Aging aggravates long-term renal ischemia-reperfusion injury in a rat model

Aim

Ischemia-reperfusion injury (IRI) has been considered as the major cause of acute kidney injury and can result in poor long-term graft function. Functional recovery after IRI is impaired in the elderly. In the present study, we aimed to compare kidney morphology, function, oxidative stress, inflammation, and development of renal fibrosis in young and aged rats after renal IRI.

Materials and methods

Rat models of warm renal IRI were established by clamping left pedicles for 45 min after right nephrectomy, then the clamp was removed, and kidneys were reperfused for up to 12 wk. Biochemical and histologic renal damage were assessed at 12 wk after reperfusion. The immunohistochemical staining of monocyte macrophage antigen-1 (ED-1) and transforming growth factor beta 1 (TGF-β1) and messenger RNA level of TGF-β1 in the kidney were analyzed.

Results

Renal IRI caused significant increases of malondialdehyde and 8-hydroxydeoxyguanosine levels and a decrease of superoxide dismutase activity in young and aged IRI rats; however, these changes were more obvious in the aged rats. IRI resulted in severe inflammation and tubulointerstitial fibrosis with decreased creatinine (Cr) clearance and increased histologic damage in aged rats compared with young rats. Moreover, we measured the ratio of Cr clearance between young and aged IRI rats. It demonstrated that aged IRI rats did have poor Cr clearance compared with the young IRI rats. ED-1 and TGF-β1 expression levels in the kidney were significantly higher in aged rats than in young rats after IRI.

Conclusion

Aged rats are more susceptible to IRI-induced renal failure, which may associate with the increased oxidative stress, increased histologic damage, and increased inflammation and tubulointerstitial fibrosis. Targeting oxidative stress and inflammatory response should improve the kidney recovery after IRI.     

Enhancement of Viability of Fat Grafts in Nude Mice by Endothelial Progenitor Cells

BACKGROUND: A recent discovery showed that endothelial progenitor cells (EPCs) could augment collateral vessel growth to ischemic tissues. OBJECTIVE: The objective was to demonstrate the effects of EPCs on the vasculogenesis and survival of free transplanted fat tissues in nude mice. METHODS: EPCs from human donors were cultured in vitro for 7 days. Human fat tissues were injected subcutaneously into the scalps of 20 6-week-old nude male mice. EPCs stained with CM-DiI were mixed with the transplanted fat tissues and injected into the mice. EBM-2 medium was used as control group. The animals were euthanized 15 weeks after the procedure. Graft volume were measured, and histologic evaluation was performed. The central part of fat tissues was histologically evaluated 15 weeks after the fat injection. RESULTS: The survival volume of the experimental group was significantly greater than that of the control group (p< .05). Less cyst formation and fibrosis was obtained in the experimental group. Histologic evaluation of the central part of fat tissues 15 weeks after the fat injection showed that capillary densities increased markedly in the experimental group mice. CONCLUSION: The results indicate that EPCs have the ability to enhance the survival and the quality of the transplanted fat tissues.     

Genital psoriasis: a questionnaire‐based survey on a concealed skin disease in the Netherlands

Background Psoriatic lesions may involve nearly all sites of the body. Involvement of the genital skin is frequently classified as part of intertriginous psoriasis without special awareness and treatment for this presentation of the disease. Gaining knowledge about the frequency of the involvement of genital skin in these patients will improve the overall care for patients with psoriasis. Objectives We studied the prevalence of genital psoriasis in the Netherlands and epidemiological characteristics of this specific presentation of the disease. Furthermore, we studied the relation between flexural and genital psoriasis. Patients/Methods A self‐administered questionnaire was sent to all 5300 members of the Dutch Psoriasis Society. Sociodemographic patient characteristics and disease‐related data (such as localization of psoriatic lesions, involvement of the genitalia, age at onset of genital psoriasis and severity of genital psoriatic lesions) were collected and analysed. Results A response rate of 37% was achieved. Almost 46% of the responding patients with psoriasis, that is 16.5% of all potential responders (n = 5300), report genital involvement at some time during the course of their disease. The genitalia can become affected at any age. Many patients with current genital involvement (38%) do not have the flexural skin affected. Conclusions A large part of patients with psoriasis suffer from genital psoriasis, which was not associated with flexural involvement in at least one third of them. More attention to the genital region is required in the current standard treatment of both male and female psoriatic patients at any age.