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941.
Following acute sciatic nerve crush injury (SNCI), inflammation and the improper phagocytic clearance of dying Schwann cells (SCs) has effects on remodeling that lead to morbidity and incomplete functional recovery. Therapeutic strategies like the use of erythropoietin (EPO) for peripheral nerve trauma may serve to bring immune cell phagocytotic clearance under control to support debris clearance. We evaluated EPO’s effect on SNCI and found EPO treatment increased myelination and sciatic functional index (SFI) and bolstered anti-apoptosis and phagocytosis of myelin debris via CD206+ macrophages when compared to saline treatment. EPO enhanced M2 phenotype activity, both in bone marrow-derived macrophages (BMMØs) and peritoneal-derived macrophages (PMØs) in vitro, as well as in PMØs in vivo. EPO increased efferocytosis of apoptotic sciatic nerve derived Schwann cells (SNSCs) in both settings as demonstrated using immunofluorescence (IF) and flow cytometry. EPO treatment significantly attenuated pro-inflammatory genes (IL1β, iNOS, and CD68) and augmented anti-inflammatory genes (IL10 and CD163) and the cell-surface marker CD206. EPO also increased anti-apoptotic (Annexin V/7AAD) effects after lipopolysaccharide (LPS) induction in macrophages. Our data demonstrate EPO promotes the M2 phenotype macrophages to ameliorate apoptosis and efferocytosis of dying SCs and myelin debris and improves SN functional recovery following SNCI.Subject terms: Neurodegeneration, Somatic system 相似文献
942.
Simardeep Kaur Mahesh Kumar Samota Manoj Choudhary Mukesh Choudhary Abhay K. Pandey Anshu Sharma Julie Thakur 《Physiology and Molecular Biology of Plants》2022,28(2):485
In agro-ecosystem, plant pathogens hamper food quality, crop yield, and global food security. Manipulation of naturally occurring defense mechanisms in host plants is an effective and sustainable approach for plant disease management. Various natural compounds, ranging from cell wall components to metabolic enzymes have been reported to protect plants from infection by pathogens and hence provide specific resistance to hosts against pathogens, termed as induced resistance. It involves various biochemical components, that play an important role in molecular and cellular signaling events occurring either before (elicitation) or after pathogen infection. The induction of reactive oxygen species, activation of defensive machinery of plants comprising of enzymatic and non-enzymatic antioxidative components, secondary metabolites, pathogenesis-related protein expression (e.g. chitinases and glucanases), phytoalexin production, modification in cell wall composition, melatonin production, carotenoids accumulation, and altered activity of polyamines are major induced changes in host plants during pathogen infection. Hence, the altered concentration of biochemical components in host plants restricts disease development. Such biochemical or metabolic markers can be harnessed for the development of “pathogen-proof” plants. Effective utilization of the key metabolites-based metabolic markers can pave the path for candidate gene identification. This present review discusses the valuable information for understanding the biochemical response mechanism of plants to cope with pathogens and genomics-metabolomics-based sustainable development of pathogen proof cultivars along with knowledge gaps and future perspectives to enhance sustainable agricultural production. 相似文献
943.
Singh A. Amala Mithin Minther Arul Franco P. Binoj J. S. Sahaya Elsi S. Divin Kumar M. 《Plasmonics (Norwell, Mass.)》2019,14(3):595-610
Plasmonics - Corrosion is a natural process which gradually destructs the materials with their environment by chemical or electrochemical means. Mechanized boat hull structures used in fishing were... 相似文献
944.
945.
946.
947.
Shearwin-Whyatt L Baliga B Doumanis J Kumar S 《Biochemical and biophysical research communications》2001,282(5):1114-1119
Cellular defects which prevent apoptotic cell death can result in the generation of hyperproliferative disorders and can prevent the effective treatment of such diseases. The majority of cellular defects which result in apoptosis resistance lie upstream of caspase activation. We have described chimeric caspase molecules consisting of the prodomain of caspase-2 fused to the amino terminus of caspase-3, and which are tagged at the carboxyl terminus with green fluorescent protein (GFP) to allow direct visualisation of transfected cells. Here we show that these chimeric caspase molecules possess potent, rapid cell-killing activity in cell lines which display a range of defects resulting in apoptosis resistance. 相似文献
948.
Combinatorial random mutageneses involving either Asn43 with Asn44 (set 1) or Glu46 with an adjacent insertion (set 2) were undertaken to explore the functional perfection of the guanine recognition loop of ribonuclease T(1) (RNase T(1)). Four hundred unique recombinants were screened in each set for their ability to enhance enzyme catalysis of RNA cleavage. After a thorough selection procedure, only six variants were found that were either as active or more active than wild type which included substitutions of Asn43 by Gly, His, Leu, or Thr, an unplanned Tyr45Ser substitution and Glu46Pro with an adjacent Glu47 insertion. Asn43His-RNase T(1) has the same loop sequence as that for RNases Pb(1) and Fl(2). None of the most active mutants were single substitutions at Asn44 or double substitutions at Asn43 and Asn44. A total of 13 variants were purified, and these were subjected to kinetic analysis using RNA, GpC, and ApC as substrates. Modestly enhanced activities with GpC and RNA involved both k(cat) and K(M) effects. Mutants having low activity with GpC had proportionately even lower relative activity with RNA. Asn43Gly-RNase T(1) and all five of the purified mutants in set 2 exhibited similar values of k(cat)/K(M) for ApC which were the highest observed and about 10-fold that for wild type. The specificity ratio [(k(cat)/K(M))(GpC)/(k(cat)/K(M))(ApC)] varied over 30 000-fold including a 10-fold increase [Asn43His variant; mainly due to a low (k(cat)/K(M))(ApC)] and a 3000-fold decrease (Glu46Ser/(insert)Gly47 variant; mainly due to a low (k(cat)/K(M))(GpC)) as compared with wild type. It is interesting that k(cat) (GpC) for the Tyr45Ser variant was almost 4-fold greater than for wild type and that Pro46/(insert)Glu47 RNase T(1) is 70-fold more active than the permuted variant (insert)Pro47-RNase T(1) which has a conserved Glu46. In any event, the observation that only 6 out of 800 variants surveyed had wild-type activity supports the view that functional perfection of the guanine recognition loop of RNase T(1) has been achieved. 相似文献
949.
Kumar SS Malladi V Sankaran K Haigh R Williams P Balakrishnan A 《Canadian journal of microbiology》2001,47(8):727-734
Enteropathogenic Escherichia coli (EPEC) causes persistent infantile diarrhoea. This nontoxigenic E. coli exhibits a complicated pathogenic mechanism in which its outer membrane proteins and type III secretory proteins damage intestinal epithelium and cause diarrhoea. In accordance with this, our previous study using HEp-2 cells demonstrated cytopathic effects caused by cell-free outer membrane preparations of EPEC. In this study, we report the extrusion of actin-positive strands from HEp-2 and Int 407 cells when treated with outer membrane preparations. An interesting observation of this work, perhaps relevant to the characteristic localized three-dimensional colony formation of EPEC, is the attachment of a wild type EPEC strain to these actin-positive strands. 相似文献
950.
Pattanayak D Chakrabarti SK Kumar PA Naik PS 《Indian journal of experimental biology》2001,39(9):897-901
RAPD based fingerprinting of 21 serovars of Bacillus thuringiensis (Bt) representing different serotypes was performed using 19 random decamer primers. A total of 172 polymorphic fragments, ranging in size from 161-2789 bp, were amplified from 13 of the 19 primers. Pairwise genetic similarity analysis revealed very low similarity values, ranging from 3-68%, among the serovars of Bt, indicating high genetic divergence. Nineteen serovars of Bt fell in two major clusters and remaining two formed solitary clusters in the dendogram. Clustering of Bt strains established genetic relatedness between serovars and serotypes. It has been suggested that RAPD analysis can be used for genotypic characterization of Bt to complement flagellar serotyping. 相似文献