Marked decrease in plasma apolipoprotein A-I and high density lipoprotein-cholesterol in a case with Werner syndrome

Management guideline for Werner syndrome 2020 1. Dyslipidemia and fatty liver associated with Werner syndrome

For the purpose of examining the characteristics of dyslipidemia and fatty liver in patients with Werner syndrome in Japan in recent years, we searched all case reports of Japanese Werner syndrome reported on Medical Online and PubMed since 1996, and collected and examined the data and clinical features described in these reports. In addition, as there are few descriptions of treatment methods in these reports from Medical Online and PubMed, we analyzed 12 cases for which detailed data on treatment methods are available at Chiba University. Geriatr Gerontol Int 2021; 21: 133-138.

Werner Syndrome-specific induced pluripotent stem cells: recovery of telomere function by reprogramming

Werner syndrome (WS) is a rare human autosomal recessive premature aging disorder characterized by early onset of aging-associated diseases, chromosomal instability, and cancer predisposition. The function of the DNA helicase encoded by WRN, the gene responsible for WS, has been studied extensively. WRN helicase is involved in the maintenance of chromosome integrity through DNA replication, repair, and recombination by interacting with a variety of proteins associated with DNA repair and telomere maintenance. The accelerated aging associated with WS is reportedly caused by telomere dysfunction, and the underlying mechanism of the disease is yet to be elucidated. Although it was reported that the life expectancy for patients with WS has improved over the last two decades, definitive therapy for these patients has not seen much development. Severe symptoms of the disease, such as leg ulcers, cause a significant decline in the quality of life in patients with WS. Therefore, the establishment of new therapeutic strategies for the disease is of utmost importance. Induced pluripotent stem cells (iPSCs) can be established by the introduction of several pluripotency genes, including Oct3/4, Sox2, Klf4, and c-myc into differentiated cells. iPSCs have the potential to differentiate into a variety of cell types that constitute the human body, and possess infinite proliferative capacity. Recent studies have reported the generation of iPSCs from the cells of patients with WS, and they have concluded that reprogramming represses premature senescence phenotypes in these cells. In this review, we summarize the findings of WS patient-specific iPSCs (WS iPSCs) and focus on the roles of telomere and telomerase in the maintenance of these cells. Finally, we discuss the potential use of WS iPSCs for clinical applications.

Defective cholesterol efflux in Werner syndrome fibroblasts and its phenotypic correction by Cdc42, a RhoGTPase

Werner syndrome (WS) is characterized by the early onset of senescent phenotypes including premature atherosclerotic cardiovascular diseases, although the underlying molecular mechanism for atherosclerosis has not been fully understood yet. Cholesterol efflux from the cells is the initial step of reverse cholesterol transport, a major protective system against atherosclerosis. The aim of the present study was to determine whether this crucial step may be altered in WS. We examined intracellular lipid transport and cholesterol efflux and the expression levels of its related molecules in skin fibroblasts obtained from patients with WS. Cholesterol efflux was markedly reduced in the WS fibroblasts in association with increased cellular cholesterol. Fluorescent recovery after photobleaching (FRAP) technique revealed that intracellular lipid transport around Golgi apparatus was markedly reduced when using a C6-NBD-Ceramide as a tracer. Cdc42 protein and its GTP-bound form were markedly reduced in the WS fibroblasts. The complementation of wild-type Cdc42 corrected cholesterol efflux, intracellular lipid transport, and cellular cholesterol levels in the WS fibroblasts. These data indicated that the reduced expression of Cdc42 may be responsible for the abnormal lipid transport, which in turn might be related to the cardiovascular manifestations in WS.

[A report of a case with Werner's syndrome suffering from end-stage renal failure]

A 54-year-old man was found to have hypertension at age 32, and a diagnosis of Werner's Syndrome was made at age 36 when he was examined for hyperlipidemia. Diabetes mellitus was found at age 42. Proteinuria appeared at age 49, and microscopic hematuria was seen at age 50. At age 51, serum creatinin level began to rise and atrophy of bilateral kidneys was observed by abdominal CT. There after, the renal function gradually worsened. At age 53, the serum creatinin level rose to 8.3 mg/dl, and systemic edema as well as loss of appetite appeared, resulting in the initiation of hemodialysis. In Werner's syndrome, though arteriosclerosis arises frequently, case reports with chronic renal failure are extremely rare. To investigate the cause of the renal dysfunction, renal biopsy was performed and the samples were histologically examined, revealing the presence of hypertensive glomerular changes. It is, thus, conceivable that hypertension had played a major role in the progression of renal failure in this case.