ASK1/ p38 axis inhibition blocks the release of mitochondrial "danger signals" from hepatocytes and suppresses progression to cirrhosis and liver cancer

BACKGROUND AND AIMS

Apoptosis Signal-regulating Kinase 1 (ASK1) is activated by various pathological stimuli and induces cell apoptosis through downstream p38 activation. We studied the effect of pharmacological ASK1 inhibition on cirrhosis and its sequelae using comprehensive preclinical in vivo and in vitro systems.

APPROACH AND RESULTS

Short-term (4-6 wk) and long-term (24-44 wk) ASK1 inhibition using small molecule GS-444217 was tested in thioacetamide-induced and BALB/c. Mdr2-/- murine models of cirrhosis and HCC, and in vitro using primary hepatocyte cell death assays. Short-term GS-444217 therapy in both models strongly reduced phosphorylated p38, hepatocyte death, and fibrosis by up to 50%. Profibrogenic release of mitochondrial DAMP mitochondrial deoxyribonucleic acid from dying hepatocytes was blocked by ASK1 or p38 inhibition. Long-term (24 wk) therapy in BALBc.Mdr2 - / - model resulted in a moderate 25% reduction in bridging fibrosis, but not in net collagen deposition. Despite this, the development of cirrhosis was effectively prevented, with strongly reduced p21 + hepatocyte staining (by 72%), serum ammonia levels (by 46%), and portal pressure (average 6.07 vs. 8.53 mm Hg in controls). Extended ASK1 inhibition for 44 wk in aged BALB/c. Mdr2-/- mice resulted in markedly reduced tumor number and size by ~50% compared to the control group.

CONCLUSIONS

ASK1 inhibition suppresses the profibrogenic release of mitochondrial deoxyribonucleic acid from dying hepatocytes in a p38-dependent manner and protects from liver fibrosis. Long-term ASK1 targeting resulted in diminished net antifibrotic effect, but the progression to liver cirrhosis and cancer in BALBc/ Mdr2- / - mice was effectively inhibited. These data support the clinical evaluation of ASK1 inhibitors in fibrotic liver diseases.

Immunomodulatory drugs target IKZF1-IRF4-MYC axis in primary effusion lymphoma in a cereblon-dependent manner and display synergistic cytotoxicity with BRD4 inhibitors

Primary effusion lymphoma (PEL) is an aggressive type of non-Hodgkin lymphoma localized predominantly in body cavities. Kaposi’s sarcoma-associated herpes virus is the causative agent of PEL. PEL is an incurable malignancy and has extremely poor prognosis when treated with conventional chemotherapy. Immunomodulatory drugs (IMiDs) lenalidomide and pomalidomide are FDA approved drugs for the treatment of various ailments. IMiDs display pronounced anti-proliferative effect against majority of PEL cell lines within their clinically achievable concentrations, by arresting cells at G₀/G₁ phase of cell-cycle, and without any induction of KSHV lytic-cycle reactivation. Although microarray examination of PEL cells treated with lenalidomide revealed activation of interferon (IFN) signaling, blocking the IFN pathway did not block the anti-PEL activity of IMiDs. The anti-PEL effects of IMiDs involved cereblon-dependent suppression of IRF4 and rapid degradation of IKZF1, but not IKZF3. Small hairpin-RNA (shRNA) mediated knockdown of MYC enhanced the cytotoxicity of IMiDs. Bromodomain and extraterminal domain (BET) proteins are epigenetic readers which perform a vital role in chromatin remodeling and transcriptional regulation. BRD4, a widely expressed transcriptional coactivator, belongs to BET family of proteins, which has been shown to co-occupy the super-enhancers associated with MYC. Specific BRD4 inhibitors were developed which suppress MYC transcriptionally. Lenalidomide displayed synergistic cytotoxicity with several structurally distinct BRD4 inhibitors (JQ-1, IBET151, and PFI-1). Furthermore, combined administration of lenalidomide and BRD4 inhibitor JQ-1 significantly increased the survival of PEL bearing NOD.SCID mice in an orthotopic xenograft model as compared to either agent alone. These results provide compelling evidence for clinical testing of IMiDs alone and in combination with BRD4 inhibitors for PEL.

Inhibition of bacterial growth and biofilm production by constituents from Hypericum spp

Biofilm embedded bacterial pathogens such as Staphylococcus spp., Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii are difficult to eradicate and are major sources of bacterial infections. New drugs are needed to combat these pathogens. Hypericum is a plant genus that contains species known to have antimicrobial properties. However, the specific constituents responsible for the antimicrobial properties are not entirely known, nor have most compounds been tested as inhibitors of biofilm development. The investigation presented here tested seven secondary metabolites isolated from the species Hypericum densiflorum, Hypericum ellipticum, Hypericum prolificum, and Hypericum punctatum as inhibitors of bacterial growth and biofilm production. Assays were conducted against Staphylococcus epidermidis, Staphylococcus aureus, clinical methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter baumannii. Five of the seven compounds demonstrated growth inhibition against the Gram-positive bacteria with minimum inhibitory concentrations (MIC) ranging from 1.95 µg/mL to 7.81 µg/mL. Four of the secondary metabolites inhibited biofilm production by certain Gram-positive strains at sub-MIC concentrations.

Kaposi's sarcoma-associated herpesvirus-encoded viral FLICE inhibitory protein (vFLIP) K13 suppresses CXCR4 expression by upregulating miR-146a

Kaposi's sarcoma (KS)-associated herpesvirus (KSHV)-encoded viral FLICE inhibitory protein (vFLIP) K13 is a potent activator of the nuclear factor-kappaB (NF-kappaB) pathway. In this study, we show that infection with KHSV and ectopic expression of K13, but not its NF-kappaB-defective mutant, suppressed the expression of CXCR4. Suppression of CXCR4 by KSHV and K13 was associated with upregulated expression of miR-146a, a microRNA that is known to bind to the 3'-untranslated region of CXCR4 mRNA. Reporter studies identified two NF-kappaB sites in the promoter of miR-146a that were essential for its activation by K13. Accordingly, ectopic expression of K13, but not its NF-kappaB-defective mutant or other vFLIPs, strongly stimulated the miR-146a promoter activity, which could be blocked by specific genetic and pharmacological inhibitors of the NF-kappaB pathway. Finally, expression of CXCR4 was downregulated in clinical samples of KS and this was accompanied by an increased expression of miR-146a. Our results show that K13-induced NF-kappaB activity suppresses CXCR4 through upregulation of miR-146a. Downregulation of CXCR4 expression by K13 may contribute to KS development by promoting premature release of KSHV-infected endothelial progenitors into the circulation.

Molecular and biotechnological advances in milk proteins in relation to human health

Milk and colostrum is a rich source of proteins/peptides which have crucial roles in both neonates and adults. Milk bioactive proteins and peptides are potential health-enhancing nutraceuticals for food. Many bioactive peptides/proteins may be used as nutraceuticals, for example, in the treatment of cancer, asthma, diarrhea, hypertension, thrombosis, dental diseases, as well as mineral malabsorption, and immunodeficiency. The following components of milk are of particular interest in the recent years: 1) Lactoferrin [Lf] has antibacterial, antifungal, antiviral, antiparasite and antitumor activities and accelerates immunomodulatory properties. Lf is a potent inhibitor for several enveloped and naked viruses, such as rotavirus, enterovirus and adenovirus. Lf is resistant to tryptic digestion and breast-fed infants excrete high levels of faecal Lf, so that its effect on viruses replicating in the gastrointestinal tract is of great interest. 2) Casein has been protective in experimental bacteremia by eliciting myelopoiesis. Casein hydrolyzates were also protective in diabetic animals, reduced the tumor growth and diminished colicky symptoms in infants. 3) A Proline rich polypeptide [PRP] revealed variety of immunotropic functions, including promotion of T-cell activation and inhibition of autoimmune disorders such as multiple sclerosis. 4) alpha-Lactalbumin [LA] demonstrates antiviral, antitumor and anti-stress properties. 5) Lactoperoxidase shows antibacterial properties. 6) Lysozyme is effective in treatment of periodentitis and prevention of tooth decay. Taken together, milk-derived proteins and peptides are bio-available and safe for the prevention and treatment of various disorders in humans and may play a complementary [natural agents] rather than a substitutional role to the toxic synthetic pharmacological drugs.

Induction of spindle cell morphology in human vascular endothelial cells by human herpesvirus 8-encoded viral FLICE inhibitory protein K13

Human herpesvirus 8 (HHV8), also known as Kaposi's sarcoma-associated herpesvirus, is linked to the development of Kaposi's sarcoma, a disease characterized by the presence of distinctive proliferating spindle-like cells. Although HHV8 can induce spindle cell transformation of vascular endothelial cells in vitro, the viral gene(s) responsible for this phenotype remain to be identified. We demonstrate that expression of HHV8-encoded viral Fas-associated death domain protein-like IL-1beta-converting enzyme inhibitory protein K13 is sufficient to induce spindle cell phenotype in human umbilical vein endothelial cells (HUVEC), which is associated with the activation of the nuclear factor-kappaB (NF-kappaB) pathway and can be blocked by Bay-11-7082, a specific inhibitor of this pathway. K13 induces the expression of several genes known to be upregulated in HHV8-transformed vascular endothelial cells, such as interleukin (IL)-6, IL-8, CXC ligand 3 (CXCL3), orphan G protein coupled receptor (RDC1), cyclooxygenase-2 (COX-2) and dual-specificity phosphatase 5 (DUSP5). Furthermore, similar to K13, HHV8-induced spindle cell transformation of HUVEC is associated with NF-kappaB activation and can be blocked by Bay-11-7082. Thus, ectopic expression of a single latent gene of HHV8 is sufficient for the acquisition of spindle cell phenotype by vascular endothelial cells and NF-kappaB activation plays an essential role in this process.

Induction of IL-8 expression by human herpesvirus 8 encoded vFLIP K13 via NF-kappaB activation

Human herpesvirus 8 (HHV-8) encodes a viral FLICE inhibitory protein (vFLIP), called K13, with homology to the prodomain of caspase 8. K13 has been postulated to protect virally infected cells against death receptor-induced apoptosis. We report that K13 leads to constitutive upregulation of IL-8 secretion by transcriptional upregulation of its promoter. K13-induced IL-8 promoter activation is dependent on an intact NF-kappaB-binding site and is associated with increased binding of classical NF-kappaB pathway subunits p65, c-Rel and p50, respectively. IL-8 production is defective in K13 mutants defective in classical NF-kappaB activation and is blocked by genetic and pharmacological inhibitors of this pathway. In contrast, K13 failed to activate the JNK/AP-1 pathway and deletion of AP-1-binding site in the IL-8 promoter or use of a specific JNK inhibitor had only a partial effect on K13-induced IL-8 promoter activation. Collectively, above results demonstrate that K13 is a major mediator of IL-8 production and therapeutic agents targeting K13-induced NF-kappaB pathway may have a role in the treatment of conditions in which HHV-8-induced IL-8 production plays a pathogenic role.

A case of Turcot's Syndrome in a child with malignant transformation

Turcot's syndrome or the glioma polyposis syndrome is a rare variant of the polyposis syndrome and it is characterized by colonic polyposis and central nervous system neoplasm typically a glioblastoma or a medulloblastoma. We present a case of Turcot's syndrome in a child with malignant transformation.

Intrauterine torsion of a wandering spleen presenting as an abdominal cystic swelling

Wandering spleen is a rare clinical condition that presents commonly with splenic infarction secondary to torsion. Intrauterine torsion of a wandering spleen, however, is extremely rare. An unusual case of intrauterine torsion of a wandering spleen presenting as an abdominal mass is reported.

An immunoassay for detection of heat-stable proteases from thermoduric psychrotrophic Bacillus spp. of dairy origin

A homogeneous preparation of a thermostable protease from Bacillus sp. B-17 was used to raise an antiserum in rabbits. IgG of this antiserum was used to study the antigenic relationship of proteases in cell-free extracts of 21 bacilli of milk origin. Based on immunological cross reactivity, the 21 bacilli were divided into 3 serological subgroups. To raise antibodies of broader specificity, protease from Bacillus sp. B-11 (group II) and B-3 (group III) were purified, mixed with purified B-17 protease, and an antiserum was raised against this mixture. IgG of this antiserum was purified (IgG anti-bacilli protease). A sandwich ELISA was standardized using IgG anti-bacilli protease as capture antibody. The assay could detect 1.2 ng ml(-1) of protease in milk or buffer, but the assay failed to detect 4 of 21 bacilli proteases. The results suggest that this assay is useful for the detection of proteases of Bacillus spp. in dairy industry.

Congenital Morgagni's hernia in infants and children

Morgagni's hernia is an uncommon type of diaphragmatic hernia in the pediatric age group. Out of 52 children with different types of congenital diaphragmatic hernia that we have treated, 5 (9.6%) had Morgagni's hernia. There were 2 infants and 3 children including one with Down's syndrome. All suffered from repeated attacks of chest infection, and only after a chest X-ray was the diagnosis of Morgagni's hernia suspected. In 2 cases this appeared as an opacity in the anterior mediastinum adjacent to the pericardium; diagnosis was confirmed by barium enema in one and a CT-scan in the other. The remaining 3 cases showed anterior herniation of bowel loops on chest X-ray which was bilateral in one. This bilaterality was confirmed pre-operatively by CT scan. Associated anomalies were present in all cases, including 2 with malrotation. All patients were treated surgically via a transabdominal approach. Our study shows a relative high frequency of Morgagni's hernia in our patients and, although late-presenting Morgagni hernias are relatively benign, it can cause significant morbidity. This calls for early diagnosis and early referral for surgery. Chest X-ray is to be strongly advocated in children with repeated attacks of chest infection.

Congenital pyloric atresia and junctional epidermolysis bullosa: a report of two cases

The association between epidermolysis bullosa (EB) and congenital pyloric atresia (CPA) is rare, but is known distinct clinical entity with autosomal recessive inheritance. The outcome of such an association was universally fatal. This is a report of two newborns with EB and CPA, associated with additional aplasia cutis congenita in one case. One patient was treated postoperatively with phenytoin and survived. Aspects of the diagnosis, pathogenesis, and management are also discussed.

Neonatal intestinal atresia

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Synchronous bilateral Wilms' tumor

Synchronous bilateral Wilms' tumor (WT) accounts for 5% of all WTs. Of 34 cases of WT we treated, 7 (20.6%) were bilateral, 5 of them males. This high frequency of bilaterality as well as the male preponderance in our series is different from that reported in other parts of the world; this may reflect regional variations of WT. The details of diagnosis, therapy, including the role of preoperative chemotherapy, and outcome are presented.

A method to overcome the inability to draw blood from central venous lines in children

The insertion of central venous catheters has become an established practice in the management of children with different types of malignancies for the administration of chemotherapeutic agents, antibiotics, blood and blood products, as well as drawing blood for various investigations. A commonly encountered problem is that despite the catheter being patent it may be impossible to draw blood from it. We believe this is related to the cut of the catheter tip. To overcome this problem, a technique for cutting the tip of the catheter is described.

Esophageal atresia and tracheoesophageal fistula: success and failure rates in the United Arab Emirates

The management of esophageal atresia (EA) and tracheoesophageal fistula (TEF) has improved markedly over the years, with a current overall survival of 80%-90%. This however, is not the case in developing countries, where mortality continues to be high. The results of treatment of 41 consecutive cases EA and/or TEF have been analyzed to determine factors pertinent to the outcome. The distribution of anomalies and a postoperative survival of 86.8% were comparable to those from developed countries. Aspiration pneumonia was unusually frequent in our patients (78%), but did not adversely influence outcome. Associated congenital anomalies as well as low birth weight continue to be important predictors of outcome in our setting. Our post-operative complications were similar to those from developed countries apart from a high incidence of stricture formation. This was attributed to gastroesophageal reflux, non-ventilation post-operatively, and the use of silk sutures to construct the anastomosis.

Isolation and partial characterization of a thermostable extracellular protease of Bacillus polymyxa B-17

Bacillus polymyxa B-17, a sporeforming psychrotroph produced a thermostable protease. The protease was purified to homogeneity from cell free broth culture by precipitation with ammonium sulfate and gel filtration through Sephadex G-100. The enzyme had a temperature optimum at 50 degrees C and shared significant activity at 70 degrees C. The protease was also active over a wide range of pH, 5.5 to 10.0, and had optimum activity at pH 7.5. It was inhibited by metal chelating agents and has a molecular weight of 30 kDa.

An immuno-dot blot assay for detection of thermostable protease from Pseudomonas sp. AFT-36 of dairy origin

A dot-ELISA technique for the detection of Pseudomonas protease was developed using IgG of anti-Pseudomonas AFT-36 protease as capture antibody. The detection limit of protease in buffer or milk was 1.01 ng ml-1. The procedure was performed at room temperature, took about 2.5 h and was economical. Protease AFT-36 is immunologically related to five out of seven Pseudomonas spp. The results suggest that the assay could be used to detect proteases in dairy products.

Immune response to phospholipase-A fractions of Salmonella typhi on experimental typhoid infection in mice

The intraperitoneal injection of Salmonella typhi into mice produced typhoid infection involving all the vital organs. Infection of liver was more persistent and progressive than in other organs. During the course of experimental infection, no humoral immune response was detected against phospholipase-A fractions upto 3 weeks after challenge, but significant cell mediated immunity (CMI) was found. Increased CMI response against protein antigens correlated well with the decreasing bacterial load, what suggested that CMI against proteins was important in pathogenesis of this disease.

Inefficacy of intestinal secretory immune response to Cryptosporidium in acquired immunodeficiency syndrome

BACKGROUND/AIMS

An alteration of the secretory immune response has been forwarded to explain frequent and chronic mucosal infections in patients with acquired immunodeficiency syndrome (AIDS). The aim of this study was to explore the intestinal immunoglobulin (Ig) secretions in patients with AIDS and their relationships to cryptosporidiosis.

METHODS

Patients with AIDS and enteric cryptosporidiosis (n = 12), other enteric infections (n = 10), and no identifiable enteric pathogen (n = 10) and human immunodeficiency virus-seronegative controls (n = 18) were studied. The number of intestinal IgA and IgM plasma cells of the duodenal lamina propria mucosa and total and anti-Cryptosporidium IgA, IgM, and IgG were measured in serum and feces.

RESULTS

Although not significantly increased, the number of IgA and IgM plasma cells was greater in patients with AIDS (n = 20) than in controls (n = 5). In feces, total IgA outputs and specific anti-Cryptosporidium IgA levels were significantly higher in patients with AIDS and cryptosporidiosis than in the two other groups of patients with AIDS (P < 0.05 and P < 0.01, respectively) and controls (P < 0.001 and P < 0.01, respectively). Total fecal IgM output and specific anti-Cryptosporidium IgM coproantibodies were increased only in the Cryptosporidium-infected patients relative to the controls (P < 0.05).

CONCLUSIONS

Despite the development of pathogen-specific mucosal antibody responses, patients with AIDS and cryptosporidiosis fail to clear the parasite.

Fine needle aspiration of palpable breast lesions. Results obtained with cytocentrifuge preparation of aspirates

The use of cytocentrifugation in the preparation of fine needle aspiration (FNA) specimens from the breast was evaluated. A total of 174 fine needle aspirates of breast masses were flushed into cytospin Collection Fluid, from which Papanicolaou-stained Cytospin preparations were made in the laboratory. Comparison of these preparations to conventional smears of aspirates showed no significant differences in the number or morphology of the cells. In 148 cases, the FNA cytologic study was followed up by excisional biopsy, Tru-Cut biopsy and/or a combination of mammography and clinical follow-up of two to nine months. Of 36 verified carcinomas, 31 (86%) were correctly diagnosed, with a zero false-positive rate. Among the 74 cytologically benign aspirates, 2 carcinomas were found on open biopsy, giving a false-negative rate of 3%. Lipomas were not diagnosable with this technique. This technique should be considered in institutions with a high turnover of junior staff members, which frequently results in a higher number of poorly smeared specimens or in poorly fixed/air-dried specimens that give suboptimal results with the Papanicolaou stain. With this method, there is less risk of creation of potentially hazardous aerosols and further preparations for additional studies may be made if required.