Targeted long-read sequencing identifies missing pathogenic variants in unsolved Werner syndrome cases.

BACKGROUND: Werner syndrome (WS) is an autosomal recessive progeroid syndrome caused by variants in WRN. The International Registry of Werner Syndrome has identified biallelic pathogenic variants in 179/188 cases of classical WS. In the remaining nine cases, only one heterozygous pathogenic variant has been identified. METHODS: Targeted long-read sequencing (T-LRS) on an Oxford Nanopore platform was used to search for a second pathogenic variant in WRN. Previously, T-LRS was successfully used to identify missing variants and analyse complex rearrangements. RESULTS: We identified a second pathogenic variant in eight of nine unsolved WS cases. In five cases, T-LRS identified intronic splice variants that were confirmed by either RT-PCR or exon trapping to affect splicing; in one case, T-LRS identified a 339 kbp deletion, and in two cases, pathogenic missense variants. Phasing of long reads predicted all newly identified variants were on a different haplotype than the previously known variant. Finally, in one case, RT-PCR previously identified skipping of exon 20; however, T-LRS did not detect a pathogenic DNA sequence variant. CONCLUSION: T-LRS is an effective method for identifying missing pathogenic variants. Although limitations with computational prediction algorithms can hinder the interpretation of variants, T-LRS is particularly effective in identifying intronic variants.

Identification of Novel Senescent Markers in Small Extracellular Vesicles.

Senescent cells exhibit several typical features, including the senescence-associated secretory phenotype (SASP), promoting the secretion of various inflammatory proteins and small extracellular vesicles (EVs). SASP factors cause chronic inflammation, leading to age-related diseases. Recently, therapeutic strategies targeting senescent cells, known as senolytics, have gained attention; however, noninvasive methods to detect senescent cells in living organisms have not been established. Therefore, the goal of this study was to identify novel senescent markers using small EVs (sEVs). sEVs were isolated from young and senescent fibroblasts using three different methods, including size-exclusion chromatography, affinity column for phosphatidylserine, and immunoprecipitation using antibodies against tetraspanin proteins, followed by mass spectrometry. Principal component analysis revealed that the protein composition of sEVs released from senescent cells was significantly different from that of young cells. Importantly, we identified ATP6V0D1 and RTN4 as novel markers that are frequently upregulated in sEVs from senescent and progeria cells derived from patients with Werner syndrome. Furthermore, these two proteins were significantly enriched in sEVs from the serum of aged mice. This study supports the potential use of senescent markers from sEVs to detect the presence of senescent cells in vivo.

Retrotransposons in Werner syndrome-derived macrophages trigger type I interferon-dependent inflammation in an atherosclerosis model.

The underlying mechanisms of atherosclerosis, the second leading cause of death among Werner syndrome (WS) patients, are not fully understood. Here, we establish an in vitro co-culture system using macrophages (iMφs), vascular endothelial cells (iVECs), and vascular smooth muscle cells (iVSMCs) derived from induced pluripotent stem cells. In co-culture, WS-iMφs induces endothelial dysfunction in WS-iVECs and characteristics of the synthetic phenotype in WS-iVSMCs. Transcriptomics and open chromatin analysis reveal accelerated activation of type I interferon signaling and reduced chromatin accessibility of several transcriptional binding sites required for cellular homeostasis in WS-iMφs. Furthermore, the H3K9me3 levels show an inverse correlation with retrotransposable elements, and retrotransposable element-derived double-stranded RNA activates the DExH-box helicase 58 (DHX58)-dependent cytoplasmic RNA sensing pathway in WS-iMφs. Conversely, silencing type I interferon signaling in WS-iMφs rescues cell proliferation and suppresses cellular senescence and inflammation. These findings suggest that Mφ-specific inhibition of type I interferon signaling could be targeted to treat atherosclerosis in WS patients.

Sex differences in symptom presentation and their impact on diagnostic accuracy in Werner syndrome.

AIM: Whether sex differences exist in hereditary progeroid syndromes remains unclear. In this study, we investigated sex differences in patients with Werner syndrome (WS), a model of human aging, using patient data at the time of diagnosis. METHODS: The presence of six cardinal signs in the diagnostic criteria was retrospectively evaluated. RESULTS: We found that the percentage of patients with all cardinal signs was higher in males than in females (54.2% vs. 21.2%). By the age of 40 years, 57.1% of male patients with WS presented with all the cardinal signs, whereas none of the female patients developed all of them. In particular, the frequency of having a high-pitched, hoarse voice, a characteristic of WS, was lower in female patients. The positive and negative predictive values for clinical diagnosis were 100% for males and females, indicating the helpfulness of diagnostic criteria regardless of sex. More female patients than male (86.7% vs. 64%) required genetic testing for their diagnosis because their clinical symptoms were insufficient, suggesting the importance of genetic testing for females even if they do not show typical symptoms of WS. Finally, the frequency of abnormal voice was lower in patients with WS harboring the c.3139-1G > C homozygous mutation. CONCLUSION: These results indicate, for the first time, that there are sex differences in the phenotypes of hereditary progeroid syndromes. The analysis of this mechanism in this human model of aging may lead to the elucidation of sex differences in the various symptoms of normal human aging. Geriatr Gerontol Int 2024; 24: 161-167.

Meeting Summary of The NYO3 5th NO-Age/AD Meeting and the 1st Norway-UK Joint Meeting on Aging and Dementia: Recent Progress on the Mechanisms and Interventional Strategies.

Unhealthy aging poses a global challenge with profound healthcare and socioeconomic implications. Slowing down the aging process offers a promising approach to reduce the burden of a number of age-related diseases, such as dementia, and promoting healthy longevity in the old population. In response to the challenge of the aging population and with a view to the future, Norway and the United Kingdom are fostering collaborations, supported by a "Money Follows Cooperation agreement" between the 2 nations. The inaugural Norway-UK joint meeting on aging and dementia gathered leading experts on aging and dementia from the 2 nations to share their latest discoveries in related fields. Since aging is an international challenge, and to foster collaborations, we also invited leading scholars from 11 additional countries to join this event. This report provides a summary of the conference, highlighting recent progress on molecular aging mechanisms, genetic risk factors, DNA damage and repair, mitophagy, autophagy, as well as progress on a series of clinical trials (eg, using NAD+ precursors). The meeting facilitated dialogue among policymakers, administrative leaders, researchers, and clinical experts, aiming to promote international research collaborations and to translate findings into clinical applications and interventions to advance healthy aging.

Weight loss improves inflammation by T helper 17 cells in an obese patient with psoriasis at high risk for cardiovascular events.

Psoriasis is a chronic inflammatory skin disease that is associated with obesity and myocardial infarction. Obesity-induced changes in lipid metabolism promote T helper 17 (Th17) cell differentiation, which in turn promotes chronic inflammation. Th17 cells have central roles in many inflammatory diseases, including psoriasis and atherosclerosis; however, whether treatment of obesity attenuates Th17 cells and chronic inflammatory diseases has been unknown. In this study, we found an increase in Th17 cells in a patient with obesity, type 2 diabetes and psoriasis. Furthermore, weight loss with diet and exercise resulted in a decrease in Th17 cells and improvement of psoriasis. This case supports the hypothesis that obesity leads to an increase in Th17 cells and chronic inflammation of the skin and blood vessel walls, thereby promoting psoriasis and atherosclerosis.

Renal dysfunction, malignant neoplasms, atherosclerotic cardiovascular diseases, and sarcopenia as key outcomes observed in a three-year follow-up study using the Werner Syndrome Registry.

Werner syndrome is an adult-onset progeria syndrome that results in various complications. This study aimed to clarify the profile and secular variation of the disease. Fifty-one patients were enrolled and registered in the Werner Syndrome Registry. Their data were collected annually following registration. A cross-sectional analysis at registration and a longitudinal analysis between the baseline and each subsequent year was performed. Pearson's chi-squared and Wilcoxon signed-rank tests were used. Malignant neoplasms were observed from the fifth decade of life (mean onset: 49.7 years) and were observed in approximately 30% of patients during the 3-year survey period. Regarding renal function, the mean estimated glomerular filtration rate calculated from serum creatinine (eGFRcre) and eGFRcys, which were calculated from cystatin C in the first year, were 98.3 and 83.2 mL/min/1.73 m2, respectively, and differed depending on the index used. In longitudinal analysis, the average eGFRcre for the first and fourth years was 74.8 and 63.4 mL/min/1.73 m2, showing a rapid decline. Secular changes in Werner syndrome in multiple patients were identified. The prevalence of malignant neoplasms is high, and renal function may decline rapidly. It is, therefore, necessary to carry out active and detailed examinations and pay attention to the type and dose of the drugs used.

Senescence-associated inflammation and inhibition of adipogenesis in subcutaneous fat in Werner syndrome.

Werner syndrome (WS) is a hereditary premature aging disorder characterized by visceral fat accumulation and subcutaneous lipoatrophy, resulting in severe insulin resistance. However, its underlying mechanism remains unclear. In this study, we show that senescence-associated inflammation and suppressed adipogenesis play a role in subcutaneous adipose tissue reduction and dysfunction in WS. Clinical data from four Japanese patients with WS revealed significant associations between the decrease of areas of subcutaneous fat and increased insulin resistance measured by the glucose clamp. Adipose-derived stem cells from the stromal vascular fraction derived from WS subcutaneous adipose tissues (WSVF) showed early replicative senescence and a significant increase in the expression of senescence-associated secretory phenotype (SASP) markers. Additionally, adipogenesis and insulin signaling were suppressed in WSVF, and the expression of adipogenesis suppressor genes and SASP-related genes was increased. Rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR), alleviated premature cellular senescence, rescued the decrease in insulin signaling, and extended the lifespan of WS model of C. elegans. To the best of our knowledge, this study is the first to reveal the critical role of cellular senescence in subcutaneous lipoatrophy and severe insulin resistance in WS, highlighting the therapeutic potential of rapamycin for this disease.

Atherosclerosis and Cardiovascular Diseases in Progeroid Syndromes.

Hutchinson-Gilford progeria syndrome (HGPS) and Werner syndrome (WS) are two of the representative genetic progeroid syndromes and have been widely studied in the field of aging research. HGPS is a pediatric disease in which premature aging symptoms appear in early childhood, and death occurs at an average age of 14.5 years, mainly due to cardiovascular disease (CVD). Conversely, WS patients exhibit accelerated aging phenotypes after puberty and die in their 50s due to CVD and malignant tumors. Both diseases are models of human aging, leading to a better understanding of the aging-associated development of CVD. In this review, we discuss the pathogenesis and treatment of atherosclerotic diseases presented by both progeroid syndromes with the latest findings.

Lifetime extension and the recent cause of death in Werner syndrome: a retrospective study from 2011 to 2020.

BACKGROUND: Werner syndrome (WS) is an autosomal recessive premature ageing disease that causes accelerated ageing-like symptoms after puberty. Previous studies conducted in the late 2000s reported that malignant neoplasms and atherosclerotic diseases were the two leading causes of death, with life expectancies in the mid-50 s. However, the recent lifespan and cause of death in patients with WS remain unclear. OBJECTIVE: To clarify the latest lifespan and causes of death in patients with WS. METHOD: We conducted a questionnaire-based survey in 2020 among the primary doctors of WS patients who were identified in previous nationwide surveys in Japan and clarified the following: the age of WS patients (age of death, if the patient had already died), sex, and cause of death. Patients who died in 2010 or earlier were excluded from the analysis. RESULTS: A total of 123 living patients were identified at the time of the survey in 2020. Fourteen WS patients died between 2011 and 2020, with a mean age of 59.0 ± 8.9 years (mean ± SD). The most common cause of death was non-epithelial tumours, accounting for eight deaths, while no patient died of atherosclerotic diseases. CONCLUSIONS: Compared to previous studies, this study suggests that the lifespan of patients with WS has been extended. Although there were no deaths due to atherosclerotic diseases, non-epithelial tumours were still the leading cause of death. Further development of screening and treatment methods for these tumours is required.

A high prevalence of myeloid malignancies in progeria with Werner syndrome is associated with p53 insufficiency.

Werner syndrome (WS) is a progeroid syndrome caused by mutations in the WRN gene, which encodes the RecQ type DNA helicase for the unwinding of unusual DNA structures and is implicated in DNA replication, DNA repair, and telomere maintenance. patients with WS are prone to develop malignant neoplasms, including hematological malignancies. However, the pathogenesis of WS-associated hematological malignancies remains uncharacterized. Here we investigated the somatic gene mutations in WS-associated myelodysplastic syndrome/acute myeloid leukemia (MDS/AML). Whole-exome sequencing (WES) of 4 patients with WS with MDS/AML revealed that all patients had somatic mutations in TP53 but no other recurrent mutations in MDS/AML. TP53 mutations were identified at low allele frequencies at more than one year before the MDS/AML stage. All 4 patients had complex chromosomal abnormalities including those that involved TP53. Targeted sequencing of nine patients with WS without apparent blood abnormalities did not detect recurrent mutations in MDS/AML except for a PPM1D mutation. These results suggest that patients with WS are apt to acquire TP53 mutations and/or chromosomal abnormalities involving TP53, rather than other MDS/AML-related mutations. TP53 mutations are frequently associated with prior exposure to chemotherapy; however, all four patients with WS with TP53 mutations/deletions had not received any prior chemotherapy, suggesting a pathogenic link between WRN mutations and p53 insufficiency. These results indicate that WS hematopoietic stem cells with WRN insufficiency acquire competitive fitness by inactivating p53, which may cause complex chromosomal abnormalities and the subsequent development of myeloid malignancies. These findings promote our understanding of the pathogenesis of myeloid malignancies associated with progeria.

Management guideline for Werner syndrome 2020. 2. Sarcopenia associated with Werner syndrome.

AIM: Sarcopenia is defined as a condition that combines decreased skeletal muscle mass with weakness or decreased physical function. It is well known that in older adults, the presence of sarcopenia is a risk of frailty, falls and physical dysfunction. Patients with Werner syndrome are characterized by visceral fat accumulation and thin limbs, but the prevalence of sarcopenia in patients with Werner syndrome has not been investigated. METHODS: A literature search was conducted using Werner syndrome and skeletal muscle as keywords. We also analyzed data from our 7 Werner syndrome patients. RESULTS: A literature search on the relationship between Werner syndrome and skeletal muscle yielded only one article reported from Japan. According to this paper, a decrease in skeletal muscle mass (appendicular skeletal muscle index) was observed in all 9 Werner syndromes investigated. On the other hand, in our 7 Werner syndrome patients, their appendicular skeletal muscle indexes were below the standard value except for one male patient who had continued resistance exercise. CONCLUSION: The decrease in skeletal muscle mass frequently occurs in patients with Werner syndrome. However, resistance exercise may prevent the appearance of sarcopenia and requires early intervention in patients with Werner syndrome. Geriatr Gerontol Int 2021; 21: 139-141.

Management guideline for Werner syndrome 2020. 3. Diabetes associated with Werner syndrome.

AIMS: To evaluate the characteristics of diabetes associated with Werner syndrome. METHODS: A literature search was done with search term "Werner syndrome" and "Diabetes". RESULTS AND CONCLUSIONS: Prevalence of diabetes is extremely high in Werner syndrome. Diabetes associated with Werner syndrome is classified as "accompanied with other diseases and conditions and the one occurring mainly in association with other genetic syndromes." This type of diabetes is marked by accumulated visceral fat and high insulin resistance, despite low body mass index. Thiazolidine derivatives and metformin are effective for glycemic control. New antidiabetic drugs, such as dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists, could be potentially beneficial for patients with Werner syndrome. Furthermore, the establishment of diet therapy as well as exercise therapy is warranted. Geriatr Gerontol Int 2021; 21: 142-145.

Fibroblasts from different body parts exhibit distinct phenotypes in adult progeria Werner syndrome.

Werner syndrome (WS), also known as adult progeria, is characterized by accelerated aging symptoms from a young age. Patients with WS experience painful intractable skin ulcers with calcifications in their extremities, subcutaneous lipoatrophy, and sarcopenia. However, there is no significant abnormality in the trunk skin, where the subcutaneous fat relatively accumulates. The cause of such differences between the limbs and trunk is unknown. To investigate the underlying mechanism behind these phenomena, we established and analyzed dermal fibroblasts from the foot and trunk of two WS patients. As a result, WS foot-derived fibroblasts showed decreased proliferative potential compared to that from the trunk, which correlated with the telomere shortening. Transcriptome analysis showed increased expression of genes involved in osteogenesis in the foot fibroblasts, while adipogenic and chondrogenic genes were downregulated in comparison with the trunk. Consistent with these findings, the adipogenic and chondrogenic differentiation capacity was significantly decreased in the foot fibroblasts in vitro. On the other hand, the osteogenic potential was mutually maintained and comparable in the foot and trunk fibroblasts. These distinct phenotypes in the foot and trunk fibroblasts are consistent with the clinical symptoms of WS and may partially explain the underlying mechanism of this disease phenotype.

Management guideline for Werner syndrome 2020 8. Calcification in tendons associated with Werner syndrome.

AIM: To clarify the diagnostic value of the calcification in the Achilles tendon for Werner syndrome. METHODS: Calcification of the Achilles tendon in the plain radiograph was investigated in 92 patients with Werner syndrome provided from the nationwide secondary survey in 2010. And the same investigation was performed for 2151 feet in 1853 patients without Werner syndrome, who underwent foot and ankle surgeries at the department of orthopaedic surgery in Nara Medical University from 2004 to 2015. RESULT AND CONCLUSION: Achilles tendon calcification was observed in 70 (76.1%) out of 92 patients with Werner syndrome, whereas that was observed only in 19 feet (0.88%) without Werner syndrome, accompanied by 1 to 4 calcified masses with a maximum diameter ranging from 9.7mm to 63.2mm. The frequency of Achilles tendon calcification in patients with Werner syndrome is far higher than that of patients without Werner syndrome. Achilles tendon calcification could be included in the diagnostic criteria for Werner syndrome. Geriatr Gerontol Int 2021; 21: 163-165.

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.

Management guideline for Werner syndrome 2020. 6. Skin ulcers associated with Werner syndrome: Prevention and non-surgical and surgical treatment.

AIM: To provide guidelines on the diagnosis, treatment, and prevention of skin ulcers in Werner syndrome. METHODS: This article was based on literature from 1996, when WRN was identified as a gene responsible for Werner syndrome, and we evaluated several authentic clinical cases of genetically diagnosed patients. There were 63 patients with Werner syndrome in the Japanese reports retrieved from Medical Online between January 1996 and December 2017. There were 56 patients with Werner syndrome in English reports written by Japanese authors and retrieved from PubMed during the same period. RESULTS: Records on skin ulcers were found in 27 (43%) out of 63 patients and 22 (40%) out of 56 patients from the Japanese and English reports, respectively. The reported ulcers were often located at the distal one-third of the lower legs. There were 8 patients with callosities in the foot in the Japanese reports and 9 patients in the English reports. A skin ulcer in Werner syndrome is generally intractable. Weight-bearing ulcers or callosity should be critically assessed in surgical procedures because they have effects on patient pain and gait. By adopting a recently advanced technique to facilitate wound healing, the cases of ulcers that were difficult to treat and those requiring major operations can be closed with minimally invasive surgery. CONCLUSIONS: Skin ulcers in Werner syndrome are refractory, and they lead to reduced quality of life of patients. A callosity in Werner syndrome is an important therapeutic target for the prevention of ulcers. Geriatr Gerontol Int 2021; 21: 153-159.

Management guideline for Werner syndrome 2020. 7. Skin ulcer associated with Werner syndrome: Dermatological treatment.

Skin ulcers in Werner's syndrome often arise from hyperkeratotic lesions and trauma to pressure points such as the plantar region, and are more difficult to treat than wound healing in healthy individuals. Multiple factors contribute to the intractable skin ulcers in Werner's syndrome, including skin thinning, sclerosis, fatty tissue loss, impaired blood flow, calcification, and excessive pressure due to osteoarticular deformity. Treatment includes topical application of a keratolytic agent for keratosis around the ulcer. Treatment of ulcers is the same as for normal ulcers, and if the ulcer is associated with infection and necrotic tissue, surgical debridement with a scalpel or scissors should be performed as much as possible after washing with saline or mildly warm water or with an antibacterial agent. Topical medications that promote softening and debridement of the necrotic tissue are used with careful control of moisture in the wound. Topical agents that promote granulation should be used in wounds where necrotic tissue has been removed without infection. Dressings to maintain a moist environment in the wound may also be useful. If the wound does not improve with conservative treatment, surgical treatment should be considered. Geriatr Gerontol Int 2021; 21: 160-162.

Generation of disease-specific and CRISPR/Cas9-mediated gene-corrected iPS cells from a patient with adult progeria Werner syndrome.

Adult progeria Werner syndrome (WS), a rare autosomal recessive disorder, is characterized by accelerated aging symptoms after puberty. The causative gene, WRN, is a member of the RecQ DNA helicase family and is predominantly involved in DNA replication, repair, and telomere maintenance. Here, we report the generation of iPS cells from a patient with WS and correction of the WRN gene by the CRISPR/Cas9-mediated method. These iPSC lines would be a valuable resource for deciphering the pathogenesis of WS.