Shelterin dysfunction promotes CD4+ T cell senescence in Behçet's disease.

OBJECTIVES: To investigate the potential role of shelterin dysfunction in naïve CD4+ T cells in the pathogenesis of Behçet's disease (BD). METHODS: Naïve CD4+ T cells were isolated from 40 BD patients and 40 sex- and age-matched healthy controls (HC). Senescent profiles, shelterin subunits expression, telomere length, telomerase activity and critical DNA damage response (DDR) were evaluated. Telomere repeat factor-2 (TRF2) silencing was conducted for further validation. RESULTS: Compared with HC, BD patients had significantly decreased naïve CD4+ T cells, increased cell apoptosis, senescence, and productions of TNF-α and IFN-γ upon activation. Notably, BD naïve CD4+ T cells had shortened telomere, impaired telomerase activity, and expressed lower levels of shelterin subunits TRF2, TRF1- and TRF2-Interacting Nuclear Protein 2 (TIN2) and Repressor/Activator Protein 1 (RAP1). Furthermore, BD naïve CD4+ T cells exhibited significantly increased DDR, evidenced by elevated phosphorylated ataxia telangiectasia (AT) mutated (pATM), phosphorylated p53 (pp53) and p21. Finally, TRF2 silencing markedly upregulated DDR, apoptosis and proinflammatory cytokines production in HC naïve CD4+ T cells. CONCLUSION: Our study demonstrated that TRF2 deficiency in BD naïve CD4+ T cells promoted cell apoptosis and senescence, leading to proinflammatory cytokines overproduction. Therefore, restoring TRF2 might be a promising therapeutic strategy for BD.

Deforestation embodied in global trade: Integrating environmental extended input-output method and complex network analysis.

As deforestation has become an increasingly urgent issue worldwide, global initiatives and national policies have been launched to reduce deforestation. However, existing measures pay little attention to indirect deforestation and consumers' responsibilities, overlooking the different roles played by countries in the trading network. Therewith, to identify the producer's and consumers' responsibilities for deforestation, and reveal the roles and interrelations of those countries in the trading system, this study applies input-output analysis to find the main producers and consumers of embodied deforestation and complex network method to construct a network to illustrate the interrelations of the countries and identify their roles in the network. The results show the United States, China, Germany and other developed countries are the main consumers while Canada, Brazil, Indonesia and other heavily forested countries are the critical providers of embodied deforestation. Further studies find these countries have the highest level of degree, strength, and centrality, dominating the trade activities in the network. Additionally, the network features small-world nature and heterogeneity, illustrating the close connection of the network and the decisive roles of key nodes. This analysis provides findings to help policymakers more effectively address deforestation worldwide, by highlighting the flow of resources to and from key economies which have previously been overlooked.

WRN is recruited to damaged telomeres via its RQC domain and tankyrase1-mediated poly-ADP-ribosylation of TRF1.

Werner syndrome (WS) is a progeroid-like syndrome caused by WRN gene mutations. WS cells exhibit shorter telomere length compared to normal cells, but it is not fully understood how WRN deficiency leads directly to telomere dysfunction. By generating localized telomere-specific DNA damage in a real-time fashion and a dose-dependent manner, we found that the damage response of WRN at telomeres relies on its RQC domain, which is different from the canonical damage response at genomic sites via its HRDC domain. We showed that in addition to steady state telomere erosion, WRN depleted cells are also sensitive to telomeric damage. WRN responds to site-specific telomeric damage via its RQC domain, interacting at Lysine 1016 and Phenylalanine1037 with the N-terminal acidic domain of the telomere shelterin protein TRF1 and demonstrating a novel mechanism for WRN's role in telomere protection. We also found that tankyrase1-mediated poly-ADP-ribosylation of TRF1 is important for both the interaction between WRN and TRF1 and the damage recruitment of WRN to telomeres. Mutations of potential tankyrase1 ADP-ribosylation sites within the RGCADG motif of TRF1 strongly diminish the interaction with WRN and the damage response of WRN only at telomeres. Taken together, our results reveal a novel mechanism as to how WRN protects telomere integrity from damage and telomere erosion.

Tankyrase1-mediated poly(ADP-ribosyl)ation of TRF1 maintains cell survival after telomeric DNA damage.

Oxidative DNA damage triggers telomere erosion and cellular senescence. However, how repair is initiated at telomeres is largely unknown. Here, we found unlike PARP1-mediated Poly-ADP-Ribosylation (PARylation) at genomic damage sites, PARylation at telomeres is mainly dependent on tankyrase1 (TNKS1). TNKS1 is recruited to damaged telomeres via its interaction with TRF1, which subsequently facilitates the PARylation of TRF1 after damage. TNKS inhibition abolishes the recruitment of the repair proteins XRCC1 and polymerase ß at damaged telomeres, while the PARP1/2 inhibitor only has such an effect at non-telomeric damage sites. The ANK domain of TNKS1 is essential for the telomeric damage response and TRF1 interaction. Mutation of the tankyrase-binding motif (TBM) on TRF1 (13R/18G to AA) disrupts its interaction with TNKS1 concomitant recruitment of TNKS1 and repair proteins after damage. Either TNKS1 inhibition or TBM mutated TRF1 expression markedly sensitizes cells to telomere oxidative damage as well as XRCC1 inhibition. Together, our data reveal a novel role of TNKS1 in facilitating SSBR at damaged telomeres through PARylation of TRF1, thereby protecting genome stability and cell viability.

Integration of microbiome and epigenome to decipher the pathogenesis of autoimmune diseases.

The interaction between genetic predisposition and environmental factors are of great significance in the pathogenesis and development of autoimmune diseases (AIDs). The human mucosa is the most frequent site that interacts with the exterior environment, and commensal microbiota at the gut and other human mucosal cavities play a crucial role in the regulation of immune system. Growing evidence has shown that the compositional and functional changes of mucosal microbiota are closely related to AIDs. Gut dysbiosis not only influence the expression level of Toll-like receptors (TLRs) of antigen presenting cells, but also contribute to Th17/Treg imbalance. Epigenetic modifications triggered by environmental factors is an important mechanism that leads to altered gene expression. Researches addressing the role of DNA methylation, histone modification and non-coding RNA in AIDs have been increasing in recent years. Furthermore, studies showed that human microbiota and their metabolites can regulate immune cells and cytokines via epigenomic modifications. For example, short-chain fatty acids (SCFAs) produced by gut microbiota promote the differentiation of naïve T cell into Treg by suppressing histone deacetylases (HDACs). Therefore, we propose that dysbiosis and resulting metabolites may cause aberrant immune responses via epigenetic modifications, and lead to AIDs. With the development of high-throughput sequencing, metagenome analysis has been applied to investigate the dysbiosis in AIDs patients. We have tested the fecal, dental and salivary samples from treatment-naïve rheumatoid arthritis (RA) individuals by metagenomic shotgun sequencing and a metagenome-wide association study. Dysbiosis was detected in the gut and oral microbiomes of RA patients, but it was partially restored after treatment. We also found functional changes of microbiota and molecular mimicry of human antigens in RA individuals. By integrating the analysis of multi-omics of microbiome and epigenome, we could explore the interaction between human immune system and microbiota, and thereby unmasking specific and more sensitive biomarkers as well as potential therapeutic targets. Future studies aiming at the crosstalk between human dysbiosis and epigenetic modifications and their influences on AIDs will facilitate our understanding and better managing of these debilitating AIDs.

Targeted DNA damage at individual telomeres disrupts their integrity and triggers cell death.

Cellular DNA is organized into chromosomes and capped by a unique nucleoprotein structure, the telomere. Both oxidative stress and telomere shortening/dysfunction cause aging-related degenerative pathologies and increase cancer risk. However, a direct connection between oxidative damage to telomeric DNA, comprising <1% of the genome, and telomere dysfunction has not been established. By fusing the KillerRed chromophore with the telomere repeat binding factor 1, TRF1, we developed a novel approach to generate localized damage to telomere DNA and to monitor the real time damage response at the single telomere level. We found that DNA damage at long telomeres in U2OS cells is not repaired efficiently compared to DNA damage in non-telomeric regions of the same length in heterochromatin. Telomeric DNA damage shortens the average length of telomeres and leads to cell senescence in HeLa cells and cell death in HeLa, U2OS and IMR90 cells, when DNA damage at non-telomeric regions is undetectable. Telomere-specific damage induces chromosomal aberrations, including chromatid telomere loss and telomere associations, distinct from the damage induced by ionizing irradiation. Taken together, our results demonstrate that oxidative damage induces telomere dysfunction and underline the importance of maintaining telomere integrity upon oxidative damage.

Novel method for site-specific induction of oxidative DNA damage reveals differences in recruitment of repair proteins to heterochromatin and euchromatin.

Reactive oxygen species (ROS)-induced DNA damage is repaired by the base excision repair pathway. However, the effect of chromatin structure on BER protein recruitment to DNA damage sites in living cells is poorly understood. To address this problem, we developed a method to specifically produce ROS-induced DNA damage by fusing KillerRed (KR), a light-stimulated ROS-inducer, to a tet-repressor (tetR-KR) or a transcription activator (TA-KR). TetR-KR or TA-KR, bound to a TRE cassette (∼ 90 kb) integrated at a defined genomic locus in U2OS cells, was used to induce ROS damage in hetero- or euchromatin, respectively. We found that DNA glycosylases were efficiently recruited to DNA damage in heterochromatin, as well as in euchromatin. PARP1 was recruited to DNA damage within condensed chromatin more efficiently than in active chromatin. In contrast, recruitment of FEN1 was highly enriched at sites of DNA damage within active chromatin in a PCNA- and transcription activation-dependent manner. These results indicate that oxidative DNA damage is differentially processed within hetero or euchromatin.

Case report: Recurrent syncope as initial symptom in a patient with neck lymphoma.

Syncope may have many different causes, requiring careful identification. Recurrent syncope is uncommon as an initial symptom of neck lymphoma. Head and neck tumors involving the carotid artery cause syncope associate with carotid sinus syndrome. We report the case of a 72-year-old man who suffered from recurrent syncope due to compression of the right carotid sinus by diffuse large B-cell lymphoma and was successfully treated with immunochemotherapy. Syncope may be an early or sole sign of a neck or head tumor. We should be aware of the possibility of an underlying malignancy in patients with unexplained syncope after initial evaluation.

Effectiveness and safety of low-dose interferon alpha-2a treatment in Behçet's Syndrome with refractory vascular or neurological involvement: a case series.

Objective: The aim of this study was to evaluate the effectiveness and safety of low-dose interferon alpha-2a (IFNα2a) in Behçet's syndrome (BS) patients with refractory vascular/cardiac or neurological involvement. Methods: In this retrospective cohort study, we consecutively included 25 BS patients with refractory vascular/cardiac (n = 16) or neurological involvement (n = 9) who received IFNα2a treatment in our center between June 2018 and September 2021. The low-dose IFNα2a (3 million IU, every other day) was used as an add-on treatment with the continuation of glucocorticoids (GCs) and immunosuppressants. Results: In total, 25 patients (20 males, 5 females) with a mean age of 31.92 ± 9.25 years were included. IFNα2a was administered for BS patients with refractory vascular/cardiac involvement (n = 16) and neurological involvement (n = 9). Before the initiation of IFNα2a, patients had insufficient response or intolerance to conventional therapies. After a median follow-up of 23 [interquartile range (IQR), 11-30] months, all patients achieved clinical improvement. The Behçet's disease Current Activity Form (BDCAF) score improved significantly (5 versus 0, median, p < 0.0001). BS Overall Damage Index (BODI) and vasculitis damage index (VDI) remain stable (p > 0.05). Decrease in erythrocyte sedimentation rate [ESR; 24 (IQR, 12-43.5) versus 5 (IQR, 2.75-10.5) mm/h, p = 0.0001] and C-reactive protein [CRP; 6.64 (IQR, 3.67-19.82) versus 1.24 (IQR, 0.24-3.12) mg/liter, p < 0.005] was achieved effectively. The median GCs dosage tapered from 26.25 (IQR, 11.88-41.25) to 10.00 (IQR, 7.50-10.63) mg/d, p < 0.0001. Immunosuppressants were also reduced in number (p < 0.005). No serious adverse events were observed during follow-up. Conclusion: Our study suggests that low-dose IFNα2a, combined with GCs and immunosuppressants, is well-tolerated and effective for BS patients with refractory vascular/cardiac or neurological involvement and has a steroid- and immunosuppressant-sparing effect.

Outcomes of split vs full-thickness skin grafts in scalp reconstruction in outpatient local anaesthetic theatre.

BACKGROUND: Surgical excision remains the cornerstone of simultaneous diagnosis and treatment of suspicious skin lesions, and the scalp is a high-risk area for skin cancers due to increased cumulative lifetime ultraviolet (UV) exposure. Due to the inelasticity of scalp skin, most excisions with predetermined margins require reconstruction with skin grafting. METHODS: A retrospective single-centre cohort study was performed of all patients undergoing outpatient local anaesthetic scalp skin excision and skin graft reconstruction in the Plastic Surgery Department at Addenbrookes Hospital over a 20-month period between 1 April 2017 and 1 January 2019. In total, 204 graft cases were collected. Graft reconstruction techniques included both full-thickness and split-thickness skin grafts. Statistical analysis using Z tests were used to determine which skin grafting technique achieved better graft take. RESULTS: Split-thickness skin grafts had a statistically significant (P = 0.01) increased average take (90%) compared to full-thickness skin grafts (72%). Using a foam tie-over dressing on the scalp led to a statistically significant (P = 0.000036) increase in skin graft take, from 38% to 79%. CONCLUSION: In skin graft reconstruction of scalp defects after skin cancer excision surgery, split skin grafts secured with foam tie-over dressings are associated with superior outcomes compared to full-thickness skin grafts or grafts secured with sutures only.

Perioperative management with biologics on severe aortic valve regurgitation caused by Behçet syndrome: the experience from a single center.

BACKGROUND: To investigate the efficacy and safety of biologics in the perioperative management of severe aortic valve regurgitation (AR) caused by Behçet syndrome (BS). METHODS: We retrospectively analyzed 20 patients with severe AR caused by BS who were all treated with biologics during the perioperative period of cardiac surgeries in our center between February 2016 and October 2020. RESULTS: A total of 20 patients with severe AR were enrolled, including 19 males and 1 female, with a mean age of 39.1 ± 8.8 years and a median course of 8 [interquartile range (IQR) 5.25-10.00] years. Before biologic administration, 92.9% of the patients who underwent aortic valve replacement had failed conventional therapy and developed postoperative paravalvular leakage (PVL) at a median interval of 4 months. Biologics were administered with background glucocorticoids (GCs) and immunosuppressants during the perioperative period for 22 aortic valve surgeries, including preoperatively with a median interval of 3.5 (IQR 2.75-4.25) months in 13 cases and within 3 months postoperatively in 9 cases. After a median follow up of 21 (IQR 15-32) months, 2 out of 13 cases (15.4%) preoperatively, and 1 out of 9 cases (11.1%) postoperatively treated with biologics developed PVL, and the rest were event free. The Behçet's Disease Current Activity Form score improved significantly (7 versus 0, median, p < 0.0001). Decrease of erythrocyte sedimentation rate [25.0 (IQR 11.00-36.25) mm/h versus 6.5 (IQR 4.0-8.8) mm/h, p < 0.001], and C-reactive protein [20.77 (IQR 7.19-29.58) mg/l versus 1.53 (IQR 0.94-2.92) mg/l, p = 0.001] were achieved rapidly and effectively. The GC dosage tapered from 40 (IQR 30-60) mg/d to 10 (IQR 5-11.25) mg/d, p < 0.0001. Immunosuppressants were tapered in number and dosage in 6 (30%) and 20 patients (100%), respectively. No serious adverse event was observed. CONCLUSION: Our study suggests that biologics were effective and well tolerated for the perioperative management of severe and refractory AR caused by BS, which significantly reduced the occurrence of postoperative PVL and had favorable GC- and immunosuppressant-sparing effect.

Clinical Features and Risk Factors of Active Tuberculosis in Patients with Behçet's Disease.

To investigate the clinical features and potential risk factors of active tuberculosis (ATB) in Behçet's disease (BD), we conducted a case-control study on hospitalized BD patients in our institute from 2010 to 2019. BD patients with ATB were enrolled as the case group. The control group was selected by random number sampling from the remaining BD patients, including those with latent tuberculosis infection, previous tuberculosis, or without tuberculosis. Finally, we reviewed 386 BD patients and identified 21 (5.4%) ATB cases, including four (19.0%) microbiologically confirmed and 17 (81.0%) clinically diagnosed. We found that BD patients with ATB were more prone to have systemic symptoms (fever, night sweating, and unexplained weight loss) and/or symptoms related to the infection site. Multivariate logistic regression analysis revealed that erythrocyte sedimentation rate (ESR) > 60 mm/h (OR = 13.710, 95% CI (1.101, 170.702)), increased IgG (OR = 1.226, 95% CI (1.001, 1.502)), and positive T-SPOT.TB (OR = 7.793, 95% CI (1.312, 48.464), for 24-200 SFC/106PBMC; OR = 17.705 95% CI (2.503, 125.260), for >200 SFC/106PBMC) were potential risk factors for ATB in BD patients. Our study suggested that when BD patients have systemic symptoms with significantly elevated TB-SPOT, the diagnosis of ATB should be considered.

Neutrophil Extracellular Traps Promote Aberrant Macrophages Activation in Behçet's Disease.

Neutrophil extracellular traps (NETs) are upregulated and promote thrombosis in Behçet's disease (BD). However, whether NETs promote autoinflammation in BD remains unclear. This study aimed to investigate the potential role of NETs in promoting macrophage activation in BD. Firstly, we quantified NETs by measuring double-stranded DNA (dsDNA) using PicoGreen and calculating the proportion of NETosis. Then macrophages were stimulated with BD- or healthy controls (HC)-derived NETs, and IL-8 and TNF-α production and IFN-γ+ CD4+ T cells differentiation were measured using ELISA and flow cytometry, respectively. The protein components in NETs were analyzed by western blot. Macrophages were stimulated with Histone H4 neutralized NETs, and IL-8 and TNF-α production were measured using ELISA. The level of 8-hydroxydeoxyguanosine (8-OHdG) DNA in NETs was measured using ELISA. The levels of reactive oxygen species (ROS) in serum and neutrophils were measured using ROS probes by a microplate reader and flow cytometry. We found that circulating NETs and neutrophil-derived NETs were significantly higher in BD than HC. BD NETs stimulated macrophages produced higher levels of IL-8 and TNF-α, and promoted IFN-γ+ CD4+ T cells differentiation. BD NETs were enriched in Histone H4, and neutralizing Histone H4 abrogated the BD NETs-mediated IL-8 production by macrophages, but not TNF-α. Also, BD neutrophils produced more 8-OHdG DNA than HC neutrophils, and the percentage of 8-OHdG DNA in dsDNA from BD neutrophils was also higher than that of HC neutrophils. The ROS levels in serum and neutrophils were both higher in BD than HC. Our findings suggested that excessive BD NETs promoted macrophages activation and facilitated IFN-γ+ CD4+ T cells differentiation. Higher levels of Histone H4 and oxidized DNA in BD NETs might mediate macrophages hyperactivation.

Mesothelioma subtypes of the tunica vaginalis: a rare case report and review of histological criteria.

Well-differentiated papillary mesothelioma (WDPM) is a rare histological subtype of mesothelioma arising from the tunica vaginalis. We present a case of a 23-year-old male with a palpable para-testicular lump of 3 years duration. Scrotal exploration revealed a grossly abnormal cystic appearance of his tunica vaginalis. An excision biopsy confirmed WDPM of the tunica vaginalis. The three subtypes of mesothelial tumours of the tunica vaginalis are described by their distinct histological features, tumour growth and reported prognosis. A summary of immunohistochemistry and the surgical management across the disease spectrum is provided. Recent clarification of the histological criteria of WDPM provides the opportunity for surgeons to offer a limited approach to managing this indolent tumour that mimics malignant mesothelioma. However, the lack of evidence on recurrence and progression rates in WDPM restricts most surgeons to performing a radical orchidectomy, as was performed in this case.

Erratum: Mesothelioma subtypes of the tunica vaginalis: a rare case report and review of histological criteria.

[This corrects the article DOI: 10.1093/jscr/rjz040.].

The Clinical Features, Risk Factors, and Outcome of Aneurysmal Lesions in Behcet's Disease.

OBJECTIVE: To investigate the clinical features and potential risk factors of aneurysmal lesions in Behcet's disease (BD). METHODS: We retrospectively reviewed the clinical data of BD patients with aneurysmal lesions in our institute from 1997 to 2017 and compared them with 207 BD patients without aneurysmal lesions. The treatment and outcome of these patients were also analyzed. RESULTS: Sixty-nine patients were included with 117 aneurysmal lesions. The average period between BD onset and diagnosis of aneurysmal lesion was 5.4 ± 5.5 years. Thirty-three patients (47.8%) had multiple aneurysmal lesions. Ten patients developed 20 pulmonary artery aneurysms alone. For the other 97 aortic and/or peripheral artery aneurysms in 59 patients, the most commonly affected vessels were abdominal aorta (27/97, 27.8%), coronary artery (10/97, 10.3%), and superficial femoral artery (8/97, 8.2%). Multivariate analysis revealed pathergy reaction (OR = 3.78 (1.70-8.41)), arterial stenosis or occlusion (OR = 44.12 (11.56-168.35)), and arterial thrombosis (OR = 9.27 (2.33-36.93)) as independent predictors of aneurysmal lesions in BD. With a mean follow-up of 5.5 ± 4.0 years, 40 patients (58.0%) achieved clinical improvements, 15 patients (21.7%) relapsed, and 10 patients (14.5%) died. The respective estimated cumulative 1- and 5-year relapse-free rates were 91.3% and 76.3%, and the respective estimated 1- and 5-year survival rates were 95.0% and 87.2%. CONCLUSION: Aneurysmal lesions are severe complications in BD. Pathergy reaction, arterial stenosis or occlusion, and arterial thrombosis are the risk factors of aneurysmal lesions in BD. Achieving BD remission and performing surgical or interventional procedures are both important in the treatment of these patients.

Neural correlates of facial expression processing during a detection task: An ERP study.

Given finite attentional resources, how emotional aspects of stimuli are processed automatically is controversial. Present study examined the time-course for automatic processing of facial expression by assessing N170, and late positive potentials (LPPs) of event-related potentials (ERPs) using a modified rapid serial visual presentation (RSVP) paradigm. Observers were required to confirm a certain house image and to detect whether a face image was presented at the end of a series of pictures. There were no significant main effects on emotional type for P1 amplitudes, whereas happy and fearful expressions elicited larger N170 amplitudes than neutral expressions. Significantly different LPP amplitudes were elicited depending on the type of emotional facial expressions (fear > happy > neutral). These results indicated that threatening priority was absent but discrimination of expressive vs. neutral faces occurred in implicit emotional tasks, at approximately 250 ms post-stimulus. Moreover, the three types of expressions were discriminated during the later stages of processing. Encoding emotional information of faces can be automated to a relatively higher degree, when attentional resources are mostly allocated to superficial analyzing.

Advancement in regional immunity and its clinical implication.

Organs in our body have formed their own unique immune surveillance system that is finely tuned by in situ milieu. Sequestrated tissue-resident immune cells differ from their counterparts in circulation and participate in tissue physiological activities and the maintenance of local homeostasis. Dysregulation of regional immunity leads to organ-specific inflammatory injuries. Here we review the recent developments in the field of tissue-resident immune cells and organ-specific regional immunity, and discuss their clinical implication.