Localized Amyloidosis of the Upper Aerodigestive Tract: Complex Analysis of the Cellular Infiltrate and the Amyloid Mass

Comparative Proteomic Analysis of the Aqueous Humor from Patients with Pseudoexfoliation Syndrome

Purpose

The goal of this study was to pinpoint potential molecular pathways that may have contributed to the onset of pseudoexfoliation syndrome (PEX), a systemic illness associated with aging that has no known cause and is brought on by the deposition of fibrillary white flaky debris in ocular tissues.

Materials and methods

Protein pools representing each group were created using two-dimensional gel electrophoresis (2DE) in conjunction with a matrix-assisted laser desorption ionization-time of flight/time of flight (MALDI-TOF/TOF) mass spectrometer. Aqueous humor (AH) from patients with PEX and cataracts was also collected for a comprehensive study of the data; ingenuity pathway analysis (IPA) was used for the discovered proteins.

Results

In comparison to controls, 2DE showed that 10 sites in PEX patients had differently altered gene expression. Two of these proteins, transthyretin (TTR) and apolipoprotein A4 (ApoA4) were significantly overexpressed in PEX patients, but the remaining proteins were only mildly altered. The liver X receptor (LXR) and the retinoid X receptors (RXR) may play a crucial role in the pathophysiology of PEX according to IPA employing these 10 proteins.

Conclusion

The altered proteins, particularly ApoA4 and TTR, may be important in revealing the molecular process behind PEX, as anticipated by IPA.

How to cite this article

Toprak M, Yuksel N, Akpinar G, et al. Comparative Proteomic Analysis of the Aqueous Humor from Patients with Pseudoexfoliation Syndrome. J Curr Glaucoma Pract 2023;17(3):118-125.

Local Insulin-Derived Amyloidosis Model Confronted with Silymarin: Histological Insights and Gene Expression of MMP, TNF-α, and IL-6

Amyloidosis is a heterogeneous group of protein deposition diseases associated with the presence of amyloid fibrils in tissues. Analogs of insulin that are used for treating diabetic patients (including regular insulin) can form amyloid fibrils, both in vitro and in vivo as reported in patients. The main purpose of this study was the induction of localized insulin-generated amyloidosis and the observation of silymarin effects on this process. In order to obtain amyloid structures, regular insulin was incubated at 37 °C for 24 h. Congo red absorbance and transmission electron microscopy images validated the formation of amyloid fibrils. Those fibrils were then injected subcutaneously into rats once per day for 6, 12 or 18 consecutive days in the presence or absence of silymarin, and caused development of firm waxy masses. These masses were excised and stained with Hematoxylin and Eosin, Congo red and Thioflavin S. Histological examination showed adipose cells and connective tissue in which amyloid deposition was visible. Amyloids decreased in the presence of silymarin, and the same effect was observed when silymarin was added to normal insulin and injected subsequently. Furthermore, plasma concentrations of MMP2, TNF-α, and IL-6 inflammatory factors were measured, and their gene expression was locally assessed in the masses by immunohistochemistry. All three factors increased in the amyloidosis state, while silymarin had an attenuating effect on their plasma levels and gene expression. In conclusion, we believe that silymarin could be effective in counteracting insulin-generated local amyloidosis.

Extremely Rare Intraoral Presentation of Localized Amyloidosis

Purpose

To present an extremely rare case of localized amyloidosis of the mucosa of the maxillary alveolar ridge. Case Report. A 71-year-old man was referred to the Department of Oral Surgery, School of Dental Medicine, University of Zagreb, for a persistent nodular formation in the edentulous ridge of the anterior maxillary region. The nodular formation had a reddish color, solid consistency, and an approximate size of 40 × 15 mm. Orthopantomographic imaging excluded bone resorption and defects. Histopathological assessments of the biopsy specimen showed that the stroma was occupied by a multiplied, partially hyalinized connective tissue. The samples were subsequently stained with Congo red, and collagen accumulation under polarized light showed an apple-green birefringence indicating amyloid. Subsequently, the nodular formation was completely excised and a maxillary total denture was made. The patient showed normal tissue healing with no sign of recurrence at a follow-up assessment 1.5 years after the procedure.

Conclusion

This is only the third reported case of localized amyloidosis of the alveolar ridge mucosa. Histopathological analysis is the first step for diagnosis, but systemic tests, blood counts, urinalysis, bone marrow biopsy, electrocardiography, and digestive endoscopy are recommended to rule out a systemic disease.