Saccharopolyspora: an underexplored source for bioactive natural products.

Actinomycetes are a rich source for secondary metabolites with a diverse array of biological activities. Among the various genera of actinomycetes, the genus Saccharopolyspora has long been recognized as a potential source for antibiotics and other therapeutic leads that belong to diverse classes of natural products. Members of the genus Saccharopolyspora have been widely reported from several natural sources including both terrestrial and marine environments. A plethora of this genus has been chemically investigated for the production of novel natural products with interesting pharmacological effects. Therefore, Saccharopolyspora is considered one of the pharmaceutical important genera that could provide further chemical diversity with potential lead compounds. In this review, the literature from 1976 until December 2018 was covered, providing a comprehensive survey of all natural products derived from this genus and their semi-synthetic derivatives along with their biological activities, whenever applicable. Moreover, the biological diversity of Saccharopolyspora species and their habitats were also discussed.

Risk of developing antiphospholipid antibodies following viral infection: a systematic review and meta-analysis.

Objective The objective of this paper is to conduct a systematic review and meta-analysis on the risk of developing elevated antiphospholipid (aPL) antibodies and related thromboembolic and/or pregnancy events following a viral infection. Method We searched Medline, EMBASE, Web of Science, PubMed ePubs, and Cochrane Central Register of Controlled Trials through June 2016. Independent observational studies of elevated aPL antibodies in patients with a viral infection compared with controls or patients with lupus were included. Results We analyzed 73 publications for 60 studies. Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) were most commonly reported. Compared with healthy controls, patients with HIV were more likely to develop elevated anticardiolipin (aCL) antibodies (risk ratio (RR) 10.5, 95% confidence interval (CI) 5.6-19.4), as were those with HCV (RR 6.3, 95% CI 3.9-10.1), hepatitis B virus (HBV) (RR 4.2, 95% CI 1.8-9.5), and Epstein-Barr virus (EBV) (RR 10.9 95% CI 5.4-22.2). The only statistically significant increased risk for anti-ß2-glycoprotein I (anti-ß2-GPI) antibodies was observed in patients with HCV (RR 4.8 95% CI 1.0-22.3). Compared with patients with lupus, patients with HIV were more likely to develop elevated aCL antibodies (RR 1.8, 95% CI 1.3-2.6), and those with EBV, elevated anti-ß2-GPI antibodies (RR 2.2, 95% CI 1.3-3.9). Thromboembolic events were most prevalent in patients with elevated aPL antibodies who had HCV (9.1%, 95% CI 3.0-18.1), and HBV (5.9%, 95% CI 2.0-11.9) infections, and pregnancy events were most prevalent in those with parvovirus B19 (16.3%, 95% CI 0.78-45.7). However, compared to virus-infected patients with negative aPL antibodies, the only statistically significant increased risk was observed in those with HCV and positive aPL. Conclusions Viral infection can increase the risk of developing elevated aPL antibodies and associated thromboembolic events. Results are contingent on the reported information.

Systematic review of case reports of antiphospholipid syndrome following infection.

OBJECTIVE: The objective of this study was to conduct a systematic review of case reports documenting the development of antiphospholipid syndrome or antiphospholipid syndrome-related features after an infection. METHODS: We searched Medline, EMBASE, Web of Science, PubMed ePubs, and The Cochrane Library - CENTRAL through March 2015 without restrictions. Studies reporting cases of antiphospholipid syndrome or antiphospholipid syndrome-related features following an infection were included. RESULTS: Two hundred and fifty-nine publications met inclusion criteria, reporting on 293 cases. Three different groups of patients were identified; group 1 included patients who fulfilled the criteria for definitive antiphospholipid syndrome (24.6%), group 2 included patients who developed transient antiphospholipid antibodies with thromboembolic phenomena (43.7%), and group 3 included patients who developed transient antiphospholipid antibodies without thromboembolic events (31.7%). The most common preceding infection was viral (55.6%). In cases that developed thromboembolic events Human immunodeficiency and Hepatitis C viruses were the most frequently reported. Parvovirus B19 was the most common in cases that developed antibodies without thromboembolic events. Hematological manifestations and peripheral thrombosis were the most common clinical manifestations. Positive anticardiolipin antibodies were the most frequent antibodies reported, primarily coexisting IgG and IgM isotypes. Few patients in groups 1 and 2 had persistent antiphospholipid antibodies for more than 6 months. Outcome was variable with some cases reporting persistent antiphospholipid syndrome features and others achieving complete resolution of clinical events. CONCLUSIONS: Development of antiphospholipid antibodies with all traditional manifestations of antiphospholipid syndrome were observed after variety of infections, most frequently after chronic viral infections with Human immunodeficiency and Hepatitis C. The causal relationship between infection and antiphospholipid syndrome cannot be established, but the possible contribution of various infections in the pathogenesis of antiphospholipid syndrome need further longitudinal and controlled studies to establish the incidence, and better quantify the risk and the outcomes of antiphospholipid-related events after infection.

Magnetic resonance appearance of cerebral cystic echinococcosis: World Health Organization (WHO) classification.

BACKGROUND: Cystic echinococcosis (CE) of the brain is an uncommon parasitic infestation. The World Health Organization (WHO) recently published a classification of hepatic CE based upon ultrasonographic findings. PURPOSE: To evaluate whether the new WHO classification of hepatic CE can be used in the classification of cerebral CE. MATERIAL AND METHODS: The magnetic resonance (MR) imaging findings of 17 patients (14 male, three female), aged 10-24 years (mean age 16 years), with pathologically proved cerebral CE, and who underwent pre- and postcontrast MR imaging, were retrospectively evaluated. The cysts were classified according to the new WHO classification and their clinical stages. The MR imaging findings were correlated to the histopathologic findings. RESULTS: The fertile active cysts (n=12) that showed protoscoleces appeared as unilocular cysts with no visible wall (cystic lesions; CL), unilocular spherical cysts with a clear visible wall (CE1), or as a unilocular mother cyst with multiple vesicles arranged peripherally along the cyst wall (CE2). The transitional form (CE3) (n=2) containing scoleces showed multiple daughter cysts entirely filling the maternal cyst. The inactive cysts (n=3) that had lost their fertility appeared as a "ball of wool" with collapsed membrane or had detached membrane with water-lily sign (CE4) and calcified lesions (CE5). CONCLUSION: The WHO classification of hepatic CE can be used in the classification of cerebral CE when evaluated by MRI, as it can differentiate fertile active cysts from the transitional and inactive forms of cerebral cystic echinococcosis. This information is essential for treatment planning.

Serum levels of epidermal growth factor and HER-2 neu in non small-cell lung cancer: prognostic correlation.

Lung cancer is still a leading cause of cancer related mortality all over the world with the majority of cases are discovered at a late stage. Various panels of molecular prognostic markers are being studied to map the association of these markers with response and survival. The aim of this study is to study levels of epidermal growth factor receptor (EGFR), HER-2 neu in both serum and bronchoalveolar lavage (BAL) in patients with non small-cell lung cancer (NSCLC), correlate their levels with clinical, pathological characters as well as prognosis. A total of 30 patients with pathologically proven NSCLC were enrolled in this study in addition to ten normal controls subjects and ten cases with benign pulmonary diseases as broncheicatsis, chronic obstructive pulmonary disease. Results revealed significantly increased levels of EGFR and HER-2 neu in both serum and bronco-alveolar lavage compared with controls. The levels were significantly higher in those with stages III, IV compared with I, II, and in those with higher grades of the tumor. There was no statistically significant correlation with performance status or survival. In conclusion, serum measurement of these markers is a promising noninvasive technique which needs correlation with other methods of determination, measurement at different chronological points during disease evolution to explore its full potential. Standardization of techniques for determination of EGFR and HER-2 neu over-expression must become a priority in future studies that should also include larger number of patients, conducted in a prospective manner together with comparisons of various methods and correlation of protein expression with gene copy numbers.

Plasma bcl-2 and nitric oxide: possible prognostic role in patients with metastatic breast cancer.

Interest in translational studies on breast cancer is presently devoted to identifying biological predictors of disease prognosis and response to treatment. In this study, we determined the plasma levels of bcl-2 and nitric oxide in 45 patients with metastatic breast cancer using an ELISA technique and correlated them with clinical and biological factors that may affect the outcome of disease. The results were as follows. The mean level of bcl-2 was 278.44 +/- 383.2 U/L compared with 64.42 +/- 14.4 U/L (p = 0.007) for controls. Levels of bcl-2 were higher in patients less than 50 yr old, premenopausals., GIII tumors, positive nodes, ER positive tumors (p = 0.6, 0.5, 0.9, 0.4, and 0.005, respectively). The site of metastatic disease and the number of metastatic sites did not show statistically significant influences over bcl-2 levels. Furthermore, there was a trend, although not significant, toward improvement of survival in patients with higher levels of bcl-2. The mean level of the nitric oxide (NO) was 297.12 +/- 220.54 microM compared with 13.91 +/- 1.1 microM for controls (p = 0.003). The levels were higher in patients over 50 yr, postmenopausal patients, those with visceral deposits, grade III tumors, positive lymph nodes, and those with disease-free survival of less than 6 mo following primary treatment (p = 0.1, 0.2, 0.1, 0.09, 0.4, and 0.08 respectively). Furthermore, there was no correlation between NO levels and survival (r = 0.002). This study demonstrates a potential role for NO and bcl-2 as prognostic factors in patients with metastatic breast cancer. However, larger studies with more patients together with a comparison of serum levels (ELISA) and tissue levels (MOAb) are still required.

Inactivation of smad-transforming growth factor beta signaling by Ca(2+)-calmodulin-dependent protein kinase II.

Members of the transforming growth factor beta (TGF-beta) family transduce signals through Smad proteins. Smad signaling can be regulated by the Ras/Erk/mitogen-activated protein pathway in response to receptor tyrosine kinase activation and the gamma interferon pathway and also by the functional interaction of Smad2 with Ca(2+)-calmodulin. Here we report that Smad-TGF-beta-dependent transcriptional responses are prevented by expression of a constitutively activated Ca(2+)-calmodulin-dependent protein kinase II (Cam kinase II). Smad2 is a target substrate for Cam kinase II in vitro at serine-110, -240, and -260. Cam kinase II induces in vivo phosphorylation of Smad2 and Smad4 and, to a lesser extent, Smad3. A phosphopeptide antiserum raised against Smad2 phosphoserine-240 reacted with Smad2 in vivo when coexpressed with Cam kinase II and by activation of the platelet-derived growth factor receptor, the epidermal growth factor receptor, HER2 (c-erbB2), and the TGF-beta receptor. Furthermore, Cam kinase II blocked nuclear accumulation of a Smad2 and induced Smad2-Smad4 hetero-oligomerization independently of TGF-beta receptor activation, while preventing TGF-beta-dependent Smad2-Smad3 interactions. These findings provide a novel cross-talk mechanism by which Ca(2+)-dependent kinases activated downstream of multiple growth factor receptors antagonize cell responses to TGF-beta.

Regulation of gene expression by alternative polyadenylation and mRNA instability in hyperglycaemic mesangial cells.

We have used mRNA differential display to identify a novel high-glucose-regulated gene (HGRG-14) in human mesangial cells cultured for up to 21 days in 30 mM d-glucose. The mRNA of HGRG-14 seems to be regulated post-transcriptionally and encodes a small polypeptide of molecular mass 13 kDa. The native protein occurs as a dimer. The recombinant protein is a substrate for casein kinase II kinase. At high glucose concentrations, HGRG-14 protein levels decrease. This correlates with the appearance of a long form of HGRG-14 mRNA under high-glucose conditions. This form has a long 3' untranslated region containing several ATTTA RNA-destabilizing sequences and has a short half-life. A truncated, more stable mRNA that lacks the long 3' untranslated region is produced at 4 mM d-glucose. The switch from the truncated to the long-form transcript is detected within 2 h of exposure to 30 mM d-glucose, indicating that hyperglycaemic conditions have an acute effect on HGRG-14 mRNA processing.

Identification of glucose-regulated genes in human mesangial cells by mRNA differential display.

Diabetic nephropathy is characterised by an accumulation of extracellular matrix proteins in the glomerular mesangium. Hyperglycaemia is a major factor promoting this progressive expansion of the mesangial matrix. We have used the technique of mRNA differential display to investigate changes in gene expression in cultured human mesangial cells following long-term (21 days) exposure to either physiologic (4 mM) or pathologic (30 mM) D-glucose concentrations. Approximately 12,000 mRNA species were screened for evidence of altered expression and several hundred candidate cDNA fragments were obtained. Northern blot and RT-PCR analysis of ten randomly chosen candidate cDNA fragments revealed three exhibiting increased mRNA expression under elevated D-glucose levels. Nucleotide sequence analysis identified two of the cDNA fragments as encoding prolyl 4-hydroxylase alpha-subunit and thrombospondin-1. The third cDNA fragment represents a novel glucose-regulated gene, encoding a putative zinc finger protein. Upregulated expression of these genes in response to high levels of D-glucose may contribute significantly to the disease process. mRNA differential display is a useful tool to investigate the mechanism of diabetic nephropathy.

Modulation of neutral protease expression in human mesangial cells by hyperglycaemic culture.

We report on the effect of prolonged hyperglycaemic (11 and 30 mM D-glucose) culture conditions on human mesangial cell matrix metalloproteinases (MMPs), plasminogen activators and their inhibitors. The results indicate that hyperglycaemic conditions modulate the potential proteolytic activity of the enzymes secreted by confluent cultures of these cells. Gelatinase A (MMP-2) activity was always higher in cultures maintained under hyperglycaemic than under normoglycaemic conditions (4 mM D-glucose). In contrast, gelatinase B (MMP-9) activity was decreased under the same conditions. Matrilysin (MMP-7) activity was decreased by up to 100% under hyperglycaemic conditions. Reverse transcriptase-PCR and Western-blotting analyses indicate that in all cases both the transcripts and the protein level were correlated with enzymic activity. One tissue inhibitor of metalloproteinases, TIMP-2, was barely detectable under hyperglycaemic conditions (30 mM D-glucose). In contrast, TIMP-1 increased during the initial 2 weeks of culture in hyperglycaemic conditions and remained elevated to the end of the experiment (4 weeks). Under normoglycaemic conditions TIMP-1 decreased after 2 weeks of culture. Hyperglycaemic conditions also decreased markedly the activity of tissue plasminogen activator (t-PA). This seemed to be due to increased synthesis of its inhibitor, plasminogen activator inhibitor 1, under these conditions rather than to decreased expression of the t-PA enzyme.

OvB20, an Onchocerca volvulus-cloned antigen selected by differential immunoscreening with vaccination serum in a cattle model of onchocerciasis.

A cDNA of Onchocerca volvulus has been isolated by differential immunoscreening of an adult worm expression library using sera raised in cattle against the related species, O. lienalis. It was selected because of its recognition by antibodies from cattle immunized with irradiated third-stage (L3) larvae and not by antibodies from animals infected with non-irradiated larvae. The original 311-bp clone was used to isolate a 1478-bp cDNA. Designated OvB20, this codes for 460 amino acid residues, hybridizes with a approximately 1.6 kBp transcript and appears to be transcribed from a filarial-specific, single copy gene. It is expressed in developing stages from embryo to L4 larva, but not in the adult. The product of OvB20 appears to undergo co- or post-translational processing: in vitro transcription and translation give rise to a polypeptide consistent with the deduced amino acid sequence (approximately 52 kDa), whilst products of 52 and 65 kDa are detected in larvae by immunoblotting and following in vitro translations to which exogenous microsomes have been added. A 42-kDa protein was also detected in all in vitro translations. No homologous genes were found in the computer databases, although there are regions of weak sequence similarity with C-reactive proteins. The functional role of OvB20 may warrant further attention, as it has recently been shown that the recombinant protein confers host protection against a related rodent filaria following active immunization (Taylor, M.J., Abdel-Wahab, N., Wu, Y., Jenkins, R.E. and Bianco, A.E. (1995) Onchocerca volvulus larval antigen, OvB20 induces partial protection in a rodent model of onchocerciasis. Infect. Immun. 63, 4417-4422).

Onchocerca volvulus larval antigen, OvB20, induces partial protection in a rodent model of onchocerciasis.

OvB20 is an antigen of Onchocerca volvulus preferentially recognized by sera from cattle vaccinated with irradiated infective larvae of Onchocerca lienalis. Antibodies raised against the recombinant protein were used to characterize the expression of the native protein in different developmental stages of O. volvulus and the rodent filaria Acanthocheilonema viteae. In O. volvulus, antibodies reacted to a polypeptide of 42 kDa in microfilariae and with proteins of 52 and 65 kDa in third-stage larvae. No products were detected in adult stages. Immunogold electron microscopy localized the native protein to discrete patches of the hypodermis and cuticle of infective larvae. Characterization of a homologous protein in A. viteae confirmed the stage-specific expression in infective larvae of the 65-kDa protein, which was secreted during in vitro culture. Vaccination of rodents against A. viteae with a B20-maltose-binding-protein fusion protein resulted in a 49 to 60% reduction in adult worm recoveries with a corresponding 97% reduction in microfilaremia.

The Pseudomonas putida ML2 plasmid-encoded genes for benzene dioxygenase are unusual in codon usage and low in G+C content.

Benzene dioxygenase, catalyzing the oxidation of benzene to cis-1,2-dihydroxy-cyclohexa-3,5-diene, comprises four polypeptides that are encoded by plasmid pHMT112 of Pseudomonas putida ML2. In this study, the nucleotide (nt) sequences of four genes encoding this enzyme (bedC1C2BA) were determined, and the amino acid (aa) sequences were deduced. The sequence showed significant homology with the chromosomally encoded benzene dioxygenase and toluene dioxygenase genes (73-77% for nt and 83-99% for aa), but not the plasmid-encoded naphthalene dioxygenase genes (20-26% for nt and 32-36% for aa). A conserved motif (Cys-Xaa-His-15-to-17 aa-Cys-Xaa2-His, where Xaa is any aa), proposed to bind the Rieske-type [2Fe-2S] cluster, was identified in the deduced aa sequence of the iron-sulfur proteins. Three regions were also identified in the flavoprotein which are likely to be involved in FAD and NAD+ binding. The gene order of bedC1C2BA is consistent with most ring-hydroxylating dioxygenases isolated from Pseudomonas. However, the G+C content of 47% is in contrast to the high G+C content of the Pseudomonas chromosome (63%) and other Pseudomonas plasmids (57%), and with its unique codon usage preference this suggests that bedC1C2BA originated from a host derived from a different genus.