Histamine stimulates the proliferation of small and large cholangiocytes by activation of both IP3/Ca2+ and cAMP-dependent signaling mechanisms

Although large cholangiocytes exert their functions by activation of cyclic adenosine 3',5'-monophosphate (cAMP), Ca(2+)-dependent signaling regulates the function of small cholangiocytes. Histamine interacts with four receptors, H1-H4HRs. H1HR acts by Gαq activating IP(3)/Ca(2+), whereas H2HR activates Gα(s) stimulating cAMP. We hypothesize that histamine increases biliary growth by activating H1HR on small and H2HR on large cholangiocytes. The expression of H1-H4HRs was evaluated in liver sections, isolated and cultured (normal rat intrahepatic cholangiocyte culture (NRIC)) cholangiocytes. In vivo, normal rats were treated with histamine or H1-H4HR agonists for 1 week. We evaluated: (1) intrahepatic bile duct mass (IBDM); (2) the effects of histamine, H1HR or H2HR agonists on NRIC proliferation, IP(3) and cAMP levels and PKCα and protein kinase A (PKA) phosphorylation; and (3) PKCα silencing on H1HR-stimulated NRIC proliferation. Small and large cholangiocytes express H1-H4HRs. Histamine and the H1HR agonist increased small IBDM, whereas histamine and the H2HR agonist increased large IBDM. H1HR agonists stimulated IP(3) levels, as well as PKCα phosphorylation and NRIC proliferation, whereas H2HR agonists increased cAMP levels, as well as PKA phosphorylation and NRIC proliferation. The H1HR agonist did not increase proliferation in PKCα siRNA-transfected NRICs. The activation of differential signaling mechanisms targeting small and large cholangiocytes is important for repopulation of the biliary epithelium during pathologies affecting different-sized bile ducts

Chronic Cerebrospinal Venous Insufficiency (CCSVI) IN Meniere Disease. Case or Cause?

Abstract CCSVI is the acronym for Chronic Cerebrospinal Venous Insufficiency, initially described by P.Zamboni, as being strongly associated with multiple sclerosis (MS). It is a syndrome characterized by stenosis of the internal jugular veins (IJVs) and/or azygous vein (AZ) with opening of collaterals and insufficient drainage. Bavera PM carried out 823 Duplex exams on a control group of 60 patients without MS. As expected CCSVI was found only in few subjects of the control group, three, two females and one male, but all affected with Sudden Sensorineural Hearing Loss (SSHL). Successively, we reported a case of bilateral SSHL with vertigo, showing evidence of the CCSVI pattern at Duplex examination (not associated with MS). To the best of the authors' knowledge, this kind of association has never been reported. We studied 52 patients affected with cochleo-vestibular disturbances subdivided into two groups of out-patients:Definite unilateral Meniere (Men): 12 subjects (8 males and 4.females, mean age 41,6.yy) according to international AOO-HNS 1995 diagnostic criteria -No-Meniere (No-Men): 14 subjects (6.males and 8 females, mean age 44,7.yy) affected with unilateral cocleo-vestibular impairment A third group of subjects have been considered, as a "normal" group, 13 patients (8 females and 5 males, mean age 45,5 yy) affected with Benign Paroxismal Positioning Vertigo (BPPV) with cochlear involvement Asymmetrical artherious flow in VA or CA was revealed in 2 Men 9 no-Men and 1 BPPV, respectively 12,5 -60,7 -and 8,6 %. Differences between Men and NoMen and between each of this group with respect to BPPV were highly significant (p<0.001). Asymmetrical venous flow in IJV or VV was detected in 9 patients in MEN group and in 4 in no-MEN and 2 BPPV, respectively 79 -28,5 and 13 %. Differences between Men and No-Men and between each of this group with respect to BBV were highly significant (p<0.001

Conditional Genetic Elimination of Hepatocyte Growth Factor in Mice Compromises Liver Regeneration after Partial Hepatectomy

Hepatocyte growth factor (HGF) has been shown to be indispensable for liver regeneration because it serves as a main mitogenic stimulus driving hepatocytes toward proliferation. We hypothesized that ablating HGF in adult mice would have a negative effect on the ability of hepatocytes to regenerate. Deletion of the HGF gene was achieved by inducing systemic recombination in mice lacking exon 5 of HGF and carrying the Mx1-cre or Cre-ERT transgene. Analysis of liver genomic DNA from animals 10 days after treatment showed that a majority (70-80%) of alleles underwent cre-induced genetic recombination. Intriguingly, however, analysis by RT-PCR showed the continued presence of both unrecombined and recombined forms of HGF mRNA after treatment. Separation of liver cell populations into hepatocytes and non-parenchymal cells showed equal recombination of genomic HGF in both cell types. The presence of the unrecombined form of HGF mRNA persisted in the liver in significant amounts even after partial hepatectomy (PH), which correlated with insignificant changes in HGF protein and hepatocyte proliferation. The amount of HGF produced by stellate cells in culture was indirectly proportional to the concentration of HGF, suggesting that a decrease in HGF may induce de novo synthesis of HGF from cells with residual unrecombined alleles. Carbon tetrachloride (CCl4)-induced regeneration resulted in a substantial decrease in preexisting HGF mRNA and protein, and subsequent PH led to a delayed regenerative response. Thus, HGF mRNA persists in the liver even after genetic recombination affecting most cells; however, PH subsequent to CCl4 treatment is associated with a decrease in both HGF mRNA and protein and results in compromised liver regeneration, validating an important role of this mitogen in hepatic growth. © 2013 Nejak-Bowen et al

HIV Protease Inhibitors Sensitize Human Head and Neck Squamous Carcinoma Cells to Radiation by Activating Endoplasmic Reticulum Stress

Background Human head and neck squamous cell carcinoma (HNSCC) is the sixth most malignant cancer worldwide. Despite significant advances in the delivery of treatment and surgical reconstruction, there is no significant improvement of mortality rates for this disease in the past decades. Radiotherapy is the core component of the clinical combinational therapies for HNSCC. However, the tumor cells have a tendency to develop radiation resistance, which is a major barrier to effective treatment. HIV protease inhibitors (HIV PIs) have been reported with radiosensitizing activities in HNSCC cells, but the underlying cellular/molecular mechanisms remain unclear. Our previous study has shown that HIV PIs induce cell apoptosis via activation of endoplasmic reticulum (ER) stress. The aim of this study was to examine the role of ER stress in HIV PI-induced radiosensitivity in human HNSCC. Methodology and Principal Findings HNSCC cell lines, SQ20B and FaDu, and the most commonly used HIV PIs, lopinavir and ritonavir (L/R), were used in this study. Clonogenic assay was used to assess the radiosensitivity. Cell viability, apoptosis and cell cycle were analyzed using Cellometer Vision CBA. The mRNA and protein levels of ER stress-related genes (eIF2α, CHOP, ATF-4, and XBP-1), as well as cell cycle related protein, cyclin D1, were detected by real time RT-PCR and Western blot analysis, respectively. The results demonstrated that L/R dose-dependently sensitized HNSCC cells to irradiation and inhibited cell growth. L/R-induced activation of ER stress was correlated to down-regulation of cyclin D1 expression and cell cycle arrest under G0/G1 phase. Conclusion and Significance HIV PIs sensitize HNSCC cells to radiotherapy by activation of ER stress and induction of cell cycle arrest. Our results provided evidence that HIV PIs can be potentially used in combination with radiation in the treatment of HNSCC

Nuovi aspetti nella diagnosi e nel trattamento delle patologie dell’orecchio medio e interno

Numerosi studi su modelli animali hanno evidenziato che l’orecchio è un sito a tolleranza immunologica privilegiata. Il coinvolgimento del sistema immunitario nella patogenesi delle malattie dell’orecchio medio e dell’orecchio interno è stato confermato anche da numerosi studi clinici. Tuttavia, tali aspetti risultano di difficile trasposizione in ambito clinico e spesso poco indagati.Sarà condotta una revisione ragionata della letteratura inerente il ruolo del sistema immunitario sia nelle patologie dell’orecchio medio (condizione della mucosa dell’orecchio medio, atopia, flogosi reattiva e reazione granulomatosa) sia nelle malattie dell’orecchio interno (AIED, Ménière's disease) focalizzando l’attenzione sugli aspetti immuno-allerogologici che possono essere utili dal punto di vista pratico.Definizione di percorsi immuno-allergologici specifici per i pazienti otorinolaringoiatrici. Saranno descritti i punti salienti dell'anamnesi, i questionari, la valutazione e la diagnostica immunologica e allergologica e i metodi procedurali utilizzabili., metodi procedurali) al fine di mettere in rilievo gli aspetti rilevanti e ridimensionare altri fattori. Il fine di questo corso è quello di mettere in rilievo gli aspetti rilevanti e ridimensionare altri fattori; questa indagine integrata potrebbe essere definita come una branca dell'otorinolaringoiatria: "immuno-otologia"

Characteristics of multiple sclerosis patient stance control disorders, measured by means of posturography and related to brainstem lesions

Balance disorders are commonly observed during the course of multiple sclerosis (MS). The aim of this study is to report characteristics of MS patient stance control disorders, measured by means of posturography and related to the brainstem lesions. Thirty-eight patients affected by MS, mildly to moderately disable according to Kurtzke\u2019s Expanded Disability Status Scale, underwent a complete clinical neurological and vestibular evaluation and brain MRI scanning. All patients were then tested on a static posturography platform (Tetrax, Israel) in four conditions: eyes open and eyes closed standing on a firm surface and on a foam pad. Clinical and/or magnetic resonance imaging evidence of brainstem involvement was observed in 55.3% of patients. When brainstem lesion was detected, Fourier analysis showed a typical pattern characterized by inversion of the 0- 0.1 Hz and 0.1-0.25 Hz frequency bands. In conclusion, MS leads to pervasive postural disturbances in the majority of subjects, including the visuo-vestibular loops and proprioception involving vestibulospinal pathways in at least 55.3% of patients. Our results may also suggest the presence of Fourier inversion in patients with brainstem lesions

Bilateral sudden sensorineural hearing loss and chronic venous cerebrospinal insufficiency : a case report

OBJECTIVES: We report a case of bilateral sudden sensorineural hearing loss (SSHL) in a patient suffering from chronic venous cerebrospinal insufficiency (CCSVI). METHODS: Audiometric testing confirmed bilateral sensorineural hearing loss with hypoexcitability to caloric stimulation on the left side and echo-colour Doppler examination showed abnormal cerebral venous deficiency. RESULTS: The patient's condition improved after 15 days following medical treatment. CONCLUSIONS: CCSVI may explain the anatomical background which provides a predisposing factor for SSHL although further studies are needed to verify whether this observation is casual or coincidental

FXR-induced secretion of FGF15/19 inhibits CYP27 expression in cholangiocytes through p38 kinase pathway

Cholangiocytes, bile duct lining cells, actively adjust the amount of cholesterol and bile acids in bile through expression of enzymes and channels involved in transportation and metabolism of the cholesterol and bile acids. Herein, we report molecular mechanisms regulating bile acid biosynthesis in cholangiocytes. Among the cytochrome p450 (Cyp) enzymes involved in bile acid biosynthesis, sterol 27-hydroxylase (Cyp27) that is the rate-limiting enzyme for the acidic pathway of bile acid biosynthesis expressed in cholangiocytes. Expression of other Cyp enzymes for the basic bile acid biosynthesis was hardly detected. The Cyp27 expression was negatively regulated by a hydrophobic bile acid through farnesoid X receptor (FXR), a nuclear receptor activated by bile acid ligands. Activated FXR exerted the negative effects by inducing an expression of fibroblast growth factor 15/19 (FGF15/19). Similar to its repressive function against cholesterol 7α-hydroxylase (Cyp7a1) expression in hepatocytes, secreted FGF15/19 triggered Cyp27 repression in cholangiocytes through interaction with its cognate receptor fibroblast growth factor receptor 4 (FGFR4). The involvements of FXR and FGFR4 for the bile acid-induced Cyp27 repression were confirmed in vivo using knockout mouse models. Different from the signaling in hepatocytes, wherein the FGF15/19-induced repression signaling is mediated by c-Jun N-terminal kinase (JNK), FGF15/19-induced Cyp27 repression in cholangiocytes was mediated by p38 kinase. Thus, the results collectively suggest that cholangiocytes may be able to actively regulate bile acid biosynthesis in cholangiocytes and even hepatocyte by secreting FGF15/19. We suggest the presence of cholangiocyte-mediated intrahepatic feedback loop in addition to the enterohepatic feedback loop against bile acid biosynthesis in the liver