The Multi-domain Lifestyle Intervention for Cognitive Impairment in Community-Dwelling Older Adults in Hangzhou (The Heritage Study): Study Design and Protocol

BACKGROUND

The globe has been working to promote a multi-domain lifestyle intervention for dementia prevention in older adults, referring to the Worldwide-FINGERS (Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability) initiative. In China, the multi-domain lifestyle intervention has been implemented in rural communities (MIND-China), yet the adaptability of such intervention based on the urban communities in China has not been verified.

OBJECTIVE

To examine the effectiveness and feasibility of the multi-domain lifestyle intervention on dementia prevention in at-risk community-dwelling older adults in China.

DESIGN, SETTING, PARTICIPANTS

The multi-domain lifestyle intervention study is a community-based 2-year cluster randomized controlled trial (RCT). A total of 1200 participants aged 60-80 years old will be recruited from twelve communities in Hangzhou, Zhejiang. Inclusion criteria were the Montreal Cognitive Assessment 5 minutes protocol (5 min MoCA) score of 6-9 or the Ascertain Dementia 8 (AD 8) score of ≥2, and having modifiable lifestyle factors.

INTERVENTION, MEASUREMENTS, RESULTS

Participating communities will be randomized into either the structured multi-domain intervention (SMI) arm or the self-guided intervention (SGI, general health education) arm. The SMI consists of cognitive training, physical exercise, and nutritional and dietary instruction for the first 12 months; and vascular risks monitoring and control for 24 months. The primary outcome is the global cognitive performance, measured by the comprehensive Neuropsychological Test Battery (NTB). The secondary outcomes include domain-specific cognitive performances, physical function, mental health, physiological and biochemical indices, adherence to healthy lifestyles, and neuroimaging metrics. The feasibility of intervention will be evaluated around the five dimensions of the RE-AIM framework and in conjunction with quantitative data, operational data and results of focus group discussions.

CONCLUSIONS

Following the Worldwide-FINGERS, this cluster RCT will verify the adaptability of the multi-domain lifestyle intervention in the urban community settings in China. This study will add evidence for global dementia prevention and management among older adults.

CT-based radiomics for prediction of pulmonary haemorrhage after percutaneous CT-guided transthoracic lung biopsy of pulmonary nodules

AIM

To evaluate the feasibility of intranodular and perinodular computed tomography (CT) radiomics features for predicting the occurrence of pulmonary haemorrhage after percutaneous CT-guided transthoracic lung biopsy (PCTLB) in pulmonary nodules.

MATERIALS AND METHODS

The data for 332 patients with pulmonary nodules who underwent PCTLB were reviewed retrospectively. Pulmonary haemorrhage after PCTLB was evaluated using CT (144 cases occurred). Radiomics features based on gross nodular (GNV) and perinodular volumes (PNV) were extracted from pre-biopsy CT images and features selection using least absolute shrinkage and selection operator (LASSO) regression, and three radiomics scores (rad-scores) were built. Rad-scores, clinical, and clinical-radiomic models were developed and evaluated to predict the occurrence of pulmonary haemorrhage.

RESULTS

Five, five, and six significant features were selected for prediction of pulmonary haemorrhage based on GNV, PNV, and GNV + PNV, respectively. Lesion depth was the only clinical characteristics related to pulmonary haemorrhage. Lesion depth and rad-score based on GNV, PNV, and GNV + PNV for predicting the pulmonary haemorrhage achieved areas under the curves (AUCs) of 0.656, 0.645, 0.651, and 0.635 in the validation group, respectively. Three clinical-radiomic models improved the AUCs to 0.743, 0.723, and 0.748. The performance of rad-score_GNV + PNV combined with lesion depth outperformed the clinical model (p=0.024) and the radiomics signature (p=0.038). In addition, the radiomics signatures were significantly associated with higher-grade pulmonary haemorrhage (p<0.05).

CONCLUSIONS

Radiomics features from intranodular and perinodular regions of pulmonary nodules have good predictive ability for pulmonary haemorrhage after PCTLB, which may provide additional predictive value for clinical practice.

Maintenance Therapy for Recurrent or Metastatic Cervical Cancer: A Multicenter, Cohort Study

PURPOSE/OBJECTIVE(S)

Maintenance therapy with alternative agents after chemotherapy was shown to improve the overall survival in some advanced cancers such as breast cancer, lung cancer, ovarian cancer and so on. However, maintenance therapy is not accepted as the standard treatment for recurrent/metastatic cervical cancer. Aim of this study is to elucidate the efficacy of maintenance therapy in cervical cancer and to explore the factors associated with the prognosis of recurrent or metastatic cervical cancer.

MATERIALS/METHODS

In this multicenter cohort study, we retrospectively collected patients with a diagnosis of either recurrent or stage IVB cervical cancer to receive first-line chemotherapy with or without maintenance therapy. Patients did not have disease progression with first-line chemotherapy and were divided into maintenance therapy group (Arm A) and conventional chemotherapy group (Arm B). Information on clinical characteristics, metastasis information, treatment outcome and survival of patients was collected using an electronic medical record system. The endpoints of the study were OS and PFS. Data were analyzed for general characteristics and survival using statistical software, and the results were considered statistically significant at P < 0.05.

RESULTS

Between January 2019 and July 2021, a total of 270 patients were enrolled from 6 institutions in China. 26 patients were excluded because of short treatment cycles (less than 3 cycles). Finally, a total of 66 patients in Arm A and 178 patients in Arm B were analyzed for survival. The addition of maintenance significantly prolonged overall survival. Overall survival at 3 year was 50.1% in Arm A and 27.8% in Arm B (median overall survival, ≥36 months vs. 22 months; P<0. 001). The median progression-free survival was 21 months in Arm A and 14 months in Arm B (P = 0.025). Univariate survival analysis showed that age, maintenance therapy, combined radiotherapy, and number of extra-pelvic metastases were associated with PFS. Further multifactorial analysis showed that maintenance therapy, combined radiotherapy, and number of extra-pelvic metastases were independent prognostic factors for patients with recurrent or metastatic cervical cancer.

CONCLUSION

The addition of maintenance therapy significantly prolonged overall survival as well as progression-free survival in patients with recurrent or metastatic cervical cancer and did not increase the incidence of serious adverse events. It is time to consider maintenance therapy as the standard treatment after conventional chemotherapy for recurrent or metastatic cervical cancer, rather than waiting for disease progression.

[Prediction of 1p/19q codeletion status in diffuse lower-grade glioma using multimodal MRI radiomics]

OBJECTIVE

To develop a noninvasive method for prediction of 1p/19q codeletion in diffuse lower-grade glioma (DLGG) based on multimodal magnetic resonance imaging (MRI) radiomics.

METHODS

We collected MRI data from 104 patients with pathologically confirmed DLGG between October, 2015 and September, 2022. A total of 535 radiomics features were extracted from T₂WI, T₁WI, FLAIR, CE-T₁WI and DWI, including 70 morphological features, 90 first order features, and 375 texture features. We constructed logistic regression (LR), logistic regression least absolute shrinkage and selection operator (LRlasso), support vector machine (SVM) and Linear Discriminant Analysis (LDA) radiomics models and compared their predictive performance after 10-fold cross validation. The MRI images were reviewed by two radiologists independently for predicting the 1p/19q status. Receiver operating characteristic curves were used to evaluate classification performance of the radiomics models and the radiologists.

RESULTS

The 4 radiomics models (LR, LRlasso, SVM and LDA) achieved similar area under the curve (AUC) in the validation dataset (0.833, 0.819, 0.824 and 0.819, respectively; P>0.1), and their predictive performance was all superior to that of resident physicians of radiology (AUC=0.645, P=0.011, 0.022, 0.016, 0.030, respectively) and similar to that of attending physicians of radiology (AUC=0.838, P>0.05).

CONCLUSION

Multiparametric MRI radiomics models show good performance for noninvasive prediction of 1p/19q codeletion status in patients with in diffuse lower-grade glioma.

A20 and the noncanonical NF-κB pathway are key regulators of neutrophil recruitment during fetal ontogeny

Newborns are at high risk of developing neonatal sepsis, particularly if born prematurely. This has been linked to divergent requirements the immune system has to fulfill during intrauterine compared with extrauterine life. By transcriptomic analysis of fetal and adult neutrophils, we shed new light on the molecular mechanisms of neutrophil maturation and functional adaption during fetal ontogeny. We identified an accumulation of differentially regulated genes within the noncanonical NF-κB signaling pathway accompanied by constitutive nuclear localization of RelB and increased surface expression of TNF receptor type II in fetal neutrophils, as well as elevated levels of lymphotoxin α in fetal serum. Furthermore, we found strong upregulation of the negative inflammatory regulator A20 (Tnfaip3) in fetal neutrophils, which was accompanied by pronounced downregulation of the canonical NF-κB pathway. Functionally, overexpressing A20 in Hoxb8 cells led to reduced adhesion of these neutrophil-like cells in a flow chamber system. Conversely, mice with a neutrophil-specific A20 deletion displayed increased inflammation in vivo. Taken together, we have uncovered constitutive activation of the noncanonical NF-κB pathway with concomitant upregulation of A20 in fetal neutrophils. This offers perfect adaption of neutrophil function during intrauterine fetal life but also restricts appropriate immune responses particularly in prematurely born infants.

Intestinal inflammation alters the antigen-specific immune response to a skin commensal

Resident microbes in skin and gut predominantly impact local immune cell function during homeostasis. However, colitis-associated neutrophilic skin disorders suggest possible breakdown of this compartmentalization with disease. Using a model wherein neonatal skin colonization by Staphylococcus epidermidis facilitates generation of commensal-specific tolerance and CD4⁺ regulatory T cells (Tregs), we ask whether this response is perturbed by gut inflammation. Chemically induced colitis is accompanied by intestinal expansion of S. epidermidis and reduces gut-draining lymph node (dLN) commensal-specific Tregs. It also results in reduced commensal-specific Tregs in skin and skin-dLNs and increased skin neutrophils. Increased CD4⁺ circulation between gut and skin dLN suggests that the altered cutaneous response is initiated in the colon, and resistance to colitis-induced effects in Cd4^creIl1r1^fl/fl mice implicate interleukin (IL)-1 in mediating the altered commensal-specific response. These findings provide mechanistic insight into observed connections between inflammatory skin and intestinal diseases.

Strain-resolved analysis in a randomized trial of antibiotic pretreatment and maintenance dose delivery mode with fecal microbiota transplant for ulcerative colitis

Fecal microbiota transplant is a promising therapy for ulcerative colitis. Parameters maximizing effectiveness and tolerability are not yet clear, and it is not known how import the transmission of donor microbes to patients is. Here (clinicaltrails.gov: NCT03006809) we have tested the effects of antibiotic pretreatment and compared two modes of maintenance dose delivery, capsules versus enema, in a randomized, pilot, open-label, 2 × 2 factorial design with 22 patients analyzed with mild to moderate UC. Clinically, the treatment was well-tolerated with favorable safety profile. Of patients who received antibiotic pretreatment, 6 of 11 experienced remission after 6 weeks of treatment, versus 2 of 11 non-pretreated patients (log odds ratio: 1.69, 95% confidence interval: −0.25 to 3.62). No significant differences were found between maintenance dosing via capsules versus enema. In exploratory analyses, microbiome turnover at both the species and strain levels was extensive and significantly more pronounced in the pretreated patients. Associations were also revealed between taxonomic turnover and changes in the composition of primary and secondary bile acids. Together these findings suggest that antibiotic pretreatment contributes to microbiome engraftment and possibly clinical effectiveness, and validate longitudinal strain tracking as a powerful way to monitor the dynamics and impact of microbiota transfer.

Nickel particles are present in Crohn's disease tissue and exacerbate intestinal inflammation in IBD susceptible mice

Crohn's disease is an inflammatory disease of the gut caused by a complex interplay among genetic, microbial, and environmental factors. The intestinal tract is constantly exposed to metals and other trace elements ingested as food. Synchrotron radiation-induced X-ray fluorescence spectroscopy and X-ray absorption fine structure analysis revealed the deposition of nickel particles within Crohn's disease tissue specimens. After nickel particle stimulation, THP-1 cells showed filopodia formation and autophagic vacuoles containing lipid bodies. Nickel particles precipitated colitis in mice bearing mutations of the IBD susceptibility protein A20/TNFAIP3. Nickel particles also exacerbated dextran sulfate sodium-induced colitis in mice harboring myeloid cell-specific Atg5 deficiency. These findings illustrate that nickel particle ingestion may worsen Crohn's disease by perturbing autophagic processes in the intestine, providing new insights into environmental factors in Crohn's disease pathogenesis.

Microbial signals, MyD88, and lymphotoxin drive TNF-independent intestinal epithelial tissue damage

Anti-TNF antibodies are effective for treating patients with inflammatory bowel disease (IBD), but many patients fail to respond to anti-TNF therapy, highlighting the importance of TNF-independent disease. We previously demonstrated that acute deletion of 2 IBD susceptibility genes, A20 (Tnfaip3) and Abin-1 (Tnip1), in intestinal epithelial cells (IECs) sensitized mice to both TNF-dependent and TNF-independent death. Here we show that TNF-independent IEC death after A20 and Abin-1 deletion was rescued by germ-free derivation or deletion of MyD88, while deletion of Trif provided only partial protection. Combined deletion of Ripk3 and Casp8, which inhibits both apoptotic and necroptotic death, completely protected against death after acute deletion of A20 and Abin-1 in IECs. A20- and Abin-1–deficient IECs were sensitized to TNF-independent, TNFR1-mediated death in response to lymphotoxin α (LTα) homotrimers. Blockade of LTα in vivo reduced weight loss and improved survival when combined with partial deletion of MyD88. Biopsies of inflamed colon mucosa from patients with IBD exhibited increased LTA and IL1B expression, including a subset of patients with active colitis on anti-TNF therapy. These data show that microbial signals, MyD88, and LTα all contribute to TNF-independent intestinal injury.

Impact of Microdevice Geometry on Transit and Retention in the Murine Gastrointestinal Tract

Oral protein delivery technologies often depend on encapsulating or enclosing the protein cargo to protect it against pH-driven degradation in the stomach or enzymatic digestion in the small intestine. An emergent methodology is to encapsulate therapeutics in microscale, asymmetric, planar microparticles, referred to as microdevices. Previous work has shown that, compared to spherical particles, planar microdevices have longer residence times in the GI tract, but it remains unclear how specific design choices (e.g., material selection, particle diameter) impact microdevice behavior in vivo. Recent advances in microdevice fabrication through picoliter printing have expanded the range of device sizes that can be fabricated in a rapid manner. However, relatively little work has explored how device size governs their behavior in the intestinal environment. In this study, we probe the impact of geometry of planar microdevices on their transit and accumulation in the murine GI tract. Additionally, we present a strategy to label, image, and quantify these distributions in intact tissue in a continuous manner, enabling a more detailed understanding of device distribution and transit kinetics than previously possible. We show that smaller particles (194.6 ± 7 μm.diameter) tend to empty from the stomach faster than midsize (293.2 ± 7 μm.diameter) and larger devices (440.9 ± 9 μm.diameter) and that larger devices distribute more broadly in the GI tract and exit slower than other geometries. In general, we observed an inverse correlation between device diameter and GI transit rate. These results inform the future design of drug delivery systems, using particle geometry as an engineering design parameter to control device accumulation and distribution in the GI tract. Additionally, our image analysis process provides greater insight into the tissue level distribution and transit of particle populations. Using this technique, we demonstrate that microdevices act and translocate independently, as opposed to transiting in one homogeneous mass, meaning that target sites will likely be exposed to devices multiple times over the course of hours post administration. This imaging technique and associated findings enable data-informed design of future particle delivery systems, allowing orthogonal control of transit and distribution kinetics in vivo independent of material and cargo selection.

Pointing in a different direction: a case of bilateral absence of extensor indicis

Understanding anatomical variations, as well as, normal anatomy of the muscles and tendons of the hand is vital for successful clinical evaluation and surgery. A number of extensor muscle and tendon variations have been reported in the literature including duplication, triplication, and absence. We report a rare anatomical variation that includes bilateral absence of the extensor indicis (EI) muscles and bilateral duplication of the extensor digitorum (ED) tendon to the second digit in the forearm of an 83-year-old male cadaver during routine upper limbs dissection. In the present case, only three muscles were present in the deep compartment: extensor pollicis longus (EPL), extensor pollicis brevis (EPB), and abductor pollicis longus (APL) with bilateral absence of EI. The reported prevalence of bilateral absence of EI muscle and tendon ranges from 0.5 to 3.5% [1, 26]. The prevalence of an additional index tendon arising bilaterally from the ED muscle belly is 3.2 % of the population [1]. Extension of the index finger is governed by the actions of EI and ED. However, the four tendons of ED are linked to each other by juncturae tendinum (JT), restricting independent extension of the digits in certain postures, e.g. when the hand is fisted. With fisted hand, EI controls extension of the index finger. Clinically, EI tendons are used for tendon reconstruction procedures to restore function to the hand and thumb after trauma or tendon rupture. This report highlights the importance of anticipating anatomical variations and conducting pre-operative evaluations to confirm the presence of EI when planning tendon transfer procedures.

Preserving immune homeostasis with A20

A20/TNFAIP3 is a TNF induced gene that plays a profound role in preserving cellular and organismal homeostasis (Lee, et al., 2000; Opipari etal., 1990). This protein has been linked to multiple human diseases via genetic, epigenetic, and an emerging series of patients with mono-allelic coding mutations. Diverse cellular functions of this pleiotropically expressed protein include immune-suppressive, anti-inflammatory, and cell protective functions. The A20 protein regulates ubiquitin dependent cell signals; however, the biochemical mechanisms by which it performs these functions is surprisingly complex. Deciphering these cellular and biochemical facets of A20 dependent biology should greatly improve our understanding of murine and human disease pathophysiology as well as unveil new mechanisms of cell and tissue biology.

TNFAIP3 Plays a Role in Aging of the Hematopoietic System

Hematopoietic stem and progenitor cells (HSPC) experience a functional decline in response to chronic inflammation or aging. Haploinsufficiency of A20, or TNFAIP3, an innate immune regulator, is associated with a variety of autoimmune, inflammatory, and hematologic malignancies. Based on a prior analysis of epigenomic and transcriptomic changes during normal human aging, we find that the expression of A20 is significantly reduced in aged HSPC as compared to young HSPC. Here, we show that the partial reduction of A20 expression in young HSPC results in characteristic features of aging. Specifically, heterozygous deletion of A20 in hematopoietic cells resulted in expansion of the HSPC pool, reduced HSPC fitness, and myeloid-biased hematopoiesis. These findings suggest that altered expression of A20 in HSPC contributes to an aging-like phenotype, and that there may be a common underlying mechanism for diminished HSPC function between inflammatory states and aging.

MOG1 restores the expression and function of SCN5A-p.R104W through sec23a-mediated forward trafficking

Background

Brugada syndrome (BrS) is an inherited disease which causes fatal arrhythmias and sudden cardiac death. Mutations in SCN5A gene, which encoding cardiac sodium channel (NaV1.5), are the most common genotype of BrS patients. Some SCN5A-related variants were reported to retain NaV1.5 in endoplasmic reticulum (ER) due to trafficking deficiency. MOG1 was previously reported to interact with NaV1.5 and increased sodium current (INa) through enhancing the trafficking. However, its molecular mechanisms are still unclear. Coat protein complex II (COPII) is responsible for the ER to Golgi transport. Sec23 forms the inner coat of COPII and participates in cargo proteins selection.

Purpose

To demonstrate that MOG1 rescues SCN5A-related variants by enhancing the forward trafficking through Sec23a-NaV1.5 interaction.

Methods

Site directed mutagenesis, immunofluorescence staining, biotinylation assay, Western blot analysis and whole-cell patch clamp recording were used. CRISPR/Cas9 was used to knock out Sec23a expression in HEK293 cells.

Results

We found that SCN5A-p.R104W was characterized as reduced NaV1.5 level and lack of INa. The variant SCN5A-p.R104W was mainly distributed in ER. MOG1 could rescue the total and surface expression of SCN5A-p.R104W but could not restore INa (Figure 1a). Considering that most patients are heterozygous, co-transfection of SCN5A-WT and SCN5A-p.R104W were obtained. We found MOG1 could increase both NaV1.5 level and INa of heterozygous expressed SCN5A-p.R104W. We further revealed an interaction between NaV1.5 and Sec23a by co-immunoprecipitation (Co-IP) assay. The interaction between NaV1.5 and Sec23a was increased by MOG1, which indicates that Sec23a participates in MOG1-mediated increase in NaV1.5 level (Figure 1b). Knockout of Sec23a reduced cell surface, but not total, NaV1.5 level (Figure 1c and 1d). Next, the Sec23a knockout HEK293 cells were co-transfected with SCN5A-p.R104W and pcDNA3 or MOG1. MOG1 could not increase SCN5A-p.R104W protein level in Sec23a knockout cells.

Conclusion

Our data demonstrated a novel mechanism that MOG1 restores the expression and function of SCN5A-p.R104W by enhancing its forward trafficking through Sec23a-NaV1.5 interaction.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Natural Science Foundation of China

U-shaped association of sphingosine-1-phosphate level with mortality in chronic systolic heart failure

Background

The immunomodulatory molecule sphingosine-1-phosphate (S1P) has received attention in the cardiovascular field due to its significant cardioprotective effects, as revealed in animal studies. Until now, it has been unclear what is the normal range of S1P in chronic heart failure patients and whether it is related to long term prognosis.

Purpose

The purpose of our study was to identify the distribution characteristics of S1P in systolic heart failure patients and the prognostic value of S1P for long-term prognosis.

Methods

We recruited 210 chronic systolic heart failure patients from June 2014 to December 2015. Meanwhile 54 healthy people in the same area were selected as controls. Plasma S1P was measured by mass spectrometry. Patients were grouped according to the baseline S1P level quartiles, and restricted cubic spline plots described a U-shaped association between S1P and all cause death. Cox proportional hazard analysis was used to determine the relationship between category of S1P and all-cause death. Survival curves were using the Kaplan-Meier method and the log-rank test was used for comparison.

Results

Compared with the control group, the plasma S1P in chronic heart failure patients demonstrated a higher mean level (1.269 μmol/L vs 1.122 μmol/L, P=0.006) and a larger standard deviation (0.441 vs 0.316, P=0.022). After a follow-up period of 31.7±10.3 months, the second quartile (0.967–1.192μml/L) with largely normal S1P levels had the lowest all-cause mortality and either an increase (HR=3.87, 95% CI 1.504–9.960, P=0.005, adjusted HR=3.134, 95% CI 1.211–8.111, P=0.019) or a decrease (HR=3.271, 95% CI 1.277–8.381, P=0.014, adjusted HR=1.90, 95% CI 0.711–5.083, P=0.200) predicted a worse prognosis.

Conclusions

Plasma S1P levels in systolic heart failure patients are related to the long-term all-cause mortality with a U-shaped correlation. Through restoring abnormal levels to a normal range instead of simply up regulation or down regulation, S1P may have the potential to be a therapeutic target for reducing the risk of death in patients with heart failure in the future.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Ministry of Science and Technology of the People's Republic of China. Ministry of Finance of the People's Republic of China.

Adaptive response to inflammation contributes to sustained myelopoiesis and confers a competitive advantage in myelodysplastic syndrome HSCs

Despite evidence of chronic inflammation in myelodysplastic syndrome (MDS) and cell-intrinsic dysregulation of Toll-like receptor (TLR) signaling in MDS hematopoietic stem and progenitor cells (HSPCs), the mechanisms responsible for the competitive advantage of MDS HSPCs in an inflammatory milieu over normal HSPCs remain poorly defined. Here, we found that chronic inflammation was a determinant for the competitive advantage of MDS HSPCs and for disease progression. The cell-intrinsic response of MDS HSPCs, which involves signaling through the noncanonical NF-κB pathway, protected these cells from chronic inflammation as compared to normal HSPCs. In response to inflammation, MDS HSPCs switched from canonical to noncanonical NF-κB signaling, a process that was dependent on TLR-TRAF6-mediated activation of A20. The competitive advantage of TLR-TRAF6-primed HSPCs could be restored by deletion of A20 or inhibition of the noncanonical NF-κB pathway. These findings uncover the mechanistic basis for the clonal dominance of MDS HSPCs and indicate that interfering with noncanonical NF-κB signaling could prevent MDS progression.

Comparative Analysis of Gait Speed Estimation Using Wideband and Narrowband Radars, Thermal Camera, and Motion Tracking Suit Technologies

Research has shown that cognitive and physical functioning of older adults can be reflected in indicators such as walking speed. While changes in cognition, mobility, or health cause changes in gait speed, often gradual variations in walking speed go undetected until severe problems arise. Discrete clinical assessments during clinical consultations often fail to detect changes in day-to-day walking speeds and do not reflect walking speeds in everyday environments, where most of the mobility issues happen. In this paper, we compare four walking speed measurement technologies to a GAITRite mat (gold standard): (1) an ultra wideband radar (covering the band from 3.3 GHz to 10 GHz), (2) a narrow band 24-GHz radar (with a bandwidth of 250 MHz), (3) a perception Neuron Motion Tracking suit, and (4) a thermal camera. Data were collected in parallel using all sensors at the same time for 10 healthy adults for normal and slow walking paces. A comparison of the sensors indicates better performance at lower gait speeds, with offsets (when compared to GAITRite) between 0.1 and 20% for the ultra wideband radar, 1.9 and 17% for the narrowband radar, 0.1 and 38% for the thermal camera, and 1.7 and 38% for the suit. This paper supports the potential of unobtrusive radar-based sensors and thermal camera technologies for ambient autonomous gait speed monitoring for contextual, privacy-preserving monitoring of participants in the community.

Fecal Microbiota Transplantation in Pouchitis: Clinical, Endoscopic, Histologic, and Microbiota Results from a Pilot Study

AIMS

This pilot study assessed the efficacy, safety, and microbiome dynamics of fecal microbiota transplantation (FMT) for patients with chronic pouchitis.

METHODS

A prospective open-label pilot study was performed at an academic center among pouchitis patients undergoing FMT. Patients received a minimum of a single FMT by pouchoscopy from healthy, screened donors. The primary outcome was clinical improvement in pouchitis assessed by patient survey at week 4. Secondary outcomes included decrease in total Pouchitis Disease Activity Index (PDAI) Score ≥ 3 at week 4, bowel movement frequency, ESR, CRP, fecal calprotectin, abdominal pain, and PDAI subscores including endoscopic and histologic changes. Stool samples were collected at baseline and 4 weeks post-FMT to assess bacterial microbiota using V4 16S rRNA sequencing.

RESULTS

Nineteen patients were enrolled; however, 1 patient was lost to follow-up. No patients had a major adverse event or escalation of therapy related to FMT. Total PDAI scores, endoscopic scores, and histologic scores did not decrease significantly post-FMT. However, there was a statistically significant improvement in bowel movement (BM) frequency (9.25-7.25 BM/day, p = 0.03) and trend for improvement in abdominal pain to improve post-FMT (p = 0.05). Bacterial microbiota profiling revealed no distinct community-level changes post-FMT, though a small number of specific bacterial taxa significantly differed in relative abundance.

CONCLUSIONS

A single FMT has a tolerable short-term safety profile and may be associated with a decrease in bowel movements in patients with chronic pouchitis; however, no robust endoscopic or histologic changes were observed.

Non-catalytic ubiquitin binding by A20 prevents psoriatic arthritis-like disease and inflammation

A20 is an anti-inflammatory protein that is strongly linked to human disease. Here, we find that mice expressing three distinct targeted mutations of A20's zinc finger 7 (ZF7) ubiquitin-binding motif uniformly developed digit arthritis with features common to psoriatic arthritis, while mice expressing point mutations in A20's OTU or ZF4 motifs did not exhibit this phenotype. Arthritis in A20^ZF7 mice required T cells and MyD88, was exquisitely sensitive to tumor necrosis factor and interleukin-17A, and persisted in germ-free conditions. A20^ZF7 cells exhibited prolonged IκB kinase activity that drove exaggerated transcription of late-phase nuclear factor-κB response genes in vitro and in prediseased mouse paws in vivo. In addition, mice expressing double-mutant A20 proteins in A20's ZF4 and ZF7 motifs died perinatally with multi-organ inflammation. Therefore, A20's ZF4 and ZF7 motifs synergistically prevent inflammatory disease in a non-catalytic manner.

The ratio of miR-21/miR-24 as a promising diagnostic and poor prognosis biomarker in colorectal cancer

OBJECTIVE

Optimal management of cancer treatment will be guided by sensitive and specific biomarkers. Searching for potential biomarkers is always a hot spot in cancer research, including colorectal cancer (CRC). MicroRNAs (miRNAs) have been recently proposed as biomarkers for cancers.

PATIENTS AND METHODS

Based on previous miRNA analysis in our hospital and data mining, we hypothesized that the ratio of miR-21/miR-24 (miR-21/24) may serve as plasma biomarkers in CRC patients. The plasma levels of miR-21 and miR-24 were analyzed from the 186 CRC patients before surgery and 97 healthy controls by qRT-PCR. Receiver operating characteristic (ROC) analysis was further used to evaluate the difference in diagnostic accuracy associated with the expression of miR-21, miR-24 and their ratio. Chi-square2-test or Fisher's exact test was performed to determine the relationship between the ratio of miR-21/24 and clinicopathological parameters. Kaplan-Meier and log-rank testing were performed to evaluate the effect of miR-21/24 ratio on the survival of colon cancer. Hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) were calculated by Cox regression models.

RESULTS

ROC curves revealed that the diagnostic accuracy AUC (area under the curve) in CRC tissue of miR-24, miR-21, and the ratio of miR-21/24 were 0.8971, 0.9128 and 0.9875, respectively. Notably, the ratio of miR-21/24, with the best accuracy among these miRNAs, was significantly correlated with several important prognosis factors in CRC, such as tumor size, TNM stage, lymph metastasis and histologic differentiation (all p<0.05). By Kaplan-Meier survival analysis and Cox regression analysis, the ratio of miR-21/24 was shown to be a significant survival risk factor for CRC patients.

CONCLUSIONS

We showed that the plasma ratio of miR-21/24 is a potentially powerful tool for detecting CRC and predicting prognosis.

A20 in dendritic cells restrains intestinal anti-bacterial peptide expression and preserves commensal homeostasis

Microbial dysbiosis commonly occurs in patients with inflammatory bowel diseases (IBD). Exogenous causes of dysbiosis such as antibiotics and diet are well described, but host derived causes are understudied. A20 is a potent regulator of signals triggered by microbial pattern molecules, and A20 regulates susceptibility to intestinal inflammation in mice and in humans. We now report that mice lacking A20 expression in dendritic cells, A20FL/FL CD11c-Cre mice (or A20dDC mice), spontaneously develop colitogenic intestinal dysbiosis that is evident upon weaning and precedes the onset of colitis. Intestines from A20dDC mice express increased amounts of Reg3β and Reg3γ, but not Ang4. A20 deficient DCs promote gut microbiota perturbation in the absence of adaptive lymphocytes. Moreover, A20 deficient DCs directly induce expression of Reg3β and Reg3γ but not Ang 4 in normal intestinal epithelial cell enteroid cultures in the absence of other cell types. These findings reveal a pathophysiological pathway in which defective expression of an IBD susceptibility gene in DCs drives aberrant expression of anti-bacterial peptides and luminal dysbiosis that in turn confers host susceptibility to intestinal inflammation.

Fecal microbiota transplant for Crohn disease: A study evaluating safety, efficacy, and microbiome profile

BACKGROUND

Emerging trials suggest fecal microbiota transplantation (FMT) is a promising treatment for ulcerative colitis; however, there is a paucity of data in Crohn disease (CD).

OBJECTIVE

The objectives of this article are to determine whether single-dose FMT improves clinical and endoscopic outcomes in CD patients and to identify meaningful changes in the microbiome in response to FMT.

METHODS

We performed a prospective, open-label, single-center study. Ten CD patients underwent FMT and were evaluated for clinical response (defined as decrease in Harvey-Bradshaw Index score ≥3 at one month post-FMT) and microbiome profile (16S ribosomal RNA sequencing) at one month post-FMT.

RESULTS

Three of 10 patients responded to FMT. Two of 10 patients had significant adverse events requiring escalation of therapy. On microbiome analysis, bacterial communities of responders had increased relative abundance of bacteria commonly found in donor gut microbiota.

CONCLUSIONS

Single-dose FMT in this cohort of CD patients showed modest effect and potential for harm. Responders tended to have lower baseline alpha diversity, suggesting baseline perturbation of microbiota may be an indicator of potential responders to FMT in this patient population. Controlled trials are needed to further assess the efficacy and safety of FMT in CD and determine whether FMT is a viable option in this patient population.Clinicaltrials.gov number: NCT02460705.

A20: A multifunctional tool for regulating immunity and preventing disease

A20, also known as TNFAIP3, is a potent regulator of ubiquitin (Ub) dependent signals. A20 prevents multiple human diseases, indicating that the critical functions of this protein are clinically as well as biologically impactful. As revealed by mouse models, cell specific functions of A20 are linked to its ability to regulate diverse signaling pathways. Aberrant expression or functions of A20 in specific cell types underlie divergent disease outcomes. Discernment of A20's biochemical functions and their phenotypic outcomes will contribute to our understanding of how ubiquitination is regulated, how Ub mediated functions can prevent disease, and will pave the way for future therapeutic interventions.

A20 Orchestrates Inflammatory Response in the Oral Mucosa through Restraining NF-κB Activity

Deregulated immune response to a dysbiotic resident microflora within the oral cavity leads to chronic periodontal disease, local tissue destruction, and various systemic complications. To preserve tissue homeostasis, inflammatory signaling pathways involved in the progression of periodontitis must be tightly regulated. A20 (TNFAIP3), a ubiquitin-editing enzyme, has emerged as one of the key regulators of inflammation. Yet, the function of A20 in the oral mucosa and the biological pathways in which A20 mitigates periodontal inflammation remain elusive. Using a combination of in vivo and ex vivo disease models, we report in this study that A20 regulates inflammatory responses to a keystone oral bacterium, Porphyromonas gingivalis, and restrains periodontal inflammation through its effect on NF-κB signaling and cytokine production. Depletion of A20 using gene editing in human macrophage-like cells (THP-1) significantly increased cytokine secretion, whereas A20 overexpression using lentivirus infection dampened the cytokine production following bacterial challenge through modulating NF-κB activity. Similar to human cells, bone marrow-derived macrophages from A20-deficient mice infected with P. gingivalis displayed increased NF-κB activity and cytokine production compared with the cells isolated from A20-competent mice. Subsequent experiments using a murine ligature-induced periodontitis model showed that even a partial loss of A20 promotes an increased inflammatory phenotype and more severe bone loss, further verifying the critical function of A20 in the oral mucosa. Collectively, to our knowledge, these findings reveal the first systematic evidence of a physiological role for A20 in the maintenance of oral tissue homeostasis as a negative regulator of inflammation.

OTUB1 non-catalytically stabilizes the E2 ubiquitin-conjugating enzyme UBE2E1 by preventing its autoubiquitination

OTUB1 is a deubiquitinating enzyme that cleaves Lys-48–linked polyubiquitin chains and also regulates ubiquitin signaling through a unique, noncatalytic mechanism. OTUB1 binds to a subset of E2 ubiquitin-conjugating enzymes and inhibits their activity by trapping the E2∼ubiquitin thioester and preventing ubiquitin transfer. The same set of E2s stimulate the deubiquitinating activity of OTUB1 when the E2 is not charged with ubiquitin. Previous studies have shown that, in cells, OTUB1 binds to E2-conjugating enzymes of the UBE2D (UBCH5) and UBE2E families, as well as to UBE2N (UBC13). Cellular roles have been identified for the interaction of OTUB1 with UBE2N and members of the UBE2D family, but not for interactions with UBE2E E2 enzymes. We report here a novel role for OTUB1–E2 interactions in modulating E2 protein ubiquitination. We observe that Otub1^−/− knockout mice exhibit late-stage embryonic lethality. We find that OTUB1 depletion dramatically destabilizes the E2-conjugating enzyme UBE2E1 (UBCH6) in both mouse and human OTUB1 knockout cell lines. Of note, this effect is independent of the catalytic activity of OTUB1, but depends on its ability to bind to UBE2E1. We show that OTUB1 suppresses UBE2E1 autoubiquitination in vitro and in cells, thereby preventing UBE2E1 from being targeted to the proteasome for degradation. Taken together, we provide evidence that OTUB1 rescues UBE2E1 from degradation in vivo.

A Metabolite-Triggered Tuft Cell-ILC2 Circuit Drives Small Intestinal Remodeling

The small intestinal tuft cell-ILC2 circuit mediates epithelial responses to intestinal helminths and protists by tuft cell chemosensory-like sensing and IL-25-mediated activation of lamina propria ILC2s. Small intestine ILC2s constitutively express the IL-25 receptor, which is negatively regulated by A20 (Tnfaip3). A20 deficiency in ILC2s spontaneously triggers the circuit and, unexpectedly, promotes adaptive small-intestinal lengthening and remodeling. Circuit activation occurs upon weaning and is enabled by dietary polysaccharides that render mice permissive for Tritrichomonas colonization, resulting in luminal accumulation of acetate and succinate, metabolites of the protist hydrogenosome. Tuft cells express GPR91, the succinate receptor, and dietary succinate, but not acetate, activates ILC2s via a tuft-, TRPM5-, and IL-25-dependent pathway. Also induced by parasitic helminths, circuit activation and small intestinal remodeling impairs infestation by new helminths, consistent with the phenomenon of concomitant immunity. We describe a metabolic sensing circuit that may have evolved to facilitate mutualistic responses to luminal pathosymbionts.

A20 and ABIN-1 synergistically preserve intestinal epithelial cell survival

A20 (TNFAIP3) and ABIN-1 (TNIP1), two candidate inflammatory bowel disease (IBD) susceptibility genes, preserve intestinal homeostasis by cooperatively restricting intestinal epithelial cell death. A20 and ABIN-1 synergistically restrict both TNF-dependent and TNF-independent cell death.

A20 (TNFAIP3) and ABIN-1 (TNIP1) are candidate susceptibility genes for inflammatory bowel disease and other autoimmune or inflammatory diseases, but it is unclear how these proteins interact in vivo to prevent disease. Here we show that intestinal epithelial cell (IEC)-specific deletion of either A20 or ABIN-1 alone leads to negligible IEC loss, whereas simultaneous deletion of both A20 and ABIN-1 leads to rapid IEC death and mouse lethality. Deletion of both A20 and ABIN-1 from enteroids causes spontaneous cell death in the absence of microbes or hematopoietic cells. Studies with enteroids reveal that A20 and ABIN-1 synergistically restrict death by inhibiting TNF-induced caspase 8 activation and RIPK1 kinase activity. Inhibition of RIPK1 kinase activity alone, or caspase inhibition combined with RIPK3 deletion, abrogates IEC death by blocking both apoptosis and necroptosis in A20 and ABIN-1 double-deficient cells. These data show that the disease susceptibility proteins A20 and ABIN-1 synergistically prevent intestinal inflammation by restricting IEC death and preserving tissue integrity.

IL-17RC is critically required to maintain baseline A20 production to repress JNK isoform-dependent tumor-specific proliferation

The IL-17/IL-17R axis has controversial roles in cancer, which may be explained by tumor-specific results. Here, we describe a novel molecular mechanism underlying IL-17RC-controlled tumor-specific proliferation. Triggered by IL-17RC knockdown (KD), B16 melanoma and 4T1 carcinoma cells inversely altered homeostatic tumor proliferation and tumor growth in vitro and in vivo. In contrast to the existing dogma that IL-17RC-dependent signaling activates the JNK pathway, IL-17RC KD in both tumor cell lines caused aberrant expression and activation of different JNK isoforms along with markedly diminished levels of the ubiquitin-editing enzyme A20. We demonstrated that differential up-regulation of JNK1 and JNK2 in the two tumor cell lines was responsible for the reciprocal regulation of c-Jun activity and tumor-specific proliferation. Furthermore, we showed that A20 reconstitution of IL-17RCKD clones with expression of full-length A20, but not a truncation-mutant, reversed aberrant JNK1/JNK2 activities and tumor-specific proliferation. Collectively, our study reveals a critical role of IL-17RC in maintaining baseline A20 production and a novel role of the IL-17RC-A20 axis in controlling JNK isoform-dependent tumor-specific homeostatic proliferation.

Anti-TNF and thiopurine therapy in pregnant IBD patients does not significantly alter a panel of B-cell and T-cell subsets in 1-year-old infants

Objectives

Infants exposed to combination therapy with anti-tumor necrosis factor (anti-TNF) agents and thiopurines may exhibit increased infections at 1 year of age compared to unexposed infants. We hypothesized that this increased risk of infection is due to abnormal development of the newborn immune system.

Methods

We immunophenotyped B-cell and T-cell subsets using multiparameter flow cytometry in 1-year-old infants whose mothers were exposed to therapeutic agents for IBD. We analyzed samples from infants exposed to infliximab (IFX) or adalimumab (ADA) monotherapy (IFX/ADA, n = 11), certolizumab pegol (CZP) monotherapy (CZP, n = 4), IFX or ADA plus thiopurine combination therapy (IFX/ADA + IM, n = 4), and CZP plus thiopurine combination therapy (CZP + IM, n = 2).

Results

Percentages of B cells, CD4⁺ T helper cells, T regulatory cells (T_regs), and CD8⁺ cytotoxic T cells, were similar among the groups. Infants exposed to combination therapy (IFX/ADA + IM) exhibited trends toward fewer CD27⁺ B cells, switched memory B cells, plasmablasts, interferon gamma (IFNγ)-producing CD4⁺ and CD8⁺ T cells, and CCR5⁺CD4⁺ T cells, but these did not reach statistical significance.

Conclusions

Multiparameter immunophenotyping of major B-cell and T-cell subsets suggests that the adaptive newborn immune system develops largely unaltered after exposure to combination therapy as compared to anti-TNF monotherapy.

A20 upregulation during treated HIV disease is associated with intestinal epithelial cell recovery and function

TRIAL REGISTRATION

ClinicalTrials.gov Clinical Trial NCT00594880.

Inflammatory Th1 and Th17 in the Intestine Are Each Driven by Functionally Specialized Dendritic Cells with Distinct Requirements for MyD88

Normal dynamics between microbiota and dendritic cells (DCs) support modest numbers of T cells, yet these do not cause inflammation. The DCs that induce inflammatory T cells and the signals that drive this process remain unclear. Here, we demonstrate that small intestine DCs lacking the signaling attenuator A20 induce inflammatory T cells and that the signals perceived and antigen-presenting cell (APC) functions are unique for different DC subsets. Thus, although CD103⁺CD11b^- DCs exclusively instruct IFNγ⁺ T cells, CD103⁺CD11b⁺ DCs exclusively instruct IL-17⁺ T cells. Surprisingly, APC functions of both DC subsets are upregulated in a MyD88-independent fashion. In contrast, CD103^-CD11b⁺ DCs instruct both IFNγ⁺ and IL-17⁺ T cells, and only the IL-17-inducing APC functions require MyD88. In disease pathogenesis, both CD103^-CD11b⁺ and CD103⁺CD11b⁺ DCs expand pathologic Th17 cells. Thus, in disease pathogenesis, specific DCs instruct specific inflammatory T cells.

Ubiquitin-Modifying Enzymes and Regulation of the Inflammasome

Ubiquitin and ubiquitin-modifying enzymes play critical roles in a wide variety of intracellular signaling pathways. Inflammatory signaling cascades downstream of TNF, TLR agonists, antigen receptor cross-linking, and cytokine receptors, all rely on ubiquitination events to direct subsequent immune responses. In the past several years, inflammasome activation and subsequent signal transduction have emerged as an excellent example of how ubiquitin signals control inflammatory responses. Inflammasomes are multiprotein signaling complexes that ultimately lead to caspase activation and release of the interleukin-1 (IL-1) family members, IL-1β and IL-18. Inflammasome activation is critical for the host's defense against pathogens, but dysregulation of inflammasomes may contribute to the pathogenesis of multiple diseases. Ultimately, understanding how various ubiquitin interacting proteins control inflammatory signaling cascades could provide new pathways for therapeutic intervention. Here we review specific ubiquitin-modifying enzymes and ubiquitination events that orchestrate inflammatory responses, with an emphasis on the NLRP3 inflammasome.

Calcium-dependent Nedd4-2 upregulation mediates degradation of the cardiac sodium channel Nav1.5: implications for heart failure

AIM

Reductions in voltage-gated sodium channel (Nav1.5) function/expression provide a slowed-conduction substrate for cardiac arrhythmias. Nedd4-2, which is activated by calcium, post-translationally modulates Nav1.5. We aim to investigate whether elevated intracellular calcium ([Ca²⁺ ]_i ) reduces Nav1.5 through Nedd4-2 and its role in heart failure (HF).

METHODS

Using a combination of biochemical, electrophysiological, cellular and in vivo methods, we tested the effect and mechanism of calcium on Nedd4-2 and in turn Nav1.5.

RESULTS

Increased [Ca²⁺ ]_i , following 24-h ionomycin treatment, decreased sodium current (I_Na ) density and Nav1.5 protein without altering its mRNA in both neonatal rat cardiomyocytes (NRCMs) and HEK 293 cells stably expressing Nav1.5. The calcium chelator BAPTA-AM restored the reduced Nav1.5 and I_Na in NRCMs pre-treated by ionomycin. Nav1.5 was decreased by Nedd4-2 transfection and further decreased by 6-h ionomycin treatment. These effects were not observed in cells transfected with the catalytically inactive mutant, Nedd4-2 C801S, or with Y1977A-Nav1.5 mutant containing the impaired Nedd4-2 binding motif. Furthermore, elevated [Ca²⁺ ]_i increased Nedd4-2, the interaction between Nedd4-2 and Nav1.5, and Nav1.5 ubiquitination. Nav1.5 protein is decreased, whereas Nedd4-2 is increased in volume-overload HF rat hearts, with increased co-localization of Nav1.5 with ubiquitin or Nedd4-2 as indicated by immunofluorescence staining. BAPTA-AM rescued the reduced Nav1.5 protein, I_Na and increased Nedd4-2 in hypertrophied NRCMs induced by isoproterenol or angiotensin II.

CONCLUSION

Calcium-mediated increases in Nedd4-2 downregulate Nav1.5 by ubiquitination. Nav1.5 is downregulated and co-localizes with Nedd4-2 and ubiquitin in failing rat heart. These data suggest a role of Nedd4-2 in Nav1.5 downregulation in HF.

Interleukin-17 signaling triggers degradation of the constitutive NF-κB inhibitor ABIN-1

IL-17 activates NF-κB and inducing expression of proinflammatory genes. IL-17 drives disease in autoimmune conditions, and anti-IL-17 antibodies have shown impressive success in the clinic. Although produced by lymphocytes, IL-17 predominantly signals in fibroblasts and epithelial cells. IL-17-driven inflammation is kept in check by negative feedback signaling molecules, including the ubiquitin editing enzyme A20, whose gene TNFΑIP3 is and similarly linked to autoimmune disease susceptibility. Accordingly, we hypothesized that ABIN-1 might play a role in negatively regulating IL-17 signaling activity. Indeed, ABIN-1 enhanced both tonic and IL-17-dependent NF-κB signaling in IL-17-responsive fibroblast cells. Interestingly, the inhibitory activities of ABIN-1 on IL-17 signaling were independent of A20. ABIN-1 is a known NF-κB target gene, and we found that IL-17-induced activation of NF-κB led to enhanced ABIN-1 mRNA expression and promoter activity. Surprisingly, however, the ABIN-1 protein was inducibly degraded following IL-17 signaling in a proteasome-dependent manner. Thus, ABIN-1, acting independently of A20, restricts both baseline and IL-17-induced inflammatory gene expression. We conclude that IL-17-induced signals lead to degradation of ABIN-1, thereby releasing a constitutive cellular brake on NF-κB activation.

IL-17 signaling inducibly degrades ABIN1, a constitutive inhibitor of inflammatory signaling

IL-17 is a pro-inflammatory cytokine that drives autoimmune diseases and promotes immunity to fungi. IL-17 binding to the IL-17 receptor initiates recruitment of adaptor proteins that activate NF-κB. IL-17 also induces expression of A20, a feedback inhibitor that restricts NF-κB activation and limits IL-17-dependent inflammation. ABIN1 is an A20 binding protein that has been implicated in autoimmunity in human genetic studies, so we hypothesized that ABIN1 might also play a role in restricting IL-17-dependent signaling. Indeed, ABIN1 inhibited the IL-17 pathway based on RNA silencing analyses. Specifically, the expression of the IL-17-dependent gene lipocalin 2 (Lcn2) increased at both basal levels and after stimulation upon ABIN1 knockdown. Consistently, reconstitution of ABIN1-deficient fibroblasts with ABIN1 also decreased both Lcn2 expression and promoter activation. However, while ABIN1 mRNA increased after IL-17A stimulation, ABIN1 protein progressively decreased following its inducible phosphorylation. Although feedback loops are commonly seen in signaling pathways, differential regulation of mRNA and protein of the same gene are not as common. Thus, we now propose that ABIN1 serves as a constitutive inhibitor of NF-κB signaling. While ABIN1 mRNA is induced by NF-κB at the mRNA level, removal of the ABIN1 protein is required to initiate signal transduction. Unexpectedly, we discovered that A20 is dispensable for both IL-17-mediated degradation of ABIN1 and for ABIN1-dependent inhibition of IL-17 signaling. Altogether, these findings suggest that ABIN1 is a tonic NF-κB inhibitor, and that IL-17 signaling induces its degradation independently of A20 to enhance expression of NF-κB-dependent genes such as Lcn2.

The Ubiquitin Binding Protein TAX1BP1 Mediates Autophagasome Induction and the Metabolic Transition of Activated T Cells

During immune responses, naive T cells transition from small quiescent cells to rapidly cycling cells. We have found that T cells lacking TAX1BP1 exhibit delays in growth of cell size and cell cycling. TAX1BP1-deficient T cells exited G₀ but stalled in S phase, due to both bioenergetic and biosynthetic defects. These defects were due to deficiencies in mTOR complex formation and activation. These mTOR defects in turn resulted from defective autophagy induction. TAX1BP1 binding of LC3 and GABARAP via its LC3-interacting region (LIR), but not its ubiquitin-binding domain, supported T cell proliferation. Supplementation of TAX1BP1-deficient T cells with metabolically active L-cysteine rescued mTOR activation and proliferation but not autophagy. These studies reveal that TAX1BP1 drives a specialized form of autophagy, providing critical amino acids that activate mTOR and enable the metabolic transition of activated T cells.

ASP2409, A Next-Generation CTLA4-Ig, Versus Belatacept in Renal Allograft Survival in Cynomolgus Monkeys

Belatacept is the first costimulatory blockade agent approved for maintenance immunosuppression in kidney transplant recipients. Clinical results have indicated that belatacept is associated with superior renal function and improved metabolic profile; however, higher incidence of acute rejection and posttransplant lymphoproliferative disorder are the shortcomings of this agent. In this study, ASP2409, a new cytotoxic T-lymphocyte associated protein 4-immunoglobulin possessing 14-fold higher in vitro CD86 binding affinity than belatacept, was tested for renal allograft survival in cynomolgus monkeys. ASP2409 monotherapy dose-dependently prolonged renal allograft survival. Low-dose ASP2409 in combination with a subtherapeutic dose of tacrolimus showed much longer median survival time than monotherapy. Similar allograft survival results were observed in regimens based on high-dose ASP2409, belatacept, and therapeutic-dose tacrolimus. The results of renal allograft histopathology with high-dose ASP2409-based regimens were not inferior to the belatacept-based regimen. Moreover, higher frequencies of FoxP3-positive regulatory T cells in renal allografts were observed in ASP2409- and belatacept-based regimens compared with tacrolimus-based regimens. No serious side effects related to ASP2409 administration were found during the study. These data suggest that ASP2409 is a promising candidate for calcineurin inhibitor-sparing or -avoidance regimens.

TNFAIP3 promotes survival of CD4 T cells by restricting MTOR and promoting autophagy

Autophagy plays important roles in metabolism, differentiation, and survival in T cells. TNFAIP3/A20 is a ubiquitin-editing enzyme that is thought to be a negative regulator of autophagy in cell lines. However, the role of TNFAIP3 in autophagy remains unclear. To determine whether TNFAIP3 regulates autophagy in CD4 T cells, we first analyzed Tnfaip3-deficient naïve CD4 T cells in vitro. We demonstrated that Tnfaip3-deficient CD4 T cells exhibited reduced MAP1LC3/LC3 (microtubule-associated protein 1 light chain 3) puncta formation, increased mitochondrial content, and exaggerated reactive oxygen species (ROS) production. These results indicate that TNFAIP3 promotes autophagy after T cell receptor (TCR) stimulation in CD4 T cells. We then investigated the mechanism by which TNFAIP3 promotes autophagy signaling. We found that TNFAIP3 bound to the MTOR (mechanistic target of rapamycin) complex and that Tnfaip3-deficient cells displayed enhanced ubiquitination of the MTOR complex and MTOR activity. To confirm the effects of enhanced MTOR activity in Tnfaip3-deficient cells, we analyzed cell survival following treatment with Torin1, an MTOR inhibitor. Tnfaip3-deficient CD4 T cells exhibited fewer cell numbers than the control cells in vitro and in vivo. In addition, the impaired survival of Tnfaip3-deficient cells was ameliorated with Torin1 treatment in vitro and in vivo. The effect of Torin1 was abolished by Atg5 deficiency. Thus, enhanced MTOR activity regulates the survival of Tnfaip3-deficient CD4 T cells. Taken together, our findings illustrate that TNFAIP3 restricts MTOR signaling and promotes autophagy, providing new insight into the manner in which MTOR and autophagy regulate survival in CD4 T cells.

Homeostasis of IL-15 dependent lymphocyte subsets in the liver

IL-15 is a member of the gamma chain family of cytokines (γc - CD132). The IL-15 receptor (IL-15R) complex consists of 3 subunits: the ligand-binding IL-15Rα chain (CD215), the β chain (CD122; also used by IL-2), and the common γ chain. The biological activities of IL-15 are mostly mediated by the IL-15:IL-15Rα complex, produced by the same cell and 'trans-presented' to responder cells expressing the IL-15Rβγc. The peculiar and almost unique requirement for IL-15 to be trans-presented by IL-15Rα suggests that the biological effects of IL-15 signaling are tightly regulated even at the level of availability of IL-15. Tissue-specific deletion of IL-15Rα has shown macrophage-and dendritic cell-derived IL-15Rα mediate the homeostasis of different CD8(+) T cell subsets. Here we show that hepatocyte and macrophage- specific expression of IL-15Rα is required to maintain the homeostasis of NK and NKT cells in the liver. Thus, homeostasis of IL-15-dependent lymphocyte subsets is also regulated by trans-presentation of IL-15 by non-hematopoietic cells in the tissue environment.