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Objective: To investigate the relationship between serum a proliferation-inducing ligand (APRIL), leucine-rich a-2 glycoprotein 1 (LRG1), multiligand proteoglycan-1 (Syndecan-1) and renal function and short-term prognosis in patients with sepsis combined with acute kidney injury (AKI). Methods: 247 patients with sepsis admitted to Jinan Fifth People's Hospital from January 2021 to January 2023 were selected, and patients were divided into non-AKI group (122 cases) and AKI group (125 cases) according to whether AKI was combined, patients with sepsis combine with AKI were divided into death group and survival group according to the 30 days clinical outcome. Serum APRIL, LRGI and Syndecan-1 were detected by enzyme-linked immunosorbent assay, and renal function indexes [urinary albumin/creatinine ratio (UACR), estimated glomerular filtration rate (eGFR)] were calculated. The correlation between serum APRIL, LRGI, Syndecan-1 and UACR and eGFR in patients with sepsis combine with AKI were analyzed by Spearman correlation analysis. The influencing factors of short-term prognosis in patients with sepsis combine with AKI were analyzed by multivariate Logistic regression, the predictive value of serum APRIL, LRG1 and Syndecan-1 levels for short-term prognosis in patients with sepsis combine with AKI were analyzed by receiver operating characteristic (ROC) curve. Results: The levels of serum APRIL, LRG1, Syndecan-1 and UACR in AKI group were higher than those in non-AKI group, and eGFR was lower than that in non-AKI group (P<0.05). Spearman correlation analysis showed that, serum APRIL, LRG1 and Syndecan-1 were positively correlated with UACR and negatively correlated with eGFR in patients with sepsis combine with AKI (P<0.05). The 30 day mortality rate of 125 patients with sepsis combine with AKI was 40.80%. The levels of serum APRIL, LRG1, Syndecan-1 and UACR in death group were higher than those in survival group, and eGFR was lower than that in survival group (P<0.05). Multivariate Logistic regression analysis showed that, the increase of acute physiology and chronic health evaluation II (APACHE II) score, sequential organ failure assessment (SOFA) score, UACR, APRIL, LRG1 and Syndecan-1 were independent risk factors for short-term prognosis in patients with sepsis combine with AKI, and the increase of eGFR was an independent protective factor (P<0.05). The area under the curve of combined prediction of serum APRIL, LRG1 and Syndecan-1 levels was 0.908, which was greater than that of serum APRIL, LRG1 and Syndecan-1 levels alone. Conclusion: The increase of serum APRIL, LRG1 and Syndecan-1 levels are closely relate to the decrease of renal function in patients with sepsis combine with AKI, and are independent risk factors for poor short-term prognosis in patients with sepsis combined with AKI. The combination of serum APRIL, LRG1 and Syndecan-1 levels has a high value in predicting the short-term prognosis in patients with sepsis combine with AKI. [ABSTRACT FROM AUTHOR]

Atherosclerosis is a chronic inflammatory disease of the arterial wall characterized by the accumulation of cholesterol-rich lipoproteins in macrophages. How macrophages commit to proinflammatory polarization under atherosclerosis conditions is not clear. Report here that the level of a circulating protein, leucine-rich alpha-2 glycoprotein 1 (LRG1), is elevated in the atherosclerotic tissue and serum samples from patients with coronary artery disease (CAD). LRG1 stimulated macrophages to proinflammatory M1-like polarization through the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK) pathways. The LRG1 knockout mice showed significantly delayed atherogenesis progression and reduced levels of macrophage-related proinflammatory cytokines in a high-fat diet-induced Apoe-/- mouse atherosclerosis model. An anti-LRG1 neutralizing antibody also effectively blocked LRG1-induced macrophage M1-like polarization in vitro and conferred therapeutic benefits to animals with ApoE deficiency-induced atherosclerosis. LRG1 may therefore serve as an additional biomarker for CAD and targeting LRG1 could offer a potential therapeutic strategy for CAD patients by mitigating the proinflammatory response of macrophages. [ABSTRACT FROM AUTHOR]

Leucine-rich α-2 glycoprotein 1 (LRG1), a secreted glycoprotein, has been identified as significantly upregulated in renal fibrosis, potentially exacerbating the condition by enhancing TGF-β-Smad3-dependent signaling pathways. Herein, utilizing our developed LRG1-targeting peptide for LRG1 recruitment and lenalidomide for E3 ubiquitin ligase engagement, we developed an advanced proteolysis targeting chimera, ET TAC-2, specifically designed for LRG1 degradation. Our cellular degradation assays validated that ET TAC-2 effectively degraded LRG1 through a proteasome-dependent mechanism, achieving halfmaximal degradation at a concentration of 8.38 μM. Furthermore, anti-fibrotic experiments conducted both in vitro and in vivo revealed that ET TAC-2 efficiently induced LRG1 degradation in fibrotic kidneys. This action effectively inhibited the TGF-β-Smad3 signaling pathway and diminished the secretion of fibrosis-associated proteins, consequently attenuating the progression of renal fibrosis. Our study highlights the pivotal role of LRG1 in renal fibrosis and positions ET TAC-2 as a promising therapeutic candidate for targeted LRG1 intervention. [ABSTRACT FROM AUTHOR]

Introduction Cigarette smoking is one of the most important causes of COPD and could induce the apoptosis of pulmonary microvascular endothelial cells (PMVECs). The conditional knockout of LRG1 from endothelial cells reduced emphysema in mice. However, the mechanism of the deletion of LRG1 from endothelial cells rescued by cigarette smoke (CS) induced emphysema remains unclear. This research aimed to demonstrate whether LRG1 promotes the apoptosis of PMVECs through KLK10 in COPD. Methods Nineteen patients were divided into three groups: control non-COPD (n=7), smoker non-COPD (n=7), and COPD (n=5). The emphysema mouse model defined as the CS exposure group was induced by CS exposure plus cigarette smoke extract (CSE) intraperitoneal injection for 28 days. Primary PMVECs were isolated from the mouse by magnetic bead sorting method via CD31-Dynabeads. Apoptosis was detected by western blot and flow cytometry. Results LRG1 was increased in lung tissue of COPD patients and CS exposure mice, and CSE-induced PMVECs apoptosis model. KLK10 was over-expressed in lung tissue of COPD patients and CS exposure mice, and CSE-induced PMVECs apoptosis model. LRG1 promoted apoptosis in PMVECs. LRG1 knockdown reversed CSE-induced apoptosis in PMVECs. The mRNA and protein expression of KLK10 were increased after over-expressed LRG1 in PMVECs isolated from mice. Similarly, both the mRNA and protein levels of KLK10 were decreased after LRG1 knockdown in PMVECs. The result of co-immunoprecipitation revealed a protein-protein interaction between LRG1 and KLK10 in PMVECs. KLK10 promoted apoptosis via the down-regulation of Bcl-2/Bax in PMVECs. KLK10 knockdown could reverse CSE-induced apoptosis in PMVECs. Conclusions LRG1 promotes apoptosis via up-regulation of KLK10 in PMVECs isolated from mice. KLK10 promotes apoptosis via the down-regulation of Bcl-2/ Bax in PMVECs. There was a direct protein-protein interaction between LRG1 and KLK10 in PMVECs. Our novel findings provide insights into the understanding of LRG1/KLK10 function as a potential molecule in COPD.

Objective To investigate the role of lipopolysaccharide(LPS)in regulating the inflammatory response of neutrophil through the leucine-rich α-2 glycoprotein 1(LRG1)/ Rho-associated protein kinase(ROCK1)signaling. Methods HL-60 cells were treated with 1 μmol/L all-trans retinoic acid(ATRA)and 12.5 μL/mL dimethyl sulfoxide(DMSO)for 72 h and 96 h, and the morphological changes were observed by Wright-Giemsa staining. The expression of CD11b was detected by flow cytometry. LPS induced the activation of dHL-60 and human peripheral blood neutrophils. The transcription and secretion levels of LRG1, ROCK1 and inflammatory cytokines were detected by qPCR and ELISA, respectively. The expression levels of LRG1 and ROCK1 after the activation of dHL-60 were detected by Western blotting. Furthermore, dHL-60 was treated with the recombinant protein LRG1 and ROCK1 inhibitor Y-27632; the transcription levels of inflammatory cytokines were detected by qPCR. Results Neutrophils were activated by LPS. The expression levels of LRG1 and ROCK1 were significantly increased, and the transcription levels of inflammatory cytokines were significantly increased. The recombinant protein LRG1 activated dHL-60 in vitro, and the transcription levels of ROCK1 and inflammatory cytokines were significantly increased. Using the ROCK1 inhibitor Y-27632, the production levels of inflammatory cytokines were significantly reduced. Conclusion LPS can regulate the production levels of neutrophil inflammatory cytokines through activating the LRG1/ROCK1 signaling, thus exacerbating the inflammatory response. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The aim of this prospective, single-center cohort study was to analyze serum leucine-rich a-2-glycoprotein-1 (LRG1) expression in patients with acute cholecystitis (AC) and to investigate its variation depending on symptom duration. PATIENTS AND METHODS: Participants were divided into patients with AC and a healthy control group. At the time of diagnosis, blood samples were collected, and symptom onset times were questioned. Collected serum LRG1 levels were measured. RESULTS: 30 patients and 30 healthy volunteers were included in the study. LRG1 (p=0.008), white blood cells (WBC) (p<0.001), platelet (p=0.003), neutrophil (p<0.001), lymphocyte (p=0.001), and CRP (p=0.014) were significantly different in AC patients vs. the control group. When the correlations of serum laboratory values with the time of onset of symptoms were compared, LRG1 (p<0.001) was significantly correlated, while no significant correlation was observed in C-reactive protein (CRP) (p=0.572), WBC (p=0.155), and neutrophil (p=0.155). CONCLUSIONS: LRG1 expression increases after 24 hours in AC patients. Due to its correlation with symptom duration, we believe it can be helpful for timing cholecystectomy. [ABSTRACT FROM AUTHOR]

Abstract Background Currently, no useful serum markers exist for clear cell renal cell carcinoma (ccRCC), making early detection challenging as diagnosis relies solely on imaging tests. Radiation exposure is also a concern due to multiple required CT examinations during treatment. Renal cell carcinoma (RCC) histological types include ccRCC and non-clear cell RCC (non-ccRCC); however, treatment response to medications varies which necessitates accurate differentiation between the two. Therefore, we aimed to identify a novel serum marker of RCC. Increased LRG1 expression in the serum has been demonstrated in multiple cancer types. However, the expression of LRG1 expression in the serum and cancer tissues of patients with RCC has not been reported. Since ccRCC is a hypervascular tumor and LRG1 is capable of accelerating angiogenesis, we hypothesized that the LRG1 levels may be related to ccRCC. Therefore, we examined LRG1 expression in sera from patients with RCC. Methods Using an enzyme-linked immunosorbent assay, serum levels of leucine-rich-alpha-2-glycoprotein 1 (LRG1) were measured in 64 patients with ccRCC and 22 patients non-ccRCC who underwent radical or partial nephrectomy, as well as in 63 patients without cancer. Results Median values of serum LRG1 and their inter-quartile ranges were 63.2 (42.8–94.2) µg/mL in ccRCC, 23.4 (17.7–29.6) µg/mL in non-ccRCC, and 36.0 (23.7–56.7) µg/mL in patients without cancer, respectively (ccRCC vs. non-ccRCC or patients without cancer: P

Background: Currently, no useful serum markers exist for clear cell renal cell carcinoma (ccRCC), making early detection challenging as diagnosis relies solely on imaging tests. Radiation exposure is also a concern due to multiple required CT examinations during treatment. Renal cell carcinoma (RCC) histological types include ccRCC and non-clear cell RCC (non-ccRCC); however, treatment response to medications varies which necessitates accurate differentiation between the two. Therefore, we aimed to identify a novel serum marker of RCC. Increased LRG1 expression in the serum has been demonstrated in multiple cancer types. However, the expression of LRG1 expression in the serum and cancer tissues of patients with RCC has not been reported. Since ccRCC is a hypervascular tumor and LRG1 is capable of accelerating angiogenesis, we hypothesized that the LRG1 levels may be related to ccRCC. Therefore, we examined LRG1 expression in sera from patients with RCC. Methods: Using an enzyme-linked immunosorbent assay, serum levels of leucine-rich-alpha-2-glycoprotein 1 (LRG1) were measured in 64 patients with ccRCC and 22 patients non-ccRCC who underwent radical or partial nephrectomy, as well as in 63 patients without cancer. Results: Median values of serum LRG1 and their inter-quartile ranges were 63.2 (42.8–94.2) µg/mL in ccRCC, 23.4 (17.7–29.6) µg/mL in non-ccRCC, and 36.0 (23.7–56.7) µg/mL in patients without cancer, respectively (ccRCC vs. non-ccRCC or patients without cancer: P < 0.001). C-reactive protein (CRP) levels (P = 0.002), anemia (P = 0.037), hypercalcemia (P = 0.023), and grade (P = 0.031) were independent predictors of serum LRG1 levels in ccRCC. To assess diagnostic performance, the area under the receiver operating characteristic curve of serum LRG1 was utilized to differentiate ccRCC from non-cancer and non-ccRCC, with values of 0.73 (95% CI, 0.64–0.82) and 0.91 (95% CI, 0.82–0.96), respectively. Conclusions: LRG1 served as a serum marker associated with inflammation, indicated by CRP, anemia, hypercalcemia, and malignant potential in ccRCC. Clinically, serum LRG1 levels may assist in differentiating ccRCC from non-ccRCC with excellent diagnostic accuracy. [ABSTRACT FROM AUTHOR]

Most meningiomas, which are frequent central nervous system tumors, are classified as World Health Organization (WHO) grade 1 because of their slow‐growing nature. However, the recurrence rate varies and is difficult to predict using conventional histopathological diagnoses. Leucine‐rich α‐2 glycoprotein 1 (LRG1) is involved in cell signal transduction, cell adhesion, and DNA repair and is a predictive biomarker in different malignant tumors; however, such a relationship has not been reported in meningiomas. We examined tissue microarrays of histological samples from 117 patients with grade 1 and 2 meningiomas and assessed their clinical and pathological features, including expression of LRG1 protein. LRG1‐high meningiomas showed an increased number of vessels with CD3‐positive cell infiltration (P = 0.0328) as well as higher CD105‐positive vessels (P = 0.0084), as compared to LRG1‐low cases. They also demonstrated better progression‐free survival (hazard ratio [HR] 0.11, 95% confidence interval [CI] 0.016–0.841) compared to LRG1‐low patients (P = 0.033). Moreover, multivariate analysis indicated that high LRG1 expression was an independent prognostic factor (HR, 0.13; 95% CI, 0.018–0.991; P = 0.049). LRG1 immunohistochemistry may be a convenient tool for estimating the prognosis of meningiomas in routine practice. Further studies are required to elucidate the key role of LRG1 in meningioma progression. [ABSTRACT FROM AUTHOR]

Implant loosening is a severe complication after total joint replacement. Here, differential diagnosis between septic and aseptic cases is crucial for further surgical treatment, but low-grade periprosthetic joint infections (PJIs) in particular remain a challenge. In this study, we analyzed the synovial fluid proteome of 21 patients undergoing revision surgery for septic (eight cases) or aseptic (thirteen cases) implant failure using LC-MS/MS to identify potential new biomarkers as future diagnostic tools. Staphylococci were found in four cases, Streptococci in two cases, Serratia marcescens and Cutibacterium acnes in one case. Proteomic analysis of the synovial fluid resulted in the identification of 515 different proteins based on at least two peptides. A statistical comparison revealed 37 differentially abundant proteins (p < 0.05), of which 17 proteins (46%) showed a higher abundance in the septic group. The proteins with the highest fold change included the known marker proteins c-reactive protein (7.57-fold) and the calprotectin components protein S100-A8 (4.41-fold) and protein S100-A9 (3.1-fold). However, the protein with the highest fold change was leucine-rich alpha-2-glycoprotein 1 (LRG1) (9.07-fold), a currently discussed new biomarker for inflammatory diseases. Elevated LRG1 levels could facilitate the diagnosis of PJI in the future, but their significance needs to be further investigated. [ABSTRACT FROM AUTHOR]

Objective: To investigate the relationship between serum leucine-rich alpha-2 glycoprotein 1 (LRG1), glucose-regulated protein 78 (GRP78) and secondary acute lung injury (ALI) in patients with emergency sepsis. Methods: 155 patients with emergency sepsis who were treated in the emergency intensive care unit (EICU) of our hospital from January 2021 to October 2022 were retrospectively selected as observation group, patients were divided into ALI group (43 cases) and non-ALI group (112 cases) according to whether secondary ALI occurred, and 100 healthy subjects in our hospital during the same period were selected as control group. The levels of serum LRG1 and GRP78 were detected by enzyme-linked immunosorbent assay kit. The influencing factors of secondary ALI in patients with emergency sepsis were analyzed by univariate and multivariate logistic regression. The predictive value of serum LRG1 and GRP78 levels for secondary ALI in patients with emergency sepsis were analyzed by receiver operating characteristic (ROC) curve was used to analyze. Results: Compared with control group, the levels of serum LRG1 and GRP78 in observation group were increased (P<0.05). Univariate analysis showed that, ALI secondary to emergency sepsis was related to sepsis grade, EICU time, mechanical ventilation, sepsis-related organ failure assessment (SOFA) score, blood lactic acid, LRG1 and GRP78 (P<0.05). Multivariate logistic regression analysis showed that, septic shock, prolonged EICU time and increased SOFO score, blood lactic acid, LRG1 and GRP78 were independent risk factors for secondary ALI in patients with emergency sepsis (P<0.05). ROC curve analysis showed that, the area under the curve (AUC) of serum LRG1 and GRP78 levels alone and in combination in predicting ALI secondary to emergency sepsis were 0.790, 0.782 and 0.884 respectively, and the AUC of combined prediction was the largest (P<0.05). Conclusion: The increase of serum LRG1 and GRP78 levels in patients with emergency sepsis is closely relate to secondary ALI, and the combination of serum LRG1 and GRP78 levels has a higher value in predicting secondary ALI in patients with emergency sepsis. [ABSTRACT FROM AUTHOR]

Purpose: The primary objective was to establish whether blood-based leucine-rich alpha-2-glycoprotein (LRG1) can predict outcomes in patients with locally advanced prostate cancer undergoing androgen-deprivation therapy (ADT) and radiotherapy (RT) and to determine how it may relate to 92 immune-oncology (I-O)-related proteins in this setting. Methods: Baseline blood level of LRG1 from patients treated with ADT and RT enrolled in the CuPCa (n = 128) and IMRT (n = 81) studies was measured using ELISA. A longitudinal cohort with matched blood samples from start of ADT, start of RT, and end of RT protocol from 47 patients from the IMRT cohort was used to establish levels of I-O proteins by high-multiplexing Proximal Extension Assay by Olink Proteomics. Statistical analyses using Kaplan–Meier, Cox regression, and LIMMA analyses were applied to predict the prognostic value of LRG1 and its correlation to I-O proteins. Results: High baseline levels of LRG1 predicted a low frequency of treatment failure in patients undergoing ADT + RT in both the CuPCa and the IMRT cohorts. LRG1 was moderately correlated with CD4, IL6, and CSF1. We identified I-O proteins predicting metastatic failure (MF) at different timepoints. Conclusion: LRG1 biomarker is associated with I-O proteins and can be used to improve stratification and monitoring of prostate cancer patients undergoing ADT + RT. This work will require further in-depth analyses in independent cohorts with treatment outcome data. Study outline. A) Study cohorts. B) Sampling time points in a longitudinal cohort. [ABSTRACT FROM AUTHOR]

The establishment of new blood vessels, and their subsequent stabilization, is a critical process that facilitates tissue growth and organ development. Once established, vessels need to diversify to meet the specific needs of the local tissue and to maintain homeostasis. These processes are tightly regulated and fundamental to normal vessel and tissue function. The mechanisms that orchestrate angiogenesis and vessel maturation have been widely studied, with signaling crosstalk between endothelium and perivascular cells being identified as an essential component. In disease, however, new vessels develop abnormally, and existing vessels lose their specialization and function, which invariably contributes to disease progression. Despite considerable research into the vasculopathic mechanisms in disease, our knowledge remains incomplete. Accordingly, the identification of angiocrine and angiopathic molecules secreted by cells within the vascular microenvironment, and their effect on vessel behaviour, remains a major research objective. Over the last decade the secreted glycoprotein leucine-rich α-2 glycoprotein 1 (LRG1), has emerged as a significant vasculopathic molecule, stimulating defective angiogenesis, and destabilizing the existing vasculature mainly, but not uniquely, by altering both canonical and non-canonical TGF-β signaling in a highly cell and context dependent manner. Whilst LRG1 does not possess any overt homeostatic role in vessel development and maintenance, growing evidence provides a compelling case for LRG1 playing a pleiotropic role in disrupting the vasculature in many disease settings. Thus, LRG1 has now been reported to damage vessels in various disorders including cancer, diabetes, chronic kidney disease, ocular disease, and lung disease and the signaling processes that drive this dysfunction are being defined. Moreover, therapeutic targeting of LRG1 has been widely proposed to re-establish a quiescent endothelium and normalized vasculature. In this review, we consider the current status of our understanding of the role of LRG1 in vascular pathology, and its potential as a therapeutic target.

Implant loosening is a severe complication after total joint replacement. Here, differential diagnosis between septic and aseptic cases is crucial for further surgical treatment, but low-grade periprosthetic joint infections (PJIs) in particular remain a challenge. In this study, we analyzed the synovial fluid proteome of 21 patients undergoing revision surgery for septic (eight cases) or aseptic (thirteen cases) implant failure using LC-MS/MS to identify potential new biomarkers as future diagnostic tools. Staphylococci were found in four cases, Streptococci in two cases, Serratia marcescens and Cutibacterium acnes in one case. Proteomic analysis of the synovial fluid resulted in the identification of 515 different proteins based on at least two peptides. A statistical comparison revealed 37 differentially abundant proteins (p < 0.05), of which 17 proteins (46%) showed a higher abundance in the septic group. The proteins with the highest fold change included the known marker proteins c-reactive protein (7.57-fold) and the calprotectin components protein S100-A8 (4.41-fold) and protein S100-A9 (3.1-fold). However, the protein with the highest fold change was leucine-rich alpha-2-glycoprotein 1 (LRG1) (9.07-fold), a currently discussed new biomarker for inflammatory diseases. Elevated LRG1 levels could facilitate the diagnosis of PJI in the future, but their significance needs to be further investigated.

Background: Prostate cancer (PC) is one of the most frequently diagnosed non-skin solid cancers and is a leading cause of cancer-related death and the incidence increasing. Early diagnosis of the disease improves the outcomes. There is an urgent need for new biomarkers with greater discriminative precision for diagnosis, risk-stratification and treatment. The aim of our study was to evaluate the diagnostic and prognostic potential of Fetuin-A and LRG1 in patients with PC., Methods: Serum levels of Fetuin-A and LRG1 were compared in patients with PC (n=46), a control group 1 including young, healthy subjects (n=26) and control group 2 including patients with negative prostate biopsy (n=46). In PC patients, the levels of both biomarkers were compared in subgroups with different tumour characteristics., Results: We demonstrated a statistically significant higher concentrations of Fetuin-A in PC patients compared to control group 2 (439 mg/L vs. 372 mg/L), P<0.001. No statistically significant difference was found between PC patients and control group 1, nor for LRG1 levels between the three groups. In PC patients, higher serum levels of LRG1 were found in M1 patients compared to M0 (98 mg/L vs. 42 mg/L), P=0.059., Conclusion: Fetuin-A levels are significantly higher in patients with prostate cancer than in patients without malignancy but LRG1 levels do not differ between patients with PC and controls., Competing Interests: The authors report no conflicts of interest in this work.

Renal fibrosis lacks effective nephroprotective drugs in clinical settings due to poor accumulation of therapeutic agents in damaged kidneys, underscoring the urgent need for advanced renal-targeted delivery systems. Herein, we exploited the significantly increased expression of the leucine-rich α-2 glycoprotein 1 (LRG1) protein during renal fibrosis to develop a novel drug delivery system. Our engineered nanocarrier, DEN NM , preferentially targets fibrotic kidneys via the decorated ET peptide's high affinity for LRG1. Once internalized by damaged renal cells, DEN NM releases its encapsulated nintedanib, triggered by the active caspase-3 protease, disrupting the nanomedicine's structural integrity. The released nintedanib effectively reduces the level of expression of the extracellular matrix and impedes the progression of renal fibrosis by inhibiting the transforming growth factor-β (TGF-β)-Smad2/3 pathway. Our comprehensive in vitro and in vivo studies validate DEN NM 's antifibrotic efficacy, emphasizing LRG1's potential in renal targeted drug delivery and introducing an innovative approach to nanomedicine for treating renal fibrosis.

Transforming growth factor (TGF)-β signaling is a well-established pathogenic mediator of diabetic kidney disease (DKD). However, owing to its pleiotropic actions, its systemic blockade is not therapeutically optimal. The expression of TGF-β signaling regulators can substantially influence TGF-β's effects in a cell- or context-specific manner. Among these, leucine-rich α2-glycoprotein 1 (LRG1) is significantly increased in glomerular endothelial cells (GECs) in DKD. As LRG1 is a secreted molecule that can exert autocrine and paracrine effects, we examined the effects of LRG1 loss in kidney cells in diabetic OVE26 mice by single-cell transcriptomic analysis. Gene expression analysis confirmed a predominant expression of Lrg1 in GECs, which further increased in diabetic kidneys. Loss of Lrg1 led to the reversal of angiogenic and TGF-β-induced gene expression in GECs, which were associated with DKD attenuation. Notably, Lrg1 loss also mitigated the increased TGF-β-mediated gene expression in both podocytes and mesangial cells in diabetic mice, indicating that GEC-derived LRG1 potentiates TGF-β signaling in glomerular cells in an autocrine and paracrine manner. Indeed, a significant reduction in phospho-Smad proteins was observed in the glomerular cells of OVE26 mice with LRG1 loss. These results indicate that specific antagonisms of LRG1 may be an effective approach to curb the hyperactive glomerular TGF-β signaling to attenuate DKD., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The American Society of Gene and Cell Therapy. All rights reserved.)

Atherosclerosis is a chronic inflammatory disease of the arterial wall characterized by the accumulation of cholesterol-rich lipoproteins in macrophages. How macrophages commit to proinflammatory polarization under atherosclerosis conditions is not clear. Report here that the level of a circulating protein, leucine-rich alpha-2 glycoprotein 1 (LRG1), is elevated in the atherosclerotic tissue and serum samples from patients with coronary artery disease (CAD). LRG1 stimulated macrophages to proinflammatory M1-like polarization through the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK) pathways. The LRG1 knockout mice showed significantly delayed atherogenesis progression and reduced levels of macrophage-related proinflammatory cytokines in a high-fat diet-induced Apoe -/- mouse atherosclerosis model. An anti-LRG1 neutralizing antibody also effectively blocked LRG1-induced macrophage M1-like polarization in vitro and conferred therapeutic benefits to animals with ApoE deficiency-induced atherosclerosis. LRG1 may therefore serve as an additional biomarker for CAD and targeting LRG1 could offer a potential therapeutic strategy for CAD patients by mitigating the proinflammatory response of macrophages., Competing Interests: Competing interests statement:The authors declare no competing interest.

Leucine-rich α-2 glycoprotein 1 (LRG1), a secreted glycoprotein, has been identified as significantly upregulated in renal fibrosis, potentially exacerbating the condition by enhancing TGF-β-Smad3-dependent signaling pathways. Herein, utilizing our developed LRG1-targeting peptide for LRG1 recruitment and lenalidomide for E3 ubiquitin ligase engagement, we developed an advanced proteolysis targeting chimera, ET TAC-2, specifically designed for LRG1 degradation. Our cellular degradation assays validated that ET TAC-2 effectively degraded LRG1 through a proteasome-dependent mechanism, achieving half-maximal degradation at a concentration of 8.38 µM. Furthermore, anti-fibrotic experiments conducted both in vitro and in vivo revealed that ET TAC-2 efficiently induced LRG1 degradation in fibrotic kidneys. This action effectively inhibited the TGF-β-Smad3 signaling pathway and diminished the secretion of fibrosis-associated proteins, consequently attenuating the progression of renal fibrosis. Our study highlights the pivotal role of LRG1 in renal fibrosis and positions ET TAC-2 as a promising therapeutic candidate for targeted LRG1 intervention., Competing Interests: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article., (© 2024 Shenyang Pharmaceutical University. Published by Elsevier B.V.)

Leucine-rich α2-glycoprotein-1 (LRG1) is overexpressed in various cancers, including non-small cell lung cancer (NSCLC), but its role in NSCLC cell metastasis is not well understood. In this study, NSCLC cell exosomes were analyzed using different techniques, and the impact of exosomal LRG1 on NSCLC cell behavior was investigated through various assays both in vitro and in vivo. The study revealed that LRG1, found abundantly in NSCLC cells and exosomes, enhanced cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT). Exosomal LRG1 was shown to promote NSCLC cell metastasis in animal models. Additionally, the interaction between LRG1 and fibronectin 1 (FN1) in the cytoplasm was identified. It was observed that FN1 could counteract the effects of LRG1 knockdown on cell regulation induced by exosomes derived from NSCLC cells. Overall, the findings suggest that targeting exosomal LRG1 or FN1 may hold therapeutic potential for treating NSCLC. • Reducing the expression level of LRG1 decreases the ability of exosomes secreted by NSCLC cells to regulate cell proliferation, migration, invasion, and EMT. • LRG1 interacted with FN1 and regulated FN1, and FN1 can counteract the effects of exosomes with LRG1 knockdown on cell regulation. • LRG1 or FN1 may play a role in promoting NSCLC progression and metastasis. Therefore, targeting exosomal LRG1 or FN1 proteins could be a promising approach for NSCLC treatment. [ABSTRACT FROM AUTHOR]

Introduction: Cigarette smoking is one of the most important causes of COPD and could induce the apoptosis of pulmonary microvascular endothelial cells (PMVECs). The conditional knockout of LRG1 from endothelial cells reduced emphysema in mice. However, the mechanism of the deletion of LRG1 from endothelial cells rescued by cigarette smoke (CS) induced emphysema remains unclear. This research aimed to demonstrate whether LRG1 promotes the apoptosis of PMVECs through KLK10 in COPD., Methods: Nineteen patients were divided into three groups: control non-COPD (n=7), smoker non-COPD (n=7), and COPD (n=5). The emphysema mouse model defined as the CS exposure group was induced by CS exposure plus cigarette smoke extract (CSE) intraperitoneal injection for 28 days. Primary PMVECs were isolated from the mouse by magnetic bead sorting method via CD31-Dynabeads. Apoptosis was detected by western blot and flow cytometry., Results: LRG1 was increased in lung tissue of COPD patients and CS exposure mice, and CSE-induced PMVECs apoptosis model. KLK10 was over-expressed in lung tissue of COPD patients and CS exposure mice, and CSE-induced PMVECs apoptosis model. LRG1 promoted apoptosis in PMVECs. LRG1 knockdown reversed CSE-induced apoptosis in PMVECs. The mRNA and protein expression of KLK10 were increased after over-expressed LRG1 in PMVECs isolated from mice. Similarly, both the mRNA and protein levels of KLK10 were decreased after LRG1 knockdown in PMVECs. The result of co-immunoprecipitation revealed a protein-protein interaction between LRG1 and KLK10 in PMVECs. KLK10 promoted apoptosis via the down-regulation of Bcl-2/Bax in PMVECs. KLK10 knockdown could reverse CSE-induced apoptosis in PMVECs., Conclusions: LRG1 promotes apoptosis via up-regulation of KLK10 in PMVECs isolated from mice. KLK10 promotes apoptosis via the down-regulation of Bcl-2/Bax in PMVECs. There was a direct protein-protein interaction between LRG1 and KLK10 in PMVECs. Our novel findings provide insights into the understanding of LRG1/KLK10 function as a potential molecule in COPD., Competing Interests: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors declare that they have no competing interests, financial or otherwise, related to the current work. All authors report that since the initial planning of the work they received grants from the National Natural Science Foundation of China (Grant numbers: 82270045 and 81970044) and payments were made to P. Chen., (© 2024 Cheng W. et al.)

For the advancement of DKD treatment, identifying unrecognized residual risk factors is essential. We explored the impact of obesity diversity derived from different carbohydrate qualities, with an emphasis on the increasing trend of excessive fructose consumption and its effect on DKD progression. In this study, we utilized db/db mice to establish a novel diabetic model characterized by fructose overconsumption, aiming to uncover the underlying mechanisms of renal damage. Compared to the control diet group, the fructose-fed db/db mice exhibited more pronounced obesity yet demonstrated milder glucose intolerance. Plasma cystatin C levels were elevated in the fructose model compared to the control, and this elevation was accompanied by enhanced glomerular sclerosis, even though albuminuria levels and tubular lesions were comparable. Single-cell RNA sequencing of the whole kidney highlighted an increase in Lrg1 in glomerular endothelial cells (GECs) in the fructose model, which appeared to drive mesangial fibrosis through enhanced TGF-β1 signaling. Our findings suggest that excessive fructose intake exacerbates diabetic kidney disease progression, mediated by aberrant Lrg1-driven crosstalk between GECs and mesangial cells. • The role of fructose overconsumption in the progression of DKD is to be elucidated. • Fructose overconsumption is a risk for DKD progression independent of hyperglycemia. • Fructose overconsumption increases Lrg1 expression in glomerular endothelial cells. • Secreted Lrg1 from glomerular endothelial cells leads to mesangial cell activation. [ABSTRACT FROM AUTHOR]

Dysfunction in the processes of autophagy and apoptosis within renal tubular epithelial cells (RTEc) contributes to renal ischemia-reperfusion injury (IRI). However, the factors influencing this dysfunction remain unclear. Leucine-rich alpha-2-glycoprotein 1 (Lrg1) plays a role in the progression of diabetic nephropathy and kidney fibrosis by modulating the activin receptor-like kinase 1 (ALK1)-Smad1/5/8 and TGF-β1/Smad3 pathways, respectively. Therefore, we aimed to investigate whether Lrg1 is involved in the pathological mechanisms of renal IRI and whether its effects are related to the dysregulation of autophagy and apoptosis in RTEc. We conducted in vitro and in vivo experiments using CoCl 2 -induced hypoxic human kidney-2 (HK-2) cells and mice with renal IRI, respectively. Lrg1 was silenced using siRNA and lentiviral vectors in HK-2 cells and mouse kidneys. Rapamycin (Rapa) and methyladenine were applied to regulate autophagy in renal IRI models. Increased Lrg1 expression was observed in hypoxic HK-2 cells and in the kidneys of mice with renal IRI. Silencing of Lrg1 through siRNA and lentiviral approaches restored autophagy and suppressed apoptosis in CoCl 2 -induced hypoxic HK-2 cells and renal IRI models. Additionally, reduced Lrg1 expression alleviated kidney damage caused by renal IRI. The downregulation of Lrg1 expression restrained the TGFβ-Smad1/5 signaling pathway in hypoxic-induced HK-2 cells and renal IRI by reducing ALK1 expression. Lastly, the enhancement of autophagy, achieved through Rapa treatment, provided protection against renal IRI in mice. Our findings suggest that Lrg1 silencing can be applied as a potential therapeutic target to inhibit the TGFβ1-Smad1/5 pathway, thereby enhancing autophagy and decreasing apoptosis in patients with acute kidney injury. [Display omitted] • Role of Lrg1 in the pathological mechanisms of renal IRI is studied. • Lrg1 expression is upregulated in HK-2 cells and the kidneys of mice with renal IRI. • Silencing Lrg1 restores autophagy, suppresses apoptosis, and reduces kidney damage. • Lrg1 regulates TGFβ-Smad1/5 signaling pathway by modulating ALK1 expression. • This is the first study to identify Lrg1 as a therapeutic target for AKI. [ABSTRACT FROM AUTHOR]

The establishment of new blood vessels, and their subsequent stabilization, is a critical process that facilitates tissue growth and organ development. Once established, vessels need to diversify to meet the specific needs of the local tissue and to maintain homeostasis. These processes are tightly regulated and fundamental to normal vessel and tissue function. The mechanisms that orchestrate angiogenesis and vessel maturation have been widely studied, with signaling crosstalk between endothelium and perivascular cells being identified as an essential component. In disease, however, new vessels develop abnormally, and existing vessels lose their specialization and function, which invariably contributes to disease progression. Despite considerable research into the vasculopathic mechanisms in disease, our knowledge remains incomplete. Accordingly, the identification of angiocrine and angiopathic molecules secreted by cells within the vascular microenvironment, and their effect on vessel behaviour, remains a major research objective. Over the last decade the secreted glycoprotein leucine-rich α-2 glycoprotein 1 (LRG1), has emerged as a significant vasculopathic molecule, stimulating defective angiogenesis, and destabilizing the existing vasculature mainly, but not uniquely, by altering both canonical and non-canonical TGF-β signaling in a highly cell and context dependent manner. Whilst LRG1 does not possess any overt homeostatic role in vessel development and maintenance, growing evidence provides a compelling case for LRG1 playing a pleiotropic role in disrupting the vasculature in many disease settings. Thus, LRG1 has now been reported to damage vessels in various disorders including cancer, diabetes, chronic kidney disease, ocular disease, and lung disease and the signaling processes that drive this dysfunction are being defined. Moreover, therapeutic targeting of LRG1 has been widely proposed to re-establish a quiescent endothelium and normalized vasculature. In this review, we consider the current status of our understanding of the role of LRG1 in vascular pathology, and its potential as a therapeutic target., Competing Interests: JG and SEM are founders of a company spun out by UCL Business to commercialize a LRG1 function-blocking therapeutic antibody developed through the UK Medical Research Council DPFS funding scheme. JG and SEM are members of the scientific advisory board and are shareholders of this company and named inventors on three patents related to LRG1 as a therapeutic target. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Dritsoula, Camilli, Moss and Greenwood.)

Objective: To assess the relationship between LRG1 and CD4 + T cells, cognitive impairment and neurological function in acute ischemic stroke (AIS). Methods: Plasma LRG1 was detected by ELISA in 175 patients with AIS at baseline, day (D) 1, D7, month (M) 1 and M3. Results: LRG1 was negatively related to Th2 and Treg cells and positively linked to Th17 (all p < 0.05). LRG1 increased from baseline to D1, then decreased until M3 (p < 0.001). LRG1 at each assessment point was increased in patients with cognitive impairment or poor neurological function at M3 versus those without (all p < 0.05). Conclusion: LRG1 is linked to decreased Th2 and Tregs, increased Th17, cognitive impairment and nonideal neurological function recovery in patients with AIS.

Background: Macrophages constitute the main part of infiltrating immune cells in Malignant pleural mesothelioma (MPM) and abnormally high ratios of M2 macrophages are present in both pleural effusion and tissue samples of MPM patients. Whether MPM cells affect formation of M2 macrophages is poorly understood. In this study, we focused on identification of MPM-cells-derived soluble factors with M2-promoting effects. Methods: Media of malignant pleural mesothelioma cells were collected and soluble factors affecting macrophages were analyzed by mass spectrometry. TGF-β receptor inhibitor SB431542 was used as the entry point to explore the downstream mechanism of action by qRT-PCR, WB and immunofluorescence. Results: The serum-free culture media collected from the human MPM cells Meso1 and Meso2 significantly enhanced expression of the M2 signature molecules including IL-10, TGF-β and CD206 in the human macrophages THP-1, while the culture medium of the human MPM cells H2452 did not show such M2-promoting effects. Analysis of proteins by mass spectrometry and ELISA suggested that Leucine rich α2 glycoprotein 1(LRG1) was a potential candidate. LRG1 time- and dose-dependently increased expression of the M2 signature molecules, confirming its M2-promoting effects. Furthermore, LRG1's M2-promoting effects were reduced by the TGF-β receptor inhibitor SB431542, and LRG1 increased phosphorylation of Smad2, indicating that M2-promoting effects of LRG1 were via the TGF-β receptor/Smad2 signaling pathway. Conclusions: Our results provide a potential M2-promoting new member, LRG1, which contributes to the immune escape of MPM via the TGF-β receptor/Smad2 signaling pathway.