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| 2. |
- Bivehed, Erik, et al.
(författare)
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Region-specific bioconversion of dynorphin neuropeptide detected by in situ histochemistry and MALDI imaging mass spectrometry
- 2017
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Ingår i: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 87, s. 20-27
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Tidskriftsartikel (refereegranskat)abstract
- Brain region-specific expression of proteolytic enzymes can control the biological activity of endogenous neuropeptides and has recently been targeted for the development of novel drugs, for neuropathic pain, cancer, and Parkinson's disease. Rapid and sensitive analytical methods to profile modulators of enzymatic activity are important for finding effective inhibitors with high therapeutic value. Combination of in situ enzyme histochemistry with MALDI imaging mass spectrometry allowed developing a highly sensitive method for analysis of brain-area specific neuropeptide conversion of synthetic and endogenous neuropeptides, and for selection of peptidase inhibitors that differentially target conversion enzymes at specific anatomical sites. Conversion and degradation products of Dynorphin B as model neuropeptide and effects of peptidase inhibitors applied to native brain tissue sections were analyzed at different brain locations. Synthetic dynorphin B (2 pmol) was found to be converted to the N-terminal fragments on brain sections whereas fewer C-terminal fragments were detected. N-ethylmaleimide (NEM), a non-selective inhibitor of cysteine peptidases, almost completely blocked the conversion of dynorphin B to dynorphin B(1-6; Leu-Enk-Arg), (1-9), (2-13), and (7-13). Proteinase inhibitor cocktail, and also incubation with acetic acid displayed similar results. Bioconversion of synthetic dynorphin B was region-specific producing dynorphin B(1-7) in the cortex and dynorphin B (2-13) in the striatum. Enzyme inhibitors showed region-and enzyme-specific inhibition of dynorphin bioconversion. Both phosphoramidon (inhibitor of the known dynorphin converting enzyme neprilysin) and opiorphin (inhibitor of neprilysin and aminopeptidase N) blocked cortical bioconversion to dynorphin B(1-7), wheras only opiorphin blocked striatal bioconversion to dynorphin B(2-13). This method may impact the development of novel therapies with aim to strengthen the effects of endogenous neuropeptides under pathological conditions such as chronic pain. Combining histochemistry and MALDI imaging MS is a powerful and sensitive tool for the study of inhibition of enzyme activity directly in native tissue sections. (C) 2016 The Authors. Published by Elsevier Inc.
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| 3. |
- Nikulin, Sergey, et al.
(författare)
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Effect of the Expression of ELOVL5 and IGFBP6 Genes on the Metastatic Potential of Breast Cancer Cells
- 2021
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Ingår i: Frontiers in Genetics. - : Frontiers Media S.A.. - 1664-8021. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Breast cancer (BC) is the leading cause of death from malignant neoplasms among women worldwide, and metastatic BC presents the biggest problems for treatment. Previously, it was shown that lower expression of ELOVL5 and IGFBP6 genes is associated with a higher risk of the formation of distant metastases in BC. In this work, we studied the change in phenotypical traits, as well as in the transcriptomic and proteomic profiles of BC cells as a result of the stable knockdown of ELOVL5 and IGFBP6 genes. The knockdown of ELOVL5 and IGFBP6 genes was found to lead to a strong increase in the expression of the matrix metalloproteinase (MMP) MMP1. These results were in good agreement with the correlation analysis of gene expression in tumor samples from patients and were additionally confirmed by zymography. The knockdown of ELOVL5 and IGFBP6 genes was also discovered to change the expression of a group of genes involved in the formation of intercellular contacts. In particular, the expression of the CDH11 gene was markedly reduced, which also complies with the correlation analysis. The spheroid formation assay showed that intercellular adhesion decreased as a result of the knockdown of the ELOVL5 and IGFBP6 genes. Thus, the obtained data indicate that malignant breast tumors with reduced expression of the ELOVL5 and IGFBP6 genes can metastasize with a higher probability due to a more efficient invasion of tumor cells.
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| 4. |
- Sui, Ping, et al.
(författare)
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Dimethyl-Labeling-Based Protein Quantification and Pathway Search : A Novel Method of Spinal Cord Analysis Applicable for Neurological Studies
- 2013
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 12:5, s. 2245-2252
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we describe a simple, fast, and inexpensive approach for quantitative analysis of proteins originated from small central nervous system (CNS) samples, i.e., rat spinal cord. The presented sample preparation protocol and quantification results from isotope dimethyl labeling were statistically evaluated and approved as a reliable and robust method for animal model studies of neurological disorders. Combined with the biopathway analysis tool IPA, the method was applied for comparative analysis of proteins in the dorsal and ventral segments of the rat spinal cord. The results are in agreement with the previously published protein patterns in these tissues. A majority (73%) of proteins identified as “related with CNS development and functions” were found to be overexpressed in the dorsal section compared to the ventral segment. The pathway related to neuropathic pain was overrepresented in the dorsal tissue samples. The developed novel approach may be applied for analyses of the spinal cord mediated neurological dysfunctions and pathological pain.
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| 5. |
- Sui, Ping, 1985-, et al.
(författare)
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Neuropeptide imaging in rat spinal cord with MALDI-TOF MS : Method development for the application in pain-related disease studies
- 2017
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Ingår i: European journal of mass spectrometry. - : SAGE Publications. - 1469-0667 .- 1751-6838. ; 23:3, s. 105-115
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Tidskriftsartikel (refereegranskat)abstract
- Spinal cord as a connection between brain and peripheral nervous system is an essential material for studying neural transmission, especially in pain-related research. This study was the first to investigate pain-related neuropeptide distribution in rat spinal cord using a matrix-assisted laser desorption ionization-time of flight imaging mass spectrometry (MALDI TOF MS) approach. The imaging workflow was evaluated and showed that MALDI TOF MS provides efficient resolution and robustness for neuropeptide imaging in rat spinal cord tissue. The imaging result showed that in naive rat spinal cord the molecular distribution of haeme, phosphatidylcholine, substance P and thymosin beta 4 were well in line with histological features. Three groups of pain-related neuropeptides, which are cleaved from prodynorphin, proenkephalin and protachykinin-1 proteins were detected. All these neuropeptides were found predominantly localized in the dorsal spinal cord and each group had unique distribution pattern. This study set the stage for future MALDI TOF MS application to elucidate signalling mechanism of pain-related diseases in small animal models.
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| 6. |
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| 7. |
- Sui, Ping, et al.
(författare)
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Proteomics of Neuropathic Pain : Proteins and Signaling Pathways Affected in a Rat Model
- 2014
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 13:9, s. 3957-3965
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Tidskriftsartikel (refereegranskat)abstract
- The myriad proteins may be involved in the mechanisms underlying the development and maintenance of neuropathic pain, an extremely disabling condition that originates from pathology of the nervous system. To address the mechanisms, we here analyzed proteins and cellular networks in the dorsal spinal cord mediating pain processing in a well-established rat model of neuropathic pain induced by spinal nerve ligation (SNL). Labeling-based proteomic methods together with high-resolution mass spectrometry for proteome analysis were applied. 38 proteins including synapsin 1 and microtubule-associated protein 2 were identified as differently expressed in the SNL group. Pathway analysis suggests that maladaptive changes in the levels of these proteins may contribute to abnormal synaptic transmission and neuronal intracellular signaling underlying the onset and development of neuropathic pain.
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