A Novel PTPRQ c.3697del Variant Causes Autosomal Dominant Progressive Hearing Loss in Both Humans and Mice

PTPRQ plays an important role in the development of inner ear hair cell stereocilia. While many autosomal recessive variants in PTPRQ have been identified as the pathogenic cause for nonsyndromic hearing loss (DFNB84A), so far only one autosomal dominant PTPRQ variant, c.6881G>A (p.Trp2294*), has been reported for late-onset, mild-to-severe hearing loss (DFNA73). By using targeted next-generation sequencing, this study identified a novel PTPRQ truncating pathogenic variant, c.3697del (p.Leu1233Phefs*11), from a Chinese Han family that co-segregated with autosomal dominant, postlingual, progressive hearing loss. A Ptprq-3700del knock-in mouse model was generated by CRISPR-Cas9 and characterized for its hearing function and inner ear morphology. While the homozygous knock-in mice exhibit profound hearing loss at all frequencies at the age of 3 weeks, the heterozygous mutant mice resemble the human patients in mild, progressive hearing loss from age 3 to 12 weeks, primarily affecting high frequencies. At this stage, the homozygous knock-in mice have a normal hair cell count but disorganized stereocilia. Cochlear proteosome analysis of the homozygous mutant mice revealed differentially expressed genes and pathways involved in oxidative phosphorylation, regulation of angiogenesis and synaptic vesicle cycling. Our study provides a valuable animal model for further functional studies of the pathogenic mechanisms underlying DFNA73.

Hidden hearing loss in a Charcot-Marie-Tooth type 1A mouse model

Hidden hearing loss (HHL), a recently described auditory neuropathy characterized by normal audiometric thresholds but reduced sound-evoked cochlear compound action potentials, has been proposed to contribute to hearing difficulty in noisy environments in people with normal hearing thresholds and has become a widespread complaint. While most studies on HHL pathogenesis have focused on inner hair cell (IHC) synaptopathy, we recently showed that transient auditory nerve (AN) demyelination also causes HHL in mice. To test the effect of myelinopathy on hearing in a clinically relevant model, we studied a mouse model of Charcot-Marie-Tooth type 1A (CMT1A), the most prevalent hereditary peripheral neuropathy in humans. CMT1A mice exhibited the functional hallmarks of HHL together with disorganization of AN heminodes near the IHCs with minor loss of AN fibers. These results support the hypothesis that mild disruptions of AN myelination can cause HHL and that heminodal defects contribute to the alterations in the sound-evoked cochlear compound action potentials seen in this mouse model. Furthermore, these findings suggest that patients with CMT1A or other mild peripheral neuropathies are likely to suffer from HHL. Furthermore, these results suggest that studies of hearing in patients with CMT1A might help develop robust clinical tests for HHL, which are currently lacking.

Mangiferin alleviates cisplatin-induced ototoxicity in sensorineural hearing loss

Mangiferin(MGF) exhibits crucial biological roles, including antioxidant and anti-inflammatory functions. However, how to clearly elucidate the functioning mechanism of MGF for inhibiting cisplatin-induced hearing loss requires in-depth investigation. In this work, we aimed at gaining insight into how MGF functions as the protective agent against cisplatin-triggered ototoxicity using various assays. The variation for reactive oxygen species (ROS) concentrations was determined with MitoSOX-Red and 2',7'-Dichlorodihydrofluorescein diacetate staining (DCFH-DA). The protective function and corresponding mechanism of MGF in hair cell survival in the House Ear Institute-Organ of Corti (HEI-OC1) cell line were assessed using RNA sequencing (RNA-Seq). Our findings demonstrated that MGF significantly alleviated cisplatin-induced injury to hair cells in vitro, encompassing cell lines and cochlear explants, as well as in vivo models, including C57BL/6 J mice and zebrafish larvae. Mechanistic studies revealed that MGF reversed the increased accumulation of ROS and inhibited cell apoptosis through mitochondrial-mediated intrinsic pathway. Moreover, real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting data indicated MGF protected against cisplatin-mediated ototoxicity via the mitogen-activated protein kinase pathway (MAPK). These findings demonstrated MGF has significant potential promise in combating cisplatin-induced ototoxicity, offering a foundation for expanded investigation into therapeutic approaches for auditory protection.

Hidden hearing loss in a Charcot-Marie-Tooth type 1A mouse model

Hidden hearing loss (HHL), a recently described auditory neuropathy characterized by normal audiometric thresholds but reduced sound-evoked cochlear compound action potentials, has been proposed to contribute to hearing difficulty in noisy environments in people with normal hearing thresholds, a widespread complaint. While most studies on HHL pathogenesis have focused on inner hair cell (IHC) synaptopathy, we recently showed that transient auditory nerve (AN) demyelination also causes HHL in mice. To test the impact of myelinopathy on hearing in a clinically relevant model, we studied a mouse model of Charcot-Marie-Tooth type 1A (CMT1A), the most prevalent hereditary peripheral neuropathy in humans. CMT1A mice exhibited the functional hallmarks of HHL together with disorganization of AN heminodes near the IHCs with minor loss of AN fibers. These results support the hypothesis that mild disruptions of AN myelination can cause HHL, and that heminodal defects contribute to the alterations in the sound-evoked cochlear compound action potentials seen in this mouse model. Also, these findings suggest that patients with CMT1A or other mild peripheral neuropathies are likely to suffer from HHL. Furthermore, these results suggest that studies of hearing in CMT1A patients might help develop robust clinical tests for HHL, which are currently lacking.

From hidden hearing loss to supranormal auditory processing by neurotrophin 3-mediated modulation of inner hair cell synapse density

Loss of synapses between spiral ganglion neurons and inner hair cells (IHC synaptopathy) leads to an auditory neuropathy called hidden hearing loss (HHL) characterized by normal auditory thresholds but reduced amplitude of sound-evoked auditory potentials. It has been proposed that synaptopathy and HHL result in poor performance in challenging hearing tasks despite a normal audiogram. However, this has only been tested in animals after exposure to noise or ototoxic drugs, which can cause deficits beyond synaptopathy. Furthermore, the impact of supernumerary synapses on auditory processing has not been evaluated. Here, we studied mice in which IHC synapse counts were increased or decreased by altering neurotrophin 3 (Ntf3) expression in IHC supporting cells. As we previously showed, postnatal Ntf3 knockdown or overexpression reduces or increases, respectively, IHC synapse density and suprathreshold amplitude of sound-evoked auditory potentials without changing cochlear thresholds. We now show that IHC synapse density does not influence the magnitude of the acoustic startle reflex or its prepulse inhibition. In contrast, gap-prepulse inhibition, a behavioral test for auditory temporal processing, is reduced or enhanced according to Ntf3 expression levels. These results indicate that IHC synaptopathy causes temporal processing deficits predicted in HHL. Furthermore, the improvement in temporal acuity achieved by increasing Ntf3 expression and synapse density suggests a therapeutic strategy for improving hearing in noise for individuals with synaptopathy of various etiologies.

[Research progress on differential diagnosis of thalassemia trait and iron deficiency anemia by blood erythrocyte parameters]

Thalassemia trait is an autosomal recessive genetic disease, which is a hemolytic anemia caused by disturbance of erythrocyte hemoglobin production caused by gene mutation or deletion. Iron deficiency anemia is caused by a lack of iron in the body due to an imbalance between the demand and supply of iron. The laboratory manifestations of both are microcytic hypochromic anemia, but the treatment schemes are completely different, and it is difficult to distinguish them from the results of blood count. Erythrocyte parameters can be used to establish a formula or model to differentiate them, which can achieve the purpose of early screening, early diagnosis and early treatment,preventing the occurrence of severe anemia and providing a scientific basis for the thalassemia and iron deficiency anemia prevention. This article will review the research progress of using erythrocyte parameters to distinguish thalassemia trait with iron deficiency anemia.

[Analysis on missed diagnosis or misdiagnosis of anomalous origin of left coronary artery from pulmonary artery by echocardiography from one single medical center]

Objectives: To analyze the reasons of missed diagnosis or misdiagnosis on anomalous origin of left coronary artery from pulmonary artery (ALCAPA) by echocardiography. Methods: This is a retrospective study. Patients with ALCAPA who underwent surgical treatment in Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from August 2008 to December 2021 were included. According to the results of preoperative echocardiography and surgical diagnosis, the patients were divided into confirmed group or missed diagnosis/misdiagnosis group. The results of preoperative echocardiography were collected, and the specific echocardiographic signs were analyzed. According to the experience of the doctors, the echocardiographic signs were divided into four types, namely clear displayed, vague/doubtful displayed, no display and no notice, and the display rate of each sign was calculated (display rate=number of clearly displayed cases/total number of cases×100%). By referring the surgical data, we analyzed and recorded the pathological anatomy and pathophysiological characteristics of the patients, and the rate of missed diagnosis/misdiagnosis of echocardiography in patients with different characteristics was compared. Results: A total of 21 patients were enrolled, including 11 males, aged 1.8 (0.8, 12.3) years (range 1 month to 47 years). Except for one patient with anomalous origin of left anterior descending artery, the others were all originated from the main left coronary artery (LCA). There were 13 cases of ALCAPA in infant and children, and 8 cases of adult ALCAPA. There were 15 cases in the confirmed group (diagnostic accuracy was 71.4% (15/21)), and 6 cases in the missed diagnosis/misdiagnosis group (three cases were misdiagnosed as primary endocardial fibroelastosis, two cases were misdiagnosed as coronary-pulmonary artery fistula; and one case was missed diagnosis). The working years of the physicians in the confirmed group were longer than those in the missed diagnosis/misdiagnosed group ((12.8±5.6) years vs. (8.3±4.7) years, P=0.045). In infants with ALCAPA, the detection rate of LCA-pulmonary shunt (8/10 vs. 0, P=0.035) and coronary collateral circulation (7/10 vs. 0, P=0.042) in confirmed group was higher than that in missed diagnosis/misdiagnosed group. In adult ALCAPA patients, the detection rate of LCA-pulmonary artery shunt was higher in confirmed group than that in missed diagnosis/misdiagnosed group (4/5 vs. 0, P=0.021). The missed diagnosis/misdiagnosis rate of adult type was higher than that of infant type (3/8 vs. 3/13, P=0.410). The rate of missed diagnosis/misdiagnosis was higher in patients with abnormal origin of branches than that of abnormal origin of main trunk (1/1 vs. 5/21, P=0.028). The rate of missed diagnosis/misdiagnosis in patients with LCA running between the main and pulmonary arteries was higher than that distant from the main pulmonary artery septum (4/7 vs. 2/14, P=0.064). The rate of missed diagnosis/misdiagnosis in patients with severe pulmonary hypertension was higher than that in patients without severe pulmonary hypertension (2/3 vs. 4/18, P=0.184). The reasons with an echocardiography missed diagnosis/misdiagnosis rate of≥50% included that (1) the proximal segment of LCA ran between the main and pulmonary arteries; (2) abnormal opening of LCA at the right posterior part of the pulmonary artery; (3) abnormal origin of LCA branches; (4) complicated with severe pulmonary hypertension. Conclusions: Echocardiography physicians' knowledge of ALCAPA and diagnostic vigilance are critical to the accuracy of diagnosis. Attention should be paid to the pediatric cases with no obvious precipitating factors of left ventricular enlargement, regardless of whether the left ventricular function is normal or not, the origin of coronary artery should be routinely explored.

Xanthotoxol alleviates secondary brain injury after intracerebral hemorrhage by inhibiting microglia-mediated neuroinflammation and oxidative stress

BACKGROUND

Oxidative damage and inflammation are two critical mechanisms underlying secondary brain injury (SBI) following intracerebral hemorrhage (ICH). Xanthotoxol is reported to alleviate brain edema and inhibit inflammatory responses. Herein, we investigated the effects of xanthotoxol and its related mechanisms in SBI post-ICH.

METHODS

To explore the clinical effects of xanthotoxol an animal model of ICH was established. Neurological scores, survival rates and brain water content were measured. Inflammatory responses and oxidative damage in the peri-hemorrhagic areas were determined by measuring pro-inflammatory cytokines and oxidative related factors. The activation of the M1/M2 phenotype was detected by western blotting and immunofluorescence.

RESULTS

Xanthotoxol improved the neurological functions and reduced cerebral edema in ICH mice. Additionally, xanthotoxol inhibited microglia activation and promotes microglial phagocytosis. Simultaneously, xanthotoxol promoted the transformation of BV2 cells from M1 phenotype to M2 phenotype, and protected BV2 cells against hemin-induced inflammation and oxidative stress. Mechanistically, xanthotoxol inactivated the NF-κB p65 signaling pathway in the hemin-challenged BV2 cells.

CONCLUSION

Xanthotoxol ameliorates SBI post-ICH by suppressing microglia-mediated neuroinflammation and oxidative stress and enhancing microglial phagocytosis through inhibition of NF-κB signaling.

Electrical nerve stimulation for sensory-neural pathway reconstruction in upper-limb amputees

Introduction

The loss of the neural sensory function pathways between the stump limbs and the brain greatly impacts the rehabilitation of limb function and the daily lives of amputees. Non-invasive physical stressors, such as mechanical pressure and transcutaneous electrical nerve stimulation (TENS), could be potential solutions for recovering somatic sensations in amputees. Previous studies have shown that stimulating the residual or regenerated nerves in the stumps of some amputees can produce phantom hand sensations. However, the results are inconclusive due to unstable physiological responses caused by inaccurate stimulus parameters and positions.

Methods

In this study, we developed an optimal TENS strategy by mapping the distribution of the nerves in the stump skin that elicitsphantom sensations known as a "phantom hand map." We evaluated the effectiveness and stability of the confirmed stimulus configuration in a long-term experiment using single- and multi-stimulus paradigms. Additionally, we evaluated the evoked sensations by recording electroencephalograms (EEG) and analyzing brain activities.

Results

The results demonstrated that various types of intuitive sensations for amputees could be stably induced by adjusting TENS frequencies, particularly at 5 and 50 Hz. At these frequencies, 100% stability of sensory types was achieved when the stimuli were applied to two specific locations on the stump skin. Furthermore, at these locations, the stability of sensory positions was 100% across different days. Moreover, the evoked sensations were objectively supported by specific patterns of event-related potentials in brain responses.

Discussion

This study provides an effective method for developing and evaluating physical stressor stimulus strategies, which could play an important role in the somatosensory rehabilitation of amputees and other patients suffering from somatomotor sensory dysfunction. The paradigm developed in this study can provide effective guidelines for stimulus parameters in physical and electrical nerve stimulation treatments for a variety of symptoms related to neurological disorders.

Cochlear Neurotrophin-3 overexpression at mid-life prevents age-related inner hair cell synaptopathy and slows age-related hearing loss

Age-related hearing loss (ARHL) is the most prevalent sensory deficit in the elderly. This progressive pathology often has psychological and medical comorbidities, including social isolation, depression, and cognitive decline. Despite ARHL's enormous societal and economic impact, no therapies to prevent or slow its progression exist. Loss of synapses between inner hair cells (IHCs) and spiral ganglion neurons (SGNs), a.k.a. IHC synaptopathy, is an early event in cochlear aging, preceding neuronal and hair cell loss. To determine if age-related IHC synaptopathy can be prevented, and if this impacts the time-course of ARHL, we tested the effects of cochlear overexpression of neurotrophin-3 (Ntf3) starting at middle age. We chose Ntf3 because this neurotrophin regulates the formation of IHC-SGN synapses in the neonatal period. We now show that triggering Ntf3 overexpression by IHC supporting cells starting in middle age rapidly increases the amplitude of sound-evoked neural potentials compared with age-matched controls, indicating that Ntf3 produces a positive effect on cochlear function when the pathology is minimal. Furthermore, near the end of their lifespan, Ntf3-overexpressing mice have milder ARHL, with larger sound-evoked potentials along the ascending auditory pathway and reduced IHC synaptopathy compared with age-matched controls. Our results also provide evidence that an age-related decrease in cochlear Ntf3 expression contributes to ARHL and that Ntf3 supplementation could serve as a therapeutic for this prevalent disorder. Furthermore, these findings suggest that factors that regulate synaptogenesis during development could prevent age-related synaptopathy in the brain, a process involved in several central nervous system degenerative disorders.

POS0718 SIROLIMUS MONOTHERAPY FOR THROMBOCYTOPENIA IN PRIMARY ANTIPHOSPHOLIPID SYNDROME: A PILOT STUDY FROM A TERTIARY REFERRAL CENTER

Background

Thrombocytopenia (TP) is considered as a warning sign of high-risk antiphospholipid syndrome (APS) and sometimes a paradoxical sign of anti-thrombosis treatment. Currently there is an extreme paucity of effective and safe drugs for long-term management of TP in primary APS patients.

Objectives

We aimed to explore the efficacy and safety of sirolimus monotherapy.

Methods

In this real-world study, we included 7 consecutive patients with primary APS who received sirolimus monotherapy for TP. Oral sirolimus was initiated at a dose of 1-2 mg once daily and then adjusted primarily based on clinical efficacy and tolerance, with consideration of sirolimus trough concentration of ≤15 ng/ml.

Results

Of included patients, the median age was 58 years with median disease course of 1.5 years and 4 patients were treatment-naïve. All patients completed 6 months of sirolimus therapy with median follow-up of 6 months (range: 6-15). All patients received sirolimus monotherapy for TP during entire follow-up, without adding any additional agents. Overall, platelet count exhibited substantially increasing trend after sirolimus administration during the first six months (p<0.001) and being stable later. Specifically, median platelet count was significantly increased from 59×109/L before sirolimus to 90×109/L at month 1 (p=0.028), 131×109/L at 3 months (p=0.028) and 178×109/L at 6 months (P=0.018). Overall and complete response were respectively achieved in 6 (85.7%) and 5 (71.4%) patients at month 6. Importantly, overall response was achieved in all 4 treatment-naïve patients. Additionally, there was different extents of decline in the titers of antiphospholipid antibodies after sirolimus treatment. Regrading safety, only one patient experienced elevated cholesterol level with recovery after atorvastatin treatment.

Conclusion

Sirolimus monotherapy confers good efficacy and tolerance for TP in primary APS patients, and therefore may be considered as a first-line therapy.

Figure 1.

Changes in platelets levels after sirolimus therapy in primary antiphospholipid syndrome patients with thrombocytopenia, (A) platelet count of individual patient during the whole follow-up, (B) Median platelet count of included patients during the first six months.

Disclosure of Interests

None declared

POS0720 LOW-DOSE GLUCOCORTICOIDS WITHDRAWN IN SYSTEMIC LUPUS ERYTHEMATOSUS: A DESIRABLE AND ATTAINABLE GOAL

Background

Prolonged use of GC may cause irreversible organ damage, leading to impaired quality of life and even increased mortality. However, many physicians are worried about severe flares after GC withdrawal in daily practice.

Objectives

To assess the risk of flare in systemic lupus erythematosus (SLE) patients after low dose glucocorticoids (GC) discontinuation and evaluate the risk factors of flare.

Methods

SLE patients who ever discontinued GC were identified from PKUFHS cohort. The disease flare profile after GC discontinuation were analyzed. Flare rate was analyzed using Kaplan-Meier analysis. COX regression was used to determine the effect of variables on SLE flare. A prognostic nomogram using Cox proportional hazards regression modeling were developed.

Results

132 SLE patients were eligible for the final analysis. They were followed up for a median (IQR) period of 21.8 (9.01, 36.7) months. The cumulative probability of flare after GC discontinuation was 8.3 % at 6 months, 16.8% at year 1 and 27.5% at year 2 (Figure 1A). In multivariate COX analysis, hypocomplementemia and serologically active clinically quiescent (SACQ) were independent risk factors of flare [HR 2.53, 95% CI (1.32, 4.88); HR 3.17, 95% CI (1.44, 6.97), respectively]. Age ≥ 40y at GC withdrawal and hydroxychloroquine usage were independent protective factors of flare [HR 0.53, 95% CI (0.29, 0.99); HR 0.32, 95% CI (0.17, 0.62), respectively] (Table 1). The protective effect of hydroxychloroquine was dosage related. From the prospective of different tapering strategies embodied as duration from prednisone 5mg/d to complete discontinuation, slower tapering strategy (12-24 months) significantly reduced the risk of flare compared to faster tapering strategy (< 3 months) [HR 0.30, 95% CI (0.11, 0.82), p=0.019]. The prognostic nomogram including aforementioned factors effectively predicted 1- and 2-year probability of flare-free (Figure 1B).

Table 1.

Predictors of flare by univariate and multivariate COX analysis.

UnivariatepMultivariatepMultivariatepModel 1Model 2age≥40y at GC withdrawal0.59 (0.33,1.07)0.0840.53 (0.29, 0.99)0.0490.63 (0.33, 1.18)0.147Age at onset ≥18y2.03 (0.62, 6.66)0.2442.75 (0.77, 9.85)0.1212.88 (0.81, 10.2)0.103Remission duration≥60 months since the last flare0.66 (0.35, 1.27)0.2170.81 (0.41, 1.57)0.5260.73 (0.38, 1.41)0.346history of thrombocytopenia1.73 (0.94, 3.18)0.0771.36 (0.70, 2.65)0.3591.45 (0.74, 2.83)0.278history of lupus nephritis0.86 (0.47, 1.55)0.610////Hypocomplementemia1.97 (1.06, 3.66)0.0312.53 (1.32, 4.88)0.005//anti-dsDNA positive1.25 (0.70, 2.23)0.456////SACQ (both)2.91 (1.38, 6.15)0.005//3.17 (1.44, 6.97)0.004SACQ (or)1.29 (0.73, 2.30)0.380////Hydroxychloroquine or not0.29 (0.16, 0.53)<0.0010.29 (0.15, 0.56)<0.0010.32 (0.17, 0.62)0.001Immunosuppressant or not0.77 (0.40, 1.48)0.426////

There was strong collinearity between hypocomplementemia and SACQ, so the two parameters were separated into two models. SACQ (both): anti-dsDNA positive and hypocomplementemia; SACQ (or): anti-dsDNA positive or hypocomplementemia; GC: glucocorticoids. Data were shown as HR (95% CI).

Figure 1.

Conclusion

Low-dose GC is feasibly discontinued with infrequent flare in real-life setting. SACQ and younger age are potential risk factors of SLE flare, while hydroxychloroquine usage and slow GC tapering to withdrawal can reduce relapse. The visualized model we developed may help to predict risk of flare among SLE patients who discontinued GC.

Disclosure of Interests

None declared

AB0030 THE BIOLOGICAL FUNCTION AND MECHANISM EXPLORATION OF TACI IN SJOGREN’S SYNDROME

Background

primary Sjogren’s syndrome (pSS) is a chronic autoimmune disease that affects the lacrimal, salivary and other exocrine glands. More and more studies have shown that B cells play a central role in the pathogenesis of SS.

Objectives

We intended to explore the expression of the transmembrane activator, calcium modulator and cyclophilin ligand interactor (TACI) on the B cells, its role in pSS, and possible signal transduction pathways.

Methods

We included 34 naive pSS patients who visited the rheumatology department of Peking University First Hospital, and 37 gender- and age-distribution matched healthy controls (HCs). (1) To compare the B cell subsets, expression of TACI and relevant receptors in pSS patients, peripheral blood mononuclear cells were separated to analyze the ratio of B subsets, TACI, and BAFF-R by flow cytometry; ELISA was applied to detect the serum BAFF and soluble TACI (sTACI) concentration. (2) As for functional research of TACI, CD19+ B cells separated by magnetic sorting were treated under in vitro culture circumstances with raw TACI, TACI knocked down by siRNA, and sTACI analog (telitacicept) intervention with varing doses. The apoptosis, proliferation, differentiation and regulatory capacity on T cells were analyzed by flow cytometry, inflammatory cytokines and immunoglobulin levels in the culture supernatants were detected by CBA. (3) As for TACI-associated signaling pathway exploration, based on our previous miRNA data and relevant report of high quality, miRNA associated with TACI with significantly biased expression was confirmed by RT-qPCR. Screening the target gene of the candidate miRNA, and miRNA overexpression and inhibition experiments were conducted to validate the targeted relationship in B cells. And TACI-associated signaling pathway was explored via overexpressing and inhibiting the target gene.

Results

(1) Compared to HC, peripheral blood B subsets of pSS patients exhibited a significant bias, manifesting as increased proportion of CD19+CD24hiCD38hi Breg and decreased ratio of CD19+CD24+CD38- memory B cells. The expression of TACI in all B subsets was down-regulated, while that of BAFF-R was up-regulated. Both the serum concentration of BAFF and sTACI in pSS patients increased significantly. (2) As for functional research of TACI, in the setting of raw TACI, B cells in the pSS group showed higher apoptosis rate than HC under culture in vitro, where the ligand of TACI (APRIL or BAFF) addition turned the rate comparable; more active proliferation, and impaired capacity of inducing Treg cells to secrete IL-10. When TACI was knocked down by 50%, B cells performed less late apoptosis, significantly increased proliferation, impaired differentiation, significant dysfunction of Breg itself and impaired induction of Treg cells to secrete IL-10. While telitacicept intervention increased early apoptosis rate of B cells, significantly inhibited proliferation in 500ng/mL group and impaired ability of Breg and Treg cells to secrete IL-10. Besides, increased TACI on B cells treated with telitacicept, decreased IgG and increased IgA in the culture supernatants were observed. (3) As for TACI-associated signaling pathway exploration, hsa-miR-30b-5p showed satisfactory correlation between both transmembrane and sTACI. Besides, the expression of hsa-miR-30b-5p was significantly down-regulated, and inhibition its expression in vitro could lead to differentiation retard, impaired secretion of IL-10 by Breg cells. SMAD1 was screened based on database and validated as its target gene by overexpressing and inhibiting hsa-miR-30b-5p in B cell. After targeted up- or down-regulating the transcription of SMAD1 further, the transcription of ID2 downstream the TGF-β/Hippo signaling pathway changed accordingly.

Conclusion

The expression of TACI on peripheral blood B cells was deficient in pSS patients. TACI deficiency was closely associated with the downregulation of hsa-miR-30b-5p, activating TGF-β/Hippo pathway mediated by its target gene SMAD1 and taking part in the pathogenesis of pSS.

Disclosure of Interests

None declared

[Heartbeat-aware convolutional neural network for R-peak detection of wearable device ECG data]

OBJECTIVE

To develop a method for R-peak detection of ECG data from wearable devices to allow accurate estimation of the physiological parameters including heart rate and heart rate variability.

METHODS

A fully convolutional neural network was applied to predict the R-peak heatmap of ECG data and locate the R-peak positions. The heartbeat-aware (HA) module was introduced to enable the model to learn to predict the heartbeat number and R-peak heatmap simultaneously, thereby improving the capability of the model for extraction of the global context. The R-R interval estimated by the predicted heartbeat number was adopted to calculate the minimum horizontal distance for peak positioning. To achieve real-time R-peak detection on mobile devices, the deep separable convolution was adopted to reduce the number of parameters and the computational complexity of the model.

RESULTS

The proposed model was trained only with ECG data from wearable devices. At a tolerance window interval of 150 ms, the proposed method achieved R peak detection sensitivities of 100% for both wearable device ECG dataset and a public dataset (i.e. LUDB), and the true positivity rates exceeded 99.9%. As for the ECG signal of a 10 s duration, the CPU time of the proposed method for R-peak detection was about 23.2 ms.

CONCLUSION

The proposed method has good performance for R-peak detection of both wearable device ECG data and routine ECG data and also allows real-time R-peak detection of the ECG data.

Digital intervention increases influenza vaccination rates for people with diabetes in a decentralized randomized trial

People with diabetes (PWD) have an increased risk of developing influenza-related complications, including pneumonia, abnormal glycemic events, and hospitalization. Annual influenza vaccination is recommended for PWD, but vaccination rates are suboptimal. The study aimed to increase influenza vaccination rate in people with self-reported diabetes. This study was a prospective, 1:1 randomized controlled trial of a 6-month Digital Diabetes Intervention in U.S. adults with diabetes. The intervention group received monthly messages through an online health platform. The control group received no intervention. Difference in self-reported vaccination rates was tested using multivariable logistic regression controlling for demographics and comorbidities. The study was registered at clinicaltrials.gov: NCT03870997. A total of 10,429 participants reported influenza vaccination status (5158 intervention, mean age (±SD) = 46.8 (11.1), 78.5% female; 5271 control, Mean age (±SD) = 46.7 (11.2), 79.4% female). After a 6-month intervention, 64.2% of the intervention arm reported influenza vaccination, vers us 61.1% in the control arm (diff = 3.1, RR = 1.05, 95% CI [1.02, 1.08], p = 0.0013, number needed to treat = 33 to obtain 1 additional vaccination). Completion of one or more intervention messages was associated with up to an 8% increase in vaccination rate (OR 1.27, 95% CI [1.17, 1.38], p < 0.0001). The intervention improved influenza vaccination rates in PWD, suggesting that leveraging new technology to deliver knowledge and information can improve influenza vaccination rates in high-risk populations to reduce public health burden of influenza. Rapid cycle innovation could maximize the effects of these digital interventions in the future with other populations and vaccines.

Axon-glia interactions in the ascending auditory system

The auditory system detects and encodes sound information with high precision to provide a high-fidelity representation of the environment and communication. In mammals, detection occurs in the peripheral sensory organ (the cochlea) containing specialized mechanosensory cells (hair cells) that initiate the conversion of sound-generated vibrations into action potentials in the auditory nerve. Neural activity in the auditory nerve encodes information regarding the intensity and frequency of sound stimuli, which is transmitted to the auditory cortex through the ascending neural pathways. Glial cells are critical for precise control of neural conduction and synaptic transmission throughout the pathway, allowing for the precise detection of the timing, frequency, and intensity of sound signals, including the sub-millisecond temporal fidelity is necessary for tasks such as sound localization, and in humans, for processing complex sounds including speech and music. In this review, we focus on glia and glia-like cells that interact with hair cells and neurons in the ascending auditory pathway and contribute to the development, maintenance, and modulation of neural circuits and transmission in the auditory system. We also discuss the molecular mechanisms of these interactions, their impact on hearing and on auditory dysfunction associated with pathologies of each cell type.

Sex-specific associations of serum insulin-like growth factor-1 with bone density and risk of fractures in Chinese patients with type 2 diabetes

We evaluated the associations of serum insulin-like growth factor-1 (IGF-1) with bone mineral density (BMD) and risk of fractures in Chinese patients with type 2 diabetes (T2D). We found positive associations between IGF-I and BMD and negative associations between IGF-I and all three modified 10-year probabilities of MOFs and HFs in men, but not in women.

INTRODUCTION

The objective was to investigate the associations of serum insulin-like growth factor-1 (IGF-1) with bone mineral density (BMD) and risk of fractures in Chinese patients with type 2 diabetes (T2D) in each gender.

METHODS

This was a cross-sectional, retrospective study that included men over 50 years and postmenopausal women with T2D without medical conditions or medications known to significantly affect BMD or serum IGF-I levels. Data of IGF-1, bone metabolism markers, lumbar spine (LS), femoral neck (FN), and total hip (TH) BMD were obtained; 10-year probability of major osteoporotic fractures (MOFs) and hip fractures (HFs) was calculated and modified with rheumatoid arthritis, femoral neck T-score, and age. Correlations of IGF-1 levels with bone metabolism and risk of fractures were statistically analyzed in men and women, respectively.

RESULTS

A total of 391 patients, including 226 men and 165 women, were included. The age, serum fasting C-peptide, glycosylated hemoglobin (HbA1c), bone formation marker, and all three modified 10-year probabilities of MOFs and HFs were higher in women than those in men (all p < 0.05). The levels of 25 hydroxyvitamin D (25OHD), IGF-1, and BMD were lower in women than those in men (all p < 0.05). In men, IGF-1 was positively correlated with FN and TH BMD (FN BMD: r = 0.267, p < 0.001; TH BMD: r = 0.235, p < 0.001) and negatively correlated with all three modified 10-year probabilities of MOFs (RA-modified MOFs: r = - 0.289, p < 0.001; age-modified MOFs: r = - 0.237, p < 0.001; FN T-score-modified MOFs: r = - 0.280, p < 0.001) and HFs (RA-modified HFs: r = - 0.291, p < 0.001; age-modified HFs: r = - 0.271, p < 0.001; FN T-score-modified HFs: r = - 0.270, p < 0.001), while no significant correlations were found between serum IGF-I and BMD and three modified 10-year probability in women.

CONCLUSIONS

According to this study, we found sex differences in the associations of serum IGF-1 with BMD and risk of fractures in Chinese patients with T2D. These results suggested that increasing serum IGF-1 might be a clinical target for protecting fractures in T2D, especially in men.

AB0280 THE INFLUENCE OF TARGET THERAPY AS WELL AS GLUCOCORTICOIDS TAPERING ON DISEASE FLARE IN SYSTEMIC LUPUS ERYTHEMATOSUS: RESULTS FROM A PROSPECTIVE CHINESE COHORT

Background:

Treat-to-target in systemic lupus erythematosus (SLE) has been proposed for 7 years and several recommendations were developed [1]. In these recommendations, prevention of flares should be a realistic target. Meanwhile, ‘remission’ or ‘low disease activity’ was recommended as the treatment target and minimizing glucocorticoids (GC) dose or withdrawal if possible was suggested in the maintenance treatment. However, would target therapy and GC tapering/withdrawal influence disease flare?

Objectives:

To investigate the frequency and determinants of disease flare, especially the influence of target therapy as well as GC tapering on flare in Chinese lupus patients.

Methods:

The baseline and follow-up data of all consecutive patients in a prospective longitudinal lupus cohort from January 2017 to June 2020 were collected. The lupus low disease activity state (LLDAS) was defined as in Golder et al., 2019[2]. The criteria for remission were from DORIS definitions [3]. Flare was assessed using the SELENA-SLEDAI flare index [4].

Results:

We enrolled 185 patients with disease duration at recruitment of 2.3 (0.8–7.7) years. During the 26.2 (12.5-34.5) months of follow-up, 73 (39.5%) patients experienced 95 flares, including 70 mild/moderate and 25 severe flares. The incidence of flare per patient-year was 0.27. Kaplan-Meier analyses showed that compared with those who never achieved LLDAS or DORIS, the patients who achieved the target at least once had a higher flare free survival rate; meanwhile, the patients with prednisone withdrawn had significantly lower flare free rate compared with those with small dose of GC maintained (≤7.5mg/d) (Figure 1A), but among the patients with different prednisone maintain doses (7.5~5mg, 5~2.5mg, and ≤2.5mg) there was not significant difference (Figure 1B). Cox regression analysis showed that younger age at disease onset and lower Complement 3 (C3) level at recruitment were independent risk factors for flare and achieving LLDAS or DORIS ≥50% of visits was independent protective factor (Table 1).

Conclusion:

In this Chinese prospective SLE cohort, age at disease onset, C3 level at recruitment and therapeutic target achieving influenced disease flare independently and significantly. GC tapering in appropriate patients and with appropriate pace did not increase the flare rate, but prednisone withdrawal may induce more disease exacerbation, which needs to be confirmed by large prospective studies.

References:

[1]Van Vollenhoven R F, et al. Treat-to-target in systemic lupus erythematosus: recommendations from an international task force. Ann Rheum Dis, 2014. 73(6): 958-967

[2]Golder, V., et al. Lupus low disease activity state as a treatment endpoint for systemic lupus erythematosus: a prospective validation study. The Lancet Rheumatology, 2019. 1(2): p. e95-e102.

[3]van Vollenhoven R, et al. A framework for remission in SLE: consensus findings from a large international task force on definitions of remission in SLE (DORIS). Ann Rheum Dis. 2017. 76(3): 554–561.

[4]Petri M, et al. Classification and definition of major flares in SLE clinical trials. Lupus. 1999. 8(8): 685-691.

Table 1.

Determinants of disease flare by multivariate Cox regression analyses

Model 1(LLDAS) ΔModel 2(RONT) ΔModel 3(Complete RONT) ΔHR95%CIP valueHR95%CIP valueHR95%CIP valueAge at disease onset (years)†0.970.95-0.990.0040.970.95-0.990.0030.970.95-0.990.003Anti-dsDNA positive at recruitment1.340.82-2.180.2171.120.68-1.850.6491.190.73-1.960.486C3 (mg/L) at recruitment0.9980.997-0.9990.0040.9980.997-0.9990.0070.9980.997-1.0000.010Minimum prednisone dose during follow- up (mg/d)0.980.90-1.080.7161.010.94-1.080.7471.040.97-1.110.243Therapeutic target achieved≥50% of observationsΔ0.600.39-0.940.0010.540.34-0.870.0110.680.51-0.920.011

Δ In the three hazard models, the different target achievement status were included respectively.

RONT: Clinical remission on treatment; Complete RONT: Complete remission on treatment.

Disclosure of Interests:

None declared

The role of Dock2 on macrophage migration and functions during Citrobacter rodentium infection

Dedicator of cytokinesis 2 (Dock2), an atypical guanine exchange factor, is specifically expressed on immune cells and mediates cell adhesion and migration by activating Rac and regulates actin cytoskeleton remodeling. It plays a crucial role in the migration, formation of immune synapses, cell proliferation, activation of T and B lymphocytes and chemotaxis of pDCs and neutrophils. However, in-vivo physiological functions of Dock2 have been relatively seldom studied. Our previous studies showed that Dock2^-/- mice were highly susceptible to colitis induced by Citrobacter rodentium infection, and in early infection, Dock2^-/- mice had defects in macrophage migration. However, the specific roles of Dock2 in the migration and functions of macrophages are not clear. In this study, we found that the expression of chemokines such as chemokine (C-C motif) ligand (CCL)4 and CCL5 and chemokine receptors such as chemokine (C-C motif) receptor (CCR)4 and CCR5 in bone marrow-derived macrophages (BMDM) of Dock2^-/- mice decreased after infection, which were supported by the in-vivo infection experimental results; the Transwell experiment results showed that Dock2^-/- BMDM had a defect in chemotaxis. The bacterial phagocytic and bactericidal experiment results also showed that Dock2^-/- BMDM had the defects of bacterial phagocytosis and killing. Furthermore, the adoptive transfer of wild-type BMDM alleviated the susceptibility of Dock2^-/- mice to C. rodentium infection. Our results show that Dock2 affects migration and phagocytic and bactericidal ability of macrophages by regulating the expression of chemokines, chemokine receptors and their responses to chemokine stimulation, thus playing an essential role in the host defense against enteric bacterial infection.

Relationship between inflammatory factors and arrhythmia and heart rate variability in OSAS patients

OBJECTIVE

Obstructive Sleep Apnea Syndrome (OSAS) is a disorder characterized by recurrent upper airway obstruction, apnea, and hypopnea, associated with decreased oxygen saturation and disturbed sleep structure during sleep. It was found that OSAS was associated with a variety of arrhythmia and conduction disorders, but the relationship between multiple types of arrhythmia and the severity of OSAS, and its possible mechanism remain unclear. The purpose of this study was to observe the main types of arrhythmia and the condition of heart rate variability (HRV) in patients with OSAS, to detect the levels of multiple inflammatory factors in serum of OSAS patients, and to observe the correlation between polysomnographic parameters or inflammatory factors, and arrhythmia or HRV, as well as its possible mechanisms.

PATIENTS AND METHODS

141 patients with suspected OSAS were collected in the Second Affiliated Hospital of Soochow University and Xinghua People's Hospital from February 2016 to February 2018. According to the sleep apnea hypopnea index (AHI), they were divided into control group (AHI <5, n = 34), mild-moderate OSAS group (5≤ AHI <30, n = 48), and severe OSAS group (AHI ≥30, n = 59). Clinical data such as gender and age were collected. All patients completed polysomnography (PSG), 24-hour Holter monitoring and blood routine, biochemical indexes and serum hs-CRP, TNF-α, IL-6, and IL-1β testing. The indicators in the three groups were compared, and the correlation between PSG parameters, HRV and inflammatory biomarkers was investigated.

RESULTS

Compared with control group, there were significant differences in age, sex ratio, BMI, uric acid, TC, and TG in the mild-moderate OSAS group (p<0.05), and in age, sex ratio, BMI, red blood cell count, hemoglobin, hematocrit, uric acid, FBS, TC, TG, LDL, and HDL in severe OSAS group (p<0.05). There were significant differences in gender ratio, BMI, red blood cell count, hemoglobin, hematocrit, uric acid, FBS, TC, TG, LDL, and HDL between mild-moderate OSAS group and severe OSAS group (p<0.05). Heart rate variability (HRV) parameters include SDNN, SDNN index, RMSSD, PNN50, LF, HF, and LF/HF. SDNN, PNN50, and HF in severe OSAS group and mild-moderate OSAS group were significantly lower than those in control group (p<0.05). LF/HF was significantly higher than that of control group (p<0.05). There was a significant difference in PNN50, HF, and LF/HF between severe OSAS group and mild-moderate OSAS group (p<0.05). In terms of inflammation, serum hs-CRP was significantly higher in mild-moderate OSAS group and severe OSAS group than that in control group (p<0.05). Serum IL-1β was significantly higher in mild-moderate OSAS group than that in severe OSAS group (p<0.05). There was no significant difference in other indicators (p>0.05). There was a significant positive correlation between hs-CRP and oxygen reduction index (ODI) (r=0.209, p=0.013) and a significant negative correlation with PNN50 (r=-0.188, p=0.025). There is no significant correlation between other indicators.

CONCLUSIONS

Systemic inflammatory reactions existed in patients with OSAS. With the increase of OSAS, inflammation was aggravated, especially serum hs-CRP. Hs-CRP was significantly and negatively correlated with PNN50 and positively correlated with ODI. The results suggested that the inflammatory response was involved in the occurrence of heart rate variability in OSAS patients.