Quantitative proteomic analysis of formalin-fixed, paraffin-embedded clear cell renal cell carcinoma tissue using stable isotopic dimethylation of primary amines

Background

Formalin-fixed, paraffin-embedded (FFPE) tissues represent the most abundant resource of archived human specimens in pathology. Such tissue specimens are emerging as a highly valuable resource for translational proteomic studies. In quantitative proteomic analysis, reductive di-methylation of primary amines using stable isotopic formaldehyde variants is increasingly used due to its robustness and cost-effectiveness.

Results

In the present study we show for the first time that isotopic amine dimethylation can be used in a straightforward manner for the quantitative proteomic analysis of FFPE specimens without interference from formalin employed in the FFPE process. Isotopic amine dimethylation of FFPE specimens showed equal labeling efficiency as for cryopreserved specimens. For both FFPE and cryopreserved specimens, differential labeling of identical samples yielded highly similar ratio distributions within the expected range for dimethyl labeling. In an initial application, we profiled proteome changes in clear cell renal cell carcinoma (ccRCC) FFPE tissue specimens compared to adjacent non–malignant renal tissue. Our findings highlight increased levels of glyocolytic enzymes, annexins as well as ribosomal and proteasomal proteins.

Conclusion

Our study establishes isotopic amine dimethylation as a versatile tool for quantitative proteomic analysis of FFPE specimens and underlines proteome alterations in ccRCC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1768-x) contains supplementary material, which is available to authorized users.

Improvement of type 2 diabetes mellitus in obese and non-obese patients after the duodenal switch operation

Introduction. Type 2 diabetes mellitus (T2DM) is one of the most important obesity-related comorbidities. This study was undertaken to characterise the effect of the biliopancreatic diversion with duodenal switch (BPD-DS) in morbidly obese and nonmorbidly obese diabetic patients. Methods. Outcome of 74 obese diabetic patients after BPD-DS and 16 non-obese diabetic patients after BPD or gastric bypass surgery was evaluated. Insulin usage, HbA(1c)-levels, and index of HOMA-IR (homeostasis model assessment of insulin resistence) were measured. Results. A substantial fraction of patients is free of insulin and shows an improved insulin sensitivity early after the operation, another fraction gets free of insulin in a 12-month period after the operation and a small fraction of long-term insulin users will not get free of insulin but nevertheless shows an improved metabolic status (less insulin needed, normal HbA(1c)-levels). Conclusion. BPD-DS leads to an improvement of T2DM in obese and non-obese patients. Nevertheless, more data is needed to clarify indications and mechanisms of action and to adjust our operation techniques to the needs of non-obese diabetic patients.

Influence of Sleeve Gastrectomy on NASH and Type 2 Diabetes Mellitus

Background. Nonalcoholic fatty liver disease is present in up to 85% of adipose patients and may proceed to nonalcoholic steatohepatitis (NASH). With insulin resistance and obesity being the main risk factors for NASH, the effect of isolated sleeve gastrectomy (ISG) on these parameters was examined. Methods. 236 patients underwent ISG with intraoperative liver biopsy from December 2002 to September 2009. Besides demographic data, pre-operative weight/BMI, HbA1c, AST, ALT, triglycerides, HDL and LDL levels were determined. Results. A significant correlation of NASH with higher HbA1c, AST and ALT and lower levels for HDL was observed (P < .05, <.0001, <.0001, <.01, resp.). Overall BMI decreased from 45.0 ± 6.8 to 29.7 ± 6.5 and 31.6 ± 4.4 kg/m(2) at 1 and 3 years. An impaired weight loss was demonstrated for patients with NASH and patients with elevated HbA1c (plateau 28.08 kg/m(2) versus 29.79 kg/m(2) and 32.30 kg/m(2) versus 28.79 kg/m(2), resp.). Regarding NASH, a significant improvement of AST, ALT, triglyceride and HDL levels was shown (P < .0001 for all). A resolution of elevated HbA1c was observed in 21 of 23 patients. Summary. NASH patients showed a significant loss of body weight and amelioration of NASH status. ISG can be successfully performed in these patients and should be recommended for this subgroup.

[Redo operations after bariatric and metabolic surgery]

Because of the growing prevalence of morbid obesity, bariatric surgery is getting more and more important. According to the growing number of bariatric operations, the number of patients in need of revisionary surgery is also growing, mostly because of insufficient weight loss. This article gives an outline of indications, preoperative diagnostics and revisionary operations in bariatric surgery.

Ebselen--an in vivo immune response modifier

Numerous biochemical activities are known for the selenoorganic drug ebselen [(2-phenyl-1,2-benzoisoselenazol-3-(2H)-one]. The initial interest focussed on its GSH peroxidase-like activity and its inhibitory activity on 5-lipoxygenase, however, further activities of the drug on oxidative burst of leukocytes, nitric oxide synthases, protein kinases and on leukocyte migration were recognized. Here we report that Ebselen differentially interacts in vivo with the production and action of systemically released cytokines in various hyperinflammation models in mice. Ebselen given orally to mice protected dose-dependently from Concanavalin A-induced, T-cell dependent inflammatory liver injury. The release of the proinflammatory cytokines Tumor Necosis Factor alpha and Interferon gamma was downregulated, while the production of the anti-inflammatory cytokine Interleukin 10 was increased. Similar results were found in galactosamine-sensitized mice in an inflammatory liver model using the superantigen staphylococcal enterotoxin B as a T-cell activator. Moreover, Ebselen inhibited the release of TNF alpha initiated by endotoxin in vivo in mice. In galactosamine-pretreated mice. Ebselen also attenuated liver injury induced by recombinant Tumor Necosis Factor alpha and initiated enhanced release of Interleukin 10. These findings expand the pharmacological knowledge on ebselen to hitherto unknown immunomodulatory properties which encourage to develop the drug for treatment of T-cell related autoimmune diseases.