Pax2-cre-mediated deletion of Lgl1 causes abnormal development of the midbrain

Lgl1 protein plays a critical role in neurodevelopment, including hippocampus, olfactory bulb, and Purkinje cell. However, the specific mechanism of LGL1 function in the midbrain remains elusive. In this study, we generated Lgl1 conditional knockout mice using Pax2-Cre, which is expressed in the midbrain, and examined the functions of Lgl1 in the midbrain. Histological analysis exhibited abnormal midbrain development characterized by enlarged ventricular aqueduct and thinning tectum cortex. Lgl1 deletion caused excessive proliferation and heightened apoptosis of neural progenitor cells in the tectum of LP cko mice. BrdU labeling studies demonstrated abnormal neuronal migration. Immunofluorescence analysis of Nestin demonstrated an irregular and clustered distribution of glial cell fibers, with the adhesion junction marker N-cadherin employed for immunofluorescent labeling, unveiling abnormal epithelial connections within the tectum of LP cko mice. The current findings suggest that the deletion of Lgl1 leads to the disruption of the expression pattern of N-cadherin, resulting in abnormal development of the midbrain.

Role of LGL1 in cerebellar primordium of embryonic mice

Lethal giant larvae 1 (LGL1) is originally recognized as a tumor suppressor, implicated in maintaining cell polarity in Drosophila and mammalian cells. Cell polarity plays a crucial role in tumorigenesis. We previously established Pax2-LGL1 -/- conditional knockout mice but did not focus on the tumorigenesis in cerebellar primordium. HE staining was used to detect the morphological structure of the cerebellar primordium during early embryonic development in Pax2-LGL1 -/- mice. Immunofluorescence assays were used to detect the expression of polar molecules. TUNEL staining assessed tissue apoptosis. Our findings reveal that deletion of LGL1 leads to the emergence of neuroblastoma-like tissues within the cerebellum primordium during early embryogenesis. This outcome can be attributed to alterations in expression patterns of polar molecules Cdc42 and β-catenin following early deletion of LGL1, resulting in loss of cell polarity among neuroepithelial cells and subsequent formation of tumor-like tissues. However, further histological examination demonstrated that these tumor-like tissues disappear from embryonic day 15.5 onwards within the cerebellar primordium of Pax2-LGL1 -/- mice due to apoptosis-mediated cellular compensation. Our data emphasize the importance of LGL1 in maintaining neuroepithelial cell polarity and reveal a novel role for LGL1 in regulating tumorigenesis and ablation in the cerebellar primordium.

A novel mouse model carrying a gene trap insertion into the Hmgxb4 gene locus to examine Hmgxb4 expression in vivo

HMG (high mobility group) proteins are a diverse family of nonhistone chromosomal proteins that interact with DNA and a wide range of transcriptional regulators to regulate the structural architecture of DNA. HMGXB4 (also known as HMG2L1) is an HMG protein family member that contains a single HMG box domain. Our previous studies have demonstrated that HMGXB4 suppresses smooth muscle differentiation and exacerbates endotoxemia by promoting a systemic inflammatory response in mice. However, the expression of Hmgxb4 in vivo has not fully examined. Herein, we generated a mouse model that harbors a gene trap in the form of a lacZ gene insertion into the Hmgxb4 gene. This mouse enables the visualization of endogenous HMGXB4 expression in different tissues via staining for the β-galactosidase activity of LacZ which is under the control of the endogenous Hmgxb4 gene promoter. We found that HMGXB4 is widely expressed in mouse tissues and is a nuclear protein. Furthermore, the Hmgxb4 gene trap mice exhibit normal cardiac function and blood pressure. Measurement of β-galactosidase activity in the Hmgxb4 gene trap mice demonstrated that the arterial injury significantly induces Hmgxb4 expression. In summary, the Hmgxb4 gene trap reporter mouse described here provides a valuable tool to examine the expression level of endogenous Hmgxb4 in both physiological and pathological settings in vivo.

[Key microbial monitoring and clinical analysis of bloodstream infections and CRO colonization after hematopoietic stem cell transplantation in hematological patients]

Objective: To investigate the distribution and clinical characteristics of pathogenic bacteria following hematopoietic stem cell transplantation (HSCT), as well as to provide a preliminary research foundation for key microbial monitoring, and clinical diagnosis and treatment of infections after HSCT in hematological patients. Methods: We retrospectively analyzed the clinical data of 190 patients who tested positive for microbial testing [G-bacteria blood culture and/or carbapenem-resistant organism (CRO) screening of perianal swabs] at our center from January 2018 to December 2022. Patients were divided into blood culture positive, perianal swab positive, and double positive groups based on the testing results. The three patient groups underwent statistical analysis and comparison. Results: The top four pathogenic bacteria isolated from sixty-three patients with G-bacteria bloodstream infection (BSI) were Escherichia coli (28 strains, 43.75% ), Klebsiella pneumonia (26 strains, 40.63% ), Pseudomonas aeruginosa (3 strains, 4.69% ), and Enterobacter cloacae (3 strains, 4.69% ). The top three pathogenic bacteria isolated from 147 patients with CRO perianal colonization were carbapenem-resistant Klebsiella pneumoniae (58 strains, 32.58% ), carbapenem-resistant Escherichia coli (49 strains, 27.53% ), and carbapenem-resistant Enterobacter cloacae (20 strains, 11.24% ). The 3-year disease-free survival (DFS ) and overall survival (OS) of double positive group patients were significantly lower compared to those in the blood culture and perianal swab positive groups (DFS: 35.6% vs 53.7% vs 68.6%, P=0.001; OS: 44.4% vs 62.4% vs 76.9%, P<0.001), while non-relapse mortality (NRM) was significantly higher (50.0% vs 34.9% vs 10.6%, P<0.001). Failed engraftment of platelets and BSI are independent risk factors for NRM (P<0.001). Using polymyxin and/or ceftazidime-avibactam for more than 7 days is an independent protective factor for NRM (P=0.035) . Conclusion: This study suggests that the occurrence of BSI significantly increases the NRM after HSCT in patients with hematological diseases; CRO colonization into the bloodstream has a significant impact on the DFS and OS of HSCT patients.

Gss deficiency causes age-related fertility impairment via ROS-triggered ferroptosis in the testes of mice

Glutathione synthetase (GSS) catalyzes the final step in the synthesis of glutathione (GSH), a well-established antioxidant. Research on the specific roles of the Gss gene during spermatogenesis remains limited due to the intricate structure of testis. In this study, we identified pachytene spermatocytes as the primary site of GSS expression and generated a mouse model with postnatal deletion of Gss using Stra8-Cre (S8) to investigate the role of GSS in germ cells. The impact of Gss knockout on reducing male fertility is age-dependent and caused by ferroptosis in the testis. The 2-month-old S8/Gss-/- male mice exhibited normal fertility, due to a compensatory increase in GPX4, which prevented the accumulation of ROS. With aging, there was a decline in GPX4 and an increase in ALOX15 levels observed in 8-month-old S8/Gss-/- mice, resulting in the accumulation of ROS, lipid peroxidation, and ultimately testicular ferroptosis. We found that testicular ferroptosis did not affect spermatogonia, but caused meiosis disruption and acrosome heterotopia. Then the resulting aberrant sperm showed lower concentration and abnormal morphology, leading to reduced fertility. Furthermore, these injuries could be functionally rescued by inhibiting ferroptosis through intraperitoneal injection of GSH or Fer-1. In summary, Gss in germ cells play a crucial role in the resistance to oxidative stress injury in aged mice. Our findings deepen the understanding of ferroptosis during spermatogenesis and suggest that inhibiting ferroptosis may be a potential strategy for the treatment of male infertility.

Peroxisome Deficiency in Cochlear Hair Cells Causes Hearing Loss by Deregulating BK Channels

The peroxisome is a ubiquitous organelle in rodent cells and plays important roles in a variety of cell types and tissues. It is previously indicated that peroxisomes are associated with auditory function, and patients with peroxisome biogenesis disorders (PBDs) are found to have hearing dysfunction, but the specific role of peroxisomes in hearing remains unclear. In this study, two peroxisome-deficient mouse models (Atoh1-Pex5^-/- and Pax2-Pex5^-/- ) are established and it is found that peroxisomes mainly function in the hair cells of cochleae. Furthermore, peroxisome deficiency-mediated negative effects on hearing do not involve mitochondrial dysfunction and oxidative damage. Although the mammalian target of rapamycin complex 1 (mTORC1) signaling is shown to function through peroxisomes, no changes are observed in the mTORC1 signaling in Atoh1-Pex5^-/- mice when compared to wild-type (WT) mice. However, the expression of large-conductance, voltage-, and Ca2⁺ -activated K⁺ (BK) channels is less in Atoh1-Pex5^-/- mice as compared to the WT mice, and the administration of activators of BK channels (NS-1619 and NS-11021) restores the auditory function in knockout mice. These results suggest that peroxisomes play an essential role in cochlear hair cells by regulating BK channels. Hence, BK channels appear as the probable target for treating peroxisome-related hearing diseases such as PBDs.

Acute myocardial infarction and myocarditis following COVID-19 vaccination

Emerging reports raise concerns on the potential association between the COVID-19 vaccines and cardiac manifestations. We sought to evaluate cardiac complications associated with COVID-19 vaccination in a pooled analysis from our institution's cohort study and systematic review. Consecutive patients admitted to a tertiary hospital in Singapore between 1 January 2021 and 31 March 2021, with the onset of cardiac manifestations within 14 days following COVID-19 vaccination, were studied. Furthermore, a systematic review was performed, with PubMed, Embase, Research Square, MedRxiv and LitCovid databases accessed from inception up to 29 June 2021. Relevant manuscripts reporting individual patient data on cardiac complications following COVID-19 vaccination were included. Thirty patients were included in the study cohort, with 29 diagnosed with acute myocardial infarction (AMI) and 1 with myocarditis. Five patients developed heart failure, two had cardiogenic shock, three intubated, and one had cardiovascular-related mortality. In the systematic review, 16 studies were included with 41 myocarditis and 6 AMI cases. In the pooled analysis of the study cohort and the systematic review, 35 patients had AMI and 42 had myocarditis. Majority were men, and myocarditis patients were younger than AMI patients. Myocarditis patients tended to present 72 h postvaccination, while AMI patients were older and typically presented 24 h postvaccination. Majority with AMI or myocarditis developed symptoms after the first and second vaccination dose, respectively. This pooled analysis of patients presenting with cardiac manifestations following COVID-19 vaccination highlights the differences between myocarditis and AMI presentations in temporal association with the vaccination.

Robotic versus laparoscopic left colectomy with complete mesocolic excision for left-sided colon cancer: a multicentre study with propensity score matching analysis

BACKGROUND

Robotic surgery for right-sided colon and rectal cancer has rapidly increased; however, there is limited evidence in the literature of advantages of robotic left colectomy (RLC) for left-sided colon cancer. The purpose of this study was to compare the outcomes of RLC versus laparoscopic left colectomy (LLC) with complete mesocolic excision (CME) for left-sided colon cancer.

METHODS

Patients who had RLC or LLC with CME for left-sided colon cancer at 5 hospitals in China between January 2014 and April 2022 were included. A one-to-one propensity score matched analysis was performed to decrease confounding. The primary outcome was postoperative complications occurring within 30 days of surgery. Secondary outcomes were disease-free survival, overall survival and the number of harvested lymph nodes.

RESULTS

A total of 292 patients (187 males; median age 61.0 [20.0-85.0] years) were eligible for this study, and propensity score matching yielded 102 patients in each group. The clinical-pathological characteristics were well-matched between groups. The two groups did not differ in estimated blood loss, conversion to open rate, time to first flatus, reoperation rate, or postoperative length of hospital stay (p > 0.05). RLC was associated with a longer operation time (192.9 ± 53.2 vs. 168.9 ± 52.8 minutes, p=0.001). The incidence of postoperative complications did not differ between the RLC and LLC groups (18.6% vs. 17.6%, p = 0.856). The total number of lymph nodes harvested in the RLC group was higher than that in the LLC group (15.7 ± 8.3 vs. 12.1 ± 5.9, p< 0.001). There were no significant differences in 3-year and 5-year overall survival or 3-year and 5-year disease-free survival.

CONCLUSIONS

Compared to laparoscopic surgery, RLC with CME for left-sided colon cancer was found to be associated with higher numbers of lymph nodes harvested and similar postoperative complications and long-term survival outcomes.

Pre-meiotic deletion of PEX5 causes spermatogenesis failure and infertility in mice

Peroxisomes are involved in the regulation of various pathological processes. Peroxisomal biogenesis factor 5 (PEX5), which plays an essential role in peroxisomal biogenesis, is critical for reactive oxygen species (ROS) accumulation. However, its underlying functions in spermatogenesis have not yet been identified. Pex5 was deleted by crossing Stra8-Cre mice with Pex5^flox/flox mice before the onset of meiosis. The morphology of testes and epididymides, spermatogenesis function, and fertility in both wild type (WT) and Pex5^-/- mice were analysed by haematoxylin and eosin (HE) and immunofluorescent staining. Mechanism of PEX5 affecting peroxisomes and spermatogenesis were validated by Western blot and transmission electron microscopy (TEM). Transcriptome RNA sequencing (RNA-seq) was used to profile the dysregulated genes in testes from WT and Pex5^-/- mice on postnatal day (P) 35. The adult Pex5 knockout male mice were completely sterile with no mature sperm production. Loss of Pex5 in spermatocytes resulted in multinucleated giant cell formation, meiotic arrest, abnormal tubulin expression, and deformed acrosome formation. Furthermore, Pex5 deletion led to delayed DNA double-strand break repair and improper crossover at the pachytene stage. Impaired peroxisome function in Pex5 knockout mice induced ROS redundancy, which in turn led to an increase in germ cell apoptosis and a decline in autophagy. Pex5 regulates ROS during meiosis and is essential for spermatogenesis and male fertility in mice.

RhoGDIα regulates spermatogenesis through Rac1/cofilin/F-actin signaling

Spermatogenesis is an extremely complex process, and any obstruction can cause male infertility. RhoGDIα has been identified as a risk of male sterility. In this study, we generate RhoGDIα knockout mice, and find that the males have severely low fertility. The testes from RhoGDIα^-/- mice are smaller than that in WT mice. The numbers of spermatogonia and spermatocytes are decreased in RhoGDIα^-/- testis. Spermatogenesis is compromised, and spermatocyte meiosis is arrested at zygotene stage in RhoGDIα^-/- mice. Acrosome dysplasia is also observed in sperms of the mutant mice. At the molecular level, RhoGDIα deficiency activate the LIMK/cofilin signaling pathway, inhibiting F-actin depolymerization, impairing testis and inducing low fertility in mouse. In addition, the treatment of RhoGDIα^-/- mice with Rac1 inhibitor NSC23766 alleviate testis injury and improve sperm quality by inhibiting the LIMK/cofilin/F-actin pathway during spermatogenesis. Together, these findings reveal a previously unrecognized RhoGDIα/Rac1/F-actin-dependent mechanism involved in spermatogenesis and male fertility.

Conditional deletion of Hspa5 leads to spermatogenesis failure and male infertility in mice

Heat shock proteins (HSPs) have important roles in different developmental stages of spermatogenesis. The heat shock 70 kDa protein 5 (HSPA5) is an important component of the unfolded protein response that promotes cell survival under endoplasmic reticulum (ER) stress conditions. In this study, we explored the function of HSPA5 in spermatogenesis, by generating a germ cell-specific deletion mutant of the Hspa5 gene (conditional knockout of the Hspa5 gene, Hspa5-cKO) using CRISPR/Cas9 technology and the Cre/Loxp system. Hspa5 knockout resulted in severe germ cell loss and vacuolar degeneration of seminiferous tubules, leading to complete arrest of spermatogenesis, testicular atrophy, and male infertility in adult mice. Furthermore, defects occurred in the spermatogenic epithelium of Hspa5-cKO mice as early as Cre recombinase expression. Germ cell ablation of Hspa5 impaired spermatogonia proliferation and differentiation from post-natal day 7 (P7) to P10, which led to a dramatic reduction of differentiated spermatogonia, compromised meiosis, and led to impairment of testis development and the disruption of the first wave of spermatogenesis. Consistent with these results, single-cell RNA sequencing (scRNA-seq) analysis showed that germ cells, especially differentiated spermatogonia, were dramatically reduced in Hspa5-cKO testes compared with controls at P10, further confirming that HSPA5 is crucial for germ cell development. These results suggest that HSPA5 is indispensable for normal spermatogenesis and male reproduction in mice.

Cathepsin B plays a role in spermatogenesis and sperm maturation through regulating autophagy and apoptosis in mice

Spermatogenesis and sperm maturation are complex and highly ordered biological processes. Any failure or disorder in these processes can cause defects in sperm morphology, motility, and fertilization ability. Cathepsin B (CTSB) is involved in the regulation of a variety of pathological processes. In the present study, we found that CTSB was abundantly expressed in the male reproductive system, however, the specific role of CTSB in regulating spermatogenesis and sperm maturation remained elusive. Hence, we generated Ctsb ^-/- mice using CRISPR/Cas9 technology. In Ctsb ^-/- mice, sperm count was significantly decreased while the level of morphologically abnormal sperm was markedly increased. Additionally, these mice had significantly lower levels of progressive motility sperm and elevated levels of immobilized sperm. Histological analysis showed slight vacuolization in the testis epithelium, as well as the loss of epididymal epithelium cells. Further investigation showed that autophagic activity was inhibited and apoptotic activity was increased in both the testis and epididymis of Ctsb ^-/- mice. Together, our findings demonstrate that CTSB plays an important role in spermatogenesis and sperm maturation in mice.

Hadh deficiency induced oligoasthenoteratozoospermia through the TNF-α/Bcl-2 pathway in male mice

The process of spermatogenesis is a complex and delicate process that is still not fully understood. In this study, we examined the role of fatty acid oxidase 3-hydroxy acyl CoA dehydrogenase (HADH) in maintaining normal spermatogenesis in mice. In male mice, ablation of the Hadh gene using CRISPR/Cas9 technology arrested spermatocyte meiosis, increased multinucleated giant germ cells and vacuoles in seminiferous tubules, and accompanied with acrosomal dysplasia. Hadh^-/- male mice showed the typical features of oligoasthenoteratozoospermia (OAT), including decreased sperm concentration and motility and increased sperm abnormalities. Next, we explored the molecular events in the testes of the mutant mice. We found fatty acids accumulated in the testis of Hadh^-/- mice. And also, inflammatory factors TNF-α, IL-1β, and IL-6 were significantly increased, apoptosis-related protein Bcl-2 was decreased, and Bax and cleaved-Caspase3 were increased in Hadh^-/- male mice testis. After using etanercept, a specific inhibitor of TNF-α, testis injury caused by Hadh knockout was significantly alleviated, the sperm quality and motility were improved, and germ cell apoptosis was reduced. So our study demonstrated that Hadh deletion caused an increase in fatty acids. The accumulated fatty acids further induced testicular inflammation and germ cell apoptosis through the TNF-α/Bcl-2 signaling pathway, finally resulting in OAT in the Hadh^-/- mice. Inhibiting TNF-α may be used as a new treatment approach for testicular inflammation and OAT.

Higher long-term mortality in patients with concomitant acute coronary syndrome and aortic stenosis

Background

Aortic stenosis (AS) and acute coronary syndrome (ACS) share similar cardiovascular risk factors, and their concomitant presentation is increasing in incidence with the aging population. Yet literature regarding the prognosis of patients with concomitant ACS and AS remains scarce.

Methods

This retrospective cohort study examined consecutive patients presenting with ACS (ST-segment elevation myocardial infarction [STEMI] and non-STEMI [NSTEMI]) and concomitant AS between 1 January 2011 and 31 March 2021 in a tertiary hospital. The cohort was divided into mild, moderate and severe AS based on index echocardiogram. The primary outcome was all-cause mortality. Kaplan-Meier curves were constructed to compare all-cause mortality among the three groups of patients, based on ACS type and left ventricular ejection fraction (LVEF). Multivariable Cox regression was performed to identify independent predictors of all-cause mortality.

Results

Of a total of 563 patients, 264 had mild (46.9%), 193 moderate (34.3%) and 106 severe AS (18.8%). The mean follow-up duration was 2.5 (± 2.4) years. Majority of patients (72.5%) presented with NSTEMI. Patients with moderate and severe AS had higher rates of all-cause mortality compared to those with mild AS (49.7% vs. 51.4% vs. 35.6% respectively, p=0.002). Concomitant moderate (HR 1.439, 95% CI 1.012–2.048, p=0.043) and severe AS (HR 1.844, 95% CI 1.159–2.933, p=0.010) were independent predictors of all-cause mortality after adjusting for age, gender, LVEF, ACS type, chronic kidney disease, diabetes, hypertension, coronary artery bypass grafting and aortic valve replacement as a time-dependent variable. The Kaplan-Meier curves demonstrated excess mortality in moderate and severe AS, compared to the mild AS group (p&lt;0.001), with similar survival trends observed in the STEMI and the NSTEMI groups, as well as those with preserved LVEF.

Conclusion

Regardless of the ACS presentation type, long-term excess mortality in those with concomitant moderate or severe AS was observed. The adverse prognosis typically observed in patients with concomitant severe AS, in the setting of ACS, extends to patients with moderate AS.

Funding Acknowledgement

Type of funding sources: None.

Prognostically distinct phenotypes of metabolic health beyond obesity in aortic stenosis

Background

Whilst current evidence are in favour of metabolic health and non-obesity in the reduction of incident cardiovascular disease, little is known regarding the prognosis across the metabolic phenotypes once cardiovascular disease occurs. This study examined the prognosis of patients with significant aortic stenosis (AS) based on the presence of metabolic health and obesity.

Methods

This retrospective cohort on consecutive patients presenting with moderate-to-severe AS to a tertiary hospital between 2010 and 2015. Patients were allocated into 4 groups based on obesity and metabolic health: metabolically healthy obese (MHO), metabolically healthy non-obese (MHNO), metabolically unhealthy obese (MUO) and metabolically unhealthy non-obese (MUNO). Metabolic health was defined in accordance to Program Adult Treatment Panel III criteria. The primary outcome was all-cause mortality. Cox regression examined independent associations between mortality and metabolic phenotypes, adjusting for aortic valve area, ejection fraction, age, sex, chronic kidney disease and AVR as a time-dependent covariate.

Results

Of 727 patients, the majority (51.6%) were MUNO, followed by MUO (32.7%), MHNO (11.4%), and MHO (4.3%). MHNO had the highest mortality (43.0%), followed by the MUNO (37.5%), MUO (30.0%) and MHO (6.9%) groups (p=0.001). Compared to MHNO, MHO (HR 0.159, 95% CI 0.038–0.668, p=0.012) and MUO (HR 0.614, 95% CI 0.403–0.937, p=0.024) were independently associated with lower all-cause mortality rates, after adjusting for confounders. In obese patients, metabolic health had favourable survival compared to metabolically unhealthy (p=0.015), but this protective impact of metabolic health was not observed in overweight or normal weight individuals. Obesity had favourable survival compared to overweight and normal weight, in both metabolically health (p=0.002) and unhealthy (p=0.007) patients,

Conclusion

MHO patients with AS have the most favourable prognosis whilst the seemingly healthy MHNO group had the worst survival. There should be a paradigm shift towards prioritising metabolic health rather than weight reduction in patients with significant AS.

Funding Acknowledgement

Type of funding sources: None.

Abstract P2003: ER-resident UFBP1 Maintains ER Homeostasis And Represses Cardiac Inflammation To Constrain Pathological Cardiac Remodeling

Ufmylation is a novel protein modification by which protein substrates are covalently modified by the ubiquitin-like protein, UFM1 (ubiquitin-fold modifier 1) via a UFM1-specific E1-E2-E3 enzymatic cascade. Through its ability to regulate protein function, ufmylation participates in diverse pathophysiological events and is implicated in various human diseases. We recently reported that ufmylation is dysregulated by cardiomyopathy in both human and mouse hearts. Inhibition of ufmylation by targeting the E3 ligase, UFL1, in the heart evokes ER stress, leading to dilated cardiomyopathy and heart failure under resting and stress conditions, demonstrating its critical role in maintaining ER and cardiac homeostasis. However, how ufmylation regulates ER and cardiac function remain unclear. Here, we report that UFBP1 (UFM1 binding protein 1), an ER-resident ufmylation target, is a crucial downstream effector of ufmylation in the heart. UFBP1 is downregulated in UFL1-deficient hearts but upregulated in pressure overload hearts. Condition knockout (KO) of UFBP1 in mouse heart caused dilated cardiomyopathy during aging and exacerbated pressure overload-induced pathological cardiac remodeling. Of note, the timeline of disease progression in UFBP1 KO mice closely aligned with that of UFL1 KO mice. Transcriptomics analysis revealed the involvement of ER stress signaling and unexpectedly, inflammation in the pathogenesis. Biochemical analyses confirmed the pronounced ER stress, increased cytokine expression, and remarkable infiltration of inflammatory cells into the myocardium, which preceded the severe cardiac phenotype. Alleviation of ER stress via TUDCA administration mitigated UFBP1KO-induced cardiac dysfunction, suggesting a causal role of ER stress in the pathogenesis. Re-expression of wild-type UFBP1, but not its ER-binding–deficient mutant, in UFBP1 KO hearts rescued the pathological cardiac phenotype. UFPB1 expression was stabilized by UFL1, and depletion of UFBP1 in cardiomyocytes (CMs) induced ER stress and promoted cell death, recapitulating most aspects of UFL1-deficient CMs. Collectively, our data suggest that ER-resident UFBP1 represses ER stress and cardiac inflammation to constrain pathological cardiac remodeling.

A scintillator attenuation spectrometer for intense gamma-rays

A new type of compact high-resolution high-sensitivity gamma-ray spectrometer for short-pulse intense gamma-rays (250 keV to 50 MeV) has been developed by combining the principles of scintillators and attenuation spectrometers. The first prototype of this scintillator attenuation spectrometer (SAS) was tested successfully in Trident laser experiments at LANL. Later versions have been used extensively in the Texas Petawatt laser experiments in Austin, TX, and more recently in OMEGA-EP laser experiments at LLE, Rochester, NY. The SAS is particularly useful for high-repetition-rate laser applications. Here, we give a concise description of the design principles, capabilities, and sample preliminary results of the SAS.

Effects of Moxa Cone Moxibustion Therapy on Cognitive Function and Brain Metabolic Changes in MCI Patients: A Pilot 1H-MRS Study

Objective

To explore the effect of moxa cone moxibustion on N-acetyl aspartate/total creatinine (NAA/tCr) and choline/total creatinine (Cho/tCr) in the bilateral hippocampus (HIP) and bilateral posterior cingulate gyrus (PCG) in patients with mild cognitive impairment (MCI) using hydrogen proton magnetic resonance spectroscopy (¹H-MRS) and to provide imaging basis for moxa cone moxibustion treatment for MCI.

Methods

One hundred eight patients with MCI were served as the MCI group, and 67 age-matched subjects were enrolled as the normal control group. The MCI group was randomized and allocated into acupoint group, drug group, and sham acupoint group, with 36 cases in each group. Some patients in each group withdrew. Finally, 25 cases were included in the acupoint group, 24 cases in the drug group, and 20 cases in the sham acupoint group. The drug group was treated with oral donepezil hydrochloride. The acupoint group and sham acupoint group received moxa cone moxibustion treatment. Mini-mental state exam (MMSE) and Montreal cognitive assessment (MoCA) scores were recorded before intervention, at the end of the first and the second months of intervention, and in the 5th month of follow-up. The NAA/tCr and Cho/tCr ratios in the HIP and PCG were bilaterally measured by ¹H-MRS before and after intervention.

Results

Before intervention, compared with the normal control group, the MMSE and MoCA scores, the Cho/tCr ratio in the right HIP, the NAA/tCr ratio in the bilateral HIP, and the NAA/tCr ratio in the left PCG in the three treatment groups decreased significantly (both p < 0.01), and the NAA/tCr ratio in the right PCG significantly reduced in the acupoint and drug groups (p < 0.05). After two months of treatment, compared with the normal control group, there were no differences in the MoCA scores, the NAA/tCr, and Cho/tCr ratios in the bilateral PCG and bilateral HIP in the three treatment groups (p > 0.05). However, the MMSE scores in the drug group decreased when compared with the acupoint group and normal control group (p < 0.05, p < 0.01). The scores of MMSE and MoCA in the acupoint group and sham acupoint group at all time points were better than those in the drug group, which were similar to those in the normal control group.

Conclusion

Our findings suggest that moxibustion could improve the cognitive function of patients with MCI. The mechanism may be related to the improvement of abnormal brain metabolism in HIP and PCG.

OP0015 PROINFLAMMATORY MONOCYTES AND MACROPHAGES IN SYNOVIAL FLUID AND BURSAL TISSUE OF PATIENTS WITH POLYMYALGIA RHEUMATICA: POTENT PRODUCERS OF IL-6 AND GM-CSF

Background

Polymyalgia rheumatica (PMR) is a common, rheumatic inflammatory disease. Inflammation of bursae and tendon sheaths is a characteristic finding in patients with PMR. Glucocorticoid treatment remains the mainstay treatment for PMR. A study published in 1996 reported that macrophages dominate the inflammatory infiltrates in the glenohumeral synovium of PMR patients1, suggesting the importance of these cells in the immunopathology of PMR. However, the functional and phenotypical heterogeneity of the tissue-infiltrating macrophages in PMR remains obscure. Although treatment with anti-IL-6 receptor (tocilizumab) has shown promising results2, it is unclear whether macrophages contribute to IL-6 production in PMR. Additionally, anti-GM-CSF receptor therapy (mavrilimumab), recently shown to be efficacious in the closely related disease giant cell arteritis3, may also be useful for the treatment of PMR. Knowledge on the functional heterogeneity of monocytes/macrophages in PMR may aid in identifying novel therapeutic targets for this condition.

Objectives

To determine the phenotype of monocyte/macrophages in peripheral blood, bursal/tenosynovial fluid and bursal tissue of patients with PMR.

Methods

Paired peripheral blood (PB), bursal/tenosynovial fluid (SF) and bursal tissue biopsy samples from 11 PMR patients were included in our study. Bursal and tenosynovial samples were obtained from the shoulder. Distribution of the monocyte subsets (classical, intermediate and non-classical monocytes) was determined based on the level of CD14 and CD16 expression by flow cytometry. To study monocyte activation status, markers of ‘M1’ like (CD80 and CD64) and ‘M2’ like (CD206 and FRβ) macrophage polarization were included in the flow cytometry analysis. Immunohistochemistry of bursal tissue biopsies was focused on macrophage markers (CD68, CD86, CD64, CD206 and FRβ) andproinflammatory cytokines (IL-6 and GM-CSF), which were scored semi-quantitatively. Double immunofluorescence stainings were performed to determine the expression of IL-6 and GM-CSF by tissue-infiltrating macrophages in bursal tissue.

Results

Monocytes were detected in the SF of PMR patients. The proportion of classical monocytes was significantly lowered (p=0.001) in SF versus PB, while the proportion of intermediate monocytes was significantly elevated (p=0.001). The expression of CD206 was significantly elevated (p=0.001) but not FRβ in SF monocytes, suggesting GM-CSF skewed phenotype. In bursal tissue, macrophages displayed mixed ‘M1’/’M2’ traits with high expression of all macrophage polarization markers. Proinflammatory cytokines IL-6 and GM-CSF were highly expressed throughout the bursal tissue biopsies. Double immunofluorescence staining confirmed the expression of IL-6 and GM-CSF by the infiltrating macrophages.

Conclusion

SF monocytes and bursal tissue macrophages show a pro-inflammatory phenotype in PMR. Moreover, tissue-infiltrating macrophages show a prominent IL-6 and GM-CSF response in PMR. Our data add to the rationale of targeting IL-6 and GM-CSF as treatment options in PMR.

References

[1]Meliconi R, Pulsatelli L, Uguccioni M, et al. Leukocyte infiltration in synovial tissue from the shoulder of patients with polymyalgia rheumatica. Quantitative analysis and influence of corticosteroid treatment. Arthritis Rheum. 1996;39(7):1199-1207.

[2]Devauchelle-Pensec V, Berthelot JM, Cornec D, et al. Efficacy of first-line tocilizumab therapy in early polymyalgia rheumatica: a prospective longitudinal study. Ann Rheum Dis. 2016;75(8):1506-1510.

[3]Cid MC, Unizoni S, Pupim L, et al. Mavrilimumab (anti GM-CSF Receptor α Monoclonal Antibody) Reduces Time to Flare and Increases Sustained Remission in a Phase 2 Trial of Patients with Giant Cell Arteritis [Abstract]. Arthritis Rheumatol. 2020; 72 (suppl 10).

Acknowledgements

This work was supported by a research grant from FOREUM Foundation for Research in Rheumatology. The PMR Research On disease Mechanisms In Synovium (PROMIS) study was also funded by the Rheumatology Grant (Dutch Society for Rheumatology) and Mandema Stipend (University Medical Center Groningen).

Disclosure of Interests

William Febry Jiemy: None declared, Rosanne Reitsema: None declared, Anqi Zhang: None declared, Maria Sandovici: None declared, Annemieke Boots: None declared, Peter Heeringa: None declared, Elisabeth Brouwer Speakers bureau: E. Brouwer reports speaker and consulting fees from Roche in 2017-2018, outside the submitted work, Consultant of: E. Brouwer reports speaker and consulting fees from Roche in 2017-2018, outside the submitted work, Kornelis van der Geest Consultant of: K. van der Geest reports personal fees from Roche, outside the submitted work.

Thermal Analysis of PE Extended Chain Crystal of PE Extended Chain Crystal from Gel Spinning

It has been recognized that ultra-high strength and high modulus ultra-highly drawn Polyethylene (PE) fiber is produced from the formation of extended chain crystal. Nevertheless, whether extended chain crystal exists in gel spinning ultra-highly drawn PE fiber is still an unsettled question. In this work, decalin was adopted as a solvent for PE gel spinning. By means of thermal analysis, X-ray diffraction methods etc, the existence of extended chain crystal was explored. Reasons for confusion in previous studies of this problem were discussed.

In PE fiber from 3 wt-°/o dope, extended chain crystal starts to form during draw ratios over 20. When draw ratio equals 42, the content of extended chain crystal roughly equals that of folded chain crystal. The melting point of extended chain crystal is 6°C higher than that of folded chain crystal. They are 145.5° C and 150° C to 152.5° C respectively. The latter would slightly rise with arise of draw ratio.

Multi-crystallization behavior of annealed PE fiber was determined and discussed. It was also confirmed that there is a linear logarithm relationship between thermal shrinkage (internal stresses) and fiber moduli.

Evidence for X(3872) in Pb-Pb Collisions and Studies of its Prompt Production at sqrt[s_{NN}]=5.02 TeV

The first evidence for X(3872) production in relativistic heavy ion collisions is reported. The X(3872) production is studied in lead-lead (Pb-Pb) collisions at a center-of-mass energy of sqrt[s_{NN}]=5.02  TeV per nucleon pair, using the decay chain X(3872)→J/ψπ^{+}π^{-}→μ^{+}μ^{-}π^{+}π^{-}. The data were recorded with the CMS detector in 2018 and correspond to an integrated luminosity of 1.7  nb^{-1}. The measurement is performed in the rapidity and transverse momentum ranges |y|<1.6 and 15<p_{T}<50  GeV/c. The significance of the inclusive X(3872) signal is 4.2 standard deviations. The prompt X(3872) to ψ2S yield ratio is found to be ρ^{Pb-Pb}=1.08±0.49(stat)±0.52(syst), to be compared with typical values of 0.1 for pp collisions. This result provides a unique experimental input to theoretical models of the X(3872) production mechanism, and of the nature of this exotic state.

An application research for near-surface repository of strontium-90 sorption kinetic model on mudrocks

In this study,90Sr was used as the test radionuclide to characterize the sorption kinetics and effects of initial 90Sr activity and remaining 90Sr in solid concentration were simulated for a near-surface repository. The study focused on the sorption characteristics of radionuclides in unsaturated groundwater environment (or vadose zone) is the important information for investigating the near-surface disposal of intermediate and low-level radioactive waste (ILLW). Moreover, the 90Sr sorption experiments reached equilibrium within 56 h, which fit to the first order sorption kinetic model, and the remaining 90Sr in mudrock samples showed obvious sorption equilibrium hysteresis, which fit to the second order sorption kinetic model. Before reaching the maximum sorption capacity, the sorption rate constant increases with 90Sr increasing; the distribution coefficient (Kd) of 56 h decreases with the remaining 90Sr decreasing. In addition, it showed that the slow sorption process dominated before the sorption reaches equilibrium. In fact, a reliable safety assessment methodology for on-going near-surface repository required a lot of the radionuclides parameters with local environment including the radionuclides sorption/desorption rate constant and maximum sorption capacity.

SMPX Deficiency Causes Stereocilia Degeneration and Progressive Hearing Loss in CBA/CaJ Mice

The small muscle protein, x-linked (SMPX) encodes a small protein containing 88 amino acids. Malfunction of this protein can cause a sex-linked non-syndromic hearing loss, named X-linked deafness 4 (DFNX4). Herein, we reported a point mutation and a frameshift mutation in two Chinese families who developed gradual hearing loss with age. To explore the impaired sites in the hearing system and the mechanism of DFNX4, we established and validated an Smpx null mouse model using CRISPR-Cas9. By analyzing auditory brainstem response (ABR), male Smpx null mice showed a progressive hearing loss starting from high frequency at the 3rd month. Hearing loss in female mice was milder and occurred later compared to male mice, which was very similar to human beings. Through morphological analyses of mice cochleas, we found the hair cell bundles progressively degenerated from the shortest row. Cellular edema occurred at the end phase of stereocilia degeneration, followed by cell death. By transfecting exogenous fluorescent Smpx into living hair cells, Smpx was observed to be expressed in stereocilia. Through noise exposure, it was shown that Smpx might participate in maintaining hair cell bundles. This Smpx knock-out mouse might be used as a suitable model to explore the pathology of DFNX4.

Robust Evaluation of Ultraviolet-C Sensitivity for SARS-CoV-2 and Surrogate Coronaviruses

UV light, more specifically UV-C light at a wavelength of 254 nm, is often used to disinfect surfaces, air, and liquids. In early 2020, at the cusp of the COVID-19 pandemic, UV light was identified as an efficient means of eliminating coronaviruses; however, the variability in published sensitivity data is evidence of the need for experimental rigor to accurately quantify the effectiveness of this technique. In the current study, reliable and reproducible UV techniques have been adopted, including accurate measurement of light intensity, consideration of fluid UV absorbance, and confirmation of uniform dose delivery, including dose verification using an established biological target (T1UV bacteriophage) and a resistant recombinant virus (baculovirus). The experimental results establish the UV sensitivity of SARS-CoV-2, HCoV-229E, HCoV-OC43, and mouse hepatitis virus (MHV) and highlight the potential for surrogate viruses for disinfection studies. All four coronaviruses were found to be easily inactivated by 254 nm irradiation, with UV sensitivities of 1.7, 1.8, 1.7, and 1.2 mJ/cm2/log10 reduction for SARS-CoV-2, HCoV-229E, HCoV-OC43, and MHV, respectively. Similar UV sensitivities for these species demonstrate the capacity for HCoV-OC43, HCoV-229E, and MHV to be considered surrogates for SARS-CoV-2 in UV-inactivation studies, greatly reducing hazards and simplifying procedures for future experimental studies. IMPORTANCE Disinfection of SARS-CoV-2 is of particular importance due to the global COVID-19 pandemic. UV-C irradiation is a compelling disinfection technique because it can be applied to surfaces, air, and water and is commonly used in drinking water and wastewater treatment facilities. UV inactivation depends on the dose received by an organism, regardless of the intensity of the light source or the optical properties of the medium in which it is suspended. The 254 nm irradiation sensitivity was accurately determined using benchmark methodology and a collimated beam apparatus for four coronaviruses (SARS-CoV-2, HCoV-229E, HCoV-OC43, and MHV), a surrogate indicator organism (T1UV), and a resistant recombinant virus (baculovirus vector). Considering the light distribution across the sample surface, the attenuation of light intensity with fluid depth, the optical absorbance of the fluid, and the sample uniformity due to mixing enable accurate measurement of the fundamental inactivation kinetics and UV sensitivity.

High levels of unbound bilirubin are associated with acute bilirubin encephalopathy in post-exchange transfusion neonates

BACKGROUND

Although it is known that unbound bilirubin can enter the brain, there is little evidence of its association with the development of acute bilirubin encephalopathy. Here, we investigated this potential relationship in neonates who had undergone exchange transfusion.

METHODS

Data from 46 newborns who underwent exchange transfusion between 2016 and 1-1 to 2018-12-31 at the First People's Hospital of Changde City in China were analyzed. The unbound bilirubin level was taken as the independent variable and the development of the acute bilirubin encephalopathy as the dependent variable. The covariates were age, birth weight, sex, red blood cell count, blood glucose, hemolytic disease, and whether the infant had received phototherapy.

RESULTS

The mean age and gestational age of the neonates were 146.5 ± 86.9 h and 38.6 ± 1.3 weeks [38.7(34.6-41.1) weeks] old, respectively; 52.17% were male. Binary logistic regression analysis after adjustment for covariates showed a positive association between the levels of unbound bilirubin and the development of acute bilirubin encephalopathy (odds ratio = 1.41, 95% confidence intervals 1.05-1.91, P = < 0.05).

CONCLUSION

There is a significant association between unbound bilirubin levels and the development of acute bilirubin encephalopathy in neonates. Further investigations are required to explore the mechanisms.

Toward the Association Between EFL/ESL Teachers' Work Engagement and Their Students' Academic Engagement

Given the fact that EFL/ESL students' academic engagement is of high importance for their learning success, numerous studies have been carried out to identify factors contributing to students' engagement. However, the role of teacher personal factors, notably teacher work engagement has received scant attention. Moreover, no review study has been conducted on this issue. Accordingly, the present review intends to explicate the multidimensional essence of teacher work engagement and student academic engagement and the association between these constructs. In light of the theoretical and empirical evidence, the role of EFL/ESL teachers' work engagement in improving their students' academic engagement was proved. The pedagogical implications of the findings are also highlighted.

Isobutanol tolerance and production of Saccharomyces cerevisiae can be improved by engineering its TATA-binding protein Spt15

Low isobutanol tolerance of Saccharomyces cerevisiae limits its application in isobutanol fermentation. Here, we used global transcription machinery engineering to screen mutants with higher isobutanol tolerance and elevated isobutanol titres. TATA-binding protein Spt15 was used as the target of global transcription machinery engineering for improvement of such complex phenotypes. A random mutagenesis library of S. cerevisiae TATA-binding protein Spt15 was constructed and subjected to screening under isobutanol stress. A mutant strain (denoted as spt15-3) with improved isobutanol tolerance was identified. There were three mutations of Spt15 in strain spt15-3, including deletion of A at position -132 nt upstream of initiation codon, insertion of G at position -65 nt upstream of initiation codon and a synonymous mutation at position 315 nt (T → C) downstream of initiation codon. We then metabolically engineered isobutanol synthesis in strains harbouring plasmids YCplac22 containing these Spt15 mutations. Delta integration was used to overexpress ILV3 gene, and 2μ plasmids carrying PGK1p-ILV2 and PGK1p-ARO10 were used to overexpress ILV2 and ARO10 genes. After 24-h micro-aerobic fermentation, Engi-3 produced 0·556 g l^-1 isobutanol, which was 404% and 25·3% greater than isobutanol produced by control Engi-1 and engineered Engi-2, respectively. After 28 h, Engi-4 produced 0·459 g l^-1 isobutanol, which was 315% and 3·2% greater than isobutanol produced Engi-1 and Engi-2, respectively. RNA-Seq-based transcriptome analysis shows that mutations of Spt15 in strain spt15-3 increased the expression of SPT15. Meanwhile, compared with strain Engi-3, the spt15-3 mutation downregulated the expression of genes involved in the TCA cycle and glyoxylic acid cycle, but increased the expression of genes related to cell stability. This work demonstrates that isobutanol tolerance and production of S. cerevisiae can be improved by engineering its TATA-binding protein Spt15. This study clarified the molecular mechanisms regulating isobutanol production and tolerance in S. cerevisiae.

Hearing Loss in Id1-/-; Id3+/- and Id1+/-; Id3-/- Mice Is Associated With a High Incidence of Middle Ear Infection (Otitis Media)

Inhibitors of differentiation/DNA binding (Id) proteins are crucial for inner ear development, but whether Id mutations affect middle ear function remains unknown. In this study, we obtained Id1-/-; Id3+/- mice and Id1+/-; Id3-/- mice and carefully examined their middle ear morphology and auditory function. Our study revealed a high incidence (>50%) of middle ear infection in the compound mutant mice. These mutant mice demonstrated hearing impairment starting around 30 days of age, as the mutant mice presented elevated auditory brainstem response (ABR) thresholds compared to those of the littermate controls. The distortion product of otoacoustic emission (DPOAE) was also used to evaluate the conductive function of the middle ear, and we found much lower DPOAE amplitudes in the mutant mice, suggesting sound transduction in the mutant middle ear is compromised. This is the first study of the middle ears of Id compound mutant mice, and high incidence of middle ear infection determined by otoscopy and histological analysis of middle ear suggests that Id1/Id3 compound mutant mice are a novel model for human otitis media (OM).

A Review of Mechano-Biochemical Models for Testing Composite Restorations

Due to the severe mechano-biochemical conditions in the oral cavity, many dental restorations will degrade and eventually fail. For teeth restored with resin composite, the major modes of failure are secondary caries and fracture of the tooth or restoration. While clinical studies can answer some of the more practical questions, such as the rate of failure, fundamental understanding on the failure mechanism can be obtained from laboratory studies using simplified models more effectively. Reviewed in this article are the 4 main types of models used to study the degradation of resin-composite restorations, namely, animal, human in vivo or in situ, in vitro biofilm, and in vitro chemical models. The characteristics, advantages, and disadvantages of these models are discussed and compared. The tooth-restoration interface is widely considered the weakest link in a resin composite restoration. To account for the different types of degradation that can occur (i.e., demineralization, resin hydrolysis, and collagen degradation), enzymes such as esterase and collagenase found in the oral environment are used, in addition to acids, to form biochemical models to test resin-composite restorations in conjunction with mechanical loading. Furthermore, laboratory tests are usually performed in an accelerated manner to save time. It is argued that, for an accelerated multicomponent model to be representative and predictive in terms of both the mode and the speed of degradation, the individual components must be synchronized in their rates of action and be calibrated with clinical data. The process of calibrating the in vitro models against clinical data is briefly described. To achieve representative and predictive in vitro models, more comparative studies of in vivo and in vitro models are required to calibrate the laboratory studies.

P–138 When is low quality really low? Should we transfer low-grade blastocysts?

Study question

What is the live birth rate after single, low-grade blastocyst (LGB) transfer?

Summary answer

The live birth rate for LGBs is 28%, ranging between 15–31% for the different inner cell mass (ICM) and trophectoderm (TE) subgroups of LGBs.

What is known already

Live birth rates following LGB transfer are varied and have been reported to be in the range of 5–39%. However, these estimates are inaccurate as studies investigating live birth rates following LGB transfer are inherently limited by sample size (n = 10–440 for LGB transfers) due to LGBs being ranked last for transfer. Further, these studies are heterogenous with varied LGB definitions and design. Collating LGB live birth data from multiple clinics is warranted to obtain sufficient numbers of LGB transfers to establish reliable live birth rates, and to allow for delineation of different LGB subgroups, including blastocyst age and female age.

Study design, size, duration

We performed a multicentre, multinational retrospective cohort study in 9 IVF centres in China and New Zealand from 2012 to 2019. We studied the outcome of 6966 single blastocyst transfer cycles on days 5–7 (fresh and frozen) according to blastocyst grade, including 875 transfers from LGBs (&lt;3bb, this being the threshold typically applied to LGB studies). Blastocysts with expansion stage 1 or 2 (early blastocysts) were excluded.

Participants/materials, setting, methods

The main outcome measured was live birth rate. Blastocysts were grouped according to quality grade: good-grade blastocysts (GGBs; n = 3849, aa, ab and ba), moderate-grade blastocysts (MGBs; n = 2242, bb) and LGBs (n = 875, ac, ca, bc, cb and cc) and live birth rates compared using the Pearson Chi-squared test. A logistic regression analysis explored the relationship between blastocyst grade and live birth after adjustment for the confounders: clinic, female age, expansion stage, and blastocyst age.

Main results and the role of chance

The live birth rates for GGBs, MGBs and LGBs were 45%, 36% and 28% respectively (p &lt; 0.0001). Within the LGB group, the highest live birth rates were for grade c TE (30%) and the lowest were for grade c ICM (19%). The lowest combined grade (cc) maintained a 15% live birth rate (n = 7/48). After accounting for confounding factors, including female age and blastocyst characteristics, the odds of live birth were 2.33 (95% CI = 1.88–2.89) for GGBs compared to LGBs and 1.56 (95% CI = 1.28–1.92) for MGBs compared to LGBs following fresh and frozen blastocyst transfers (p &lt; 0.0001, odds ratios confirmed in exclusively frozen blastocyst transfer cycles). When stratified by individual ICM and TE grade, the odds of live birth according to ICM grade were 1.31 (a versus b; 95% CI = 1.15–1.48), 2.82 (a versus c; 95% CI = 1.91–4.18) and 2.16 (b versus c; 95% CI = 1.48–3.16; all p &lt; 0.0001). The odds of live birth according to TE grade were 1.33 (a versus b; 95% CI = 1.17–1.50, p &lt; 0.0001), 1.85 (a versus c; 95% CI = 1.45–2.34, p &lt; 0.0001) and 1.39 (b versus c; 95% CI = 1.12–1.73, p = 0.0024).

Limitations, reasons for caution

Despite the large multicentre design of the study, analyses of transfers occurring within the smallest subsets of the LGB group were limited by sample size. The study was not randomised and had a retrospective character.

Wider implications of the findings: LGBs maintain satisfactory live birth rates (averaging 28%) in the general IVF population. Even those in the lowest grading tier maintain modest live birth rates (15%; cc). It is recommended that LGBs not be universally discarded, and instead considered for subsequent frozen embryo transfer to maximize cumulative live birth rates.

Trial registration number

Not applicable

Second-trimester abdominal circumference discordance and adverse perinatal outcomes in monochorionic twins

OBJECTIVE

The perinatal outcomes in second-trimester abdominal circumference (AC) discordant twins are yet to be established. The aim of this study was to ascertain perinatal risks associated with second-trimester AC discordance in monochorionic (MC) twins.

METHOD

We conducted a retrospective study of all MC twin pregnancies over a 7-year period. Intertwin AC discordance at 14-26 gestational weeks was analyzed in relation to Doppler abnormalities, obstetric complications, and perinatal adverse outcomes.

RESULTS

A total of 246 MC twin pregnancies were included in the analysis. The smaller twins of second-trimester AC discordant pairs were at increased prevalence of abnormal umbilical artery flow (50% versus 24%, p < .001) and low positive A wave of ductus venous flow (24% versus 9%, p = .002). The second-trimester AC discordant twins were at increased risk of oligohydramnios in smaller twin (OR = 2.44, 95% CI = 1.37-4.32, p < .01), cardiomegaly in larger twin (OR = 2.95, 95% CI = 1.01-8.60, p < .05), birth weight of either twin below the 10th percentile for gestational age (OR = 5.56, 95% CI = 2.67-11.59, p < .001), birth weight discordance > 25% (OR = 9.41, 95% CI = 4.46-19.87, p < .001), IUFD (OR = 3.26, 95% CI = 1.76-6.05, p < .001), and severe neonatal morbidity (OR = 1.83, 95% CI = 1.03-3.26, p < .05). The intact survival rate in discordant and concordant twin pairs was 70% and 89%, respectively (p < .001).

CONCLUSIONS

Early and increase fetal surveillance of the second-trimester AC discordant twins should be utilized to establish perinatal risks, thus allowing prenatal care to improve.

Development and validation of HERWIG 7 tunes from CMS underlying-event measurements

This paper presents new sets of parameters ("tunes") for the underlying-event model of the H E R W I G 7 event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in H E R W I G 7 , and are obtained from a fit to minimum-bias data collected by the CMS experiment at s = 0.9 , 7, and 13 Te . The tunes are based on the NNPDF 3.1 next-to-next-to-leading-order parton distribution function (PDF) set for the parton shower, and either a leading-order or next-to-next-to-leading-order PDF set for the simulation of MPI and the beam remnants. Predictions utilizing the tunes are produced for event shape observables in electron-positron collisions, and for minimum-bias, inclusive jet, top quark pair, and Z and W boson events in proton-proton collisions, and are compared with data. Each of the new tunes describes the data at a reasonable level, and the tunes using a leading-order PDF for the simulation of MPI provide the best description of the data.

Deficiency for Lcn8 causes epididymal sperm maturation defects in mice

Lipocalin family members, LCN8 and LCN9, are specifically expressed in the initial segment of mouse caput epididymis. However, the biological functions of the molecules in vivo are yet to be clarified. In this study, CRISPR/Cas9 technology was used to generate Lcn8 and Lcn9 knockout mice, respectively. Lcn8-/- and Lcn9-/- male mice showed normal spermatogenesis and fertility. In the cauda epididymis of Lcn8-/- male mice, morphologically abnormal sperm was increased significantly, the proportion of progressive motility sperm was decreased, the proportion of immobilized sperm was elevated, and the sperm spontaneous acrosome reaction (AR) frequency was increased. Conversely, the knockout of Lcn9 did not have any effect on the ratio of morphologically abnormal sperm, sperm motility, and sperm spontaneous AR frequencies. These results demonstrated the role of LCN8 in maintaining the sperm quality in the epididymis, and suggested that the deficiency of LCN8 leads to epididymal sperm maturation defects.

EpsR Negatively Regulates Streptococcus mutans Exopolysaccharide Synthesis

Streptococcus mutans is considered the primary etiological agent of human dental caries. Glucosyltransferases (Gtfs) from S. mutans play important roles in the formation of biofilm matrix and the development of cariogenic oral biofilm. Therefore, Gtfs are considered an important target to prevent the development of dental caries. However, the role of transcription factors in regulating gtf expression is not yet clear. Here, we identify a MarR (multiple antibiotic resistance regulator) family transcription factor named EpsR (exopolysaccharide synthesis regulator), which negatively regulates gtfB expression and exopolysaccharide (EPS) production in S. mutans. The epsR in-frame deletion strain grew slowly, aggregated more easily in the presence of dextran, and displayed different colony morphology and biofilm structure. Notably, epsR deletion resulted in altered 3-dimensional biofilm architecture, increased water-insoluble EPS production, and upregulated GtfB protein content and activity. In addition, global gene expression profiling revealed differences in the expression levels of 69 genes in which gtfB was markedly upregulated. The conserved DNA motif for EpsR binding was determined by electrophoretic mobility shift assay and DNase I footprinting assays. Moreover, analysis of β-galactosidase activity suggested that EpsR acted as a repressor and inhibited gtfB expression. Taken together, our findings indicate that EpsR is an important transcription factor that regulates gtfB expression and EPS production in S. mutans. These results add new aspects to the complexity of regulating the expression of genes involved in the cariogenicity of S. mutans, which might lead to novel strategies to prevent the formation of cariogenic biofilm that may favor diseases.

A6 THE ROLE OF TUFT CELLS IN INTESTINAL HOMEOSTASIS

Background

Intestinal epithelial cells may actively regulate homeostasis by recognizing and responding to extracellular signals. One of these cell types, tuft cells, has been proposed to have a role in secretion, absorption, and reception. However, their role in the intestine has not been fully characterized. We have found that tuft cells express the SH2 domain-containing inositol 5’-phosphatase (SHIP), which was formerly thought to be restricted to hematopoietic cells. SHIP negatively regulates PI3K-mediated cell growth, proliferation, and activation. Tuft cells secrete IL-25, which activates group 2 innate lymphoid cells (ILC2s), leading to type 2 immune responses. Tuft cells may contribute to inflammation in the intestine by increasing ILC2 numbers and/or activation, leading to type II inflammation.

Aims

My hypothesis is that SHIP inhibits tuft cell responses to innate immune stimuli by limiting PI3K activation. Moreover, SHIP deficiency will increase tuft cell responses to commensal microbes, causing ILC2-mediated type II inflammation. To investigate the role of SHIP in tuft cell responses in vivo, I will use a tuft cell-specific SHIP deficient mouse in the dextran sodium sulfate (DSS)-induced colitis model.

Methods

We created a mouse deficient in SHIP only in intestinal tuft cells (Fabpcre x SHIPfl/fl) to investigate the impact of SHIP deficiency in tuft cells on responses to luminal microbes. Tuft cell-specific SHIP deficient mice (8-week-old) and their wild type littermates were subjected to DSS-induced colitis for 7 days. Clinical disease activity was monitored daily and gross pathology, including total colon length, was examined at the experimental endpoint. The concentrations of pro-inflammatory type I and type II cytokines were assessed in colonic tissue homogenates via ELISA.

Results

During DSS-induced colitis, mice with SHIP deficient tuft cells had increased disease activity compared to their wild type littermates, particularly evident in their weight loss. Mice with SHIP deficient tuft cells also had significantly shorter colons than their wild type littermates. IL-25 concentrations (produced by tuft cells) were increased in full thickness colon homogenates from mice with SHIP deficient tuft cells. In contrast, pro-inflammatory cytokines IL-1β, IL-6, and TNF did not differ between genotypes. Thus, increased tuft cell activity due to SHIP deficiency correlated with increased disease severity during DSS-induced colitis.

Conclusions

SHIP deficiency in intestinal tuft cells leads to increased tuft cell activity and exacerbated colitis during DSS treatment. Tuft cells may contribute to inflammation via IL-25 production, leading to increased type II inflammation by ILC2s. In future studies, we will target IL-25 in this model to determine whether increased tuft cell IL-25 production plays a causal role in disease exacerbation.

Funding Agencies

NSERC