P2X7 accelerate tissue fibrosis via metalloproteinase 8‐dependent macrophage infiltration in a murine model of unilateral ureteral obstruction

Abstract Renal fibrosis is tightly associated with chronic kidney disease, irrespective of the underlying pathogenesis. We previously demonstrated mild antifibrotic effects of targeting the P2X7 receptor in a pyelonephritis model. Reduced P2X7R‐activation elevated the neutrophil‐to‐macrophage ratio, resulting in less matrix accumulation without affecting the initial tissue healing. Here, we test if this P2X7R‐dependent modification of matrix accumulation also applies to a noninfectious fibrosis model of unilateral ureteral obstruction (7dUUO) and whether the response is gender‐dependent. We found that P2X7−/− mice show reduced fibrosis compared to wild type after 7dUUO: the effect was most pronounced in females, with a 55% decrease in collagen deposition after 7dUUO (p < 0.0068). P2X7R deficiency did not affect early fibrosis markers (TGF‐β, α‐SMA) or the renal infiltration of neutrophils. However, a UUO‐induced increase in macrophages was observed in wildtypes only (p < 0.001), leaving the P2X7−/− mice with ≈50% fewer CD68+ cells in the renal cortex (p = 0.018). In males, 7dUUO triggered an increase in diffusely interstitial scattering of the profibrotic, macrophage‐attracting metalloproteinase MMP8 and showed significantly lower MMP8 tissue expression in both male and female P2X7−/− mice (p < 0.0008). Thus, the P2X7R is advocated as a late‐stage fibrosis moderator by reducing neutrophil‐dependent interstitial MMP8 release, resulting in less macrophage infiltration and reduced matrix accumulation

Staging of Cervical Lymph Nodes in Oral Squamous Cell Carcinoma:Adding Ultrasound in Clinically Lymph Node Negative Patients May Improve Diagnostic Work-Up

Clinical staging of patients with oral squamous cell carcinoma (OSCC) is crucial for the choice of treatment. Computed tomography (CT) and/or magnetic resonance imaging (MRI) are typically recommended and used for staging of the cervical lymph nodes (LNs). Although ultrasonography (US) is a non-expensive, accessible and non-ionising imaging modality this method is not consistently used. This study aimed to investigate if addition of US of patients classified as clinically LN negative (cN0) by CT and/or MRI, increases the detection of LN metastases. Also, we aimed to identify which of the sonographic characteristics: echogenicity, border, shape, appearance of hilum and nodal blood-flow pattern best detect metastases in this patient group.Fifty-one patients with OSCC classified as cN0 by CT/MRI were consecutively included and prospectively examined with US prior to sentinel node biopsy or selective neck dissection. Localisation, size and sonographic characteristics were registered for each LN and compared with the pathological findings. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for different size measurements and sonographic characteristics.We found that short axial diameter was the best size criterion for detection of metastases. However, the sonographic characteristics were better predictors than size and the presence at least four of the sonographic characteristics: hypo-echoic or heterogeneous appearance; irregular border; spherical shape; absence of nodal hilum; and peripheral nodal blood-flow resulted in a sensitivity of 43.8; specificity 91.4; PPV 70.0; and NPV 78.0. The number of patients with occult metastases decreased from 16 out of 51 (31%) to nine out of 51 (18%). Three patients (6%) were over-staged by US.The addition of US to the clinical work-up of patients with cN0 OSCC increases the detection of metastases, thus US potentially reduces the number of patients requiring a secondary neck surgery after sentinel node biopsy

Regulation of renal aquaporin water channels in acute pyelonephritis

: Acute pyelonephritis (APN) is most frequently caused by uropathogenic Escherichia coli (UPEC), which ascends from the bladder to the kidneys during a urinary tract infection. Patients with APN have been reported to have reduced renal concentration capacity under challenged conditions, polyuria and increased aquaporin-2 (AQP2) excretion in the urine. We have recently shown increased AQP2 accumulation in the plasma membrane in cell cultures exposed to E. coli lysates and in the apical plasma membrane of inner medullary collecting ducts in a 5-day APN mouse model. This study aimed to investigate if AQP2 expression in host cells increases UPEC infection efficiency and to identify specific bacterial components that mediate AQP2 plasma membrane insertion. Since the transepithelial water permeability in the collecting duct is co-determined by AQP3 and AQP4, we also investigated whether AQP3 and AQP4 localization is altered in the APN mouse model. We show that AQP2 expression does not increase UPEC infection efficiency and that AQP2 was targeted to the plasma membrane in AQP2 expressing cells in response to the two pathogen-associated molecular patterns (PAMPs), lipopolysaccharide and peptidoglycan. In contrast to AQP2, the subcellular localizations of AQP1, AQP3, and AQP4 were unaffected both in lysate-incubated cell cultures and in the APN mouse model. Our finding demonstrated that cellular exposure to lipopolysaccharide and peptidoglycan can trigger the insertion of AQP2 in the plasma membrane revealing a new regulatory pathway for AQP2 plasma membrane translocation, which may potentially be exploited in intervention strategies

Sensitivity, specificity, PPV and NPV for different short axial diameter cut-offs.

<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0090360#pone-0090360-t001" target="_blank">Table 1</a> shows the sensitivity, specificity, PPV (positive predictive value) and NPV (negative predictive value) for different cut-off values of ultrasonically measured short axial diameter. A one millimetre larger cut-off was used for LNs in level IB and IIA.</p