Introduction:Thyroid eye disease (TED) is a prevalent autoimmune inflammatory condition in patients diagnosed with Graves' disease (GD). The lacrimal glands are implicated as an additional target organ of autoimmune reactions in TED, alongside orbital connective tissues. However, the underlying pathogenesis of lacrimal gland enlargement in TED and its associated symptoms and effective therapeutic strategies remain to be elucidated. This study aimed to investigate the ocular manifestations and immunological profiles of TED with lacrimal gland enlargement. Methods:This study collected patients diagnosed with TED, divided into the enlarged lacrimal gland (ELG) and the normal lacrimal gland (NLG) groups based on magnetic resonance imaging (MRI) measurement. Ocular manifestations, thyroid function tests, and immunological examinations of the peripheral blood were systematically compared between the two groups. Results:123 TED patients (NLG: ELG = 36: 87) were enrolled in this study. Patients in the ELG group exhibited worse proptosis, decreased tear film break-up time (TBUT), and increased Schirmer I test values, compared to the NLG group (P < 0.05), with no statistical difference in clinical activity score (CAS). Lacrimal gland enlargement in TED was accompanied by an elevation in thyroid peroxidase antibody (TPO-Ab) levels. Moreover, the proportions of CD8+ T cells and regulatory T (Treg) cells were remarkably elevated in the ELG group (P < 0.05). Correlation analyses demonstrated that serum TPO-Ab levels and Treg cell proportions were significantly correlated with lacrimal gland area. Further multivariate regression analyses confirmed that both TPO-Ab and Treg cells served as independent influencing factors for lacrimal gland enlargement in patients with TED. Conclusions:TED patients with enlarged lacrimal glands exhibited worse proptosis, unstable tear film, and excessive tearing. TPO-Ab and Treg cells were positively correlated with lacrimal gland enlargement in TED. Furthermore, Treg cell frequency emerged as a predictive biomarker for lacrimal gland involvement in TED patients.
To investigate the effect of retinal microglia on the quiescence-activation balance and angiogenesis potential of endothelial cells in diabetic retinopathy (DR). Retinal microglia from diabetic mice were isolated and cocultured with endothelial cells. The quiescence-activation status of endothelial cells was determined by flow cytometry, EdU staining and expressions of activation markers including P21 and CDK1, and the angiogenesis potential was detected by tube formation assays. RNA sequencing was performed to identify the critical gene, which was regulated by inhibiting or overexpressing lentiviruses transfection. The concentration of cholesterol and its effect on the status and function of endothelial cells, as well as the signal pathways activation, were measured. The critical m5C modification related protein was identified using Western blotting and lentiviruses transfection. Retinal microglia isolated from diabetic mice impeded quiescence but promoted the activation of endothelial cells, and then subsequently enhanced the angiogenesis potential of endothelial cells. Besides, the expression of squalene epoxidase (SQLE) was significantly increased in endothelial cells cocultured with retinal microglia isolated from diabetic mice. Inhibiting SQLE expression in endothelial cells restrained their activation levels and angiogenesis potential, and overexpressing SQLE activated endothelial cells to facilitate angiogenesis. Mechanistically, SQLE increased the concentration of cholesterol in endothelial cells, which promoted their activation via the PI3K-AKT signaling pathway. Moreover, NSUN2 increased the m5C modification level of SQLE and increased its stability, increasing the expression of SQLE in endothelial cells cocultured with retinal microglia isolated from diabetic mice. This study provides new perspectives on the interaction between microglia and endothelial cells involved in the pathogenesis of DR and elucidates the detailed mechanism of NSUN2-mediated m5C modification of SQLE to regulate cholesterol metabolism and signaling pathway activation.
Abstract Purpose To identify foveal structure-function topographic association and relationship in patients with idiopathic epiretinal membrane (ERM) related to ectopic inner foveal layer (EIFL). Methods This was a cross-sectional, observational study that involved 40 individuals with idiopathic ERM: 22 without EIFL (Group 1) and 18 with EIFL (Group 2). Quantitative foveal light sensitivity was measured using microperimetry, and foveal microstructure was assessed using spectral-domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA). Multiple indices of microvascular parameters of OCTA images were further processed using the AngioTool software. LASSO regression and quantile regression analyses were performed to identify the spatial distribution correlation between foveal light sensitivity and foveal microstructure parameters. Results Group 2 exhibited reduced light sensitivity across all parameters of microperimetry compared to Group 1 (P < 0.001). Additionally, the central foveal thickness, the percentage of ellipsoid zone disruption, and the foveal avascular zone area were significantly lower in Group 1 than in Group 2 (all P < 0.005). Compared to Group 1, the vessel density (VD) and perfusion density of the foveal region was significantly increased in Group 2 (P < 0.001). In contrast, Group 2 showed significantly decreased VD in the parafoveal region compared with Group 1 (P < 0.05). Significant differences in OCTA parameters including ‘total number of junctions’, ‘junction density’, ‘total vessel length’, ‘average vessel length’, ‘total number of end points’ were observed between Group 1 and Group 2 (all P < 0.01). The foveal light sensitivity was significantly positively correlated with VD in the parafoveal region and negatively correlated with EIFL alteration, best-corrected visual acuity and ellipsoid zone disruption [Log(λ) = − 0.18303, λ = 0.6561]. Conclusions The presence of EIFL and decreased VD in the parafoveal region, factors that collectively elevate the risk of disease progression, are significantly and independently correlated with reduced microperimetric retinal sensitivity in patients with idiopathic ERM.
Diabetic retinopathy (DR) is still the major cause of visual loss in working-aged people, one of the critical pathological processes are retinal microglia-mediated inflammation. Our previous study demonstrated that enhanced M1 microglial polarization was involved in retinal inflammation in DR, but the detailed mechanism needs further investigation. Circular RNAs (circRNAs) are important kind of noncoding RNAs involved in the regulation of various cell biological processes. Herein, the circRNA expression profiles of BV2 mouse microglia treated with or without glucose were detected, and a total of 347 differentially expressed circRNAs were identified in glucose-treated BV2 cells. The key circRNA mm9_circ_014683 increased after glucose stimulation. Inhibiting or overexpressing mm9_circ_014683 showed no effect on the proliferation and apoptosis of microglia. Inhibiting mm9_circ_014683 impeded M1 polarization and promoted M2 polarization, and overexpressing mm9_circ_014683 showed the opposite effect. A total of 216 differentially expressed genes were identified in mm9_circ_014683-knockdown BV2 cells, which were enriched in several signaling pathways, including the NFκB signaling pathway. Moreover, mm9_circ_014683 positively regulated the canonical, NFκB signaling pathway. Besides, mm9_circ_014683 was highly expressed in the retinal microglia of diabetic mice, and intraocular injection of Lv-circRNA inhibited M1 but enhanced M2 retinal microglial polarization. In conclusion, mm9_circ_014683 regulates microglial polarization through the canonical NFκB signaling pathway in diabetic retinopathy. This study may provide insight into the pathogenesis and treatment of DR.
Purpose: Lupus-like chronic graft-versus-host disease (cGVHD) has been previously described, but the ocular findings have not been elucidated. Recipient mice in a lupus-like cGVHD model manifested notable and persistent ocular surface phenotypes. Herein, we further explored immunopathogenic mechanisms underlying these ocular phenotypes. Methods: A previously described lupus-like cGVHD model was established by intraperitoneal injection of splenocytes from bm12 mice into C57BL/6J mice. Systemic findings were evaluated for the presence of splenomegaly, proteinuria, and autoantibodies. Comprehensive evaluations were conducted on ocular manifestations and immunopathological features in this model. Results: The lupus-like cGVHD model was successfully constructed 2 weeks post-transplantation. The recipient mice developed lupus-like phenotypes, including splenomegaly, proteinuria, and increased autoantibodies, and their ocular presentations included corneal epithelial defects and decreased tear secretion. Histological analysis revealed a reduction in corneal nerve fiber density and corneal endothelial cells, along with conjunctival fibrosis and loss of goblet cells. Moreover, cGVHD induced progressive aggravation of immune cell infiltration and fibrosis in the lacrimal glands. RNA-Sequencing (RNA-seq) results of the lacrimal glands demonstrated that the differentially expressed genes (DEGs) between the control and cGVHD groups were associated with GVHD pathways. Immune infiltration analysis using RNA-seq and flow cytometry confirmed that CD8+ T lymphocytes predominantly constituted the inflammatory infiltrating cells within the lacrimal glands. Conclusions: This lupus-like cGVHD model (bm12→C57BL/6J) exhibited persistent ocular surface manifestations, characterized by immune infiltration of CD8+ T lymphocytes in the lacrimal glands. Thus, this ocular cGVHD model may be used to explore the underlying mechanisms and discover novel therapeutic interventions.
This study aimed to investigate the expression of glucagon-like peptide 1 receptor (GLP-1R) in the lacrimal gland and explore the effects of topical application of GLP-1R agonist on lacrimal gland function in a murine model of type 1 diabetes. Tear secretion was evaluated using phenol red threads, RNA sequencing was used to explore gene expression profiles associated with hyperglycemia-induced lacrimal gland injuries, and histologic analysis was conducted to evaluate the degree of damage. The expression of GLP-1R in the lacrimal gland was first identified, and a down-regulation trend associated with diabetes was observed. RNA-sequencing data from lacrimal gland tissues revealed that differentially expressed genes were enriched in inflammatory response pathways. Histologic analysis demonstrated persistent hyperglycemia-induced infiltration of inflammatory cells and progressive fibrosis in the lacrimal gland, resulting in atrophy and diminished tear secretion. Topical application of liraglutide effectively attenuated inflammation and alleviated fibrosis, thus promoting tear production in diabetic mice. Additionally, local intervention with liraglutide promoted autophagy degradation function in the lacrimal gland. This study represents the first validation of GLP-1R expression in the lacrimal gland and its down-regulation induced by diabetes. Additionally, these findings demonstrate that topical administration of liraglutide eye drops, a GLP-1R agonist, can effectively mitigate hyperglycemia-induced damage in the lacrimal gland while enhancing tear secretion.
The urinary tract is constantly exposed to microorganisms. Host defense mechanisms in protection from microbial colonization and development of urinary tract infections require better understanding to control kidney infection. Here we report that the lectin collectin 11 (CL-11), particularly kidney produced, has a pivotal role in host defense against uropathogen infection. CL-11 was found in mouse urine under normal and pathological conditions. Mice with global gene ablation of Colec11 had increased susceptibility to and severity of kidney and to an extent, bladder infection. Mice with kidney-specific Colec11 ablation exhibited a similar disease phenotype to that observed in global Colec11 deficient mice, indicating the importance of kidney produced CL-11 for protection against kidney and bladder infection. Conversely, intravesical or systemic administration of recombinant CL-11 reduced susceptibility to and severity of kidney and bladder infection. Mechanism analysis revealed that CL-11 can mediate several key innate defense mechanisms (agglutination, anti- adhesion, opsonophagocytosis), and limit local inflammatory responses to pathogens. Furthermore, CL-11-mediated innate defense mechanisms can act on clinically relevant microorganisms including multiple antibiotic resistant strains. CL-11 was detectable in eight of 24 urine samples from patients with urinary tract infections but not detectable in urine samples from ten healthy individuals. Thus, our findings demonstrate that CL-11 is a key factor of host defense mechanisms in kidney and bladder infection with therapeutic potential for human application.
BackgroundDiabetic retinopathy (DR) is deemed a microangiopathy and neurodegenerative disorder, which is a primary reason of visual impairment in the world. Ferritinophagy is a critical regulator of ferroptosis and has a vital part in the etiopathogenesis of DR. Nevertheless, its molecular mechanism in DR remains to be expounded.MethodsThe GSE146615 dataset was adopted to identify ferritinophagy-related differentially expressed genes (FRDEGs). The interactions and biological functions of the genes were described by means of functional enrichment analysis (FEA). The enriched gene sets were analyzed utilizing gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA). Identification of hub genes was performed utilizing protein–protein interaction (PPI) analysis. mRNA–miRNA, mRNA–transcription factors (TF), mRNA–drugs, mRNA–RNA-binding proteins (RBP) interaction networks were constructed. In addition, datasets GSE60436 and GSE94019 were utilized for validation. The diagnostic performance of FRDEGs was assessed by means of receiver-operating characteristic curve monofactor analysis, followed by immune infiltration analysis. Lastly, quantitative real-time polymerase chain reaction (qRT-PCR) was implemented to analyze the validation of genes.ResultsIn total, the identification of eight FRDEGs was completed utilizing differential expression analysis. FEA mainly implicated the autophagy of mitochondrion, mitochondrion disassembly, autophagosome assembly, and organization pathways. GSEA and GSVA mainly implicated the interferon alpha response, ultraviolet response up, interferon gamma response, apical junction, pical surface, and allograft rejection pathways. BECN1 and HERC2 displayed high diagnostic accuracies in validation sets. Immune infiltration analysis revealed that several immune cells related to ferritinophagy may be play potential roles in DR. Finally, qRT-PCR was utilized to validate the upregulated expression of BECN1 as well as the downregulated expression of BCAT2 and ATG7 in the DR model.ConclusionBECN1, HERC2, ATG7, and BCAT2 act as potential biomarkers for DR and might regulate ferritinophagy and the immune microenvironment to influence its development and progression. This research can provide new insights into pathogenesis of DR related to ferritinophagy.
Collectin-11 (CL-11) is a recently described soluble C-type lectin that has distinct roles in embryonic development, host defence, autoimmunity, and fibrosis. Here we report that CL-11 also plays an important role in cancer cell proliferation and tumor growth. Melanoma growth was found to be suppressed in Colec11–/– mice in a s.c. B16 melanoma model. Cellular and molecular analyses revealed that CL-11 is essential for melanoma cell proliferation, angiogenesis, establishment of more immunosuppressive tumor microenvironment, and the reprogramming of macrophages to M2 phenotype within melanomas. In vitro analysis revealed that CL-11 can activate tyrosine kinase receptors (EGFR, HER3) and ERK, JNK, and AKT signaling pathways and has a direct stimulatory effect on murine melanoma cell proliferation. Furthermore, blockade of CL-11 (treatment with L-fucose) inhibited melanoma growth in mice. Analysis of open data sets revealed that COLEC11 gene expression is upregulated in human melanomas and that high COLEC11 expression has a trend toward poor survival. CL-11 also had direct stimulatory effects on human tumor cell proliferation in melanoma and several other types of cancer cells in vitro. Overall, our findings provide the first evidence to our knowledge that CL-11 is a key tumor growth–promoting protein and a promising therapeutic target in tumor growth.
BackgroundTo investigate the role of microglia polarization in the pathogenesis of diabetic retinopathy, and study the mechanism of ALKBH5-mediated m(6)A modification of A20 of retinal microglia polarization. MethodsDiabetics rats were constructed and the M1/M2 polarization of retinal microglia was determined using immunofluorescence, flow cytometry, and quantitative real-time PCR (qRT-PCR). Glucose at different concentrations was added to treat the microglia, and the polarization rate was detected. RNA sequencing was performed to identify the differentially expressed gene in glucose treated microglia, and A20 expression was confirmed by qRT-PCR and western blotting. Lentiviruses encoding shRNA for A20 or overexpressing A20 were constructed to clarify the role of A20 in microglia polarization in vitro and vivo. N-6-methyladenosine (m(6)A) modification level and degradation rate of A20 were determined and m(6)A related proteins were detected. ResultsDiabetics rats showed a higher M1 polarization rate but lower M2 polarization rate of retinal microglia. With the increase of glucose concentration, microglia tend to polarize into M1 inflammatory type rather than M2 anti-inflammatory type. Shown by RNA sequencing, glucose treated microglia showed a differentially expressed gene profile, which was enriched in kinds of inflammatory categories and pathways. A20 expression was lower in microglia with glucose treatment, which was demonstrated to negatively regulate the M1 polarization. Moreover, intraocular injection of A20-overexpression lentiviruses (OE-A20) rectified the enhanced M1 retinal microglia polarization of diabetes rats. The higher m(6)A modification level and faster degradation rate of A20 was observed in glucose treated microglia, which was mediated by m(6)A demethylase ALKBH5. ConclusionLower expression A20 resulted in the enhanced M1 polarization of retinal microglia in diabetic retinopathy, which was caused by ALKBH5 mediated m(6)A modification. This study may provide new perspectives on not only the pathogenesis but also the diagnosis and treatment for diabetic retinopathy.
Acute retinal necrosis (ARN) is a clinical syndrome featuring severe vitritis and occlusive vasculitis characterised by full thickness necrotising retinitis. ARN is usually caused by an acute infection by either varicella zoster virus or herpes simplex virus, rarely cytomegalovirus (CMV). ARN often occurs in healthy adults; occasionally affecting immunocompromised patients with poor prognosis including significant visual loss and detachment of the atrophic retina regardless of antiviral treatment. We presented a man in his early 30s with a history of left eye floaters and blurred vision. He was diagnosed with T-cell acute lymphoblastic leukaemia 1 year ago and treated with chemotherapy and allogenic haematopoietic stem cell transplant 5 months ago. His clinical diagnosis was left eye ARN caused by acute viral infection with CMV being the most likely cause, which is rarely seen in immunocompromised patients. Our case highlighted a diagnostic and therapeutic challenge in the absence of guideline or evidence-based literature to follow.
BACKGROUND:Human tumors are highly heterogeneous at the cellular, molecular, genetic and functional levels. Tumor heterogeneity has tremendous impact on cancer progression and treatment responses. However, the mechanisms for tumor heterogeneity have been poorly understood due to the lack of experimental models.METHODS:This study provides a novel exploration and analysis of the impacts of cellular and molecular heterogeneity of human lung epithelial cells on their malignant transformation following chronic exposure to cigarette smoke extracts.RESULTS:The ability of cigarette smoke extract (CSE) to cause malignant transformation of the human bronchial epithelial cells (16HBE) is dependent on the sizes of the cells. Epithelial-mesenchymal transition (EMT) plays an important role in this process. Mechanistically, CSE-induced malignant transformation of 16HBE cells was closely linked to the reduced relative telomere length of the larger 16HBE cells, thereby up-regulation of the expression of stemness genes.CONCLUSIONS:These findings provide novel insights for understanding the impact of cellular heterogeneity in lung cancer development. The in vitro transformation model described in this study could be extrapolated to studying the pathogenesis of other malignancies, as well as for mechanistic studies that are not feasible in vivo.
Alzheimer's disease (AD) is a neurodegenerative disease that can be induced by heavy metals such as lead. However, there is limited information on the role of blood-brain barrier (BBB) in lead induced AD-like pathology. This study investigates the potential mechanism of lead exposure aggravating the progression of Alzheimer's disease in mice through the BBB. 200 mg/L and 500 mg/L lead acetate were given to C57BL/6J and APP/PS1 mice through drinking water from a week before mating, until the offspring were 7-months-old. 8 female juvenile mice in each group were selected for this investigation. Lead exposure increased blood lead concentration which revealed the internal exposure level, accelerated A beta 1-42 deposition in APP/PS1 mouse cortexes and abnormal change in Zonula Occludin-1 (ZO-1) and Claudin-5 protein. It also increased the expression of p-tau in both the C57BL/6J and APP/PS1 mice, and decreased mRNA and protein expression in lowdensity lipoprotein receptor (LRP-1). Additionally, it increased the mRNA and protein expression of amyloid beta precursor protein (APP) and beta secretase 1 (BACE-1). The activated astrocytes increased in the brains of APP/PS1 mice, and coalesced around the A beta 1-42 deposition after lead exposure. The main vessels in deuto-cerebrum were attached with A beta 1-42 deposition. These results offer insight into the mechanism of preventing lead induced AD through cerebrovascular pathways.
Collectin-11 is a recently described soluble C-type lectin, a pattern recognition molecule of the innate immune system that has distinct roles in host defense, embryonic development, and acute inflammation. However, little is known regarding the role of collectin-11 in tissue fibrosis. Here, we investigated collectin-11 in the context of renal ischemia-reperfusion injury. Compared with wild-type littermate controls, Collec11 deficient (CL-11-/- ) mice had significantly reduced renal functional impairment, tubular injury, renal leukocyte infiltration, renal tissue inflammation/fibrogenesis, and collagen deposition in the kidneys after renal ischemia-reperfusion injury. In vitro, recombinant collectin-11 potently promoted leukocyte migration and renal fibroblast proliferation in a carbohydrate-dependent manner. Additionally, compared with wild-type kidney grafts, CL-11-/-mice kidney grafts displayed significantly reduced tubular injury and collagen deposition after syngeneic kidney transplant. Our findings demonstrate a pathogenic role for collectin-11 in the development of tubulointerstitial fibrosis and suggest that local collectin-11 promotes this fibrosis through effects on leukocyte chemotaxis and renal fibroblast proliferation. This insight into the pathogenesis of tubulointerstitial fibrosis may have implications for CKD mediated by other causes as well.
Complement receptor 3 (CR3) is expressed abundantly on natural killer (NK) cells; however, whether it plays roles in NK cell-dependent tumor surveillance is largely unknown. Here, we show that CR3 is an important negative regulator of NK cell function, which has negative impact on tumor surveillance. Mice deficient in CR3 (CD11b(-/-) mice) exhibited a more activated NK phenotype and had enhanced NK-dependent tumor killing. In a B16-luc melanoma-induced lung tumor growth and metastasis model, mice deficient in CR3 had reduced tumor growth and metastases, compared with WT mice. In addition, adaptive transfer of NK cells lacking CR3 (into NK-deficient mice) mediated more efficient suppression of tumor growth and metastases, compared with the transfer of CR3 sufficient NK cells, suggesting that CR3 can impair tumor surveillance through suppression of NK cell function. In vitro analyses showed that engagement of CR3 with iC3b (classical CR3 ligand) on NK cells negatively regulated NK cell activity and effector functions (i.e. direct tumor cell killing, antibody-dependent NK-mediated tumor killing). Cell signaling analyses showed that iC3b stimulation caused activation of Src homology 2 domain-containing inositol-5-phosphatase-1 (SHIP-1) and JNK, and suppression of ERK in NK cells, supporting that iC3b mediates negative regulation of NK cell function through its effects on SHIP-1, JNK, and ERK signal transduction pathways. Thus, our findings demonstrate a previously unknown role for CR3 in dysregulation of NK-dependent tumor surveillance and suggest that the iC3b/CR3 signaling is a critical negative regulator of NK cell function and may represent a new target for preserving NK cell function in cancer patients and improving NK cell-based therapy.
In this paper, we report previously unknown roles for collectin-11 (CL-11, a soluble C-type lectin) in modulating the retinal pigment epithelial (RPE) cell functions of phagocytosis and cytokine production. We found that CL-11 and its carbohydrate ligand are expressed in both the murine and human neural retina; these resemble each other in terms of RPE and photoreceptor cells. Functional analysis of murine RPE cells showed that CL-11 facilitates the opsonophagocytosis of photoreceptor outer segments and apoptotic cells, and also upregulates IL-10 production. Mechanistic analysis revealed that calreticulin on the RPE cells is required for CL-11-mediated opsonophagocytosis whereas signal-regulatory protein α and mannosyl residues on the cells are involved in the CL-11-mediated upregulation of IL-10 production. This study is the first to demonstrate the role of CL-11 and the molecular mechanisms involved in modulating RPE cell phagocytosis and cytokine production. It provides a new insight into retinal health and disease and has implications for other phagocytic cells.
C5a receptor 1 (C5aR1) is a G protein-coupled receptor for C5a and also an N-linked glycosylated protein. In addition to myeloid cells, C5aR1 is expressed on epithelial cells. In this study, we examined the role of C5aR1 in bacterial adhesion/colonization of renal tubular epithelium and addressed the underlying mechanisms of this role. We show that acute kidney infection was significantly reduced in mice with genetic deletion or through pharmacologic inhibition of C5aR1 following bladder inoculation with uropathogenic E. coli (UPEC). This was associated with reduced expression of terminal α-mannosyl residues (Man; a ligand for type 1 fimbriae of E. coli) on the luminal surface of renal tubular epithelium and reduction of early UPEC colonization in these mice. Confocal microscopy demonstrated that UPEC bind to Man on the luminal surface of renal tubular epithelium. In vitro analyses showed that C5a stimulation enhances Man expression in renal tubular epithelial cells and subsequent bacterial adhesion, which, at least in part, is dependent on TNF-α driven by C5aR1-mediated intracellular signaling. Our findings demonstrate a previously unknown pathogenic role for C5aR1 in acute pyelonephritis, proposing a potentially novel mechanism by which C5a/C5aR1 signaling mediates upregulation of carbohydrate ligands on renal tubules to facilitate UPEC adhesion.