The deletion of AQP4 and TRPV4 affects astrocyte swelling/volume recovery in response to ischemia-mimicking pathologies.

Introduction: Astrocytic Transient receptor potential vanilloid 4 (TRPV4) channels, together with Aquaporin 4 (AQP4), are suspected to be the key players in cellular volume regulation, and therefore may affect the development and severity of cerebral edema during ischemia. In this study, we examined astrocytic swelling/volume recovery in mice with TRPV4 and/or AQP4 deletion in response to in vitro ischemic conditions, to determine how the deletion of these channels can affect the development of cerebral edema. Methods: We used three models of ischemia-related pathological conditions: hypoosmotic stress, hyperkalemia, and oxygenglucose deprivation (OGD), and observed their effect on astrocyte volume changes in acute brain slices of Aqp4-/-, Trpv4-/- and double knockouts. In addition, we employed single-cell RT-qPCR to assess the effect of TRPV4 and AQP4 deletion on the expression of other ion channels and transporters involved in the homeostatic functioning of astrocytes. Results: Quantification of astrocyte volume changes during OGD revealed that the deletion of AQP4 reduces astrocyte swelling, while simultaneous deletion of both AQP4 and TRPV4 leads to a disruption of astrocyte volume recovery during the subsequent washout. Of note, astrocyte exposure to hypoosmotic stress or hyperkalemia revealed no differences in astrocyte swelling in the absence of AQP4, TRPV4, or both channels. Moreover, under ischemia-mimicking conditions, we identified two distinct subpopulations of astrocytes with low and high volumetric responses (LRA and HRA), and their analyses revealed that mainly HRA are affected by the deletion of AQP4, TRPV4, or both channels. Furthermore, gene expression analysis revealed reduced expression of the ion transporters KCC1 and ClC2 as well as the receptors GABAB and NMDA in Trpv4-/- mice. The deletion of AQP4 instead caused reduced expression of the serine/cysteine peptidase inhibitor Serpina3n. Discussion: Thus, we showed that in AQP4 or TRPV4 knockouts, not only the specific function of these channels is affected, but also the expression of other proteins, which may modulate the ischemic cascade and thus influence the final impact of ischemia.

Cell-specific modulation of mitochondrial respiration and metabolism by the pro-apoptotic Bcl-2 family members Bax and Bak.

Proteins from the Bcl-2 family play an essential role in the regulation of apoptosis. However, they also possess cell death-unrelated activities that are less well understood. This prompted us to study apoptosis-unrelated activities of the Bax and Bak, pro-apoptotic members of the Bcl-2 family. We prepared Bax/Bak-deficient human cancer cells of different origin and found that while respiration in the glioblastoma U87 Bax/Bak-deficient cells was greatly enhanced, respiration of Bax/Bak-deficient B lymphoma HBL-2 cells was slightly suppressed. Bax/Bak-deficient U87 cells also proliferated faster in culture, formed tumours more rapidly in mice, and showed modulation of metabolism with a considerably increased NAD+/NADH ratio. Follow-up analyses documented increased/decreased expression of mitochondria-encoded subunits of respiratory complexes and stabilization/destabilization of the mitochondrial transcription elongation factor TEFM in Bax/Bak-deficient U87 and HBL-2 cells, respectively. TEFM downregulation using shRNAs attenuated mitochondrial respiration in Bax/Bak-deficient U87 as well as in parental HBL-2 cells. We propose that (post)translational regulation of TEFM levels in Bax/Bak-deficient cells modulates levels of subunits of mitochondrial respiratory complexes that, in turn, contribute to respiration and the accompanying changes in metabolism and proliferation in these cells.

Higher levels of matrix metalloproteinase-3 in patients with RA reflect disease activity and structural damage.

AIMS: To evaluate the serum levels of matrix metalloproteinase-3 (MMP-3) as a potential marker of disease activity and joint damage in 92 patients with rheumatoid arthritis (RA), compared to 24 osteoarthritis (OA) patients and 26 healthy controls. METHODS: The concentrations of MMP-3 were measured by ELISA using the commercial kit AESKULISA DF MMP-3 (AESKU.Diagnostics, Germany) and compared with other laboratory parameters routinely used to assess the disease status, clinical score (DAS28) and radiographic stage in the group of RA patients. RESULTS: The mean serum concentrations of MMP-3 were 199.1 ± 160 ng/mL in RA patients, 113.9 ± 96.9 ng/mL in OA patients and 48.3 ± 19.2 in healthy controls. The differences were highly significant: RA patients and healthy controls (P<0.0001), RA and OA patients (P=0.008) as well as between OA patients and controls (P=0.009). MMP-3 concentrations were further compared with other laboratory parameters and clinical and structural damage data. There were correlations between MMP-3 and CRP (r=0.304, P<0.01), DAS28 (r=0.301, P<0.05), levels of anti-cyclic citrullinated peptide antibodies (r=0.241, P<0.05), erythrocyte sedimentation rate (r=0.200, P=0.059) and radiographic disease stage (r=0.197, P=0.063). CONCLUSION: These results demonstrated that measurement of MMP-3 could become a marker of disease activity in RA patients.

Prospective study of signalling pathways in myeloma bone disease with regard to activity of the disease, extent of skeletal involvement and correlation to bone turnover markers.

AIMS: The aim of our study was to address the utility of serum levels of selected parameters of myeloma bone disease (MBD) signalling with regard to the pathogenesis of multiple myeloma (MM), activity, markers of bone turnover and extent of skeletal changes. PATIENTS AND METHODS: We assessed prospectively 77 individuals with monoclonal gammopathies - 46 patients with active MM (AMM), 12 patients with smouldering MM (SMM) and 19 individuals with monoclonal gammopathy of undetermined significance (MGUS) to determine the role of HGF, MIP-1α, Syndecan-1, osteoprotegerin, Activin A, DKK1, Annexin A2 and NF-κB. RESULTS: We found significant differences of most of the parameters between MGUS and AMM, and with respect to the activity of MM assessed by International Staging System. Most of the parameters of MBD signalling correlated with traditional markers of bone turnover. CONCLUSIONS: All the signalling pathways were activated in MM with more pronounced osteoclastogenesis in comparison with bone formation but not in MGUS regardless of its risk category, suggesting that MBD is not activated in MGUS until the process of transformation into MM. The parameters of MBD signalling might precede the increase of conventional parameters of bone turnover suggesting their possible role in early indication of anti-resorption therapy.

[Ultrasound elastography and its use in the head and neck imaging]. / Ultrazvuková elastografie a její vyuzití v oblasti hlavy a krku.

Ultrasound elastography (sonoelastography, USE) is a relatively new, rapidly evolving area of imaging that measures elasticity of tissues. Its development started in the last decade of the 20th century and was accelerated after devices allowing real-time imaging and quantification (shear wave elastography, SWE) became broadly available for clinical practise. First results suggest that combination of sonoelastography and conventional ultrasound gives more precise results than ultrasound alone in certain areas. In head and neck imaging, just a few mostly pilot studies have been published till January 2014. This article summarizes available information about sonoelastography and current view on USE imaging in otorhinolaryngology.

The levels of sCD30 and of sCD40L in a group of patients with systemic lupus erythematodes and their diagnostic value.

CD30/CD30L and CD40/CD40L are molecules from the tumor necrosis factor (TNF) superfamily. They have a major effect on communications between the B and T cells, which leads to control of maturation, proliferation, and apoptosis of those cells. The aim of this study was to compare the levels of a soluble form of CD30 (sCD30) and a soluble ligand CD40 (sCD40L) in patients with systemic lupus erythematosus (SLE) (n=65) and healthy controls (sCD30 n=20, sCD40L n=10) with other parameters of SLE activity. Patients were divided into subgroups according to presence or absence of lupus nephritis (LN; 33 with LN, 32 without LN). The serum levels of selected parameters were assessed also in the subgroups with low active disease characterized by European Lupus Activity Measure (ECLAM) at most 3(n=29) and active disease with ECLAM more than 3 (n=36). The serum levels of sCD30 were 66.0+/-40.2 UI/ml in the whole group. The mean serum levels were 60.0+/-45.2 UI/ml in the subgroups with LN, 67.1+/-38.9 UI/ml in the subgroup without LN, 80.2+/-51.9 UI/ml in the subgroup with active disease, 55.4+/-24.1 UI/ml in the subgroup with low active disease, and finally, 40.1+/-19.2 U/ml in the controls. Significant differences were found between the SLE patients and controls (p=0.0001) and between the active and nonactive groups (p=0.002). A correlation was found between levels of CD30 and ECLAM (r=0.25, p

Monocyte chemoattractant protein-1 in patients with peripheral arterial disease.

BACKGROUND: Chemokine-driven migration of inflammatory cells has been implicated in the pathogenesis of atherosclerotic conditions including peripheral arterial disease (PAD). Monocyte chemoattractant protein-1 (MCP-1) is elevated in patients with coronary artery disease and in hypertensive patients. This study therefore investigated MCP-1 in patients with PAD. METHODS: Serum MCP-1 was determined by enzyme-linked immunosorbent assay in 36 healthy, control subjects and in 19 patients with PAD. Statistical analysis utilised the Mann-Whitney test and Spearman correlation (p < 0.05). RESULTS: MCP-1 (pg/ml) was increased in patients compared with in controls (mean+/-standard error of the mean: PAD group, 748+/-60; control group, 459+/-27; p=0.0001). MCP-1 levels tended to decrease with progressing disease. From atherosclerosis risk factors, diabetes inclined to increase MCP-1 levels; hypertension had no effect. Serum MCP-1 correlated with cholesterol, triglycerides, low-density lipoprotein but not high-density lipoprotein. CONCLUSION: Elevation of MCP-1 in the circulation of PAD patients shown in the present pilot study implicates this CC chemokine ligand 2 in inflammatory processes contributing to PAD clinical symptomatology. Further investigations are necessary to evaluate whether MCP-1 can be used as a potential marker of peripheral arterial disease follow-up and/or prognosis.