Generation of SARS-CoV-2 spike receptor binding domain mutants and functional screening for immune evaders using a novel lentivirus-based system.

The emergence of rapid and continuous mutations of severe acute respiratory syndrome 2 (SARS-CoV-2) spike glycoprotein that increased with the Omicron variant points out the necessity to anticipate such mutations for conceiving specific and adaptable therapies to avoid another pandemic. The crucial target for the antibody treatment and vaccine design is the receptor binding domain (RBD) of the SARS-CoV-2 spike. It is also the site where the virus has shown its high ability to mutate and consequently escape immune response. We developed a robust and simple method for generating a large number of functional SARS-CoV-2 spike RBD mutants by error-prone PCR and a novel nonreplicative lentivirus-based system. We prepared anti-RBD wild type (WT) polyclonal antibodies and used them to screen and select for mutant libraries that escape inhibition of virion entry into recipient cells expressing human angiotensin-converting enzyme 2 and transmembrane serine protease 2. We isolated, cloned, and sequenced six mutants totally bearing nine mutation sites. Eight mutations were found in successive WT variants, including Omicron and other recombinants, whereas one is novel. These results, together with the detailed functional analyses of two mutants provided the proof of concept for our approach.

In Situ Construction of Zinc-Mediated Fe, N-Codoped Hollow Carbon Nanocages with Boosted Oxygen Reduction for Zn-Air Batteries.

The rational design of bifunctional oxygen electrocatalysts with unique morphology and luxuriant porous structure is significant but challenging for accelerating the reaction kinetics of rechargeable Zn-air batteries (ZABs). Herein, zinc-mediated Fe, N-codoped carbon nanocages (Zn-FeNCNs) are synthesized by pyrolyzing the polymerized iron-doped polydopamine on the surface of the ZIF-8 crystal polyhedron. The formation of the chelate between polydopamine and Fe serves as the covering layer to prevent the porous carbon nanocages from collapsing and boosts enough exposure and utilization of metal-based active species during carbonization. Furthermore, both the theoretical calculation and experimental results show that the strong interaction between polyhedron and polydopamine facilitates the evolution of high-activity zinc-modulated FeNx sites and electron transportation and then stimulates the excellent bifunctional catalytic activity for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). As expected, the Zn-air battery with Zn-FeNCNs as an air cathode displays a superior power density (256 mW cm-2 ) and a high specific capacity (813.3 mA h gZn-1 ), as well as long-term stability over 1000 h. Besides, when this catalyst is applied to the solid-state battery, the device exhibited outstanding mechanical stability and a high round-trip efficiency under different bending angles.

Defective autophagy contributes to endometrial epithelial-mesenchymal transition in intrauterine adhesions.

Intrauterine adhesions (IUA), characterized by endometrial fibrosis, is a common cause of uterine infertility. We previously demonstrated that partial epithelial-mesenchymal transition (EMT) and the loss of epithelial homeostasis play a vital role in the development of endometrial fibrosis. As a pro-survival strategy in maintaining cell and tissue homeostasis, macroautophagy/autophagy, conversely, may participate in this process. However, the role of autophagy in endometrial fibrosis remains unknown. Here, we demonstrated that autophagy is defective in endometria of IUA patients, which aggravates EMT and endometrial fibrosis, and defective autophagy is related to DIO2 (iodothyronine deiodinase 2) downregulation. In endometrial epithelial cells (EECs), pharmacological inhibition of autophagy by chloroquine (CQ) promoted EEC-EMT, whereas enhanced autophagy by rapamycin extenuated this process. Mechanistically, silencing DIO2 in EECs blocked autophagic flux and promoted EMT via the MAPK/ERK-MTOR pathway. Inversely, overexpression of DIO2 or triiodothyronine (T3) treatment could restore autophagy and partly reverse EEC-EMT. Furthermore, in an IUA-like mouse model, the autophagy in endometrium was defective accompanied by EEC-EMT, and CQ could inhibit autophagy and aggravate endometrial fibrosis, whereas rapamycin or T3 treatment could improve the autophagic levels and blunt endometrial fibrosis. Together, we demonstrated that defective autophagy played an important role in EEC-EMT in IUA via the DIO2-MAPK/ERK-MTOR pathway, which provided a potential target for therapeutic implications.Abbreviations: ACTA2/α-SMA: actin alpha 2, smooth muscle; AMPK: adenosine 5'-monophosphate-activated protein kinase; AKT/protein kinase B: AKT serine/threonine kinase; ATG: autophagy related; CDH1/E-cadherin: cadherin 1; CDH2/N-cadherin: cadherin 2; CQ: chloroquine; CTSD: cathepsin D; DIO2: iodothyronine deiodinase 2; DEGs: differentially expressed genes; EECs: endometrial epithelial cells; EMT: epithelial-mesenchymal transition; FN1: fibronectin 1; IUA: intrauterine adhesions; LAMP1: lysosomal associated membrane protein 1; LPS: lipopolysaccharide; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAPK: mitogen-activated protein kinase; MTOR: mechanistic target of rapamycin kinase; Rapa: rapamycin; SQSTM1/p62: sequestosome 1; T3: triiodothyronine; T4: tetraiodothyronine; TFEB: transcription factor EB; PBS: phosphate-buffered saline; TEM: transmission electron microscopy; TGFB/TGFß: transforming growth factor beta.

Algorithms to Predict Anxiety and Depression Among University Students in China After Analyzing Lifestyles and Sport Habits.

PURPOSE: This study aims to identify potential risk factors associated with anxiety or depression and propose algorithms to predict anxiety and depression especially among university students. METHODS: We included and analyzed 881 university students from eight colleges in China in November 2020. Student's basic information, lifestyles, sport habits, comorbidities, and mental health conditions were collected. Anxiety and depression were measured using the generalized anxiety disorder 7 (GAD-7) and the patient health questionnaire 9 (PHQ-9), respectively. A multiple linear regression analysis was used to assess the ability of 25 potential risk factors for predicting anxiety and depression, and significant risk factors were included in the algorithms. RESULTS: Of all the included students, 44.27% lived with mild or above anxious symptoms and 50.62% had mild or above depressive symptoms. According to the multiple linear regression model, grade levels (P<0.01), member of college sports dance team (P=0.05), sedentary time (P=0.02), exercise frequency (P<0.01), only child status (P=0.05), addiction of drinking (P<0.01), and prefer eating vegetable (P<0.01) were significantly associated with anxiety; grade levels (P<0.01), member of college sports dance team (P<0.01), sedentary time (P<0.01), exercise frequency (P<0.01), academic study period during free time (P=0.03), only child status (P<0.01), addiction of drinking (P<0.01), prefer eating vegetables (P<0.01), and main types of drinking water (P<0.01) were significantly associated with depression. Based on these significant factors, two algorithms were successfully developed, and two risk groups were created according to the algorithms. CONCLUSION: The study proposed two algorithms to calculate anxiety and depression, respectively, which can be useful tools to identify students with different risk of anxiety or depression. Effective measures are warranted to improve student's sport habits and healthy lifestyles in order to mitigate anxiety and depression, especially among students in the high risk group.

circPTPN12/miR-21-5 p/∆Np63α pathway contributes to human endometrial fibrosis.

Emerging evidence demonstrates the important role of circular RNAs (circRNAs) in regulating pathological processes in various diseases including organ fibrosis. Endometrium fibrosis is the leading cause of uterine infertility, but the role of circRNAs in its pathogenesis is largely unknown. Here, we provide the evidence that upregulation of circPTPN12 in endometrial epithelial cells (EECs) of fibrotic endometrium functions as endogenous sponge of miR-21-5 p to inhibit miR-21-5 p expression and activity, which in turn results in upregulation of ΔNp63α to induce the epithelial mesenchymal transition (EMT) of EECs (EEC-EMT). In a mouse model of endometrium fibrosis, circPTPN12 appears to be a cofactor of driving EEC-EMT and administration of miR-21-5 p could reverse this process and improve endometrial fibrosis. Our findings revealed that the dysfunction of circPTPN12/miR-21-5 p/∆Np63α pathway contributed to the pathogenesis of endometrial fibrosis.

Frequent Sports Dance May Serve as a Protective Factor for Depression Among College Students: A Real-World Data Analysis in China.

PURPOSE: This study aims to investigate the role of frequent sports dance in preventing mental disorders, including anxiety and depression, among college students using real-world data, and to further analyze potential risk factors associated with anxiety and depression. METHODS: We investigated 921 college students from eight universities in China. A survey was completed by 901 students and they were included in the analysis. The anxiety score was evaluated by the Generalized Anxiety Disorder 7-item (GAD-7) scale and the depression score was evaluated by the Patient Health Questionnaire-9 (PHQ-9). Subgroup comparisons were performed among frequent sports dance students and non-frequent sports dance students. RESULTS: Of all the students, 9.98% had moderate-to-severe anxiety and 14.65% students suffered from moderate-to-severe depression. Compared with non-frequent sports dance students, frequent sports dance students had significantly lower depression scores (P=0.04). According to the multiple logistic regression models, when potential confounding factors were all adjusted, frequent sports dance was also significantly associated with less depression (OR=0.55, 95% CI: 0.36-0.84, P<0.01). We also found that higher college grade levels (P<0.01), non-physical education students (P=0.02), higher body mass index (P=0.02), lower exercise frequency per week (P<0.01), addiction to drinking (P=0.02), and previous diagnosis of anxiety or depression in hospital (P<0.01) were significantly associated with more anxiety; higher college grade levels (P<0.01), addiction to drinking (P<0.01), preference for eating fried food (P=0.02), soda as the main source of drinking water (P=0.01), and previous diagnosis of anxiety or depression (P=0.03) were significantly associated with more depression, while higher exercise frequency per week (P<0.01), only-child status (P<0.01), and preference for eating vegetables (P=0.02) were significantly associated with less depression. CONCLUSION: Anxiety and depression are common among college students. Frequent sports dance may serve as a protective factor for preventing depression and it can be recommended for college students.

HMGA2-induced epithelial-mesenchymal transition is reversed by let-7d in intrauterine adhesions.

Intrauterine adhesions (IUAs), the leading cause of uterine infertility, are characterized by endometrial fibrosis. The management of IUA is challenging because the pathogenesis of the disease largely unknown. In this study, we demonstrate that the mRNA and protein levels of high mobility group AT-hook 2 (HMGA2) were increased by nearly 3-fold (P < 0.0001) and 5-fold (P = 0.0095) in the endometrial epithelial cells (EECs) of IUA patients (n = 18) compared to controls. In vivo and in vitro models of endometrial fibrosis also confirmed the overexpression of HMGA2 in EECs. In vitro cell experiments indicated that overexpression of HMGA2 promoted the epithelial-mesenchymal transition (EMT) while knockdown of HMGA2 reversed transforming growth factor-ß-induced EMT. A dual luciferase assay confirmed let-7d microRNA downregulated HMGA2 and repressed the pro-EMT effect of HMGA2 in vitro and in vivo. Therefore, our data reveal that HMGA2 promotes IUA formation and suggest that let-7d can depress HMGA2 and may be a clinical targeting strategy in IUA.

Proteolytic cleavage of Slit by the Tolkin protease converts an axon repulsion cue to an axon growth cue in vivo.

Slit is a secreted protein that has a canonical function of repelling growing axons from the CNS midline. The full-length Slit (Slit-FL) is cleaved into Slit-N and Slit-C fragments, which have potentially distinct functions via different receptors. Here, we report that the BMP-1/Tolloid family metalloprotease Tolkin (Tok) is responsible for Slit proteolysis in vivo and in vitro. In Drosophilatok mutants lacking Slit cleavage, midline repulsion of axons occurs normally, confirming that Slit-FL is sufficient to repel axons. However, longitudinal axon guidance is highly disrupted in tok mutants and can be rescued by midline expression of Slit-N, suggesting that Slit is the primary substrate for Tok in the embryonic CNS. Transgenic restoration of Slit-N or Slit-C does not repel axons in Slit-null flies. Slit-FL and Slit-N are both biologically active cues with distinct axon guidance functions in vivo Slit signaling is used in diverse biological processes; therefore, differentiating between Slit-FL and Slit fragments will be essential for evaluating Slit function in broader contexts.

Overexpression of histone deacetylase SIRT1 exerts an antiangiogenic role in diabetic retinopathy via miR-20a elevation and YAP/HIF1α/VEGFA depletion.

As a basic member of the Class III histone deacetylases, SIRT1 has been implicated in the occurrence and progression of diabetic retinopathy (DR). The current study aimed to investigate the roles of SIRT1/miR-20a/Yse-associated protein (YAP)/hypoxia-inducible factor 1 α (HIF1α)/vascular endothelial growth factor A (VEGFA) in DR. The expression of SIRT1 was initially determined through quantitative RT-PCR and Western blot analysis following the successful establishment of a DR mouse model, followed by detection of SIRT1 catalytic activity. Retinal microvascular endothelial cells (RMECs) were cultured in media supplemented with normal glucose (NG) or high glucose (HG). Thereafter, SIRT1 was either silenced or overexpressed in RMECs, after which EdU staining and Matrigel-based tube formation assay were performed to assess cell proliferation and tube formation. The binding relationship between YAP, HIF1α, and VEGFA was further illustrated using dual-luciferase reporter assay. Preretinal neovascular cell number was tallied with the IB4-positive vascular endothelial cells, as determined by immunofluorescence. SIRT1 was poorly expressed in mice with DR and HG-treated RMECs with low catalytic activity. The proliferation and tube formation capabilities of RMECs were elevated under HG conditions, which could be reversed following overexpression of SIRT1. SIRT1 was identified as positively regulating the expression of miR-20a with YAP detected as the key target gene of miR-20a. Our data suggested that YAP could upregulate VEGFA via induction of HIF1α. Moreover, SIRT1 overexpression strongly repressed RMEC proliferation and angiogenesis, which could be reversed via restoration of YAP/HIF1α/VEGFA expression. Taken together, the key findings of our study suggest that upregulation of SIRT1 inhibits the development of DR via miR-20a-induced downregulation of YAP/HIF1α/VEGFA.

ΔNp63α-induced DUSP4/GSK3ß/SNAI1 pathway in epithelial cells drives endometrial fibrosis.

Epithelial homeostasis plays an essential role in maintaining endometrial function. But the epithelial role in endometrial fibrosis has been less studied. Previously, we showed that ectopic expression of ΔNp63α is associated with fibrosis process and epithelial dysfunction in endometria of patients with intrauterine adhesions (IUAs). Since ΔNp63α is profoundly involved in maintaining the epithelial homeostasis, we hereby focused on its roles in regulating the function and phenotype of endometrial epithelial cells (EECs) in context of endometrial fibrosis. We identified a typical type 2 epithelial-to-mesenchymal transition (EMT) in EECs from IUA patients and this process was induced by the forced expression of ΔNp63α in EECs. In transcriptomic analysis, we found that diverse signaling pathways regulated by ΔNp63α were involved in pro-EMT. We demonstrated that the DUSP4/GSK-3ß/SNAI1 pathway was critical in transducing the pro-EMT signals initiated by ΔNp63α, while bFGF reversed ΔNp63α-induced EMT and endometrial fibrosis both in vitro and in vivo by blocking DUSP4/GSK3ß/SNAI1 pathway. Taken together, our findings are important to understand the molecular mechanisms of endometrial fibrosis and to provide potential therapeutic targets.

CSF1-associated decrease in endometrial macrophages may contribute to Asherman's syndrome.

PROBLEM: Asherman's syndrome (AS) is characterized by endometrial fibrosis leading to intrauterine adhesions and symptoms like hypomenorrhea, infertility, and recurrent pregnancy loss. Macrophages are key regulators of inflammation, tissue repair, regeneration, and fibrosis. However, the role of macrophages in AS remains unclear. METHOD OF STUDY: Endometrial biopsies of AS patients and controls were collected during the late proliferating phase of menstrual cycle. Fibrosis and proliferation markers were detected by Masson's trichrome staining and immunohistochemistry. Macrophages were examined by immunostaining and flow cytometry. The expression levels of CCL2, CSF1, CSF1R, and GM-CSF were detected by quantitative real-time polymerase chain reaction (q-PCR) and immunohistochemistry. A well-differentiated endometrial cell line Ishikawa (IK) was used for in vitro studies. Macrophages differentiating from THP-1 monocytic cells were polarized by IL-4/IL-13. Their culture supernatants (M(IL-4/13)-S) were applied to H2 O2 or bleomycin-damaged IK cells. RESULTS: In AS patients, endometrial stroma was replaced by fibrous tissue and cell proliferation was reduced. Macrophages in endometrial tissue were mainly alternative activated macrophages and their number was significantly decreased in AS patients. The CSF1 expression level was reduced in AS patients. M(IL-4/13)-S promoted the growth and migration of IK cells and inhibited H2 O2 -induced apoptosis. M(IL-4/13)-S protected IK cells from bleomycin-induced fibrosis. CONCLUSION: Macrophages are critical cells involved in the process of endometrial repair and fibrosis. The decreased amount of endometrial macrophages may be attributed to the reduced expression level of CSF1. Manipulation of macrophage activation/function may provide a novel therapeutic target for AS.

Vascular endothelial growth factor 165 inhibits pro-fibrotic differentiation of stromal cells via the DLL4/Notch4/smad7 pathway.

Endometrial fibrosis is the main pathological feature of Asherman's syndrome (AS), which is the leading cause of uterine infertility. Much is known about the expression of VEGF165 in luminal/glandular epithelial cells and stromal cells of the endometrium in normal menstrual cycles; however, less is known about the role and mechanism of VEGF165 in endometrial fibrosis. Herein, we report that VEGF165 is a key regulator in endometrial stromal cells to inhibit α-SMA and collagen 1 expression. Compared to human control subjects, patients with AS exhibited decreased VEGF165 expression in the endometrium along with increased fibrotic marker expression and collagen production. A fibrotic phenotype was shown in both mice with conditional VEGF reduction and VEGF165-deleted endometrial stromal cells. Exogenous VEGF165 could suppress TGFß1-induced α-SMA and collagen 1 expression in human primary endometrial stromal cells. However, this beneficial effect was hindered when the expression of smad7 or Notch4 was inhibited or when Notch signaling was blocked, suggesting that smad7 and Notch4 are essential downstream molecules for VEGFA functioning. Overall, our results uncover a clinical targeting strategy for VEGF165 to inhibit pro-fibrotic differentiation of stromal cells by inducing DLL4/Notch4/smad7, which paves the way for AS treatment.

Collagen-binding basic fibroblast growth factor improves functional remodeling of scarred endometrium in uterine infertile women: a pilot study.

Intrauterine adhesion (IUA) is a common cause of uterine infertility and one of the most severe clinical features is endometrial fibrosis namely endometrial scarring for which there are few cures currently. Blocked angiogenesis is the main pathological change in the scarred endometrium. The fibroblast growth factor 2 (bFGF), a member of FGF family, is usually applied to promote healing of refractory ulcer and contributes to angiogenesis of tissues. In this study, the sustained-release system of bFGF 100 µg was administrated around scarred endometrium guiding by ultrasound every 4 weeks in 18 patients (2-4 times). Results showed that after treatment, the menstrual blood volume, endometrial thickness and the scarred endometrial area were improved. Histological study showed blood vessel density increased obviously. Three patients (3/18) achieved pregnancy over 20 gestational weeks. Therefore, administrating the bFGF surrounding scarred endometrium may provide a new therapeutic approach for the patients with endometrial fibrosis.

Leukemia inhibitory factor promotes the regeneration of rat uterine horns with full-thickness injury.

Severe uterine injuries may lead to infertility or pregnancy complications. There is a lack of effective methods to restore the structure and function of seriously injured uteri. Leukemia inhibitory factor (LIF), which plays a crucial role in blastocyst implantation, promotes the process of regeneration after injury in several different tissues. In this study, we explored the effect of LIF on the regeneration of rat uterine horns following full-thickness injury. One hundred and twenty four female Sprague-Dawley rats were assigned to three groups, including a sham-operated group (n = 34 uterine horns), a PBS/collagen group (n = 90 uterine horns), and a LIF/collagen group (n = 124 uterine horns). The regenerated uterine horns were collected at 1, 2, 4, 8, or 12 weeks after the surgery. The results showed that LIF/collagen scaffolds increased the number of endometrial cells and neovascularization 2 weeks after uterine full-thickness defect in excision sites (p < 0.001 vs PBS/collagen). Eight weeks after the surgery, the number of endometrial glands was dramatically higher in the LIF/collagen scaffolds group (35.2 ± 4.1/field) than in the PBS/collagen scaffolds (15.1 ± 1.4/field). The percentage of a-smooth muscle actin (a-SMA)-positive areas in the LIF/collagen scaffolds (88.8% ± 9.8%) was also significantly higher than that in the PBS/collagen group (52.9% ± 3.7%). Moreover, LIF improved the pregnancy rate and fetus number. We also found that LIF inhibited the infiltration of inflammatory cells and down-regulated the pro-inflammatory cytokine IL-12 expression while up-regulating the anti-inflammatory cytokine IL-10 expression in the injured part of the uterine horns. Our results indicate that LIF promotes regeneration of the uterus after injury, and this is at least partially due to its immunomodulatory properties. In addition, it is worth to explore further the possibility for LIF/collagen to be an alternative therapeutic approach for uterine damage in the clinic in near future.

Simulation of generation and dynamics of polarization singularities with circular Airy beams.

The generation and dynamics of polarization singularities have been underresearched for years, while the focusing property of the topological configuration has not been explored much. In this paper, we simulated the generation of low-order polarization singularities with a circular Airy beam and explored the focusing property of the synthetic light field during propagation due to the autofocusing of the component. Our work researched the focusing properties of the polarization singularity configuration, which may help to develop its application prospect.

Condition for far-zone spectral isotropy of light transmitted from Young's pinholes scattering on a quasi-homogeneous medium.

The far-zone spectral isotropy of light transmitted from Young's pinholes on scattering from a quasi-homogeneous medium has been discussed. A sufficient condition for the far-zone spectral isotropy has been derived as a new scaling law. Our result not only is analogous with the scaling law for weak scattering in previous works but is also applicable for a more general situation where the incident light has an arbitrary spectral degree of coherence. More discussion about cross-spectral purity of the far field is presented.

Second-order moments of Schell-model beams with various correlation functions in atmospheric turbulence.

The general formulae for second-order moments of Schell-model beams with various correlation functions in atmospheric turbulence are derived and validated by the Bessel-Gaussian Schell-model beams and cosine-Gaussian-correlated Schell-model beams. Our finding shows that the second-order moments of partially coherent Schell-model beams are related to the second-order partial derivatives of source spectral degree of coherence at the origin. The formulae we provide are much more convenient to analyze and research propagation problems in turbulence.

Polarization properties of superposed vector Laguerre-Guassian beams during propagation.

We use analytical and numerical techniques to study the superposition of two vector Laguerre-Guassian (LG) beams. Vector LG beams contain rich polarization information and have many interesting intensity and polarization features. The composited electric field shows an inhomogeneous polarization distribution. We focus on looking for the distribution laws for the singularities obtained. The number and positions of singularity points are calculated and confirmed by numerical methods. We also study the fundamental cases for nonconcentric superposed vector LG beams and discover the difference distribution laws of several types of singular points in all the possible combinations.

Far-zone coherence changes of electromagnetic scattered field generated by an anisotropic particulate medium.

The far-zone scattered field generated by an anisotropic particulate medium with electromagnetic plane incident waves is discussed. The analytical expressions of the spectral density and spectral degree of coherence of the scattered field are derived, which show that the coherence properties of the scattered field depend on the characteristics of each particle and the distribution of particles. By simulations of two special cases, i.e., anisotropic random particles with isotropic determinate distribution and isotropic determinate particles with anisotropic random distribution, the properties of the medium and the polarization states of the incident wave play roles in the distribution of the spectral degree of coherence of the scattered field. Moreover, the general condition, anisotropic particles with anisotropic distribution, is briefly discussed. By comparing the results generated by different parameters, the coherence changes of scattered field are found in the scattered field.

Condition for far-zone spectral isotropy of light radiated from a quasi-homogeneous source scattering on a quasi-homogeneous random medium.

The far-zone spectral isotropy of light radiated from a secondary planar quasi-homogeneous (QH) source scattering on a QH medium has been discussed. Without assuming the specified function of incident light, a sufficient condition for the far-zone spectral isotropy has been expressed as a new scaling law, which is analogous with the scaling law for weak scattering in previous works. Special examples are discussed to validate the obtained scaling law.