The protein p27Kip1 is an inhibitor of cell division. An increase in p27 causes proliferating cells to exit from the cell cycle, and a decrease in p27 is necessary for quiescent cells to resume ...division. Abnormally low amounts of p27 are associated with pathological states of excessive cell proliferation, especially cancers. In normal and tumour cells, p27 is regulated primarily at the level of translation and protein turnover. Phosphorylation of p27 on threonine 187 (T187) by cyclin-dependent kinase 2 (Cdk2) is thought to initiate the major pathway for p27 proteolysis. To critically test the importance of this pathway in vivo, we replaced the murine p27 gene with one that encoded alanine instead of threonine at position 187 (p27T187A). Here we show that cells expressing p27T187A were unable to downregulate p27 during the S and G2 phases of the cell cycle, but that this had a surprisingly modest effect on cell proliferation both in vitro and in vivo. Our efforts to explain this unexpected result led to the discovery of a second proteolytic pathway for controlling p27, one that is activated by mitogens and degrades p27 exclusively during G1.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Tumor necrosis factor (TNF)-alpha is a potent inducer of apoptotic cell death in various tissues, whereas the transcription factor nuclear factor (NF)-kappaB is essential to protect against ...TNF-alpha-induced apoptosis. Human hepatoma cell lines were used to investigate the effectiveness and specificity of the fungal metabolite gliotoxin in inhibiting TNF-alpha-induced NF-kappaB activation in transformed cells.
Background & aims: Knowledge about innate antimicrobial defense of the liver is limited. We investigated hepatic expression and regulation of antimicrobial peptides with focus on the human beta ...defensin-1 (hBD-1). Methods: Radial diffusion assay was used to analyze antimicrobial activity of liver tissue. Different defensins including hBD-1 and its activator thioredoxin-1 (TXN) were analyzed in healthy and cholestatic liver samples by qPCR and immunostaining. Regulation of hBD-1 expression was studied in vitro and in vivo using bile duct-ligated mice. Regulation of hBD-1 via bilirubin and bile acids (BAs) was studied using siRNA. Results: We found strong antimicrobial activity of liver tissue against Escherichia coli. As a potential mediator of this antimicrobial activity we detected high expression of hBD-1 and TXN in hepatocytes, whereas other defensins were minimally expressed. Using a specific antibody for the reduced, antimicrobially active form of hBD-1 we found hBD-1 in co-localization with TXN within hepatocytes. hBD-1 was upregulated in cholestasis in a graded fashion. In cholestatic mice hepatic AMP expression (Defb-1 and Hamp) was enhanced. Bilirubin and BAs were able to induce hBD-1 in hepatic cell cultures in vitro. Treatment with siRNA and/or agonists demonstrated that the farnesoid X receptor (FXR) mediates basal expression of hBD-1, whereas both constitutive androstane receptor (CAR) and FXR seem to be responsible for the induction of hBD-1 by bilirubin. Conclusion: hBD-1 is prominently expressed in hepatocytes. It is induced during cholestasis through bilirubin and BAs, mediated by CAR and especially FXR. Reduction by TXN activates hBD-1 to a potential key player in innate antimicrobial defense of the liver.
Acute kidney injury in liver failure Werner, Christoph R; Wagner, Verena; Sipos, Bence ...
Deutsche medizinische Wochenschrift (1946)
141, Številka:
21
Journal Article
We report on a 76-year-old man presenting with painless jaundice who developed dialysis-dependent acute kidney injury.
Biliary tract was examined with endoscopy, in addition kidney biopsy was ...performed.
A stenosing process could be seen in the biliary tract, leading to stent implantation. However, jaundice did not resolve. Kidney biopsy revealed bile casts indicating cholemic nephropathy. After switch of concomitant medication, hyperbilirubinemia resolved and kidney function was completely restored.
Cholestatic liver disease can cause acute kidney injury by formation of bile casts in the tubuli defining cholemic nephropathy. Resolution of cholestasis can restore kidney function.
Sometimes a liver can cause you headaches Müller, Niklas F; Lauer, Ulrich M; Horger, Marius ...
Deutsche medizinische Wochenschrift (1946)
139, Številka:
25-26
Journal Article
We report on a 41-year-old patient who was taken over from an outside hospital with headache, fever, polydipsy and profound sweating.
Blood cultures revealed an infection due to Klebsiella pneumonia. ...CT exhibited a large liver abscess in segments VI and VII (7,6 x 7,2 x 9,9 cm).
We started an empiric antibiotic treatment with meropenem, linezolid and fluconazole. After susceptibility testing the antibiotic treatment was adapted to ciprofloxacin and continued for 4 weeks. Furthermore, we placed a CT-guided drainage of the abscess. In follow-up visits, his lab values normalized and the size of the abscess decreased.
A pyogenic liver abscess is a rare but severe inflammatory disease. The etiology is often unclear. Depending on localisation a conservative, a surgical or a treatment with a targeted drainage is necessary. However, an isolation of the pathogen for antibiotic testing should be achieved and long term antibiotic treatment should be performed.
Objectives The aim of this multicenter retrospective study was to investigate safety and efficacy of direct acting antiviral (DAA) treatment in the rare subgroup of patients with HCV/HIV-coinfection ...and advanced liver cirrhosis on the liver transplant waiting list or after liver transplantation, respectively. Methods When contacting 54 German liver centers (including all 23 German liver transplant centers), 12 HCV/HIV-coinfected patients on antiretroviral combination therapy were reported having received additional DAA therapy while being on the waiting list for liver transplantation (patient characteristics: Child-Pugh A (n = 6), B (n = 5), C (n = 1);MELD range 7-21;HCC (n = 2);HCV genotype la (n = 8), 1 b (n = 2), 4 (n = 2)). Furthermore, 2 HCV/HIV-coinfected patients were denoted having received DAA therapy after liver transplantation (characteristics: HCV genotype 1a (n = 1), 4 (n = 1)). Results Applied DAA regimens were SOF/DAC (n = 7), SOF/LDV/RBV (n = 3), SOF/RBV (n = 3), PTV/r/OBV/DSV (n = 1), or PTV/r/OBV/DSV/RBV (n = 1), respectively. All patients achieved SVR 12, in the end. In one patient, HCV relapse occurred after 24 weeks of SOF/DAC therapy;subsequent treatment with 12 weeks PTV/r/OBV/DSV achieved SVR 12. One patient underwent liver transplantation while on DAA treatment. Analysis of liver function revealed either stable parameters or even significant improvement during DAA therapy and in followup. MELD scores were found to improve in 9/13 therapies in patients on the waiting list for liver transplantation;in only 2 patients a moderate increase of MELD scores persisted at the end of follow-up. Conclusion DAA treatment was safe and highly effective in this nation-wide cohort of patients with HCV/HIV-coinfection awaiting liver transplantation or being transplanted.
Epoxyphomalins A (1) and B (2) are highly potent cytotoxic fungal metabolites. During the course of purifying larger quantities of 1 and 2 from Paraconiothyrium sp. fermentation extracts, three new ...epoxyphomalins (3-5) were isolated and characterized, showing modifications to the oxidation pattern of the cyclohexene moiety or of C-9 of the decalin system. IC(50) values for cytotoxicity against a panel of 36 human tumor cell lines were determined for all new compounds. Compound 4 was found to be cytotoxic particularly toward prostate PC3M (IC(50) = 0.72 μM) and bladder BXF 1218 L (IC(50) = 1.43 μM) cancer cell lines. In addition, inhibition of chymotrypsin-, caspase-, and trypsin-like activity of purified 20S proteasomes was determined for epoxyphomalins A (1) and B (2). The results indicate that compounds 1 and 2 exert their cytotoxic effect through potent inhibition of the 20S proteasome.
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