| 1. |
- Jia, Xiaohui, et al.
(författare)
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Exendin-4 Increases the Expression of Hypoxia-InducibleFactor-1 in Rat Islets and Preserves the Endocrine CellVolume of Both Free and Macroencapsulated Islet Grafts
- 2012
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Ingår i: Cell Transplantation. - 0963-6897. ; 21:6, s. 1269-1283
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we evaluated the effects of exendin-4 on free and encapsulated islet grafts in a rodent model.We also investigated the role of a transcription factor, hypoxia-inducible factor-1 (HIF-1), in mediating thebeneficial effects of exendin-4. Diabetic athymic mice were transplanted with free rat islets under the kidneycapsule or with macroencapsulated rat islets SC with or without exendin-4, islet preculture (exendin-4 0.1nM for 20 h), and/or recipient treatment (IP 100 ng/day, day 0–7). The mice were followed for 4 weeks andthe graft function andβ-cell volume were evaluated. The effects of exendin-4 on islet HIF-1α mRNAand protein expression and on ATP content in a rat insulinoma cell line (INS-1E) were also examined.Preculture with exendin-4 followed by recipient treatment improved the outcome of both free (73% graftfunction vs. 26% in controls,p = 0.03) and macroencapsulated islet grafts (100% vs. 25% in controls, p =0.02). In macroencapsulated grafts, the exendin-4-treated group had significantly larger endocrine volume,less graft necrosis, and more blood vessels around the capsule. In rat islets cultured with exendin-4, HIF-1αmRNA and protein expression were significantly enhanced. ATP content was increased in exendin-4-treatedINS-1E cells under hypoxic conditions. The improved functional outcome after transplantation of a marginalislet mass with a brief initial treatment with exendin-4 is related to a larger surviving endocrine cell volume.Exendin-4 may improve islet graft resistance to hypoxia during the peritransplant period by increasing theexpression of HIF-1
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| 2. |
- Amin, Risul, et al.
(författare)
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The kidney injury caused by the onset of acute graft-versus-host disease is associated with down-regulation of alpha Klotho
- 2020
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Ingår i: International Immunopharmacology. - : Elsevier BV. - 1567-5769 .- 1878-1705. ; 78
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Tidskriftsartikel (refereegranskat)abstract
- Acute graft-versus-host disease (aGVHD) and kidney injury are the major complications after allogeneic hematopoietic stem cell transplantation (HSCT). Although the underlying mechanisms for the development of these complications are not yet fully understood, it has been proposed that emergence of aGVHD contributes to the development of kidney injury after HSCT. We have shown previously that aGVHD targets the kidney in a biphasic manner: at the onset, inflammatory genes are up-regulated, while when aGVHD becomes established, donor lymphocytes infiltrate the kidney. Here, we characterize renal manifestations at the onset of aGVHD. Mice receiving allogeneic bone marrow and spleen cells displayed symptoms of aGVHD and elevated serum levels of tumor necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) within 4 days. There was concurrent kidney injury with the following characteristics: (1) elevated expression of the kidney injury biomarker, neutrophil gelatinase-associated lipocalin (NGAL), (2) accumulation of hetero-lysosomes in proximal tubule epithelial cells, and (3) reductions in alpha Klotho mRNA and protein and increased serum levels of fibroblast growth factor 23 (Fgf23), phosphate and urea. This situation resembled acute renal injury caused by bacterial lipopolysaccharide. We conclude that the onset of aGVHD is associated with kidney injury involving down-regulation of alpha Klotho, a sight that may inspire novel therapeutic approaches.
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| 3. |
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| 4. |
- Barman, Linda, 1972-, et al.
(författare)
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Hardness or Resignation : How Emotional Challenges During Work‑Based Education Influence the Professional Becoming of Medical Students and Student Teachers
- 2023
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Ingår i: Vocations and Learning. - : Springer Nature. - 1874-785X .- 1874-7868.
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Tidskriftsartikel (refereegranskat)abstract
- This paper addresses how emotionally challenging experiences during work-basededucation may influence the professional becoming of student teachers and medicalstudents. We conducted a qualitative analysis of eight focus group interviewswith undergraduates from two universities in Sweden who studied to become eitherphysicians or teachers, and interpreted their experiences through Wenger’s theory ofcommunities of practice. The findings show that students’ ideal view of how to becaring in their aspiring professional role as physician or teacher collided with existingpractices, which affected them emotionally. In particular, the students found itchallenging when norms and practices differed from their values of professionalismand when the professional culture within practices reflected hardness (physicians) orresignation (teachers). Both medical students and student teachers experienced thatprofessional decision making and legitimacy challenged them emotionally, howeverin different ways and for different reasons. This study makes visible both generaland specific aspects of how students view their future role in the welfare sector andchallenging dimensions of professional practice. The findings bring into focus thequestion of how professional education can support students’ professional becomingin relation to their emotional challenges.
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| 5. |
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| 6. |
- Demetris, Anthony J, et al.
(författare)
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Liver biopsy interpretation for causes of late liver allograft dysfunction.
- 2006
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Ingår i: Hepatology (Baltimore, Md.). - : Ovid Technologies (Wolters Kluwer Health). - 0270-9139 .- 1527-3350. ; 44:2, s. 489-501
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Tidskriftsartikel (refereegranskat)abstract
- Evaluation of needle biopsies and extensive clinicopathological correlation play an important role in the determination of liver allograft dysfunction occurring more than 1 year after transplantation. Interpretation of these biopsies can be quite difficult because of the high incidence of recurrent diseases that show histopathological, clinical, and serological features that overlap with each other and with rejection. Also, more than one insult can contribute to allograft injury. In an attempt to enable centers to compare and pool results, improve therapy, and better understand pathophysiological disease mechanisms, the Banff Working Group on Liver Allograft Pathology herein proposes a set of consensus criteria for the most common and problematic causes of late liver allograft dysfunction, including late-onset acute and chronic rejection, recurrent and new-onset viral and autoimmune hepatitis, biliary strictures, and recurrent primary biliary cirrhosis and primary sclerosing cholangitis. A discussion of differential diagnosis is also presented.
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| 7. |
- Dunér, Fredrik, et al.
(författare)
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Permeability, ultrastructural changes, and distribution of novel proteins in the glomerular barrier in early puromycin aminonucleoside nephrosis.
- 2010
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Ingår i: Nephron. Experimental nephrology. - : S. Karger AG. - 1660-2129. ; 116:2
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/AIMS: It is still unclear what happens in the glomerulus when proteinuria starts. Using puromycin aminonucleoside nephrosis (PAN) rats, we studied early ultrastructural and permeability changes in relation to the expression of the podocyte-associated molecules nephrin, α-actinin, dendrin, and plekhh2, the last two of which were only recently discovered in podocytes. METHODS: Using immune stainings, semiquantitative measurement was performed under the electron microscope. Permeability was assessed using isolated kidney perfusion with tracers. Possible effects of ACE inhibition were tested. RESULTS: By day 2, some patchy foot process effacement, but no proteinuria, appeared. The amount of nephrin was reduced in both diseased and normal areas. The other proteins showed few changes, which were limited to diseased areas. By day 4, foot process effacement was complete and proteinuria appeared in parallel with signs of size barrier damage. Nephrin decreased further, while dendrin and plekhh2 also decreased but α-actinin remained unchanged. ACE inhibition had no significant protective effect. CONCLUSIONS: PAN glomeruli already showed significant pathology by day 4, despite relatively mild proteinuria. This was preceded by altered nephrin expression, supporting its pivotal role in podocyte morphology. The novel proteins dendrin and plekhh2 were both reduced, suggesting roles in PAN, whereas α-actinin was unchanged.
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| 8. |
- Fenhammar, Johan, et al.
(författare)
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Renal effects of treatment with a TLR4-inhibitor in conscious septic sheep
- 2014
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Ingår i: Critical Care. - : Springer Science and Business Media LLC. - 1364-8535 .- 1466-609X. ; 18:5, s. 488-
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Acute kidney injury (AKI) is a common and feared complication of sepsis. The pathogenesis of sepsis-induced AKI is largely unknown, and therapeutic interventions are mainly supportive. In the present study, we tested the hypothesis that pharmacological inhibition of Toll-like receptor 4 (TLR4) would improve renal function and reduce renal damage in experimental sepsis, even after AKI had already developed. Methods: Sheep were surgically instrumented and subjected to a 36-hour intravenous infusion of live Escherichia coli. After 12 hours, they were randomized to treatment with a selective TLR4 inhibitor (TAK-242) or vehicle. Results: The E. coli caused normotensive sepsis characterized by fever, increased cardiac index, hyperlactemia, oliguria, and decreased creatinine clearance. TAK-242 significantly improved creatinine clearance and urine output. The increase in N-acetyl-beta-D-glucosaminidas, a marker of tubular damage, was attenuated. Furthermore, TAK-242 reduced the renal neutrophil accumulation and glomerular endothelial swelling caused by sepsis. These effects were independent of changes in renal artery blood flow and renal microvascular perfusion in both cortex and medulla. TAK-242 had no effect per se on the measured parameters. Conclusions: These results show that treatment with a TLR4 inhibitor is able to reverse a manifest impairment in renal function caused by sepsis. In addition, the results provide evidence that the mechanism underlying the effect of TAK-242 on renal function does not involve improved macro-circulation or micro-circulation, enhanced renal oxygen delivery, or attenuation of tubular necrosis. TLR4-mediated inflammation resulting in glomerular endothelial swelling may be an important part of the pathogenesis underlying Gram-negative septic acute kidney injury.
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| 9. |
- Grigore, Teodora V. V., et al.
(författare)
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Fibroblast growth factor 23 is independently associated with renal magnesium handling in patients with chronic kidney disease
- 2023
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Ingår i: Frontiers in Endocrinology. - : FRONTIERS MEDIA SA. - 1664-2392. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundDisturbances in magnesium homeostasis are common in patients with chronic kidney disease (CKD) and are associated with increased mortality. The kidney is a key organ in maintaining normal serum magnesium concentrations. To this end, fractional excretion of magnesium (FEMg) increases as renal function declines. Despite recent progress, the hormonal regulation of renal magnesium handling is incompletely understood. Fibroblast Growth Factor 23 (FGF23) is a phosphaturic hormone that has been linked to renal magnesium handling. However, it has not yet been reported whether FGF23 is associated with renal magnesium handling in CKD patients. MethodsThe associations between plasma FGF23 levels, plasma and urine magnesium concentrations and FEMg was investigated in a cross-sectional cohort of 198 non-dialysis CKD patients undergoing renal biopsy. ResultsFGF23 was significantly correlated with FEMg (Pearsons correlation coefficient = 0.37, p<0.001) and urinary magnesium (-0.14, p=0.04), but not with plasma magnesium. The association between FGF23 and FEMg remained significant after adjusting for potential confounders, including estimated glomerular filtration rate (eGFR), parathyroid hormone and 25-hydroxyvitamin D. ConclusionsWe report that plasma FGF23 is independently associated with measures of renal magnesium handling in a cohort of non-dialysis CKD patients. A potential causal relationship should be investigated in future studies.
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| 10. |
- He, Bing, et al.
(författare)
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Single-cell RNA sequencing reveals the mesangial identity and species diversity of glomerular cell transcriptomes
- 2021
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Molecular characterization of the individual cell types in human kidney as well as model organisms are critical in defining organ function and understanding translational aspects of biomedical research. Previous studies have uncovered gene expression profiles of several kidney glomerular cell types, however, important cells, including mesangial (MCs) and glomerular parietal epithelial cells (PECs), are missing or incompletely described, and a systematic comparison between mouse and human kidney is lacking. To this end, we use Smart-seq2 to profile 4332 individual glomerulus-associated cells isolated from human living donor renal biopsies and mouse kidney. The analysis reveals genetic programs for all four glomerular cell types (podocytes, glomerular endothelial cells, MCs and PECs) as well as rare glomerulus-associated macula densa cells. Importantly, we detect heterogeneity in glomerulus-associated Pdgfrb-expressing cells, including bona fide intraglomerular MCs with the functionally active phagocytic molecular machinery, as well as a unique mural cell type located in the central stalk region of the glomerulus tuft. Furthermore, we observe remarkable species differences in the individual gene expression profiles of defined glomerular cell types that highlight translational challenges in the field and provide a guide to design translational studies. The molecular identity of renal glomerular cells is poorly characterized and rodent glomerulopathy models translate poorly to humans. Here, the authors show molecular signatures of glomerulus-associated cells using single cell RNA sequencing and highlight differences between mouse and human cells.
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