Identification of apolipoprotein E-derived amyloid within cholesterol granulomas of leopard geckos (Eublepharis macularius).

Apolipoprotein E (ApoE) is involved in cholesterol transport among cells and also plays an important role in amyloid formation, co-depositing with amyloid fibrils in various types of amyloidosis. Although the in vivo amyloidogenicity of ApoE has not been previously demonstrated, this study provides evidence of ApoE amyloidogenicity in leopard geckos (Eublepharis macularius), belonging to the class Reptilia. Histologically, amyloid deposits were localized within cholesterol granulomas and exhibited positive Congo red staining, with yellow to green birefringence under polarized light. On mass spectrometry-based proteomic analysis, ApoE was detected as a dominant component of amyloid; of the full length of the 274 amino acid residues, peptides derived from Leu185-Arg230 were frequently detected with non-tryptic truncations. Immunohistochemistry with anti-leopard gecko ApoE antibody showed positive reactions of amyloid deposits. These results show that ApoE is an amyloid precursor protein within the cholesterol granulomas of leopard geckos. Although further investigations are needed, the C-terminal region of ApoE involved in amyloid formation is a lipid-binding region, and there should be a relationship between amyloidogenesis and the development of cholesterol granulomas in leopard geckos. This study provides novel insights into the pathogenesis of ApoE-related diseases.

Systemic AL kappa chain amyloidosis in a captive Bornean orangutan (Pongo pygmaeus).

Systemic amyloid light-chain (AL) amyloidosis is an infrequent disease in which amyloid fibrils derived from the immunoglobulin light chain are deposited in systemic organs, resulting in functional impairment. This disease has been notably uncommon in animals, and nonhuman primates have not been reported to develop it. In this study, we identified the systemic AL kappa chain amyloidosis in a captive Bornean orangutan (Pongo pygmaeus) and analyzed its pathogenesis. Amyloid deposits were found severely in the submucosa of the large intestine, lung, mandibular lymph nodes, and mediastinal lymph nodes, with milder lesions in the liver and kidney. Mass spectrometry-based proteomic analysis revealed an abundant constant domain of the immunoglobulin kappa chain in the amyloid deposits. Immunohistochemistry further confirmed that the amyloid deposits were positive for immunoglobulin kappa chains. In this animal, AL amyloidosis resulted in severe involvement of the gastrointestinal submucosa and lymph nodes, which is consistent with the characteristics of AL amyloidosis in humans, suggesting that AL amyloid may have a similar deposition mechanism across species. This report enhances the pathological understanding of systemic AL amyloidosis in animals by providing a detailed characterization of this disease based on proteomic analysis.

A Japanese multi-institutional phase II study of moderate hypofractionated intensity-modulated radiotherapy with image-guided technique for prostate cancer.

BACKGROUND: The aim of this multi-institutional phase II study was to confirm the safety and the potential efficacy of moderately hypofractionated intensity-modulated radiotherapy (IMRT) with prostate-based image-guidance for Japanese patients. METHODS: Patients with low- or intermediate-risk localized prostate cancer were eligible. Patients with a part of high risk (having only one of the following factors, cT3a, 20 < PSA ≤ 30, or GS = 8 or 9) were also included. Hypofractionated IMRT using daily image-guided technique with prostate matching was performed with a total dose of 70 Gy in 28 fractions. Neoadjuvant hormonal therapy for 4-8 months was mandatory for patients with intermediate or high-risk prostate cancer. RESULTS: From 20 institutions, 134 patients enrolled. The median follow-up was 5.16 years (range, 1.43-6.47 years). The number of patients with low, intermediate, and high-risk prostate cancer was 20, 80, and 34, respectively. The 5-year overall, biochemical failure-free, and clinical failure-free survival was 94.5%, 96.0%, and 99.2%, respectively. The 5-year biochemical failure-free survival for patients with low-, intermediate-, and high-risk disease was 94.1%, 97.4%, and 93.9%, respectively. The incidences of grade 2 gastrointestinal (GI) and genitourinary (GU) late toxicities at 5 years were 5.3% and 5.3%, respectively. There are no acute or late toxicities ≥ grade 3. Of 124 patients who were followed for up to 5 years, the grade 2 late GU or GI toxicities were 10.5% (90% confidence intervals, 6.3-16.2%, p = 0.0958). CONCLUSION: The safety and efficacy of moderately hypofractionated IMRT with prostate-based image-guidance was confirmed among Japanese patients with prostate cancer.

Apolipoprotein C-III amyloidosis in white lions (Panthera leo).

Apolipoprotein C-III (ApoC-III) amyloidosis in humans is a hereditary amyloidosis caused by a D25V mutation in the APOC3 gene. This condition has only been reported in a French family and not in animals. We analyzed a 19-year-old white lion (Panthera leo) that died in a Japanese safari park and found renal amyloidosis characterized by severe deposition confined to the renal corticomedullary border zone. Mass spectrometry-based proteomic analysis identified ApoC-III as a major component of renal amyloid deposits. Amyloid deposits were also positive for ApoC-III by immunohistochemistry. Based on these results, this case was diagnosed as ApoC-III amyloidosis for the first time in nonhuman animals. Five additional white lions were also tested for amyloid deposition retrospectively. ApoC-III amyloid deposition was detected in 3 white lions aged 19 to 21 years but not in 2 cases aged 0.5 and 10 years. Genetic analysis of white and regular-colored lions revealed that the APOC3 sequences of the lions were identical, regardless of amyloid deposition. These results suggest that ApoC-III amyloidosis in lions, unlike in humans, may not be a hereditary condition but an age-related condition. Interestingly, lion ApoC-III has a Val30 substitution compared with other species of Panthera that have Met30. Structural predictions suggest that the conformation of ApoC-III with Met30 and ApoC-III with Val30 are almost identical, but this substitution may alter the ability to bind to lipids. As with the D25V mutation in human ApoC-III, the Val30 substitution in lions may increase the proportion of free ApoC-III, leading to amyloid formation.