| 1. |
- Björnsson, Bergthor, et al.
(författare)
-
Conventional, but not remote ischemic preconditioning, reduces iNOS transcription in liver ischemia/reperfusion
- 2014
-
Ingår i: World Journal of Gastroenterology. - : Baishideng Publishing Group Co. Limited. - 1007-9327 .- 2219-2840. ; 20:28, s. 9506-9512
-
Tidskriftsartikel (refereegranskat)abstract
- AIM: To study the effects of preconditioning on inducible nitric oxide synthase (iNOS) and interleukin 1 (IL-1) receptor transcription in rat liver ischemia/reperfusion injury (IRI). METHODS: Seventy-two male rats were randomized into 3 groups: the one-hour segmental ischemia (IRI, n = 24) group, the ischemic preconditioning (IPC, n = 24) group or the remote ischemic preconditioning (R-IPC, n = 24) group. The IPC and R-IPC were performed as 10 min of ischemia and 10 min of reperfusion. The iNOS and the IL-1 receptor mRNA in the liver tissue was analyzed with real time PCR. The total Nitrite and Nitrate (NOx) in continuously sampled microdialysate (MD) from the liver was analyzed. In addition, the NOx levels in the serum were analyzed. RESULTS: After 4 h of reperfusion, the iNOS mRNA was significantly higher in the R-IPC (Delta Ct: 3.44 +/- 0.57) group than in the IPC (Delta Ct: 5.86 +/- 0.82) group (P = 0.025). The IL-1 receptor transcription activity was reduced in the IPC group (Delta Ct: 1.88 +/- 0.53 to 4.81 +/- 0.21), but not in the R-IPC group, during reperfusion (P = 0.027). In the MD, a significant drop in the NOx levels was noted in the R-IPC group (12.3 +/- 2.2 to 4.7 +/- 1.2 mu mol/L) at the end of ischemia compared with the levels in early ischemia (P = 0.008). A similar trend was observed in the IPC group (11.8 +/- 2.1 to 6.4 +/- 1.5 mu mol/L), although this difference was not statistically significant. The levels of NOx rose quickly during reperfusion in both groups. CONCLUSION: IPC, but not R-IPC, reduces iNOS and IL-1 receptor transcription during early reperfusion, indicating a lower inflammatory reaction. NOx is consumed in the ischemic liver lobe.
|
|
| 2. |
- Björnsson, Bergthor, et al.
(författare)
-
Nitrite, a novel method to decrease ischemia/reperfusion injury in the rat liver
- 2015
-
Ingår i: World Journal of Gastroenterology. - : Baishideng Publishing Group Co. Limited. - 1007-9327 .- 2219-2840. ; 21:6, s. 1775-1783
-
Tidskriftsartikel (refereegranskat)abstract
- AIM: To investigate whether nitrite administered prior to ischemia/reperfusion (I/R) reduces liver injury.METHODS: Thirty-six male Sprague-Dawley rats were randomized to 3 groups, including sham operated (n = 8), 45-min segmental ischemia of the left liver lobe (IR, n = 14) and ischemia/reperfusion (I/R) preceded by the administration of 480 nmol of nitrite (n = 14). Serum transaminases were measured after 4 h of reperfusion. Liver microdialysate (MD) was sampled in 30-min intervals and analyzed for glucose, lactate, pyruvate and glycerol as well as the total nitrite and nitrate (NOx). The NOx was measured in serum.RESULTS: Aspartate aminotransferase (AST) at the end of reperfusion was higher in the IR group than in the nitrite group (40 ± 6.8 μkat/L vs 22 ± 2.6 μkat/L, P = 0.022). Similarly, alanine aminotransferase (ALT) was also higher in the I/R group than in the nitrite group (34 ± 6 μkat vs 14 ± 1.5 μkat, P = 0.0045). The NOx in MD was significantly higher in the nitrite group than in the I/R group (10.1 ± 2.9 μM vs 3.2 ± 0.9 μM, P = 0.031) after the administration of nitrite. During ischemia, the levels decreased in both groups and then increased again during reperfusion. At the end of reperfusion, there was a tendency towards a higher NOx in the I/R group than in the nitrite group (11.6 ± 0.7 μM vs 9.2 ± 1.1 μM, P = 0.067). Lactate in MD was significantly higher in the IR group than in the nitrite group (3.37 ± 0.18 mM vs 2.8 ± 0.12 mM, P = 0.01) during ischemia and the first 30 min of reperfusion. During the same period, glycerol was also higher in the IRI group than in the nitrite group (464 ± 38 μM vs 367 ± 31 μM, P = 0.049). With respect to histology, there were more signs of tissue damage in the I/R group than in the nitrite group, and 29% of the animals in the I/R group exhibited necrosis compared with none in the nitrite group. Inducible nitric oxide synthase (iNOS) transcription increased between early ischemia (t = 15) and the end of reperfusion in both groups.CONCLUSION: Nitrite administered before liver ischemia in the rat liver reduces anaerobic metabolism and cell necrosis, which could be important in the clinical setting.
|
|
| 3. |
- Björnsson, Bergthor, et al.
(författare)
-
Remote or Conventional Ischemic Preconditioning -Local Liver Metabolism in Rats Studied with Microdialysis
- 2012
-
Ingår i: Journal of Surgical Research. - : Elsevier. - 0022-4804 .- 1095-8673. ; 176:1, s. 55-62
-
Tidskriftsartikel (refereegranskat)abstract
- Background. Ischemic preconditioning (IPC) of the liver decreases liver injury secondary to ischemia and reperfusion. An attractive alternative to IPC is remote ischemic preconditioning (R-IPC), but these two methods have not previously been compared. Material and Methods. Eighty-seven rats were randomized into four groups: sham operated (n = 15), 1 h segmental ischemia (IRI, n = 24), preceeded by IPC (n = 24), or R-IPC (n = 24) (to the left hindleg). IPC and R-IPC were performed with 10 min ischemia and 10 min of reperfusion. Analyses of liver microdialysate (MD), serum transaminase levels, and liver histology were made. Results. Rats treated with IPC and R-IPC had significantly lower AST, 71.5 (19.6) IU/L respective 96.6 (12.4) at 4 h reperfusion than those subjected to IRI alone, 155 (20.9), P = 0.0004 and P = 0.04 respectively. IPC also had lower ALT levels, 41.6 (11.3) IU/L than had IRI 107.4 (15.5), P = 0.003. The MD glycerol was significantly higher during ischemia in the R-IPC = 759 (84) mu M] and the IRI = 732 (67)] groups than in the IPC 514 (70) group, P = 0.022 and P = 0.046 respectively. The MD glucose after ischemia was lower in the IPC group 7.1 (1.2) than in the IRI group 12.7 (1.6), P = 0.005. Preconditioning to the liver caused an direct increase in lactate, glucose and glycerol in the ischemic segment compared with the control segment an effect not seen in the R-IPC and IRI groups. Conclusions. IPC affects glucose metabolism in the rat liver, observed with MD. IPC reduces liver cell injury during ischemic and reperfusion in rats. R-IPC performed over the same length of time as IPC does not have the same effect as the latter on ALT levels and MD glycerol; this may suggest that R-IPC does not offer the same protection as IPC in this setting of rat liver IRI.
|
|
| 4. |
- Bojmar, Linda, 1983-, et al.
(författare)
-
Extracellular vesicle and particle isolation from human and murine cell lines, tissues, and bodily fluids
- 2021
-
Ingår i: STAR protocols. - : Cell Press. - 2666-1667. ; 2:1
-
Tidskriftsartikel (refereegranskat)abstract
- We developed a modified protocol, based on differential ultracentrifugation (dUC), to isolate extracellular vesicles and particles (specifically exomeres) (EVPs) from various human and murine sources, including cell lines, surgically resected tumors and adjacent tissues, and bodily fluids, such as blood, lymphatic fluid, and bile. The diversity of these samples requires robust and highly reproducible protocols and refined isolation technology, such as asymmetric-flow field-flow fractionation (AF4). Our isolation protocol allows for preparation of EVPs for various downstream applications, including proteomic profiling. For complete details on the use and execution of this protocol, please refer to Hoshino et al. (2020).
|
|
| 5. |
- Bojmar, Linda
(författare)
-
Metastatic Mechanisms in Malignant Tumors
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The ultimate cause of cancer related deaths is metastasis. This thesis is about three of the main human cancers; breast, colorectal and pancreatic cancer, that together account for more than 25% of the cancer-related deaths worldwide. The focus of the thesis is the spread of cancer, metastasis, and the aim was to investigate mechanisms that can be of importance for this process. We analyzed patient samples to validate the role of epithelialto-mesenchymal transition in vivo and found regulations of many related factors. However, these changes tend to fluctuate along the metastatic process, something which makes targeting complicated. We, moreover, focused on the influence of the tumor microenvironment for metastatic spread. In pancreatic cancer, the stroma constitutes the main part of many tumors. We analyzed the crosstalk between tumor and stromal cell and focused on the mediating inflammatory factor interleukin-1 (IL-1) and regulation of microRNAs. The results showed that the most commonly mutated factor in pancreatic cancer, KRAS, associates with the expression of IL-1 and subsequent activation of stromal cells. Blocking KRAS signaling together with IL-1 blockage give a more pronounced effect on in vitro proliferation and migration of cancer cells and suggests the use of a combination therapy. The cancer-associated activation of the stroma was found to be related to changes in microRNA expression. microRNA was analyzed separately in epithelial cells and stromal cells after microdissection of matched samples of primary and secondary tumors of breast and colorectal cancers. miR-214 and miR-199a were upregulated in stroma associated with progressive tumors and in pancreatic cancer stroma we could show that their expression alters the activation of stromal cells and thereby the growth and migratory ability of associated pancreatic tumor cells. In breast and colorectal cancers we found several common microRNAs to be up- or downregulated in line with progression. We could show that one of these candidates, miR-18a, had a prognostic value in metastatic breast cancer. To further develop these studies we analyzed this microRNA in circulating microvesicles, i.e. exosomes, and investigated their role in the preparation of a pre-metastatic niche. MicroRNAs are stable biomarkers in the circulation, especially protected in exosomes, which can moreover specifically deliver their message to recipient cells. These studies facilitate the understanding of metastatic behavior and suggest new targets to stop cancer metastasis.
|
|
| 6. |
- Bojmar, Linda, et al.
(författare)
-
miR-18a is regulated between progressive compartments of cancers, and incorporated in exosomes with the potential of creating premetastatic niches and predict cancer outcome
- 2015
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The ultimate cause of death for many cancer patients is the spread of the cancer via metastasis. Even so, there are still a lack of knowledge regarding the metastasis process. This study was performed to investigate the role of metastamirs in exosomes and their metastatic patterns. We used the well-established isogeneic murine cancer model of low metastatic 67NR cells, mimicking luminal/basal breast tumors, and highly metastatic 4T1 cells with characteristics of basal breast tumors. We studied the exosomal properties and pre-metastatic effects in this metastasis model and compared human materials and exosomes of several other tumor types. Our data clearly demonstrated that exosomes from the highly metastatic cells home to the metastatic organs of their parental cells whereas exosomes from cells with low metastatic potential mostly located to lymph nodes. The exosome protein cargos also resembled their parental cells and potentially affects their target organs, and cells, differently. Furthermore, the exosomes from the highly metastatic cells had a more pronounced effect on tumor growth and pre-metastatic changes than the low metastatic exosomes. The microRNA-18a, a predictor of metastasis, was present to a higher extent in metastatic exosomes as compared to low metastatic exosomes, and altered the tumor progressive properties. Our findings support the role of exomirs as important players in the metastatic process, the value as biomarkers and potential therapeutic targets.
|
|
| 7. |
- Bojmar, Linda, et al.
(författare)
-
Protocol for cross-platform characterization of human and murine extracellular vesicles and particles
- 2024
-
Ingår i: STAR PROTOCOLS. - : ELSEVIER. - 2666-1667. ; 5:1
-
Tidskriftsartikel (refereegranskat)abstract
- Characterization of isolated extracellular vesicles and particles (EVPs) is crucial for determining functions and biomarker potential. Here, we present a protocol to analyze size, number, morphology, and EVP protein cargo and to validate EVP proteins in both humans and mice. We describe steps for nanoparticle tracking analysis, transmission electron microscopy, single-EVP immunodetection, EVP proteomic mass spectrometry and bioinformatic analysis, and EVP protein validation by ExoELISA and western blot analysis. This allows for EVP cross -validation across different platforms.For complete details on the use and execution of this protocol, please refer to Hoshino et al.1
|
|
| 8. |
- Bojmar, Linda, et al.
(författare)
-
The Role of MicroRNA-200 in Progression of Human Colorectal and Breast Cancer
- 2013
-
Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 8:12, s. 84815-
-
Tidskriftsartikel (refereegranskat)abstract
- The role of the epithelial-mesenchymal transition (EMT) in cancer has been studied extensively in vitro, but involvement of the EMT in tumorigenesis in vivo is largely unknown. We investigated the potential of microRNAs as clinical markers and analyzed participation of the EMT-associated microRNA-200 ZEB E-cadherin pathway in cancer progression. Expression of the microRNA-200 family was quantified by real-time RT-PCR analysis of fresh-frozen and microdissected formalin-fixed paraffin-embedded primary colorectal tumors, normal colon mucosa, and matched liver metastases. MicroRNA expression was validated by in situ hybridization and after in vitro culture of the malignant cells. To assess EMT as a predictive marker, factors considered relevant in colorectal cancer were investigated in 98 primary breast tumors from a treatment-randomized study. Associations between the studied EMTmarkers were found in primary breast tumors and in colorectal liver metastases. MicroRNA-200 expression in epithelial cells was lower in malignant mucosa than in normal mucosa, and was also decreased in metastatic compared to non-metastatic colorectal cancer. Low microRNA-200 expression in colorectal liver metastases was associated with bad prognosis. In breast cancer, low levels of microRNA-200 were related to reduced survival and high expression of microRNA-200 was predictive of benefit from radiotheraphy. MicroRNA-200 was associated with ER positive status, and inversely correlated to HER2 and overactivation of the PI3K/AKT pathway, that was associated with high ZEB1 mRNA expression. Our findings suggest that the stability of microRNAs makes them suitable as clinical markers and that the EMT-related microRNA-200 - ZEB - E-cadherin signaling pathway is connected to established clinical characteristics and can give useful prognostic and treatment-predictive information in progressive breast and colorectal cancers.
|
|
| 9. |
- Gumberger, Peter, et al.
(författare)
-
The Liver Pre-Metastatic Niche in Pancreatic Cancer : A Potential Opportunity for Intervention
- 2022
-
Ingår i: Cancers. - : MDPI. - 2072-6694. ; 14:12
-
Forskningsöversikt (refereegranskat)abstract
- Simple Summary Patients with pancreatic cancer have a very poor chance of long-term survival. This is usually due to advanced disease at the time of diagnosis, which commonly includes occult or clinically obvious liver metastases. Emerging evidence suggests that organs that develop metastases exhibit microscopic changes that favor metastatic growth, collectively known as "pre-metastatic niches". Such pre-metastatic niches result from various signals originating from the primary pancreatic tumor that reprogram immune and other cells in the liver and other organs, thus enabling the growth of cancer cells once they spread. In this review, we summarize the latest discoveries regarding the liver pre-metastatic niche in pancreatic cancer. We are optimistic that intensified future research will help to reveal powerful diagnostic markers and targetable therapeutic pathways, which will ultimately benefit patients. Cancer-related mortality is primarily a consequence of metastatic dissemination and associated complications. Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies and tends to metastasize early, especially in the liver. Emerging evidence suggests that organs that develop metastases exhibit microscopic changes that favor metastatic growth, collectively known as "pre-metastatic niches". By definition, a pre-metastatic niche is chronologically established before overt metastatic outgrowth, and its generation involves the release of tumor-derived secreted factors that modulate cells intrinsic to the recipient organ, as well as recruitment of additional cells from tertiary sites, such as bone marrow-all orchestrated by the primary tumor. The pre-metastatic niche is characterized by tumor-promoting inflammation with tumor-supportive and immune-suppressive features, remodeling of the extracellular matrix, angiogenic modulation and metabolic alterations that support growth of disseminated tumor cells. In this paper, we review the current state of knowledge of the hepatic pre-metastatic niche in PDAC and attempt to create a framework to guide future diagnostic and therapeutic studies.
|
|
| 10. |
- Hoshino, Ayuko, et al.
(författare)
-
Extracellular Vesicle and Particle Biomarkers Define Multiple Human Cancers
- 2020
-
Ingår i: Cell. - : CELL PRESS. - 0092-8674 .- 1097-4172. ; 182:4, s. 1044-
-
Tidskriftsartikel (refereegranskat)abstract
- There is an unmet clinical need for improved tissue and liquid biopsy tools for cancer detection. We investigated the proteomic profile of extracellular vesicles and particles (EVPs) in 426 human samples from tissue explants (TEs), plasma, and other bodily fluids. Among traditional exosome markers, CD9, HSPA8, ALIX, and HSP90AB1 represent pan-EVP markers, while ACTB, MSN, and RAP1B are novel pan-EVP markers. To confirm that EVPs are ideal diagnostic tools, we analyzed proteomes of TE- (n =151) and plasma-derived (n =120) EVPs. Comparison of TE EVPs identified proteins (e.g., VCAN, TNC, and THBS2) that distinguish tumors from normal tissues with 90% sensitivity/94% specificity. Machine-learning classification of plasma-derived EVP cargo, including immunoglobulins, revealed 95% sensitivity/90% specificity in detecting cancer Finally, we defined a panel of tumor-type-specific EVP proteins in TEs and plasma, which can classify tumors of unknown primary origin. Thus, EVP proteins can serve as reliable biomarkers for cancer detection and determining cancer type.
|
|
