown that endocannabinoids (eCBs) (e.g., anandamide) are involved in the maintenance of homeostatic sebaceous lipid production in human sebaceous glands and that eCB treatment dramatically increases sebaceous lipid production. Here, we aimed to investigate the expression of the major eCB synthesizing and degrading enzymes and to study the effects of eCB uptake inhibitors on human SZ95 sebocytes, thus exploring the role of the putative eCB membrane transporter, which has been hypothesized to facilitate the cellular uptake and subsequent degradation of eCBs. We found that the major eCB synthesizing (N-acyl phosphatidylethanolamine-specific phospholipase D, and diacylglycerol lipase-α and -ß) and degrading (fatty acid amide hydrolase, monoacylglycerol lipase) enzymes are expressed in SZ95 sebocytes and also in sebaceous glands (except for diacylglycerol lipase-α, the staining of which was dubious in histological preparations). eCB uptake-inhibition with VDM11 induced a moderate increase in sebaceous lipid production and also elevated the levels of various eCBs and related acylethanolamides. Finally, we found that VDM11 was able to interfere with the proinflammatory action of the TLR4 activator lipopolysaccharide. Collectively, our data suggest that inhibition of eCB uptake exerts anti-inflammatory actions and elevates both sebaceous lipid production and eCB levels; thus, these inhibitors might be beneficial in cutaneous inflammatory conditions accompanied by dry skin.

Voltage-gated K+ channel (Kv) subunit expression of the guinea pig spiral ganglion cells studied in a newly developed cochlear free-floating preparation.

The spiral ganglion accommodates the cell bodies of the acoustic nerve fibres connecting the hair cells to the central nervous system. As the ionic channels containing various voltage-gated K+ channel (Kv) subunits play pivotal roles in determining the functional properties and firing behaviour of the spiral ganglion cells (SGCs), every piece of information concerning the Kv expression of the SGCs is valuable. In the present work a comprehensive immunohistochemical analysis was performed to describe the expression of 9 Kv subunits in the guinea pig cochlea on traditional wax-embedded sections as well as employing a newly developed preparation that allowed confocal analysis, reconstruction of the three-dimensional appearance and precise morphological characterisation of the SGCs. Besides determining their Kv expression patterns, differences between type I and type II SGCs were sought. SGCs showed positivity for 8 out of the 9 Kv subunit-specific antibodies with varying intensity and proportion of the immunopositive cells; whereas no obvious Kv3.2 positivity could be noted. Type I and type II cells demonstrated similar expression patterns for all subunits tested, with the exception of Kv1.2, whose presence was confirmed in only 50% of the type II cells. Although the present findings suggest that type I and type II cells do not differ fundamentally in the Kv subunits they possess; they also imply that SGCs may not form a homogeneous cell population, and might provide explanation of the previously noted heterogeneity of the membrane properties of the SGCs.

Differential expression of androgen and estrogen receptor of appendix testis in patients with descended and undescended testes.

OBJECTIVES: The incidence of appendix testis has been shown to be 76% in descended and 24% in undescended testis in our previous intraoperative survey. To determine the possible role of the appendix testis in the process of testicular migration, we compared the androgen and estrogen receptor status of appendix testis in descended and undescended testes. METHODS: Thirty-seven appendix testes were collected intraoperatively and the expression of androgen and estrogen receptors were examined with immunostaining and immunofluorescence labeling. Based on the diagnosis, the specimens were divided into three groups. Group H (groin hernia, n = 11, as a group of descended testis), Group AU (acquired undescended testis, n = 14), and Group CU (congenital undescended testis, n = 12). RESULTS: The testicular appendages were found to express both androgen and estrogen receptors in Group H and Group AU, but specimens in Group CU were only estrogen receptor positive, whereas androgen receptors were not present. CONCLUSION: The presence of the androgen receptor in the appendix testis of the descended testes and acquired undescended testes and its absence in patients with congenital undescended testis suggests that the appendix testis might play a role in the process of testicular descent.

Voltage-gated potassium channel (Kv) subunits expressed in the rat cochlear nucleus.

Because the neuronal membrane properties and firing characteristics are crucially affected by the depolarization-activated K(+) channel (Kv) subunits, data about the Kv distribution may provide useful information regarding the functionality of the neurons situated in the cochlear nucleus (CN). Using immunohistochemistry in free-floating slices, the distribution of seven Kv subunits was described in the rat CN. Positive labeling was observed for Kv1.1, 1.2, 1.6, 3.1, 3.4, 4.2, and 4.3 subunits. Giant and octopus neurons showed particularly strong immunopositivity for Kv3.1; octopus neurons showed intense Kv1.1- and 1.2-specific reactions also. In the latter case, an age-dependent change of the expression pattern was also documented; although both young and older animals produced definite labeling for Kv1.2, the intensity of the reaction increased in older animals and was accompanied with the translocation of the Kv1.2 subunits to the cell surface membrane. The granule cell layer exhibited strong Kv4.2-specific immunopositivity, and markedly Kv4.2-positive glomerular synapses were also seen. It was found that neither giant nor pyramidal cells were uniform in terms of their Kv expression patterns. Our data provide new information about the Kv expression of the CN and also suggest potential functional heterogeneity of the giant and pyramidal cells.

Presence and distribution of three calcium binding proteins in projection neurons of the adult rat cochlear nucleus.

The presence and distribution of three cytoplasmic calcium binding proteins, calbindin, calretinin, and parvalbumin, have been investigated in the projection neurons of the cochlear nucleus complex in adult rats by using immunohistochemistry in free-floating slices. Identification of the individual cell types was carried out on the basis of their intranuclear localization, morphological characteristics, and (in the cases of pyramidal and bushy neurons) by retrograde labeling with rhodamine-dextran. The most important findings were confirmed by using confocal microscopy. The data obtained in these experiments are the first to demonstrate the presence of parvalbumin in pyramidal neurons and globular and spherical bushy cells of rat cochlear nucleus, whereas octopus and giant cells did not show positivity for parvalbumin. Calretinin was not present in either Purkinje-like cells or giant neurons. According to the double immunolabeling co-localization experiments, the pyramidal neurons, Purkinje-like cells, globular bushy cells, and octopus cells express two different calcium binding proteins in their cytoplasm (although in different combinations) whereas giant cells and spherical bushy cells contain solely calbindin and parvalbumin, respectively. The presence of calretinin in globular bushy cells provides a tool for distinguishing them from spherical bushy cells. The immunolabeling of the fibers and axonal endings of the acoustic nerve in the ventral part of the cochlear nucleus indicated that these structures are also parvalbumin positive. It is concluded that the heterogenous cell composition of the cochlear nucleus is accompanied by a rather complex expression pattern of the cytoplasmic calcium binding proteins.

Voltage-gated and background K+ channel subunits expressed by the bushy cells of the rat cochlear nucleus.

Bushy cells of the ventral cochlear nucleus produce a single, short latency action potential at the beginning of long depolarisations. In the present work an immunochemical survey was performed to detect the presence of K+ channel subunits which may contribute to the specific membrane properties of the bushy cells. The immunocytochemical experiments conducted on enzymatically isolated bushy cells indicated positive immunolabelling for several subunits known to be responsible for the genesis of rapidly inactivating K+ currents. Bushy cells showed strong expression of Kv3.4, 4.2 and 4.3 subunits, with the lack of Kv1.4 specific immunoreaction. The Kv3.4-specific immunoreaction had a specific, patchy appearance. Bushy cells also expressed various members of the Kv1 subunit family, most notably Kv1.1, 1.2, 1.3 and 1.6. Weak positivity could be observed for Kv3.2 subunits. The positive immunolabelling for Kv3.4, Kv4.2 and Kv4.3 was confirmed in free-floating tissue slices. Voltage-clamp experiments performed on positively identified bushy cells in brain slices corroborated the presence and activity of Kv3.4 and Kv4.2/4.3 containing K+ channels. Bushy cell showed strong immunopositivity for TASK-1 channels too. The results presented in this work indicate that bushy cells possess several types of voltage-gated K+ channel subunits whose activity may contribute to the membrane properties and firing characteristics of these neurones.

Removal of Ca(2+) following depolarization-evoked cytoplasmic Ca(2+) transients in freshly dissociated pyramidal neurones of the rat dorsal cochlear nucleus.

Cytoplasmic [Ca(2+)] ([Ca(2+)](i)) was measured using Fura-2 in pyramidal neurones isolated from the rat dorsal cochlear nucleus (DCN). The kinetic properties of Ca(2+) removal following K(+) depolarization-induced Ca(2+) transients were characterized by fitting exponential functions to the decay phase. The removal after small transients (<82 nM peak [Ca(2+)](i)) had monophasic time course (time constant of 6.43 +/- 0.48 s). In the cases of higher Ca(2+) transients biphasic decay was found. The early time constant decreased (from 3.09 +/- 0.26 to 1.46 +/- 0.11 s) as the peak intracellular [Ca(2+)] increased. The value of the late time constant was 18.15 +/- 1.60 s at the smallest transients, and showed less dependence on [Ca(2+)](i). Blockers of Ca(2+) uptake into intracellular stores (thapsigargin and cyclopiazonic acid) decreased the amplitude of the Ca(2+) transients and slowed their decay. La(3+) (3 mM) applied extracellularly during the declining phase dramatically changed the time course of the Ca(2+) transients as a plateau developed and persisted until the La(3+) was present. When the other Ca(2+) removal mechanisms were available, reduction of the external [Na(+)] to inhibit the Na(+)/Ca(2+) exchange resulted in a moderate increase of the time constants. It is concluded that in the isolated pyramidal neurones of the DCN the removal of Ca(2+) depends mainly on the activity of Ca(2+) pump mechanisms.