| 1. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 2. |
- Fransén, Karin, 1973-, et al.
(författare)
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CRP levels are significantly associated with CRP genotype and estrogen use in The Lifestyle, Biomarker and Atherosclerosis (LBA) study
- 2022
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Ingår i: BMC Cardiovascular Disorders. - : BioMed Central. - 1471-2261 .- 1471-2261. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: The C‑reactive protein (CRP) is an important biomarker for atherosclerosis and single nucleotide poly‑morphisms (SNPs) in the CRP locus have been associated with altered CRP levels and associated with risk for cardio‑vascular disease. However, the association between genetic variations in the CRP gene, estrogen use and CRP levels orearly signs of atherosclerosis in young healthy individuals is not fully characterized. We aimed to evaluate the influ‑ence of five genetic variants on both plasma CRP levels and carotid intima‑media thickness (cIMT) values, includingaspects on estrogen containing contraceptive use in females.Methods: Genotyping was performed with TaqMan real time PCR and compared with high sensitivity CRP serumlevels in 780 Swedish young, self‑reported healthy individuals. Haplotypes of the SNPs were estimated with the PHASEv 2.1. The cIMT was measured by 12 MHz ultrasound. The contraceptive use was self‑reported.Results: Strong associations between CRP and genotype were observed for rs3091244, rs1800947, rs1130864, andrs1205 in women (all p < 0.001). In men, only rs1800947 was associated with CRP (p = 0.029). The independent effectof genotypes on CRP remained significant also after adjustment for established risk factors. Female carriers of the H1/ATGTG haplotype had higher CRP than non‑carriers. This was specifically pronounced in the estrogen‑using group(p < 0.001), and they had also higher cIMT (p = 0.002) than non‑carriers but with a small cIMT difference between thehaplotype groups (0.02 mm). In parallel, a significant correlation between CRP and cIMT in the estrogen using groupwas observed (r = 0.194; p = 0.026).Conclusions: Estrogen use, genotypes and haplotypes in the CRP locus are significantly associated with CRP levels.Based on an observed interaction effect between sex/estrogen use and the H1/ATGTG haplotype on CRP, and amarginally thicker cIMT in the estrogen using group, our data suggest that both genotypes and estrogen usage couldbe involved in arterial wall structural differences. The causality between CRP levels and cIMT remains unclear, and theobserved difference in cIMT is not clinically relevant in the present state. Future larger and longitudinal studies mayshed further light on the role of more long‑term estrogen use and early atherosclerosis.
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| 3. |
- Elander, Nils, 1980-, et al.
(författare)
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Matrix metalloproteinase (MMP) -1, -2, -3 and -9 promoter polymorphisms in colorectal cancer
- 2006
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Ingår i: Anticancer Research. - : International Institute of Anticancer Research. - 0250-7005 .- 1791-7530. ; 26:1B, s. 791-795
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Tidskriftsartikel (refereegranskat)abstract
- Background: Matrix metalloproteinases (MMPs) are a group of matrix-degrading proteins implicated in several pathological processes, e.g., invasion and metastasis in malignant diseases such as colorectal cancer (CRC). Materials and methods: One hundred and twenty-seven CRC patients and 208 controls were genotyped for MMP-1, -2, -3 and -9 promoter polymorphisms. The genotyping was performed with PCR/primer-extension/DHPLC or PCR/RFLP. Results: The MMP-1 2G allele was significantly associated with CRC (p=0.037). No significant association between CRC and MMP-2, -3 or -9 polymorphisms was evident. The analysis of polymorphisms in the clinicopathological subgroups displayed no significant associations. Conclusion: The MMP-1 promoter polymorphism seems to affect the susceptibility to CRC, while MMP-2, -3 and -9 polymorphisms appear less likely to have any impact on CRC.
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| 4. |
- Fransén, Karin, 1973-, et al.
(författare)
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Association between ulcerative growth and hypoxia inducible factor-1alpha polymorphisms in colorectal cancer patients
- 2006
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Ingår i: Molecular Carcinogenesis. - : John Wiley & Sons. - 0899-1987 .- 1098-2744. ; 45:11, s. 833-840
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Tidskriftsartikel (refereegranskat)abstract
- The hypoxia inducible factor-1alpha (HIF-1alpha) has been found to be involved in several different physiological mechanisms, such as blood-vessel formation, apoptosis, and erythropoiesis. HIF-1alpha is hydroxylated at normoxia and rapidly degraded via the von Hippel-Lindau (VHL)/ubiquitin-proteasome degradation system to prevent angiogenesis. In a previous study, the C1772T (P582S) and the G1790A (A588T) polymorphisms were identified in the human HIF-1alpha gene, which was shown to have a higher transactivating capability in vitro compared to the wild type allele. However, the role for these polymorphisms in vivo is still unclear. In the present investigation, we have therefore studied the role of the two polymorphic variants in the development of colorectal cancer (CRC) with PCR/RFLP (restriction fragment length polymorphism), single strand conformation analysis (SSCA), and immunohistochemistry (IHC). A significant higher-risk was identified between patients heterozygous for the C1772T polymorphism and the more severe ulcerative growth pattern compared to homozygous C1772C wild type tumors (RR = 5.2; 95% CI 1.26-21.6; P = 0.006). This was also verified on the allelic level (RR = 6.5; 95% CI 1.58-26.8; P = 0.001). In addition, patients carrying one or more polymorphic alleles in either the HIF-1alpha C1772T or the G1790A polymorphisms display significant higher risk for the development of ulcerative CRCs (RR = 4.17; 95% CI = 1.33-13.08; P = 0.004). These results suggest that the HIF-1alpha polymorpisms are an important factor for development of a subset of ulcerative intestinal tumors. Future screening of the polymorphic HIF-1alpha allele may therefore be of importance in the selection of treatment strategies of CRC.
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| 7. |
- Fransén, Karin, 1973-, et al.
(författare)
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Nitric oxide synthase 2 (NOS2) promoter polymorphisms in colorectal cancer
- 2005
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Ingår i: Cancer Letters. - : Elsevier. - 0304-3835 .- 1872-7980. ; 225:1, s. 99-103
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Tidskriftsartikel (refereegranskat)abstract
- Previously, increased expression of nitric oxide synthase 2 (NOS2) in colorectal cancer (CRC) has been identified. The NOS2 gene is transcriptionally regulated, which suggests that polymorphisms in the NOS2 promoter may have a role for CRC development and progression. The genotyping was performed with PCR/RFLP, single strand conformation analysis or MegaBACE genotyping of normal blood DNA from CRC patients and normal healthy controls. However, no significant association between NOS2 polymorphisms and CRC onset or clinical outcome was evident. In conclusion, these results, therefore, suggest that NOS2 promoter polymorphisms have a limited effect on the onset or progression of CRC.
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| 8. |
- Fransén, Karin, 1973-, et al.
(författare)
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Polymorphism in the retinoic acid metabolizing enzyme CYP26B1 and the development of Crohn's disease
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:8, s. e72739-
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Tidskriftsartikel (refereegranskat)abstract
- Several studies suggest that Vitamin A may be involved in the pathogenesis of inflammatory bowel disease (IBD), but the mechanism is still unknown. Cytochrome P450 26 B1 (CYP26B1) is involved in the degradation of retinoic acid and the polymorphism rs2241057 has an elevated catabolic function of retinoic acid, why we hypothesized that the rs2241057 polymorphism may affect the risk of Crohn's disease (CD) and Ulcerative Colitis (UC). DNA from 1378 IBD patients, divided into 871 patients with CD and 507 with UC, and 1205 healthy controls collected at Örebro University Hospital and Karolinska University Hospital were analyzed for the CYP26B1 rs2241057 polymorphism with TaqMan® SNP Genotyping Assay followed by allelic discrimination analysis. A higher frequency of patients homozygous for the major (T) allele was associated with CD but not UC compared to the frequency found in healthy controls. A significant association between the major allele and non-stricturing, non-penetrating phenotype was evident for CD. However, the observed associations reached borderline significance only, after correcting for multiple testing. We suggest that homozygous carriers of the major (T) allele, relative to homozygous carriers of the minor (C) allele, of the CYP26B1 polymorphism rs2241057 may have an increased risk for the development of CD, which possibly may be due to elevated levels of retinoic acid. Our data may support the role of Vitamin A in the pathophysiology of CD, but the exact mechanisms remain to be elucidated.
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| 10. |
- Grahn, Niclas, et al.
(författare)
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Molecular identification of Helicobacter DNA present in human colorectal adenocarcinomas by 16S rDNA PCR amplification and pyrosequencing analysis
- 2005
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Ingår i: Journal of Medical Microbiology. - : Microbiology Society. - 0022-2615 .- 1473-5644. ; 54:11, s. 1031-1035
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Tidskriftsartikel (refereegranskat)abstract
- Seroepidemiological studies have indicated that Helicobacter pylori infection might be a possible risk factor for colorectal adenocarcinoma (CRC) development. However, limited information is available as to whether or not Helicobacter species are present in CRC tissues. In this study the presence of Helicobacter DNA in 77 CRC biopsies was investigated by means of a Helicobacter species-specific 16S rDNA PCR assay and real-time DNA pyrosequencing of the 16S rDNA variable V3 region. Pyrosequencing revealed the presence of Helicobacter DNA sequences in 21 of 77 biopsy specimens (27%). 16S rDNA sequences corresponding to H. pylori 26695 and H. pylori J99 were most commonly found. Intriguingly, one sequence belonged to Helicobacter mustelae, previously identified in ferrets. No significant correlations were found in the prevalence of Helicobacter DNA between colon and rectum tumour biopsies (P = 0.815), nor between Dukes' classes A/B and C/D (P = 0.262). 16S rDNA PCR amplification combined with pyrosequencing analysis of 16S rDNA variable V3 regions provides a powerful molecular tool to identify Helicobacter species in human biopsy specimens. © 2005 SGM.
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