Secretion,blood levels and cutaneous expression of TL1A in psoriasis patients

TL1A is a TNF‐like cytokine which has been shown to co‐stimulate TH1 and TH17 responses during chronic inflammation. The expression of this novel cytokine has been investigated in inflammatory disorders like rheumatoid arthritis and inflammatory bowel disease, but little is known about expression and induction in psoriasis. Indeed, the pathogenesis in psoriasis is still not fully understood and it is speculated that cytokines other than TNF‐α are important in subsets of patients. Also, for patients with severe disease that are treated with systemic anti‐TNF‐α blockade, novel candidates to be used as disease and response biomarkers are of high interest. Here, we demonstrate TL1A expression in biopsies from psoriatic lesions. Also, we investigated spontaneous and induced TL1A secretion from PBMCs and blood levels from a cohort of psoriasis patients. Here, increased spontaneous secretion from PBMCs was observed as compared to healthy controls and a small subset of patients had highly elevated TL1A in the blood. Interestingly, activation of PBMCs with various cytokines showed a decreased sensitivity for TL1A activation in psoriasis patients compared to healthy controls.TL1A levels in blood and biopsies could not be correlated with disease activity with this patient cohort. Thus, additional large‐scale studies are warranted to investigate TL1A as a biomarker.     

Parental death and bipolar disorder: a robust association was found in early maternal suicide

BACKGROUND: Previous studies have suggested that early parental death may be associated with the emergence of bipolar disorder in later life. However, it remains unknown whether this association applies specifically to parental death due to suicide or only to early parental death. The present study aimed to explore whether suicide as well as the non-suicidal death of father, mother, or siblings are associated with an increased risk for bipolar disorder, and whether the possible association is modified by the age at which the subject experiences such a death in the family. METHODS: The subjects were born in 1960 or later and were first admitted to or had first contact with Danish psychiatric facilities between 1981 and 1998 with a diagnosis of bipolar disorder, and fifty age-matched controls per case were extracted. The effects of the deaths of relatives were estimated by means of a conditional logistic regression analysis. RESULTS: Among 947 subjects with bipolar disorder and 47,350 controls, those having experienced the parental suicide were significantly associated with an increased risk for BPD (incidence rate ratios: 1.83 [95% confidence interval: 1.07 to 3.12] for paternal suicide, 3.44 [1.97 to 6.00] for maternal suicide), whereas the non-suicidal death of parents showed no such association. Those having experienced maternal suicide at some point before reaching 10 years of age were seven times as likely to develop bipolar disorder. LIMITATIONS: The cohort members were followed until, but not exceeding, the age of 38. CONCLUSION: Early parental, particularly maternal, suicide increases the risk for bipolar disorder in the offspring. Possible explanations include a family history of mental disorders as well as psychosocial factors.     

Acute effects of ghrelin administration on glucose and lipid metabolism

CONTEXT: Ghrelin infusion increases plasma glucose and nonesterified fatty acids, but it is uncertain whether this is secondary to the concomitant release of GH. OBJECTIVE: Our objective was to study direct effects of ghrelin on substrate metabolism. DESIGN: This was a randomized, single-blind, placebo-controlled two-period crossover study. SETTING: The study was performed in a university clinical research laboratory. PARTICIPANTS: Eight healthy men aged 27.2 +/- 0.9 yr with a body mass index of 23.4 +/- 0.5 kg/m(2) were included in the study. INTERVENTION: Subjects received infusion of ghrelin (5 pmol x kg(-1) x min(-1)) or placebo for 5 h together with a pancreatic clamp (somatostatin 330 microg x h(-1), insulin 0.1 mU x kg(-1) x min(-1), GH 2 ng x kg(-1) x min(-1), and glucagon 0.5 ng.kg(-1) x min(-1)). A hyperinsulinemic (0.6 mU x kg(-1) x min(-1)) euglycemic clamp was performed during the final 2 h of each infusion. RESULTS: Basal and insulin-stimulated glucose disposal decreased with ghrelin [basal: 1.9 +/- 0.1 (ghrelin) vs. 2.3 +/- 0.1 mg x kg(-1) x min(-1), P = 0.03; clamp: 3.9 +/- 0.6 (ghrelin) vs. 6.1 +/- 0.5 mg x kg(-1) x min(-1), P = 0.02], whereas endogenous glucose production was similar. Glucose infusion rate during the clamp was reduced by ghrelin [4.0 +/- 0.7 (ghrelin) vs. 6.9 +/- 0.9 mg.kg(-1) x min(-1); P = 0.007], whereas nonesterified fatty acid flux increased [131 +/- 26 (ghrelin) vs. 69 +/- 5 micromol/min; P = 0.048] in the basal period. Regional lipolysis (skeletal muscle, sc fat) increased insignificantly with ghrelin infusion. Energy expenditure during the clamp decreased after ghrelin infusion [1539 +/- 28 (ghrelin) vs. 1608 +/- 32 kcal/24 h; P = 0.048], but the respiratory quotient did not differ. Minor but significant elevations in serum levels of GH and cortisol were observed after ghrelin infusion. CONCLUSIONS: Administration of exogenous ghrelin causes insulin resistance in muscle and stimulates lipolysis; these effects are likely to be direct, although a small contribution of GH and cortisol cannot be excluded.     

From the Cover: Atomic resolution structure of human α-tubulin acetyltransferase bound to acetyl-CoA

Acetylation of lysine residues is an important posttranslational modification found in all domains of life. α-tubulin is specifically acetylated on lysine 40, a modification that serves to stabilize microtubules of axons and cilia. Whereas histone acetyltransferases have been extensively studied, there is no structural and mechanistic information available on α-tubulin acetyltransferases. Here, we present the structure of the human α-tubulin acetyltransferase catalytic domain bound to its cosubstrate acetyl-CoA at 1.05 Å resolution. Compared with other lysine acetyltransferases of known structure, α-tubulin acetyltransferase displays a relatively well-conserved cosubstrate binding pocket but is unique in its active site and putative α-tubulin binding site. Using acetylation assays with structure-guided mutants, we map residues important for acetyl-CoA binding, substrate binding, and catalysis. This analysis reveals a basic patch implicated in substrate binding and a conserved glutamine residue required for catalysis, demonstrating that the family of α-tubulin acetyltransferases uses a reaction mechanism different from other lysine acetyltransferases characterized to date.