Delivery of matrix metalloproteinase-1 attenuates established liver fibrosis in the rat

BACKGROUND & AIMS: During hepatic fibrogenesis, the hepatic extracellular matrix changes to fibrillar collagens types I and III, and cirrhosis is believed to produce an irreversible scar. In this study, we investigated whether gene delivery of human matrix metalloproteinase-1, which degrades collagens types I and type III, would attenuate established hepatic fibrosis in the rat, induced by either thioacetamide or bile duct ligation. METHODS: Hepatic fibrosis induced by thioacetamide for 7 weeks was persistent for at least 2 months, even after discontinuation of the treatment. The rats were infected once with a recombinant adenovirus, Ad5MMP-1, into which human pro-human matrix metalloproteinase-1 complementary DNA was packaged, or with a control adenovirus, Ad5LacZ. RESULTS: In Ad5MMP-1-infected, but not in Ad5LacZ-infected, rats, the fibrosis was dramatically attenuated at 2 weeks after the infection. It is interesting to note that the number of activated hepatic stellate cells was also decreased in Ad5MMP-1-infected rats. Moreover, disorganization of the hepatic trabecula, heterogeneity in the size of hepatocytes, and increased dried liver weight were observed only in Ad5MMP-1-treated rats, suggesting that human matrix metalloproteinase-1 stimulated hepatocyte proliferation, which was confirmed by bromodeoxyuridine staining. After 4 weeks, the proliferative effect of human matrix metalloproteinase-1 almost disappeared, but the hepatic fibrosis remained attenuated, whereas the fibrosis in Ad5LacZ-treated rats persisted. Furthermore, the administration of Ad5MMP-1, but not Ad5LacZ, decreased type I collagen and generated a small collagen fragment in hepatic fibrosis induced by bile duct ligation. CONCLUSIONS: Our findings show that transient human matrix metalloproteinase-1 overexpression in the liver effectively attenuates established fibrosis and induces hepatocyte proliferation

Primary Squamous Cell Carcinoma of the Liver: An Uncommon Finding in Contrast-Enhanced Ultrasonography Imaging

Primary squamous cell carcinoma (SCC) of the liver is rare tumor with an unfavorable prognosis. We report a case of advanced primary SCC of the liver arising adjacent to a nonparasitic liver cyst, invading into the right diaphragm and the right lung tissue. Contrast-enhanced ultrasonography (CE-US) demonstrated unique enhancement in the late vascular phase, which was incompatible with those observed in hepatocellular carcinoma, cholangiocellular carcinoma, or metastatic adenocarcinoma. The patient underwent surgical resection of the tumor followed by systemic chemotherapy with 5-fluorouracil (5-FU) and cisplatin (CDDP), while radiation chemotherapy was not applied because of relatively poor performance status. Although postoperative image analysis revealed no recurrence 4 months later, the patient died 13 months after the operation from recurrence. Immunohistological analysis of the resected specimen revealed that this SCC contained many capillary endothelial vessels expressing CD31 or CD34, possibly reflecting the unique imaging pattern in the late vascular phase of CE-US, which has been reported in choangiolocellular carcinoma. In addition, we reviewed which kind of treatment would be suitable for advanced hepatic primary SCC in the literature. From the review, it could be proposed that a combination of radiation therapy, systemic chemotherapy (5-FU and CDDP) and surgical resection, if possible, is appropriate for advanced primary SCC of the liver

Ringer's lactate improves liver recovery in a murine model of acetaminophen toxicity

<p>Abstract</p> <p>Background</p> <p>Acetaminophen (APAP) overdose induces massive hepatocyte necrosis. Liver regeneration is a vital process for survival after a toxic insult. Since hepatocytes are mostly in a quiescent state (G₀), the regeneration process requires the priming of hepatocytes by cytokines such as TNF-α and IL-6. Ringer's lactate solution (RLS) has been shown to increase serum TNF-α and IL-6 in patients and experimental animals; in addition, RLS also provides lactate, which can be used as an alternative metabolic fuel to meet the higher energy demand by liver regeneration. Therefore, we tested whether RLS therapy improves liver recovery after APAP overdose.</p> <p>Methods</p> <p>C57BL/6 male mice were intraperitoneally injected with a single dose of APAP (300 mg/kg dissolved in 1 mL sterile saline). Following 2 hrs of APAP challenge, the mice were given 1 mL RLS or Saline treatment every 12 hours for a total of 72 hours.</p> <p>Results</p> <p>72 hrs after APAP challenge, compared to saline-treated group, RLS treatment significantly lowered serum transaminases (ALT/AST) and improved liver recovery seen in histopathology. This beneficial effect was associated with increased hepatic tissue TNF-α concentration, enhanced hepatic NF-κB DNA binding and increased expression of cell cycle protein cyclin D1, three important factors in liver regeneration.</p> <p>Conclusion</p> <p>RLS improves liver recovery from APAP hepatotoxicity.</p

Effect of Gadolinium Chloride on Liver Regeneration Following Thioacetamide-Induced Necrosis in Rats

Gadolinium chloride (GD) attenuates drug-induced hepatotoxicity by selectively inactivating Kupffer cells. The effect of GD was studied in reference to postnecrotic liver regeneration induced in rats by thioacetamide (TA). Rats, intravenously pretreated with a single dose of GD (0.1 mmol/Kg), were intraperitoneally injected with TA (6.6 mmol/Kg). Hepatocytes were isolated from rats at 0, 12, 24, 48, 72 and 96 h following TA intoxication, and samples of blood and liver were obtained. Parameters related to liver damage were determined in blood. In order to evaluate the mechanisms involved in the post-necrotic regenerative state, the time course of DNA distribution and ploidy were assayed in isolated hepatocytes. The levels of circulating cytokine TNFα was assayed in serum samples. TNFα was also determined by RT-PCR in liver extracts. The results showed that GD significantly reduced the extent of necrosis. The effect of GD induced noticeable changes in the post-necrotic regeneration, causing an increased percentage of hepatocytes in S phase of the cell cycle. Hepatocytes increased their proliferation as a result of these changes. TNFα expression and serum level were diminished in rats pretreated with GD. Thus, GD pre-treatment reduced TA-induced liver injury and accelerated postnecrotic liver regeneration. No evidence of TNFα implication in this enhancement of hepatocyte proliferation and liver regeneration was found. These results demonstrate that Kupffer cells are involved in TA-induced liver damage, as well as and also in the postnecrotic proliferative liver states

Modulation of extracellular matrix by nutritional hepatotrophic factors in thioacetamide-induced liver cirrhosis in the rat

Nutritional substances associated to some hormones enhance liver regeneration when injected intraperitoneally, being denominated hepatotrophic factors (HF). Here we verified if a solution of HF (glucose, vitamins, salts, amino acids, glucagon, insulin, and triiodothyronine) can revert liver cirrhosis and how some extracellular matrices are affected. Cirrhosis was induced for 14 weeks in 45 female Wistar rats (200 mg) by intraperitoneal injections of thioacetamide (200 mg/kg). Twenty-five rats received intraperitoneal HF twice a day for 10 days (40 mL·kg-1·day-1) and 20 rats received physiological saline. Fifteen rats were used as control. The HF applied to cirrhotic rats significantly: a) reduced the relative mRNA expression of the genes: Col-&#945;1 (-53%), TIMP-1 (-31.7%), TGF-&#946;1 (-57.7%), and MMP-2 (-41.6%), whereas Plau mRNA remained unchanged; b) reduced GGT (-43.1%), ALT (-17.6%), and AST (-12.2%) serum levels; c) increased liver weight (11.3%), and reduced liver collagen (-37.1%), regenerative nodules size (-22.1%), and fibrous septum thickness. Progranulin protein (immunohistochemistry) and mRNA (in situ hybridization) were found in fibrous septa and areas of bile duct proliferation in cirrhotic livers. Concluding, HF improved the histology and serum biochemistry of liver cirrhosis, with an important reduction of interstitial collagen and increased extracelullar matrix degradation by reducing profibrotic gene expression

Matrix Metalloproteinase Gene Delivery for Liver Fibrosis

The resolution of advanced liver fibrosis has been recently recognized to be possible, if the causative stimuli are successfully removed. However, whether complete resolution from cirrhosis, the end stage of liver fibrosis, can be achieved is still questionable. Delivery of interstitial collagenases, such as matrix metalloproteinase (MMP)-1, in the liver could be an attractive strategy to treat advanced hepatic fibrosis from the view point that the imbalance between too few interstitial collagenases and too many of their inhibitors is the main obstacle to the resolution from fibrosis. Remodeling of hepatic extracellular matrix by delivered interstitial collagenases also facilitates the disappearance of activated hepatic stellate cells, the main matrix-producing cells in the liver, and promotes the proliferation of hepatocytes. This review will focus on the impact of the gene delivery of MMPs for the treatment of advanced liver fibrosis while discussing other current therapeutic strategies for liver fibrosis, and on the need for the development of a safe and effective delivery system of MMPs

Adrenomedullin and tumour angiogenesis

The angiogenic activity of peptide adrenomedullin (AM) was first shown in 1998 . Since then, a number of reports have confirmed the ability of AM to induce the growth and migration of isolated vascular endothelial and smooth muscle cells in vitro and to promote angiogenesis in xenografted tumours in vivo. In addition, knockout murine models point to an essential role for AM in embryonic vasculogenesis and ischaemic revascularisation. AM expression is upregulated by hypoxia (a typical feature of solid tumours) and a potential role as a regulator of carcinogenesis and tumour progression has been proposed based on studies in vitro and in animal models. Nevertheless, translational research on AM, and in particular, confirmation of its importance in the vascularisation of human tumours has lagged behind. In this commentary, we review current progress and potential directions for future research into the role of AM in tumour angiogenesis

MyD88 Dependent Signaling Contributes to Protective Host Defense against Burkholderia pseudomallei

Background: Toll-like receptors (TLRs) have a central role in the recognition of pathogens and the initiation of the innate immune response. Myeloid differentiation primary-response gene 88 (MyD88) and TIR-domain-containing adaptor protein inducing IFNb (TRIF) are regarded as the key signaling adaptor proteins for TLRs. Melioidosis, which is endemic in SE-Asia, is a severe infection caused by the gram-negative bacterium Burkholderia pseudomallei. We here aimed to characterize the role of MyD88 and TRIF in host defense against melioidosis. Methodology and Principal Findings: First, we found that MyD88, but not TRIF, deficient whole blood leukocytes released less TNFa upon stimulation with B. pseudomallei compared to wild-type (WT) cells. Thereafter we inoculated MyD88 knockout (KO), TRIF mutant and WT mice intranasally with B. pseudomallei and found that MyD88 KO, but not TRIF mutant mice demonstrated a strongly accelerated lethality, which was accompanied by significantly increased bacterial loads in lungs, liver and blood, and grossly enhanced liver damage compared to WT mice. The decreased bacterial clearance capacity of MyD88 KO mice was accompanied by a markedly reduced early pulmonary neutrophil recruitment and a diminished activation of neutrophils after infection with B. pseudomallei. MyD88 KO leukocytes displayed an unaltered capacity to phagocytose and kill B. pseudomallei in vitro. Conclusions: MyD88 dependent signaling, but not TRIF dependent signaling, contributes to a protective host respons