PPARγ agonist-induced fluid retention depends on αENaC expression in connecting tubules

BACKGROUND/AIMS

Thiazolidinediones (TZDs, like rosiglitazone (RGZ)) are peroxisome proliferator-activated receptor γ (PPARγ) agonists used to treat type 2 diabetes. Clinical limitations include TZD-induced fluid retention and body weight (BW) increase, which are inhibited by amiloride, an epithelial-sodium channel (ENaC) blocker. RGZ-induced fluid retention is maintained in mice with αENaC knockdown in the collecting duct (CD). Since ENaC in the connecting tubule (CNT) rather than in CD appears to be critical for normal NaCl retention, we aimed to further explore the role of ENaC in CNT in RGZ-induced fluid retention.

METHODS

Mice with conditional inactivation of αENaC in both CNT and CD were used (αENaC lox/lox AQP2-Cre; 'αENaC-CNT/CD-KO') and compared with littermate controls (αENaC lox/lox mice; 'WT'). BW was monitored and total body water (TBW) and extracellular fluid volume (ECF) were determined by bioelectrical impedance spectroscopy (BIS) before and after RGZ (320 mg/kg diet for 10 days).

RESULTS

On regular NaCl diet, αENaC-CNT/CD-KO had normal BW, TBW, ECF, hematocrit, and plasma Na(+), K(+), and creatinine, associated with an increase in plasma aldosterone compared with WT. Challenging αENaC-CNT/CD-KO with a low NaCl diet unmasked impaired NaCl and K homeostasis, consistent with effective knockdown of αENaC. In WT, RGZ increased BW (+6.1%), TBW (+8.4%) and ECF (+10%), consistent with fluid retention. These changes were significantly attenuated in αENaC-CNT/CD-KO (+3.4, 1.3, and 4.3%).

CONCLUSION

Together with the previous studies, the current results are consistent with a role of αENaC in CNT in RGZ-induced fluid retention, which dovetails with the physiological relevance of ENaC in this segment.

Anti-inflammatory activity of grains of paradise (Aframomum melegueta Schum) extract

The ethanolic extract of grains of paradise (Aframomum melegueta Schum, Zingiberaceae) has been evaluated for inhibitory activity on cyclooxygenase-2 (COX-2) enzyme, in vivo for the anti-inflammatory activity and expression of several pro-inflammatory genes. Bioactivity-guided fractionation showed that the most active COX-2 inhibitory compound in the extract was [6]-paradol. [6]-Shogaol, another compound from the extract, was the most active inhibitory compound in pro-inflammatory gene expression assays. In a rat paw edema model, the whole extract reduced inflammation by 49% at 1000 mg/kg. Major gingerols from the extract [6]-paradol, [6]-gingerol, and [6]-shogaol reduced inflammation by 20, 25 and 38%. respectively when administered individually at a dose of 150 mg/kg. [6]-Shogaol efficacy was at the level of aspirin, used as a positive control. Grains of paradise extract has demonstrated an anti-inflammatory activity, which is in part due to the inhibition of COX-2 enzyme activity and expression of pro-inflammatory genes.

Analgesic and anti-inflammatory bioactivities of eburicoic acid and dehydroeburicoic acid isolated from Antrodia camphorata on the inflammatory mediator expression in mice

Eburicoic acid (TR1) and dehydroeburicoic acid (TR2), an active ingredient from Antrodia camphorata (AC) solid-state culture, were evaluated for analgesic and anti-inflammatory effects. Treatment with TR1 and TR2 significantly inhibited a number of acetic acid-induced writhing responses and formalin-induced pain in the late phase. In the anti-inflammatory test, TR1 and TR2 decreased paw edema at the fourth and fifth hour after λ-carrageenan (Carr) administration and increased the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the paw edema tissue. We also demonstrated that TR1 and TR2 significantly attenuated the malondialdehyde (MDA), nitric oxide (NO), tumor necrosis factor (TNF-α), and interleukin-1β (IL-1β) levels in either edema paw or serum at the fifth hour after Carr injection. Western blotting revealed that TR1 and TR2 decreased Carr-induced inducible nitric oxide synthase (iNOS) and cycloxyclase (COX-2) expressions at the fifth hour in paw edema. Treatment with TR1 and TR2 also diminished neutrophil infiltration into the paw edema at the fifth hour. The present study suggests that the anti-inflammatory mechanisms of TR1 and TR2 might be related to the decrease of inflammatory cytokines and an increase of antioxidant enzyme activity.

Role of tachykinin 1 and 4 gene-derived neuropeptides and the neurokinin 1 receptor in adjuvant-induced chronic arthritis of the mouse

Objective

Substance P, encoded by the Tac1 gene, is involved in neurogenic inflammation and hyperalgesia via neurokinin 1 (NK1) receptor activation. Its non-neuronal counterpart, hemokinin-1, which is derived from the Tac4 gene, is also a potent NK1 agonist. Although hemokinin-1 has been described as a tachykinin of distinct origin and function compared to SP, its role in inflammatory and pain processes has not yet been elucidated in such detail. In this study, we analysed the involvement of tachykinins derived from the Tac1 and Tac4 genes, as well as the NK1 receptor in chronic arthritis of the mouse.

Methods

Complete Freund’s Adjuvant was injected intraplantarly and into the tail of Tac1^−/−, Tac4^−/−, Tacr1^−/− (NK1 receptor deficient) and Tac1^−/−/Tac4^−/− mice. Paw volume was measured by plethysmometry and mechanosensitivity using dynamic plantar aesthesiometry over a time period of 21 days. Semiquantitative histopathological scoring and ELISA measurement of IL-1β concentrations of the tibiotarsal joints were performed.

Results

Mechanical hyperalgesia was significantly reduced from day 11 in Tac4^−/− and Tacr1^−/− animals, while paw swelling was not altered in any strain. Inflammatory histopathological alterations (synovial swelling, leukocyte infiltration, cartilage destruction, bone damage) and IL-1β concentration in the joint homogenates were significantly smaller in Tac4^−/− and Tac1^−/−/Tac4^−/− mice.

Conclusions

Hemokinin-1, but not substance P increases inflammation and hyperalgesia in the late phase of adjuvant-induced arthritis. While NK1 receptors mediate its antihyperalgesic actions, the involvement of another receptor in histopathological changes and IL-1β production is suggested.

Anti-inflammatory properties of yellow and orange pigments from Monascus purpureus NTU 568

The Monascus species has been used in foods for thousands of years in China. In this study, 10 azaphilone pigments, including four yellow and six orange pigments, were isolated from the fermented rice and dioscorea of Monascus purpureus NTU 568. By employing lipopolysaccharide (LPS)-stimulated murine macrophage RAW 264.7 cells, we determined the inhibitory activities of these pigments on nitric oxide (NO) production. As a result, four orange pigments, monaphilols A-D, showed the highest activities (IC50 = 1.0-3.8 μM), compared with the other two orange pigments, monascorubrin (IC50 > 40 μM) and rubropunctatin (IC50 = 21.2 μM), and the four yellow pigments ankaflavin (IC50 = 21.8 μM), monascin (IC50 = 29.1 μM), monaphilone A (IC50 = 19.3 μM), and monaphilone B (IC50 = 22.6 μM). Using Western blot and ELISA kits, we found that treatments with 30 μM of the yellow pigments and 5 μM of the orange pigments could down-regulate the protein expression of inducible nitric oxide synthase (iNOS) and suppress the production of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). We also used two animal experiments to evaluate the anti-inflammatory effects of these pigments. In a 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear edema model, eight of these pigments (0.5 mg/ear) could prevent ear edema against TPA administrations on the ears of BALB/c mice. In an LPS-injection mice model, several of these pigments (10 mg/kg) could inhibit the NO, TNF-α, IL-1β, and IL-6 levels in the plasma of BALB/c mice. As concluded from the in vitro and in vivo studies, six azaphilonoid pigments, namely, ankaflavin, monaphilone A, and monaphilols A-D, showed high potential to be developed into chemopreventive foods or drugs against inflammation-associated diseases.

Cytotoxic necrotizing factor 1 and hemolysin from uropathogenic Escherichia coli elicit different host responses in the murine bladder

Cytotoxic necrotizing factor 1 (CNF1) and hemolysin (HlyA1) are toxins produced by uropathogenic Escherichia coli (UPEC). We previously showed that these toxins contribute to the inflammation and tissue damage seen in a mouse model of ascending urinary tract infection. CNF1 constitutively activates small Rho GTPases by deamidation of a conserved glutamine residue, and HlyA1 forms pores in eukaryotic cell membranes. In this study, we used cDNA microarrays of bladder tissue isolated from mice infected intraurethrally with wild-type CP9, CP9cnf1, or CP9ΔhlyA to further evaluate the role that each toxin plays in the host response to UPEC. Regardless of the strain used, we found that UPEC itself elicited a significant change in host gene expression 24 h after inoculation. The largest numbers of upregulated genes were in the cytokine and chemokine signaling and Toll-like receptor signaling pathways. CNF1 exerted a strong positive influence on expression of genes involved in innate immunity and signal transduction and a negative impact on metabolism- and transport-associated genes. HlyA1 evoked an increase in expression of genes that encode innate immunity factors and a decrease in expression of genes involved in cytoskeletal and metabolic processes. Multiplex cytokine and myeloperoxidase assays corroborated our finding that a strong proinflammatory response was elicited by all strains tested. Bladders challenged intraurethrally with purified CNF1 displayed pathology similar to but significantly less intense than the pathology that we observed in CP9-challenged mice. Our data demonstrate substantial roles for CNF1 and HlyA1 in initiation of a strong proinflammatory response to UPEC in the bladder.

Decreased Krev interaction-trapped 1 expression leads to increased vascular permeability and modifies inflammatory responses in vivo

OBJECTIVE

The regulation of vascular permeability, leukocyte trafficking, and the integrity of endothelial cell-cell contacts are closely linked by a complex mechanism of interregulation. Here, we investigate the role of Krev interaction-trapped 1 (KRIT1), an adherens junction accessory protein required for cell-cell junction stability, in regulating these vascular functions.

METHODS AND RESULTS

Krit1(+/-) mice exhibited an enhanced edematous response to the complex inflammatory stimuli found in the passive K/BxN model of inflammatory arthritis and the murine air pouch model, yet leukocyte infiltration was unchanged. Correspondingly, reduced KRIT1 expression increased baseline arteriole and venule permeability 2-fold over that of wild-type littermates, as measured by intravital microscopy of the intact cremaster muscle vascular network, but this increase was not accompanied by increased leukocyte extravasation or activation. Direct stimulation with tumor necrosis factor-α induced increased permeability in wild-type mice, but surprisingly no increase over baseline levels was observed in Krit1(+/-) mice, despite extensive leukocyte activation. Finally, adoptive transfer of Krit1(+/-) bone marrow failed to increase permeability in wild-type mice. However, reduced expression of KRIT1 in the hematopoietic lineage dampened the differences observed in baseline permeability.

CONCLUSIONS

Taken together, our data indicate an integral role for KRIT1 in microvessel homeostasis and the vascular response to inflammation.

Over-expression of DSCR1 protects against post-ischemic neuronal injury

Background and Purpose

The Down syndrome candidate region 1 (DSCR1) gene is located on human chromosome 21 and its protein is over-expressed in brains of Down syndrome individuals. DSCR1 can modulate the activity of calcineurin, a phosphatase abundant in the brain, but its influence on stroke outcome is not clear. We compared stroke outcome in wildtype (WT) and transgenic (DSCR1-TG) mice which over-express isoform 1 of human DSCR1.

Methods

Transient cerebral ischemia was produced by occlusion of the middle cerebral artery for 0.5 h. After 23.5 h reperfusion, we assessed neurological impairment, brain infarct and edema volume, leukocyte infiltration and markers of inflammation. Intrinsic resistance to apoptosis following glucose deprivation was also assessed in primary cultures of WT and DSCR1-TG neurons.

Results

In contrast to WT, DSCR1-TG mice had an improved neurological deficit score, greater grip strength, attenuated infarct volume and brain swelling, and lacked hippocampal lesions after stroke. Expression of mouse DSCR1-1, but not DSCR1-4, mRNA and protein was increased by ischemia in both WT and DSCR1-TG. Brain calcineurin activity was increased to a similar degree after ischemia in each genotype. DSCR1-TG mice had fewer infiltrating neutrophils and activated microglia compared with WT, in association with an attenuated upregulation of several pro-inflammatory genes. Neurons from DSCR1-TG mice were more resistant than WT neurons to apoptotic cell death following 24 h of glucose deprivation.

Conclusions

Over-expression of DSCR1 in mice improves outcome following stroke. Mechanisms underlying this protection may involve calcineurin-independent, anti-inflammatory and anti-apoptotic effects mediated by DSCR1 in neurons.

Insertional mutation in the Golgb1 gene is associated with osteochondrodysplasia and systemic edema in the OCD rat

Homozygous rats (ocd/ocd) of a mutant inbred strain, OCD (osteochondrodysplasia), show osteochondrodysplasia, systemic edema, cleft palate, protruding tongue, disproportionate dwarfism, and lethality immediately after birth. Their epiphyses show decreased levels of glycosaminoglycans and weak staining for extracellular matrix proteins. The epiphyseal chondrocytes have large vesicles and expanded endoplasmic reticulum and Golgi apparatus. These phenotypic features are inherited in an autosomal recessive manner, and the ocd locus responsible for these phenotypes has been mapped close to D11Mgh3 on rat chromosome 11. In the present study, we characterized the embryonic pathogenesis of ocd/ocd rats and identified the mutant gene. Subcutaneous edema in the dorsal portion was found at embryonic day (E) 16.5, and the other anomalies described above were apparent after E18.5 in ocd/ocd. Whole mount immunohistochemistry for Sox9 revealed that mesenchymal condensation was delayed in limb bud in ocd/ocd, and skeletal preparation showed that the progression of whole-body chondrogenesis was delayed in ocd/ocd. Histological and immunohistological analyses of the femur showed that cell proliferations of resting and proliferative zones of growth plate were significantly reduced in ocd/ocd embryos. Fine linkage mapping localized the ocd locus within 84kb of positions 65,584-65,668kb containing a part of Golgb1 gene on chromosome 11. Expression of Golgb1 mRNA was found in limb buds, somite derivatives and calvaria. Sequence analysis identified a 10-bp insertion in exon 13 of the Golgb1 gene in ocd/ocd rats. The Golgb1 gene encodes the COPI vesicle tethering factor, giantin. This insertion mutation causes a frame shift, and introduces a premature termination codon at codon 1082, leading to truncation of the C-terminal two thirds of giantin. By in-gel Western analysis using anti-giantin antibody that recognizes an epitope within 200 aa of the C-terminus, the expression of giantin was not detected in ocd/ocd embryos. As the C-terminal region of giantin is required for localization to the Golgi apparatus, these results strongly suggested that giantin is functionally defective in ocd/ocd rats. Therefore, we concluded that mutation of the Golgb1 gene is responsible for the phenotypic characteristics including osteochondrodysplasia of ocd/ocd, and that giantin plays a pivotal role in multiple aspects of chondrogenesis.

Comparison on the anti-inflammatory effect of Cortex Phellodendri Chinensis and Cortex Phellodendri Amurensis in 12-O-tetradecanoyl-phorbol-13-acetate-induced ear edema in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Cortex Phellodendri is derived from the dried bark of Phellodendron chinense Schneid. or Phellodendron amurense Rupr. Traditionally, Cortex Phellodendron Chinensis (CPC) and Cortex Phellodendron Amurensis (CPA) are used interchangeably under the name "Huang Bai" for the treatment of gastroenteritis, abdominal pain or diarrhea. The present study aims to compare the anti-inflammatory effect of ethanol extracts of Cortex Phellodendri Chinensis (ECPC) and Cortex Phellodendri Amurensis (ECPA) in a mouse model of inflammation induced by 12-O-tetradecanoylphorbol-acetate (TPA).

MATERIALS AND METHODS

The anti-inflammatory effect was evaluated by measuring the ear thickness, activity of myeloperoxidase (MPO) and the production reactive oxygen species (ROS). The anti-inflammatory mechanism was explored by determining the protein and mRNA levels of cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6.

RESULTS

The results showed that both ECPC and ECPA significantly decreased the ear thickness, MPO activity and the ROS level in mouse model of inflammation induced by TPA. In addition, ECPC and ECPA also remarkably inhibited the protein and mRNA levels of TNF-α, IL-1β, IL-6 and COX-2. Interestingly, ECPC has better anti-inflammatory effect than that of ECPA.

CONCLUSIONS

These results indicate that both ECPC and ECPA have potential anti-inflammatory effect on TPA-induced inflammatory in mice, and ECPC is more effective than ECPA. The anti-inflammatory effect of the herbal drugs may be mediated, at least in part, by down-regulating the mRNA expression of a panel of inflammatory mediators including TNF-α, IL-1β, IL-6 and COX-2.

Radiogenomic mapping of edema/cellular invasion MRI-phenotypes in glioblastoma multiforme

Background

Despite recent discoveries of new molecular targets and pathways, the search for an effective therapy for Glioblastoma Multiforme (GBM) continues. A newly emerged field, radiogenomics, links gene expression profiles with MRI phenotypes. MRI-FLAIR is a noninvasive diagnostic modality and was previously found to correlate with cellular invasion in GBM. Thus, our radiogenomic screen has the potential to reveal novel molecular determinants of invasion. Here, we present the first comprehensive radiogenomic analysis using quantitative MRI volumetrics and large-scale gene- and microRNA expression profiling in GBM.

Methods

Based on The Cancer Genome Atlas (TCGA), discovery and validation sets with gene, microRNA, and quantitative MR-imaging data were created. Top concordant genes and microRNAs correlated with high FLAIR volumes from both sets were further characterized by Kaplan Meier survival statistics, microRNA-gene correlation analyses, and GBM molecular subtype-specific distribution.

Results

The top upregulated gene in both the discovery (4 fold) and validation (11 fold) sets was PERIOSTIN (POSTN). The top downregulated microRNA in both sets was miR-219, which is predicted to bind to POSTN. Kaplan Meier analysis demonstrated that above median expression of POSTN resulted in significantly decreased survival and shorter time to disease progression (P<0.001). High POSTN and low miR-219 expression were significantly associated with the mesenchymal GBM subtype (P<0.0001).

Conclusion

Here, we propose a novel diagnostic method to screen for molecular cancer subtypes and genomic correlates of cellular invasion. Our findings also have potential therapeutic significance since successful molecular inhibition of invasion will improve therapy and patient survival in GBM.

A preliminary examination of the effects of genetic variants of redox enzymes on susceptibility to oedematous malnutrition and on percentage cytotoxicity in response to oxidative stress in vitro

BACKGROUND

The causes of oedematous vs non-oedematous childhood malnutrition (OM vs NOM) remain elusive. It is possible that inherited differences in handling oxidant stressors are a contributing factor.

AIMS

To test for associations between polymorphisms in five genes and (i) risk of OM, a case-control study, and (ii) percentage cytotoxicity in peripheral blood mononuclear cells (PBMCs) exposed to hydrogen peroxide (H(2)O(2)), an in vitro cell challenge study.

METHODS

Participants had been admitted previously for treatment of OM (cases, n = 74) or NOM (controls, n = 50), or were an independent set of healthy pregnant women (n = 47) who donated peripheral blood mononuclear cells. We tested for associations between genetic variation and outcome using single markers or a bivariate score constructed by counting numbers of deleterious alleles for each of 15 possible pairs of markers.

RESULTS

In the case-control study there were no significant single-marker associations with OM. We did find that higher bivariate scores were associated with OM for the pair of NAD(P)H:quinone oxidoreductase 1 and catalase (odds ratio 2·00, 95% CI 1·05-3·82). In the cell challenge experiments, there were no significant associations with percentage cytotoxicity.

CONCLUSIONS

Variation in this small set of genes seems unlikely to have a large impact on either risk of OM or cytotoxicity after H(2)O(2) exposure. The use of larger sample sizes to test the effects of a much larger set of genetic variants will be required in order to determine whether genetic variation contributes to the risk of OM. Such studies have potential for improving our understanding of causal pathways in OM.

[Congenital nephrotic syndrome of the Finnish type--key to the mechanisms of proteinuria]

Congenital nephrotic syndrome of the Finnish type is a serious renal disease belonging to the Finnish disease heritage. It appears as substantial proteinuria, hypoproteinemia and edema in a newborn. Kidney transplantation is the only effective treatment. The cause of the disease is a mutation in the gene encoding the nephrin protein. Nephrin is produced by the epithelial cell (podocyte) of the glomerulus. It is expressed in the slit membrane connecting the pedicles of the podocyte. This finding has revolutionized the concept of glomerular filtration and set off active research on the pathogenetic mechanisms of proteinuria.

The relationship between peroxisome proliferator-activated receptor-gamma and renin: a human genetics study

CONTEXT

Peroxisome proliferator-activated receptor gamma (PPARgamma) agonists often cause volume retention and edema. A relationship between PPARgamma and renin may play a role in this process.

OBJECTIVE

The aim was to examine the relationship between the PPARgamma gene and plasma renin activity (PRA) levels in human hypertension.

DESIGN, PARTICIPANTS, AND MEASURES

A candidate gene association study was conducted with two distinct groups of human participants: Caucasian hypertensives (n = 395) and African-American hypertensives (n = 55). Single nucleotide polymorphisms of the PPAR(Upsilon) gene were analyzed. Phenotype studies were conducted after participants consumed a low-salt diet (10 mmol/d) for 7 d and included PRA and aldosterone measurements before and after a 60-min angiotensin II infusion (3 ng/kg x min).

RESULTS

Participants homozygous for the minor allele of rs2959272 (CC) had significantly higher PRA levels at baseline (P = 0.016) than major allele carriers (AA, AC) in Caucasian-hypertensive participants. The association of the C allele carrier status with increased PRA levels was replicated in the group of African-American hypertensive participants (P = 0.027). The Fisher's combined P value for both observations was significant (P = 0.002).

CONCLUSIONS

These results demonstrate the first known association between a PPARgamma single nucleotide polymorphism and alterations in PRA levels in humans with hypertension. This link between PPARgamma and renin raises the possibility of a genetically based mechanism for the increased volume retention and edema in some users of PPARgamma agonists.

Analgesic effects and the mechanisms of anti-inflammation of ergostatrien-3beta-ol from Antrodia camphorata submerged whole broth in mice

Ergostatrien-3beta-ol (ST1), an active and major ingredient from Antrodia camphorata (AC) submerged whole broth was evaluated for the analgesic and anti-inflammatory effects. Treatment of male imprinting control region (ICR) mice with ST1 (1, 5, and 10 mg/kg) significantly inhibited the numbers of acetic-acid-induced writhing response in 10 min. Also, our result showed that ST1 (10 mg/kg) significantly inhibited the formalin-induced pain in the late phase (p < 0.001). In the anti-inflammatory test, ST1 (10 mg/kg) decreased the paw edema at 4 and 5 h after lambda-carrageenin (Carr) administration and increased the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the liver tissue. We also demonstrated that ST1 significantly attenuated the malondialdehyde (MDA) level in the edema paw at 5 h after Carr injection. ST1 (1, 5, and 10 mg/kg) decreased the nitric oxide (NO) levels on both the edema paw and serum level at 5 h after Carr injection. Also, ST1 (5 and 10 mg/kg) diminished the serum tumor necrosis factor (TNF-alpha) at 5 h after Carr injection. Western blotting revealed that ST1 (10 mg/kg) decreased Carr-induced inducible nitric oxide synthase (iNOS), and cycloxyclase (COX-2) expressions at 5 h in the edema paw. An intraperitoneal (ip) injection treatment with ST1 also diminished neutrophil infiltration into sites of inflammation, as did indomethacin (Indo). The anti-inflammatory mechanisms of ST1 might be related to the decrease in the level of MDA, iNOS, and COX-2 in the edema paw via increasing the activities of CAT, SOD, and GPx in the liver through the suppression of TNF-alpha and NO.

Typical and severe tumor necrosis factor receptor-associated periodic syndrome in the absence of mutations in the TNFRSF1A gene: a case series

Tumor necrosis factor receptor-1-associated periodic syndrome (TRAPS) is the most common autosomal dominant autoinflammatory disorder and is caused by mutations in the TNFRSF1A gene encoding the 55-kDa receptor for tumor necrosis factor (TNF)-α. TRAPS is characterized by recurrent attacks of fever, typically lasting from 1 to 3 weeks. In addition to fever, common clinical features include periorbital edema, a migratory erythematous plaque simulating erysipela with underlying myalgia, and arthralgia or arthritis. Serosal membrane inflammation is also a common feature, usually in the form of polyserositis. To date, at least 40 different TNFRSF1A mutations have been identified, but few patients with symptoms highly suggestive of TRAPS with no mutations in the TNFRSF1A gene have recently been described, thus suggesting that not all mutations are yet known or that alternative mechanisms might be involved in the pathogenesis of the disease. We report on three such patients here.

Akt1 is critical for acute inflammation and histamine-mediated vascular leakage

Akt1 is implicated in cell metabolism, survival migration, and gene expression; however, little is known about the role of specific Akt isoforms during inflammation in vivo. Thus, we directly explored the roles of the isoforms Akt1 and Akt2 in acute inflammation models by using mice deficient in either Akt1 or Akt2. Akt1(-/-) mice showed a markedly reduced edema versus Akt2(-/-) and WT controls, and the reduced inflammation was associated with a dramatic decrease in neutrophil and monocyte infiltration. The loss of Akt1 did not affect leukocyte functions in vitro, and bone marrow transplant experiments suggest that host Akt1 regulates leukocyte emigration into inflamed tissues. Moreover, carrageenan-induced edema and the direct propermeability actions of bradykinin and histamine were reduced dramatically in Akt1(-/-) versus WT mice. These findings are supported by in vitro experiments showing that Akt1 deficiency or blockade of nitric oxide synthase markedly reduces histamine-stimulated changes in transendothelial electrical resistance of microvascular endothelial cells. Collectively, these results suggest that Akt1 is necessary for acute inflammation and exerts its actions primarily via regulation of vascular permeability, leading to edema and leukocyte extravasation.

COX-2 expression and function in the hyperalgesic response to paw inflammation in mice

Peripheral inflammation and edema are often accompanied by primary and secondary hyperalgesia which are mediated by both peripheral and central mechanisms. The role of cyclooxygenase-2 (COX-2)-mediated prostanoid production in hyperalgesia is a topic of substantial current interest. We have established a murine foot-pad inflammation model in which both pharmacologic and genetic tools can be used to characterize the role of COX-2 in hyperalgesia. Zymosan, an extract from yeast, injected into the plantar surface of the hindpaw induces an edema response and an increase in COX-2 expression in the hindpaw, spinal cord and brain. Zymosan-induced primary hyperalgesia, measured as a decrease in hindpaw withdrawal latency in response to a thermal stimulus, is long-lasting and is not inhibited by pre-treatment with the systemic COX-2 selective inhibitor, parecoxib (20 mg/kg). In contrast, the central component of hyperalgesia, measured as a reduction in tail flick latency in response to heat, is reduced by parecoxib. Zymosan-induced primary hyperalgesia in Cox-2-/- mice is similar to that of their Cox-2+/+ littermate controls. However, the central component of hyperalgesia is substantially reduced in Cox-2-/- versus Cox-2+/+ mice, and returns to baseline values much more rapidly. Thus pharmacological data suggest, and genetic experiments confirm, (i) that primary hyperalgesia in response to zymosan inflammation in the mouse paw is not mediated by COX-2 function and (ii) that COX-2 function plays a major role in the central component of hyperalgesia in this model of inflammation.

Severe obesity and insulin resistance due to deletion of the maternal Gsalpha allele is reversed by paternal deletion of the Gsalpha imprint control region

The G protein alpha-subunit G(s)alpha mediates receptor-stimulated cAMP production and is imprinted with reduced expression from the paternal allele in specific tissues. Disruption of the G(s)alpha maternal (but not paternal) allele leads to severe obesity, hypertriglyceridemia, and insulin resistance in mice and obesity in patients with Albright hereditary osteodystrophy. Paternal deletion of a G(s)alpha imprint control region (1A) leads to loss of tissue-specific G(s)alpha imprinting. To determine whether the metabolic abnormalities resulting from disruption of the G(s)alpha maternal allele could be reversed by loss of paternal G(s)alpha imprinting, females with a heterozygous G(s)alpha exon 1 deletion were mated to males with heterozygous deletion of the imprint control region (1A) to generate mice with maternal G(s)alpha deletion (E1(m-)), paternal 1A deletion (1A(p-)), double mutants (E1(m-):1A(p-)), and wild type. E1(m-) mice developed obesity, glucose intolerance, insulin resistance, and hypertriglyceridemia, which were all normalized by the paternal 1A deletion in E1(m-):1A(p-) mice. Obesity in E1(m-) was associated with reduced energy expenditure and sympathetic nerve activity, and these were also normalized in E1(m-):1A(p-) mice. 1A(p-) mice had reduced body weight associated with proportional decreases in fat and lean mass as well as increased activity levels. The metabolic phenotype resulting from maternal G(s)alpha deletion is rescued by a genetic lesion that leads to loss of tissue-specific G(s)alpha imprinting, consistent with this phenotype being a direct consequence of G(s)alpha imprinting in one or more specific tissues.

A role for long chain myosin light chain kinase (MLCK-210) in microvascular hyperpermeability during severe burns

Microvascular leakage has been implicated in the pathogenesis of multiple organ dysfunction during trauma. Previous studies suggest the involvement of myosin light chain (MLC) phosphorylation-triggered endothelial contraction in the development of microvascular hyperpermeability. Myosin light chain kinase (MLCK) plays a key role in the control of MLC-phosphorylation status; thus, it is thought to modulate barrier function through its regulation of intracellular contractile machinery. The aim of this study was to further investigate the endothelial mechanism of MLC-dependent barrier injury in burns, focusing on the long isoform of MLCK (MLCK-210) that has recently been identified as the predominant isoform expressed in vascular endothelial cells. An MLCK-210 knockout mouse model was subjected to third-degree scald burn covering 25% total body surface area. The mesenteric microcirculation was observed using intravital microscopy, and the microvascular permeability was assessed by measuring the transvenular flux of fluorescein isothiocyanate-albumin. In a separate experiment, in vivo mesenteric hydraulic conductivity (Lp) was measured using the modified Landis technique. The injury caused a profound microvascular leakage, as indicated by a 2-fold increase in albumin flux and 4-fold increase in Lp at the early stages, which was associated with a high mortality within the 24-h period. Compared with wild-type control, the MLCK-210-deficient mice displayed a significantly improved survival with a greatly attenuated microvascular hyperpermeability response to albumin and fluid. These results provide direct evidence for a role of MLCK-210 in mediating burn-induced microvascular barrier injury and validate MLCK-210 as a potential therapeutic target in the treatment of burn edema.

Bilateral pleural effusions, ascites, and facial and peripheral oedema in a 19-year-old woman 2 weeks following commencement of insulin lispro and detemir--an unusual presentation of insulin oedema

Insulin oedema is a rare complication of insulin therapy and usually occurs in patients with Type 1 diabetes. It can present in a variety of ways, from mild peripheral oedema to cardiac failure and massive serosal effusions. We report a 19-year-old woman with newly diagnosed Type 1 diabetes who presented with bilateral pleural effusions, ascites and extensive peripheral oedema 2 weeks after starting insulin therapy. Significant cardiac disease was excluded, and the massive fluid retention resolved spontaneously with conservative management. A review of the literature is presented.

Nestling immune response to phytohaemagglutinin is not heritable in collared flycatchers

The response to intradermally injected phytohaemagglutinin (PHA-response) is a commonly used quantification of avian immunocompetence (the ability to resist pathogens). Parasite-mediated sexual selection requires heritable immunocompetence, but evidence for heritability of PHA-response in birds largely stems from full-sib comparisons. Using an animal model approach, we quantified the narrow-sense heritability of PHA-response in 1626 collared flycatcher (Ficedula albicollis) nestlings from 332 families, most of which were cross-fostered. Nestling PHA-response was not significantly heritable (h2=0.06+/-0.10), but was subject to non-heritable nest-of-origin effects (10% of variation). Our findings illustrate that full-sib comparisons of immunological measures may lead to an inflated estimate of heritability and also reveal a limited role of nestling PHA-response for sexual selection in this population.

Antenatal mitochondrial disease caused by mitochondrial ribosomal protein (MRPS22) mutation

Three patients born to the same set of consanguineous parents presented with antenatal skin oedema, hypotonia, cardiomyopathy and tubulopathy. The enzymatic activities of multiple mitochondrial respiratory chain complexes were reduced in muscle. Marked reduction of 12s rRNA, the core of the mitochondrial small ribosomal subunit, was found in fibroblasts. Homozygosity mapping led to the identification of a mutation in the MRPS22 gene, which encodes a mitochondrial ribosomal protein. Transfection of the patient cells with wild-type MRPS22 cDNA increased the 12s rRNA content and normalised the enzymatic activities. Quantification of mitochondrial transcripts is advisable in patients with multiple defects of the mitochondrial respiratory chain.

[Meningiomas: anatomical pathology and molecular biology]

In the past 5-10 years, there has been a considerable progress the understanding of the biology of meningioma. The most important advances have been made by comprehensive studies of the pathogenesis of meningioma in molecular genetics. Several target genes could be identified for mutation or inactivation. Additional chromosomal regions that are usually subject to deletion or amplification and point to the presence of tumor suppressor genes or proto-oncogenes were found. The revised and updated 2000 WHO Classification is a major innovation in the histopathology of meningiomas. The new classification system more precisely and objectively determines the grade of meningioma, which allows one to more logically make a prognosis of the recurrence and aggressive behavior of the tumor. The present overview places particular emphasis on recent advances in its molecular biology. It summarizes the most important aspects of the classification of meningiomas, which makes it possible to include the results of biological observations into the respective context, and also considers the mechanisms of angiogenesis and edema development and the role of hormonal receptors in meningiomas.