Zoltán Griger

A Hot New Twist to Hair Biology: Involvement of Vanilloid Receptor-1 (VR1/TRPV1) Signaling in Human Hair Growth Control

The vanilloid receptor-1 (VR1, or transient receptor potential vanilloid-1 receptor, TRPV1) is activated by capsaicin, the key ingredient of hot peppers. TRPV1 was originally described on sensory neurons as a central integrator of various nociceptive stimuli. However, several human skin cell populations are also now recognized to express TRPV1, but with unknown function. Exploiting the human hair follicle (HF) as a prototypic epithelial-mesenchymal interaction system, we have characterized the HF expression of TRPV1 in situ and have examined TRPV1 signaling in organ-cultured human scalp HF and outer root sheath (ORS) keratinocytes in vitro. TRPV1 immunoreactivity was confined to distinct epithelial compartments of the human HF, mainly to the ORS and hair matrix. In organ culture, TRPV1 activation by capsaicin resulted in a dose-dependent and TRPV1-specific inhibition of hair shaft elongation, suppression of proliferation, induction of apoptosis, premature HF regression (catagen), and up-regulation of intrafollicular transforming growth factor-beta(2). Cultured human ORS keratinocytes also expressed functional TRPV1, whose stimulation inhibited proliferation, induced apoptosis, elevated intracellular calcium concentration, up-regulated known endogenous hair growth inhibitors (interleukin-1beta, transforming growth factor-beta(2)), and down-regulated known hair growth promoters (hepatocyte growth factor, insulin-like growth factor-I, stem cell factor). These findings strongly support TRPV1 as a significant novel player in human hair growth control, underscore the physiological importance of TRPV1 in human skin beyond nociception, and identify TRPV1 as a promising, novel target for pharmacological manipulations of epithelial growth disorders.

Increased microRNA-146a/b, TRAF6 gene and decreased IRAK1 gene expressions in the peripheral mononuclear cells of patients with Sjögren's syndrome.

MicroRNA-146a (miR-146a) is a microRNA supposed to regulate innate immune, inflammatory response and antiviral pathway negatively. Recently, its potential use as a biomarker for disease diagnosis, prevention and treatment has become widely investigated. In the current study, we measured the expression of miR-146a/b, and their target genes, IRAK1, IRAK4, TRAF6 in the peripheral mononuclear cells of patients with Sjögrens syndrome (n=21) and healthy controls (n=10) by quantitative reverse transcription polymerase chain reaction. We found that both miR-146a and miR-146b, furthermore, the gene of TRAF6 were significantly overexpressed in the Sjögrens patients, whereas the expression of IRAK1 gene was significantly decreased. The expression of IRAK4 did not differ significantly. These results suggest that in the peripheral mononuclear cells of Sjögrens patients, the transcriptional repression of IRAK1 is taking place, whereas the other NF-κB pathway regulating gene, TRAF6 is overexpressed. As IRAK1 has been regarded a crucial gene in the pathogenesis of systemic lupus erythematosus, TRAF6 can be a Sjögrens syndrome specific biomarker, confirming and partly explaining the existance of different pathogenic pathways in the two diseases. These observations, however, need still wider confirmations.

Transient Receptor Potential Vanilloid-1 Signaling as a Regulator of Human Sebocyte Biology

Transient receptor potential vanilloid-1 (TRPV1), originally described as a central integrator of nociception, is expressed on human epidermal and hair follicle keratinocytes and is involved in regulation of cell growth and death. In human pilosebaceous units, we had shown that TRPV1 stimulation inhibits hair shaft elongation and matrix keratinocyte proliferation, and induces premature hair follicle regression and keratinocyte apoptosis. In the current study, we have explored the role of TRPV1-mediated signaling in sebaceous gland (SG) biology, using a human sebocyte cell culture model (SZ95 sebocytes). Demonstrating that human skin SG in situ and SZ95 sebocytes in vitro express TRPV1, we show that the prototypic TRPV1 agonist, capsaicin, selectively inhibits basal and arachidonic acid-induced lipid synthesis in a dose-, time-, and extracellular calcium-dependent and a TRPV1-specific manner. Low-dose capsaicin stimulates cellular proliferation via TRPV1, whereas higher concentrations inhibit sebocyte growth and induce cell death independent of TRPV1. Moreover, capsaicin suppresses the expression of genes involved in lipid homeostasis and of selected proinflammatory cytokines. Collectively, these findings support the concept that TRPV1 signaling is a significant, previously unreported player in human sebocyte biology and identify TRPV1 as a promising target in the clinical management of inflammatory SG disorders (for example, acne vulgaris).

Four dermatomyositis-specific autoantibodies—anti-TIF1γ, anti-NXP2, anti-SAE and anti-MDA5—in adult and juvenile patients with idiopathic inflammatory myopathies in a Hungarian cohort

Idiopathic inflammatory myopathies (IIMs) are chronic systemic autoimmune diseases characterised by symmetrical, proximal muscle weakness. Dermatomyositis represents one subset of IIMs, in which skin rashes are present in addition to muscle weakness. Myositis-specific antibodies can only be detected in myositis, and they are directed against specific proteins found in the cytoplasm or in the nucleus of cells. With this case-based article, we introduce the recently detected anti-TIF1γ, anti-NXP2, anti-SAE and anti-MDA5 antibodies that form various clinical groups. These antibodies could be detected in patients with dermatomyositis. The myositis-specific autoantibodies of three hundred and thirty-seven Hungarian patients with IIM were detected. Retrospective analysis of the clinical findings has also been introduced by revision of the medical history. We had twelve patients with anti-TIF1γ positivity, four patients with anti-NXP2 positivity and four patients with anti-SAE positivity. We did not have any positive anti-MDA5 patients. The most relevant clinical findings were similar to those seen in previously published reports. Eleven of the twelve patients with anti-TIF1γ positivity had classical dermatomyositis. Three of the twelve anti-TIF1γ patients had cancer during the disease progression. This was two out of four for the anti-NXP2 subgroup and one in four for the anti-SAE subgroup. In two juvenile dermatomyositis cases, typical ulceration was seen in patients with anti-TIF1γ positivity. The frequency of pulmonary fibrosis during the disease progression was 2/12, 1/4 and 1/4 in anti-TIF1γ, anti-NXP2 and anti-SAE, respectively. Other extra-muscular manifestations, such as arthralgia, dysphagia, dysphonia and dyspnoea, were also detectable. The myositis subgroups determined by these myositis-specific autoantibodies differ from each other in their symptoms, prognosis and therapy responsiveness. Their detection is helpful for the preparation of an adequate treatment, but in daily diagnostic methods, these antibodies cannot be detected. By presenting our anti-TIF1γ, anti-NXP2 and anti-SAE cases, we would like to highlight the clinical role of these antibodies.

C1-inhibitor autoantibodies in SLE

The presence of anti-C1-inhibitor (anti-C1-INH) autoantibodies is a hallmark of acquired C1-inhibitor deficiency. However, only scarce data are available on their prevalence, diagnostic value, and/or significance in systemic lupus erythematosus (SLE). In a multicentre study, we determined the levels of autoantibodies to C1-inhibitor in sera from 202 patients with SLE and 134 healthy controls. Additional clinical and laboratory parameters, such as organ involvement, as well as anti-C1q, anti-double-stranded DNA antibody, erythrocyte sedimentation rate, C-reactive protein, C3 and C4 serum complement levels have been studied in patients. The level of anti-C1-INH IgG was significantly higher (p = 0.034) in SLE patients, than in the controls. A high anti-C1-INH level of ≥0.4 U/ml (mean of controls + 2 SD) was found in 17% of the patients, but in only 4% of the controls (p = 0.0003). The SLEDAI score was significantly higher (p = 0.048) and the duration of SLE was significantly longer (p = 0.0004) among patients with elevated anti-C1-INH levels compared with patients without this autoantibody (median disease duration 8 vs. 17 years, respectively). Anti-C1-INH level was not correlated with any other laboratory parameter or organ manifestation of the disease. These findings indicate that the anti-C1-INH level is higher in SLE patients than in healthy controls and furthermore, the anti-C1-INH level correlates with the duration and activity of the disease. Lupus (2010) 19, 634—638.

Protein kinase C-β and -δ isoenzymes promote arachidonic acid production and proliferation of MonoMac-6 cells

In this study, we investigated the putative roles of certain protein kinase C (PKC) isoenzymes in the regulation of proliferation and arachidonic acid (AA) release in the human monocytoid MonoMac-6 cell line. Experiments employing specific PKC inhibitors and molecular biological methods (RNA-interference, recombinant overexpression) revealed that the two dominantly expressed isozymes, i.e., the “conventional” cPKCβ and the “novel” nPKCδ, promote AA production and cellular proliferation. In addition, using different phospholipase A2 (PLA2) inhibitors, we were able to show that the calcium-independent iPLA2 as well as diacylglycerol lipase (but not the cytosolic PLA2) function as “downstream” targets of cPKCβ and nPKCδ. In addition, we have also found that, among the other existing PKC isoforms, cPKCα plays a minor inhibitory role, whereas nPKCɛ and aPKCζ apparently do not regulate these cellular processes. In conclusion, in this paper we provide the first evidence that certain PKC isoforms play pivotal, specific, and (at least partly) antagonistic roles in the regulation of AA production and cellular proliferation of human monocytoid MonoMac-6 cells.

Abnormal Cell-Specific Expressions of Certain Protein Kinase C Isoenzymes in Peripheral Mononuclear Cells of Patients with Systemic Lupus Erythematosus: Effect of Corticosteroid Application

We have studied the expressions of various protein kinase C (PKC) isoenzymes in T cells and monocytes from patients with systemic lupus erythematosus (SLE), in comparison to those of healthy controls and patients with other immunological disorders. As measured by Western blotting, the levels of PKCβ, δ, η, ε, θ and ζ (but not of PKCα) significantly decreased in T cells of SLE patients. In monocytes, however, we observed marked suppressions only in the expressions of PKCδ, ε and ζ but not in the expressions of other PKC isoforms. In vivo corticosteroid application, as well as in vitro steroid treatment of monocytes, elevated the expressions of most isoforms close to normal values; however, the decreased levels of PKCθ and ζ were not affected by steroid application. These alterations were characteristic to SLE because we could not detect any changes in the PKC levels in mononuclear cells of primary Sjögrens syndrome and mixed connective tissue disease patients. These results suggest that impaired PKC isoenzyme pattern may exist in the T cells and monocytes of SLE patients. Furthermore, the clinically efficient glucocorticoid application in SLE can increase the expression of some members of PKC system.

Description of patients with IgG4-related disease from a Hungarian centre

Objectives: Although most reported patients with immunoglobulin G4-related disease (IgG4-RD) are from the Far East, we aimed to identify patients suffering from IgG4-RD in our University Centre in Debrecen, Hungary. Method: Serum IgG4 levels were measured at 51 of our 800 patients followed up because of Sjögren’s syndrome (SS) if one or more clinical signs during the disease course raised the possibility of IgG4-RD (persisting salivary gland swelling, absence of anti-Ro/SSA and anti-La/SSB antibodies in the serum, and positive salivary gland biopsy, coexistence of autoimmune pancreatitis, autoimmune hepatitis, or primary sclerosing cholangitis, persisting lymphadenopathy). Where available, histological samples of small salivary gland biopsies were revised to detect the particular features of IgG4-RD. Pathologists and surgeons were informed about the disease and asked to refer suspicious cases. Results: Based on our survey, eight patients were identified with IgG4-RD. Pancreatic, salivary gland, aortic, and retroperitoneal manifestations were detected. Of the 51 patients with SS, four appeared to have IgG4-RD, but eventually one was excluded. Conclusions: Although IgG4-RD is not yet well known to physicians of Western countries, it occurs in Caucasians and probably in other races as well. Moreover, our eight cases diagnosed with IgG4-RD demonstrate a relatively large European patient population collected in a single centre. European clinicians, and especially rheumatologists, should be informed and at least certain laboratories should be prepared to investigate patient samples if the suspicion of IgG4-RD is raised. The main clinical significance of an accurate diagnosis is the extreme corticosteroid sensitivity of IgG4-RD.

[Anti-NXP2-positive dermatomyositis associated with ulcerative colitis and celiac disease].

The authors discuss a rare case of a 25-year-old female patient having dermatomyositis associated with celiac disease and ulcerative colitis. The idiopathic inflammatory myopathies are systemic, chronic, immune-mediated diseases characterized by proximal, symmetrical muscle weakness. Many examples from the literature refer that celiac disease occurs more often in patients with myositis than in the general population, but its association with ulcerative colitis is a real rarity in the international literature.A szerzők az idiopathias inflammatorikus myopathia ritka, colitis ulcerosaval es coeliakiaval tarsult esetet mutatjak be egy altaluk kezelt, 25 eves dermatomyositises nőbeteg kortorteneten keresztul. Az idiopathias inflammatorikus myopathiak szisztemas, kronikus, immunmedialt megbetegedesek, amelyeket a proximalis vegtagizmok szimmetrikus gyengesege jellemez. Irodalmi peldak utalnak ra, hogy a coeliakia gyakrabban jelentkezik myositisben, mint az atlagpopulacioban. Colitis ulcerosaval valo asszociacioja azonban irodalmi ritkasagnak szamit. Orv. Hetil., 2014, 155(26), 1033–1038.

Different Effects of Bortezomib on the Expressions of Various Protein Kinase C Isoenzymes in T Cells of Patients with Systemic Lupus Erythematosus and in Jurkat Cells

The effects of proteosome inhibitor Bortezomib (BZ) were studied in vitro for 24 h on the protein kinase C (PKC) profiles, rates of proliferation and apoptosis in Jurkat cells and lymphocytes of 10 patients with systemic lupus erythematosus (SLE) and nine healthy subjects. The expressions of PKC proteins, the rates of proliferation and apoptosis were determined. The effects of BZ were different in the Jurkat and lupus T cells. Whereas BZ elevated the expression of PKC θ, δ and ξ isoenzymes in the Jurkat cells, it was unable to do that in the lupus T cells. BZ induced a dose‐dependent increase in the apoptosis of Jurkat cells, while decreased the proliferation. The same effect of BZ was observed on the apoptosis of lymphocytes both in SLE and healthy subjects at concentrations higher than the therapeutic dose. We conclude that BZ treatment in vitro was not able to restore the SLE‐specific defect (decrease) in the expression of PKC isoenzymes in the T cells as it was expected. This can be a limiting factor in the positive clinical effects of BZ in lupus.