Lipid peroxidation has been implicated in a variety of diseases. 4-Hydroxy-2-nonenal (HNE), a major oxidation by-product, is cytotoxic, mutagenic, and genotoxic, being involved in disease pathogenesis. Naturally occurring pharmacologically active small molecules are very attractive as natural nonsteroidal anti-inflammatory agents. Interest has greatly increased recently in the pharmacotherapeutic potential of curcumin, the yellow pigment found in the rhizomes of the perennial herb Curcuma longa (turmeric). Curcumin is efficacious against colon cancer, cystic fibrosis, and a variety of other disorders. Curcumin's full pharmacological potential is limited owing to its extremely limited water solubility. We report here that the water solubility of curcumin could be increased from 0.6 microg/ml to 7.4 microg/ml (12-fold increase) by the use of heat. Spectrophotometric (400-700 nm) and mass spectrometric profiling of the heat-extracted curcumin displays no significant heat-mediated disintegration of curcumin. Using an enzyme-linked immunosorbent assay that employed HNE modification of solid-phase antigen, we found that the heat-solubilized curcumin inhibited HNE-protein modification by 80%. Thus, inhibition of HNE modification may be a mechanism by which curcumin exerts its effect. We also report a simple assay to detect curcumin spectrophotometrically. Curcumin was solubilized in methanol and serially diluted in methanol to obtain a set of standards that were then read for optical density at 405 nm. Curcumin in the heat-solubilized samples was determined from this standard. Heat-solubilized curcumin should be considered in clinical trials involving curcumin, especially in the face of frustrating results obtained regarding curcumin-mediated correction of cystic fibrosis defects.
Peripheral nerve injury is often followed by the development of severe neuropathic pain. Nerve degeneration accompanied by inflammatory mediators is thought to play a role in generation of neuropathic pain. Neuronal cell death follows axonal degeneration, devastating a vast number of molecules in injured neurons and the neighboring cells. Because we have little understanding of the cellular and molecular mechanisms underlying neuronal cell death triggered by nerve injury, we conducted a proteomics study of rat 4th and 5th lumbar (L4 and L5) dorsal root ganglion (DRG) after L5 spinal nerve ligation. DRG proteins were displayed on two-dimensional gels and analyzed through quantitative densitometry, statistical validation of the quantitative data, and peptide mass fingerprinting for protein identification. Among approximately 1,300 protein spots detected on each gel, we discovered 67 proteins that were tightly regulated by nerve ligation. We find that the injury to primary sensory neurons turned on multiple cellular mechanisms critical for the structural and functional integrity of neurons and for the defense against oxidative damage. Our data indicate that the regulation of metabolic enzymes was carefully orchestrated to meet the altered energy requirement of the DRG cells. Our data also demonstrate that ligation of the L5 spinal nerve led to the upregulation in the L4 DRG of the proteins that are highly expressed in embryonic sensory neurons. To understand the molecular mechanisms underlying neuropathic pain, we need to comprehend such dynamic aspect of protein modulations that follow nerve injury.
Hyaluronan (HA) and chondroitin sulfate clearance from lymph and blood is mediated by the hyaluronan receptor for endocytosis (HARE). The purification and molecular cloning (Zhou, B., Weigel, J. A., Saxena, A., and Weigel, P. H. (2002) Mol. Biol. Cell 13, 2853-2868) of this cell surface receptor were finally achieved after we developed monoclonal antibodies (mAbs) against HARE. There are actually two independent isoreceptors for HA, which in rat are designated the 175-kDa HARE and 300-kDa HARE. Only one mAb (number 174) effectively and completely blocked the specific uptake of 125 I-HA at 37°C by rat liver sinusoidal endothelial cells.125 I-HA binding to both the 175-kDa and 300-kDa HARE proteins in a ligand blot assay was almost completely inhibited by <1 g/ml mAb-174, whereas mouse IgG had little or no effect. MAb-174 also performed very well in Western analysis, indirect fluorescence microscopy, and a variety of immuno-procedures. Immunohistochemistry using mAb-174 localized HARE to the sinusoidal cells of rat liver, spleen, and lymph node. Western analysis using mAb-174 revealed that the sizes of both HARE glycoproteins were the same in these three tissues.125 I-HA was taken up and degraded by excised rat livers that were continuously perfused ex vivo with a recirculating medium. This HA clearance and metabolism by liver, which is a physiological function of HARE, was very effectively blocked by mAb-174 but not by mouse IgG. The results indicate that mAb-174 will be a useful tool to study the functions of HARE and the physiological significance of HA clearance.After Meyer and Palmer (1) discovered hyaluronan (HA), 1 it was found to be a component of essentially all vertebrate extracellular matrices (ECMs). Fibroblasts, keratinocytes, chondrocytes, and other cells continuously synthesize and secrete HA, which is a linear polymer with a native molecular mass that may exceed 10 7 Da and is composed of the repeating disaccharide 2-deoxy,2-acetamido-D-glucopyranosyl- (1, 4)-D-glucuronopyranosyl- (1, 3). Despite its simple structure, HA is involved in many cell functions including migration, differentiation, and phagocytosis (2-6). HA is important in development (4, 7), wound healing (8, 9), angiogenesis (10, 11), and tumor growth and metastasis (12, 13). Although previously believed to be only a structural component in the ECM, HA is now also recognized as an active cell-signaling molecule. Some cell types show distinct physiological responses to HA of different sizes. In particular, some cell types respond physiologically to very small, but not large, HA. Small HA oligosaccharides containing 14 -20 sugars stimulate angiogenesis by endothelial cells (10,11,14), induce gene expression in activated macrophages (15), and induce NO synthase expression in sinusoidal LECs and Kupffer cells, but not hepatocytes or stellate cells (16). Cell surface HA receptors identified to date include CD44, RHAMM (CD168), ICAM-1 (CD54), LYVE-1 (5), and an endocytic receptor that is specific for HA and chondroitin sulfate. This latte...
The endocytic hyaluronan (HA) receptor of liver sinusoidal endothelial cells (LECs) is responsible for the clearance of HA and other glycosaminoglycans from the circulation in mammals. We report here for the first time the purification of this liver HA receptor. Using lectin and immuno-affinity chromatography, two HA receptor species were purified from detergent-solubilized membranes prepared from purified rat LECs. In nonreducing SDS-polyacrylamide gel electrophoresis (PAGE), these two proteins migrated at 175-and ϳ300 kDa corresponding to the two species previously identified by photoaffinity labeling of live cells as the HA receptor (Yannariello-Brown, J., Frost, S. J., and Weigel, P. H. (1992) J. Biol. Chem. 267, 20451-20456). These two proteins co-purify in a molar ratio of 2:1 (175:300), and both proteins are active, able to bind HA after SDS-PAGE, electrotransfer, and renaturation. After reduction, the 175-kDa protein migrates as a ϳ185-kDa protein and is not able to bind HA. The 300-kDa HA receptor is a complex of three disulfide-bonded subunits that migrate in reducing SDS-PAGE at ϳ260, 230, and 97 kDa. These proteins designated, respectively, the ␣, , and ␥ subunits are present in a molar ratio of 1:1:1 and are also unable to bind HA when reduced. The 175-kDa protein and all three subunits of the 300-kDa species contain N-linked oligosaccharides, as indicated by increased migration in SDS-PAGE after treatment with N-glycosidase F. Both of the deglycosylated, nonreduced HA receptor proteins still bind HA.HA 1 is an important extracellular matrix component of all tissues and plays a key role in development, cell proliferation, cell adhesion, recognition, morphogenesis, differentiation, and inflammation (1-4). The daily total body turnover of HA in humans is at least 1 g/day (4). HA degradation and removal in the body occurs via two clearance systems (3): one is in the lymphatic system, which accounts for ϳ85% of the HA turnover, and another system is hepatic, accounting for ϳ15% of the total body HA turnover. HA in tissues throughout the body is continuously synthesized and degraded. Very large HA molecules (ϳ10 7 Da) are partially degraded to large fragments (ϳ10 6 Da) that are then released from the matrix and flow with the lymph to lymph nodes. The majority of HA (ϳ85%) is completely degraded in the lymph nodes by unknown mechanisms and the remaining HA (ϳ15%) that passes through the nodes finally enters the blood. Clearance of this circulating HA is presumably important for normal health (3, 4). Elevated serum HA levels are found in several disease conditions such as liver cirrhosis, rheumatoid arthritis, psoriasis, scleroderma, and some cancers (5-7).LECs have a very active recycling, endocytic receptor that removes HA and other glycosaminoglycans, such as chondroitin sulfate, from the circulation (3, 8 -10). Earlier reports misidentified this LEC HAR as ICAM-1 (11, 12), also known as CD54, which is a 90-kDa protein. This finding was later recognized as an artifact in that ICAM-1 bound nonspecifica...
BackgroundNumerous formaldehyde-fixed and paraffin-embedded clinical tissues have been created in the past decades and stored in pathological depositories at hospitals as well as in clinical laboratories worldwide. In addition to the archived tissues, formaldehyde-fixation is also mandatory for preparing proteomics samples from diseased patients or animal models in order to inactivate contagious agents. Protein extraction from formaldehyde-fixed tissues is hampered by the Schiff base formation between the amino groups of proteins and formaldehyde. Although achievement of the highest extraction efficiency of proteins from the formaldehyde-fixed tissues is essential for obtaining maximum proteomics information, no attention has been paid to the concentration dependence of tris(hydroxymethyl)aminomethane on the extraction efficacy. We suspected that the concentration of tris(hydroxymethyl)aminomethane affects the protein extraction efficiency because of its property as a primary amine that reverses the Schiff base formation between the primary amines of proteins and formaldehyde. Thus we pursued optimization of the component and protocol of protein extraction buffer to achieve better extraction efficiency of proteins from formaldehyde-fixed and paraffin-embedded tissues.ResultsIn order to simulate protein extraction from diseased tissues we made formaldehyde-fixed and paraffin-embedded samples from mouse liver slices and investigated the protein extraction efficiency and speed by changing the concentration of the protein extraction buffer component tris(hydroxymethyl)aminomethane under various extraction conditions. We find, as expected, that tris(hydroxymethyl)aminomethane significantly affects the performance of protein extraction from the formaldehyde-fixed and paraffin-embedded samples both in the extraction yield and in the extraction speed.ConclusionsWe recommend the concentration of tris(hydroxymethyl)aminomethane in protein extraction buffer to be higher than 300 mM when extraction is conducted for 90 min at 90°C to achieve the most efficient protein extraction in a shorter time. The information will be essential for performing the most efficient protein extraction from formaldehyde-fixed and paraffin-embedded tissue samples for proteomics analysis.
The main objective of the present study was isolation, purification, and characterization of actinomycetes from soil samples, having antimicrobial activity against 12 selected pathogenic strains. Soils samples were taken from different niche habitats of Sheopur district, Madhya Pradesh, India. These samples were serially diluted and plated on actinomycete isolation agar media. Potential colonies were screened, purified, and stored in glycerol stock. Isolates were morphologically and biochemically characterized. These isolates were subjected to extraction for production of the antibacterial compound. Antibacterial activity and Minimum Inhibitory Concentration (MIC) of the purified extract of isolates were evaluated. Totally 31 actinomycete isolates were tested for antagonistic activity against 12 pathogenic microorganisms. Isolates AS14, AS27, and AS28 were highly active, while AS1 showed less activity against the pathogenic microorganisms. Isolate AS7 exhibited the highest antagonistic activity against Bacillus cereus (24 mm) and AS16 showed the highest activity against Enterococcus faecalis (21 mm). MIC was also determined for actinomycete isolates against all the tested microorganisms. MIC of actinomycete isolates was found to be 2.5 mg/ml against Shigella dysenteriae, Vancomycin-resistant enterococci, and Klebsiella pneumoniae, and was 1.25 mg/ml for Staphylococcus saprophyticus, Streptococcus pyogenes, Staphylococcus epidermidis, Methicillin-resistant Staphylococcus, Bacillus cereus, Staphylococcus xylosus, Methicillin-resistant Staphylococcus aureus, Enterococcus faecalis, and Staphylococcus aureus. All actinomycetes isolates showed antibacterial activity against S. aureus, while they showed less activity against S. dysenteriae. These isolates had antibacterial activity and could be used in the development of new antibiotics for pharmaceutical or agricultural purposes.
BackgroundChikungunya virus (CHIKV) has emerged as one of the most important arboviruses of public health significance in the past decade. The virus is mainly maintained through human-mosquito-human cycle. Other routes of transmission and the mechanism of maintenance of the virus in nature are not clearly known. Vertical transmission may be a mechanism of sustaining the virus during inter-epidemic periods. Laboratory experiments were conducted to determine whether Aedes aegypti, a principal vector, is capable of vertically transmitting CHIKV or not.Methodology/Principal FindingsFemale Ae. aegypti were orally infected with a novel ECSA genotype of CHIKV in the 2nd gonotrophic cycle. On day 10 post infection, a non-infectious blood meal was provided to obtain another cycle of eggs. Larvae and adults developed from the eggs obtained following both infectious and non-infectious blood meal were tested for the presence of CHIKV specific RNA through real time RT-PCR. The results revealed that the larvae and adults developed from eggs derived from the infectious blood meal (2nd gonotrophic cycle) were negative for CHIKV RNA. However, the larvae and adults developed after subsequent non-infectious blood meal (3rd gonotrophic cycle) were positive with minimum filial infection rates of 28.2 (1∶35.5) and 20.2 (1∶49.5) respectively.Conclusion/SignificanceThis study is the first to confirm experimental vertical transmission of emerging novel ECSA genotype of CHIKV in Ae. aegypti from India, indicating the possibilities of occurrence of this phenomenon in nature. This evidence may have important consequence for survival of CHIKV during adverse climatic conditions and inter-epidemic periods.
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