LILRB4 in acute myeloid leukemia: From prognostic biomarker to immunotherapeutic target

ABSTRACT

Leukocyte immunoglobulin-like receptor (LILR) B4 (also known as ILT3/CD85k) is an immune checkpoint protein that is highly expressed in solid tumors and hematological malignancies and plays a significant role in the pathophysiology of cancer. LILRB4 is highly expressed in acute myeloid leukemia (AML), and this phenotype is associated with adverse patient outcomes. Its differential expression in tumors compared to normal tissues, its presence in tumor stem cells, and its multifaceted roles in tumorigenesis position it as a promising therapeutic target in AML. Currently, several immunotherapies targeting LILRB4 are undergoing clinical trials. This review summarizes advancements made in the study of LILRB4 in AML, focusing on its structure, ligands, expression, and significance in normal tissues and AML; its protumorigenic effects and mechanisms in AML; and the application of LILRB4-targeted therapies in AML. These insights highlight the potential advantages of LILRB4 as an immunotherapeutic target in the context of AML.

Inhibitory immune checkpoints suppress the surveillance of senescent cells promoting their accumulation with aging and in age-related diseases

The accumulation of pro-inflammatory senescent cells within tissues is a common hallmark of the aging process and many age-related diseases. This modification has been called the senescence-associated secretory phenotype (SASP) and observed in cultured cells and in cells isolated from aged tissues. Currently, there is a debate whether the accumulation of senescent cells within tissues should be attributed to increased generation of senescent cells or to a defect in their elimination from aging tissues. Emerging studies have revealed that senescent cells display an increased expression of several inhibitory immune checkpoint ligands, especially those of the programmed cell death protein-1 (PD-1) ligand-1 (PD-L1) proteins. It is known that the PD-L1 ligands, especially those of cancer cells, target the PD-1 receptor of cytotoxic CD8+ T and natural killer (NK) cells disturbing their functions, e.g., evoking a decline in their cytotoxic activity and promoting their exhaustion and even apoptosis. An increase in the level of the PD-L1 protein in senescent cells was able to suppress their immune surveillance and inhibit their elimination by cytotoxic CD8+ T and NK cells. Senescent cells are known to express ligands for several inhibitory immune checkpoint receptors, i.e., PD-1, LILRB4, NKG2A, TIM-3, and SIRPα receptors. Here, I will briefly describe those pathways and examine whether these inhibitory checkpoints could be involved in the immune evasion of senescent cells with aging and age-related diseases. It seems plausible that an enhanced inhibitory checkpoint signaling can prevent the elimination of senescent cells from tissues and thus promote the aging process.

Inhibition of sugar-binding activity of Galectins-8 by thiogalactoside (TDG) attenuates secondary brain damage and improves long-term prognosis following intracerebral hemorrhage

Galectins-8 (Gal-8), the tandem repeat sequences of the galectin family, can influence the pathophysiologic processes in neurological disorders. However, its effect on intracerebral hemorrhage and related mechanisms remains nebulous. Using collagenase VII-S-induced ICH in the left striatum of mice, we investigated the effects of Gal-8 on cellular and molecular immune inflammatory responses in hemorrhagic brain and evaluated the severity of short- and long-term brain injury. Our results showed that activated microglia in the periphery of hematoma in mice with intracerebral hemorrhage expressed Gal-8, while Gal-8 could regulate the expression of cytokines, such as HMGB-1 (P = 0.0032), TNF-α (P = 0.0158), and IL-10 (P = 0.0379). Inhibition of the glucose-binding activity of Gal-8 by thiogalactoside (TDG) significantly reduced the volume of cerebral hematoma (P = 0.0241) and hydrocephalus (P = 0.0112) during the acute phase of cerebral hemorrhage and improved the long-term prognosis. TDG can reduce acute-phase brain tissue injury and improve the prognosis by inhibiting the activation of immune-inflammatory cells in the periphery of hematoma and reducing the release of pro-inflammatory factors.

Hypoxia-induced galectin-8 maintains stemness in glioma stem cells via autophagy regulation

BACKGROUND

Glioma stem cells (GSCs) are the root cause of relapse and treatment resistance in glioblastoma (GBM). In GSCs, hypoxia in the microenvironment is known to facilitate the maintenance of stem cells, and evolutionally conserved autophagy regulates cell homeostasis to control cell population. The precise involvement of autophagy regulation in hypoxic conditions in maintaining the stemness of GSCs remains unclear.

METHODS

The association of autophagy regulation and hypoxia was first assessed by in silico analysis and validation in vitro. Glioma databases and clinical specimens were used to determine galectin-8 (Gal-8) expression in GSCs and human GBMs, and the regulation and function of Gal-8 in stemness maintenance were evaluated by genetic manipulation in vitro and in vivo. How autophagy was stimulated by Gal-8 under hypoxia was systematically investigated.

RESULTS

Hypoxia enhances autophagy in GSCs to facilitate self-renewal, and Gal-8 in the galectin family is specifically involved and expressed in GSCs within the hypoxic niche. Gal-8 is highly expressed in GBM and predicts poor survival in patients. Suppression of Gal-8 prevents tumor growth and prolongs survival in mouse models of GBM. Gal-8 binds to the Ragulator-Rag complex at the lysosome membrane and inactivates mTORC1, leading to the nuclear translocation of downstream TFEB and initiation of autophagic lysosomal biogenesis. Consequently, the survival and proliferative activity of GSCs are maintained.

CONCLUSIONS

Our findings reveal a novel Gal-8-mTOR-TFEB axis induced by hypoxia in the maintenance of GSC stemness via autophagy reinforcement, highlighting Gal-8 as a candidate for GSCs-targeted GBM therapy.

Galectin-8 modulates human osteoclast activity partly through isoform-specific interactions

In overactive human osteoclasts, we previously identified an alternative splicing event in LGALS8, encoding galectin-8, resulting in decreased expression of the long isoform. Galectin-8, which modulates cell-matrix interactions and functions intracellularly as a danger recognition receptor, has never been associated with osteoclast biology. In human osteoclasts, inhibition of galectin-8 expression revealed its roles in bone resorption, osteoclast nuclearity, and mTORC1 signaling regulation. Galectin-8 isoform-specific inhibition asserted a predominant role for the short isoform in bone resorption. Moreover, a liquid chromatography with tandem mass spectrometry (LC-MS/MS) proteomic analysis of galectin-8 isoforms performed in HEK293T cells identified 22 proteins shared by both isoforms. Meanwhile, nine interacting partners were specific for the short isoform, and none were unique to the long isoform. Interactors specific for the galectin-8 short isoform included cell adhesion proteins and lysosomal proteins. We confirmed the interactions of galectin-8 with CLCN3, CLCN7, LAMP1, and LAMP2, all known to localize to secretory vesicles, in human osteoclasts. Altogether, our study reveals direct roles of galectin-8 in osteoclast activity, mostly attributable to the short isoform.

Galectin-8 inhibition and functions in immune response and tumor biology

Galectins are among organisms' most abundantly expressed lectins (carbohydrate-binding proteins) that specifically bind β-galactosides. They act not only outside the cell, where they bind to extracellular matrix glycans, but also inside the cell, where they have a significant impact on signaling pathways. Galectin-8 is a galectin family protein encoded by the LGALS8 gene. Its role is evident in both T- and B-cell immunity and in the innate immune response, where it acts directly on dendritic cells and induces some pro-inflammatory cytokines. Galectin-8 also plays an important role in the defense against bacterial and viral infections. It is known to promote antibacterial autophagy by recognizing and binding glycans present on the vacuolar membrane, thus acting as a danger receptor. The most important role of galectin-8 is the regulation of cancer growth, metastasis, tumor progression, and tumor cell survival. Importantly, the expression of galectins is typically higher in tumor tissues than in noncancerous tissues. In this review article, we focus on galectin-8 and its function in immune response, microbial infections, and cancer. Given all of these functions of galectin-8, we emphasize the importance of developing new and selective galectin-8 inhibitors and report the current status of their development.

Discovery of galectin-8 as an LILRB4 ligand driving M-MDSCs defines a class of antibodies to fight solid tumors

LILRB4 is an immunosuppressive receptor, and its targeting drugs are undergoing multiple preclinical and clinical trials. Currently, the absence of a functional LILRB4 ligand in solid tumors not only limits the strategy of early antibody screening but also leads to the lack of companion diagnostic (CDx) criteria, which is critical to the objective response rate in early-stage clinical trials. Here, we show that galectin-8 (Gal-8) is a high-affinity functional ligand of LILRB4, and its ligation induces M-MDSC by activating STAT3 and inhibiting NF-κB. Significantly, Gal-8, but not APOE, can induce MDSC, and both ligands bind LILRB4 noncompetitively. Gal-8 expression promotes in vivo tumor growth in mice, and the knockout of LILRB4 attenuates tumor growth in this context. Antibodies capable of functionally blocking Gal-8 are able to suppress tumor growth in vivo. These results identify Gal-8 as an MDSC-driving ligand of LILRB4, and they redefine a class of antibodies for solid tumors.

Assessment of the levels of some prognostic biomolecules (galectins, ACE2, SCUBE1/2/3) in COVID-19 patients

Aim: Our aim was to investigate the differences between healthy people and COVID-19 patients in terms of some immunological biomolecules, especially including those related to the inflammation process. Materials & methods: A total of 180 participants (90 healthy controls and 90 COVID-19 patients) were included. The expression levels of eight different inflammation-related biomolecules were measured by the ELISA technique. Results: The mean levels of ACE2, ANG1-7, GAL3, GAL9, SCUBE1, SCUBE2 and SCUBE3 were elevated in COVID-19 patients when compared with healthy controls, while the mean level of GAL2 was lower in COVID-19 patients than controls. Conclusion: To understand the cytokine storm mechanism and related parameters, more detailed studies should be performed investigating more related biomolecules and related signaling pathways.

Galectin-8 Immunohistochemical Profile in Pancreatic Ductal Adenocarcinoma: Emerging Evidence for Its Prognostic Role

Pancreatic ductal adenocarcinoma (PDAC) represents the most frequent pancreatic malignancy, with stromal and epithelial heterogeneity reflected in outcome variability. Therefore, a molecular classification is promoted based on the validation of new diagnostic and prognostic markers. Galectin-8 (Gal8) has been pointed out as a prognostic factor for survival in several types of tumors. Due to limited existing data on PDAC, our study aimed to evaluate the Gal8 profile in PDAC alongside its prognostic status. A total of 87 cases of PDAC were immunohistochemically investigated, and Gal8 immunoexpression was qualitatively and semi-quantitatively assessed and correlated with classical clinicopathological parameters and survival. Gal8 immunoexpression was identified to be mostly nuclear and cytoplasmic, followed by exclusively cytoplasmic and exclusively nuclear. A statistical analysis between Gal8 profiles defined by negative, low, or high scores and clinicopathological characteristics showed significant differences in tumor size, pN stage, and lympho-vascular invasion. Although a Cox regression analysis did not support the prognostic status of Gal8, and we did not confirm its relationship with OS, our results show that exclusively nuclear labeling was associated with an increased mean OS compared with cytoplasmic and nuclear labeling (29.37 vs. 17.93 months). To the best of our knowledge, this is the first study to report a detailed pattern of Gal8 immunostaining in PDAC and to correlate this pattern with clinicopathological characteristics and survival. Our results show that Gal8 immunoexpression is associated with a more aggressive phenotype, thus opening perspectives for larger studies to validate Gal8 as a prognostic factor.

Discovery of N-Arylsulfonyl-Indole-2-Carboxamide Derivatives as Galectin-3 and Galectin-8 C-Terminal Domain Inhibitors

Both galectin-3 and galectin-8 are involved in cell adhesion, migration, apoptosis, angiogenesis, and inflammatory processes by recognizing galactose-containing glycoproteins. Inhibiting galectin-3/8 activities is a potential treatment for cancer and tissue fibrosis. Herein, a series of novel N-arylsulfonyl-5-aryloxy-indole-2-carboxamide derivatives was disclosed as dual inhibitors toward galectin-3 and galectin-8 C-terminal domain with Kd values of low micromolar level (Cpd53, gal-3: Kd= 4.12 μM, gal-8C: Kd= 6.04 μM; Cpd57, gal-3: Kd= 12.8 μM, gal-8C: Kd= 2.06 μM), which are the most potent and selective noncarbohydrate-based inhibitors toward gal-3/8 isoforms to date. The molecular docking investigations suggested that the unique amino acids Arg144 in galectin-3 and Ser213 in galectin-8C could contribute to their potency and selectivity. The scratch wound assay demonstrated that Cpd53 and Cpd57 were able to inhibit the MRC-5 lung fibroblast cells migration as well. This class of inhibitors could serve as a new starting point for further discovering structurally distinct gal-3 and gal-8C inhibitors to be used in cancer and tissue fibrosis treatment.

Glycomimetics for the inhibition and modulation of lectins

Carbohydrates are essential mediators of many processes in health and disease. They regulate self-/non-self- discrimination, are key elements of cellular communication, cancer, infection and inflammation, and determine protein folding, function and life-times. Moreover, they are integral to the cellular envelope for microorganisms and participate in biofilm formation. These diverse functions of carbohydrates are mediated by carbohydrate-binding proteins, lectins, and the more the knowledge about the biology of these proteins is advancing, the more interfering with carbohydrate recognition becomes a viable option for the development of novel therapeutics. In this respect, small molecules mimicking this recognition process become more and more available either as tools for fostering our basic understanding of glycobiology or as therapeutics. In this review, we outline the general design principles of glycomimetic inhibitors (Section 2). This section is then followed by highlighting three approaches to interfere with lectin function, i.e. with carbohydrate-derived glycomimetics (Section 3.1), novel glycomimetic scaffolds (Section 3.2) and allosteric modulators (Section 3.3). We summarize recent advances in design and application of glycomimetics for various classes of lectins of mammalian, viral and bacterial origin. Besides highlighting design principles in general, we showcase defined cases in which glycomimetics have been advanced to clinical trials or marketed. Additionally, emerging applications of glycomimetics for targeted protein degradation and targeted delivery purposes are reviewed in Section 4.

Cigarette Smoke-Induced Respiratory Response: Insights into Cellular Processes and Biomarkers

Cigarette smoke (CS) poses a significant risk factor for respiratory, vascular, and organ diseases owing to its high content of harmful chemicals and reactive oxygen species (ROS). These substances are known to induce oxidative stress, inflammation, apoptosis, and senescence due to their exposure to environmental pollutants and the presence of oxidative enzymes. The lung is particularly susceptible to oxidative stress. Persistent oxidative stress caused by chronic exposure to CS can lead to respiratory diseases such as chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), and lung cancer. Avoiding exposure to environmental pollutants, like cigarette smoke and air pollution, can help mitigate oxidative stress. A comprehensive understanding of oxidative stress and its impact on the lungs requires future research. This includes identifying strategies for preventing and treating lung diseases as well as investigating the underlying mechanisms behind oxidative stress. Thus, this review aims to investigate the cellular processes induced by CS, specifically inflammation, apoptosis, senescence, and their associated biomarkers. Furthermore, this review will delve into the alveolar response provoked by CS, emphasizing the roles of potential therapeutic target markers and strategies in inflammation and oxidative stress.

The interrelation of galectins and autophagy

Autophagy is a vital physiological process that maintains intracellular homeostasis by removing damaged organelles and senescent or misfolded molecules. However, excessive autophagy results in cell death and apoptosis, which will lead to a variety of diseases. Galectins are a type of animal lectin that binds to β-galactosides and can bind to the cell surface or extracellular matrix glycans, affecting a variety of immune processes in vivo and being linked to the development of many diseases. In many cases, galectins and autophagy both play important regulatory roles in the cellular life course, yet our understanding of the relationship between them is still incomplete. Galectins and autophagy may share common etiological cofactors for some diseases. Hence, we summarize the relationship between galectins and autophagy, aiming to draw attention to the existence of multiple associations between galectins and autophagy in a variety of physiological and pathological processes, which provide new ideas for etiological diagnosis, drug development, and therapeutic targets for related diseases.

SARS-CoV-2 Mpro Protease Variants of Concern Display Altered Viral Substrate and Cell Host Target Galectin-8 Processing but Retain Sensitivity toward Antivirals

The main protease of SARS-CoV-2 (M^pro) is the most promising drug target against coronaviruses due to its essential role in virus replication. With newly emerging variants there is a concern that mutations in M^pro may alter the structural and functional properties of protease and subsequently the potency of existing and potential antivirals. We explored the effect of 31 mutations belonging to 5 variants of concern (VOCs) on catalytic parameters and substrate specificity, which revealed changes in substrate binding and the rate of cleavage of a viral peptide. Crystal structures of 11 M^pro mutants provided structural insight into their altered functionality. Additionally, we show M^pro mutations influence proteolysis of an immunomodulatory host protein Galectin-8 (Gal-8) and a subsequent significant decrease in cytokine secretion, providing evidence for alterations in the escape of host-antiviral mechanisms. Accordingly, mutations associated with the Gamma VOC and highly virulent Delta VOC resulted in a significant increase in Gal-8 cleavage. Importantly, IC50s of nirmatrelvir (Pfizer) and our irreversible inhibitor AVI-8053 demonstrated no changes in potency for both drugs for all mutants, suggesting M^pro will remain a high-priority antiviral drug candidate as SARS-CoV-2 evolves.

Hypoxia Controls the Glycome Signature and Galectin-8-Ligand Axis to Promote Protumorigenic Properties of Metastatic Melanoma

The prognosis for patients with metastatic melanoma (MM) involving distant organs is grim, and treatment resistance is potentiated by tumor-initiating cells (TICs) that thrive under hypoxia. MM cells, including TICs, express a unique glycome featuring i-linear poly-N-acetyllactosamines through the loss of I-branching enzyme, β1,6 N-acetylglucosaminyltransferase 2. Whether hypoxia instructs MM TIC development by modulating the glycome signature remains unknown. In this study, we explored hypoxia-dependent alterations in MM glycome‒associated genes and found that β1,6 N-acetylglucosaminyltransferase 2 was downregulated and a galectin (Gal)-8-ligand axis, involving both extracellular and cell-intrinsic Gal-8, was induced. Low β1,6 N-acetylglucosaminyltransferase 2 levels correlated with poor patient outcomes, and patient serum samples were elevated for Gal-8. Depressed β1,6 N-acetylglucosaminyltransferase 2 in MM cells upregulated TIC marker, NGFR/CD271, whereas loss of MM cell‒intrinsic Gal-8 markedly lowered NGFR and reduced TIC activity in vivo. Extracellular Gal-8 bound preferentially to i-linear poly-N-acetyllactosamines on N-glycans of the TIC marker and prometastatic molecule CD44, among other receptors, and activated prosurvival factor protein kinase B. This study reveals the importance of hypoxia governing the MM glycome by enforcing i-linear poly-N-acetyllactosamine and Gal-8 expression. This mechanistic investigation also uncovers glycome-dependent regulation of pro-MM factor, NGFR, implicating i-linear poly-N-acetyllactosamine and Gal-8 as biomarkers and therapeutic targets of MM.

Galectin-8 Downmodulates TLR4 Activation and Impairs Bacterial Clearance in a Mouse Model of Pseudomonas aeruginosa Keratitis

Pseudomonas aeruginosa provokes a painful, sight-threatening corneal infection. It progresses rapidly and is difficult to treat. In this study, using a mouse model of P. aeruginosa keratitis, we demonstrate the importance of a carbohydrate-binding protein, galectin-8 (Gal-8), in regulation of the innate immune response. First, using two distinct strains of P. aeruginosa, we established that Gal-8-/- mice are resistant to P. aeruginosa keratitis. In contrast, mice deficient in Gal-1, Gal-3, and Gal-9 were fully susceptible. Second, the addition of exogenous rGal-8 to LPS (TLR4 ligand)-stimulated bone marrow-derived macrophages suppressed 1) the activation of the NF-κB pathway, and 2) formation of the MD-2/TLR4 complex. Additionally, the expression level of reactive oxygen species was substantially higher in infected Gal-8-/- bone marrow neutrophils (BMNs) compared with the Gal-8+/+ BMNs, and the P. aeruginosa killing capacity of Gal-8-/- BMNs was considerably higher compared with that of Gal-8+/+ BMNs. In the bacterial killing assays, the addition of exogenous rGal-8 almost completely rescued the phenotype of Gal-8-/- BMNs. Finally, we demonstrate that a subconjunctival injection of a Gal-8 inhibitor markedly reduces the severity of infection in the mouse model of P. aeruginosa keratitis. These data lead us to conclude that Gal-8 downmodulates the innate immune response by suppressing activation of the TLR4 pathway and clearance of P. aeruginosa by neutrophils. These findings have broad implications for developing novel therapeutic strategies for treatment of conditions resulting from the hyperactive immune response both in ocular as well as nonocular tissues.

Galectin-8 involves in arthritic condylar bone loss via podoplanin/AKT/ERK axis-mediated inflammatory lymphangiogenesis

OBJECTIVE

The lymphatic system plays a crucial role in the maintenance of tissue fluid homeostasis and the immunological response to inflammation. Galectin-8 (Gal-8) regulates pathological lymphangiogenesis but the effects of which on inflammation-related condylar bone loss in temporomandibular joint (TMJ) have not been well studied.

DESIGN

We used TNFα-transgenic (TNF^TG) mice and their wildtype (WT) littermates to compare their inflammatory phenotype in TMJs. Next, lymphatic endothelial cells (LECs) were used to examine the effects of which on osteoclast formation, pro-inflammatory factor expression, and inflammatory lymphangiogenesis with or without thiodigalactoside (TDG, a Gal-8 inhibitor) treatment. At last, two murine models (TNF^TG arthritic model and forced mouth opening model) were used to explore TDG as a potential drug for the treatment of inflammation-related condylar bone loss.

RESULTS

In comparison to WT mice, lymphatic areas of lymphatic vessel endothelial receptor 1 (LYVE1)⁺/podoplanin (PDPN)⁺ and Gal-8⁺/PDPN⁺, TRAP-positive osteoclast number, and condylar bone loss are increased in TNF^TG mice. Inhibition of Gal-8 in LECs by TDG, reduces TNFα-induced osteoclast formation, pro-inflammatory factor expression, and inflammatory lymphangiogenesis. In addition, Gal-8 promotes TNFα-activated AKT/ERK/NF-κB pathways by binding to PDPN. Finally, the administration of TDG attenuates inflammatory lymphangiogenesis, inhibits osteoclast activity, and reduces condylar bone loss in TNF^TG arthritic mice and forced mouth opening mice.

CONCLUSIONS

Our findings reveal the important role of Gal-8-promoted pathological lymphangiogenesis in inflammation-related condylar bone loss.

Investigation of anti-galectin-8 levels in patients with multiple sclerosis: A consort-clinical study

BACKGROUND

Galectins are a family of endogenous mammalian lectins involved in pathogen recognition, killing, and facilitating the entry of microbial pathogens and parasites into the host. They are the intermediators that decipher glycan-containing information about the host immune cells and microbial structures to modulate signaling events that cause cellular proliferation, chemotaxis, cytokine secretion, and cell-to-cell communication. They have subgroups that take place in different roles in the immune system. The effect of galectin-8 on multiple sclerosis disease (MS) has been studied in the literature, but the results seemed unclear. In this study, we aimed to determine anti-galectin-8 (anti-Gal-8) levels in MS and their potential use as biomarkers.

METHODS

In this experimental study, 45 MS patients diagnosed according to McDonald criteria were included in the patient group. The healthy control group contained 45 people without MS diagnosis and any risk factors. Demographic data, height, weight, body mass index, blood glucose, thyroid-stimulating hormone, alanine transaminase, aspartate transaminase, creatinine, low-density lipoprotein, anti-Gal-8 levels, the prevalence of hypertension, diabetes mellitus and coronary artery disease were recorded. In addition, the expanded disability status scale and disease duration were evaluated in the patient group. Data were presented as mean ± standard deviations.

RESULTS

The mean blood anti-galectin-8 value of the patient group was 4.84 ± 4.53 ng/mL, while it was 4.67 ± 3.40 ng/mL in the control group, and the difference in these values was found statistically insignificant (P > .05). Moreover, body mass index, glucose, alanine transaminase, aspartate transaminase, thyroid-stimulating hormone, and low-density lipoprotein levels were also statistically insignificant (P > .05).

CONCLUSION

This study examined anti-Gal-8 levels in MS patients. The relationship between MS and galectin-8 and anti-Gal-8 levels in patients needs further clarification. As a result, the study's results could help elucidate the pathogenesis of MS and give more evidence for diagnosis.

Galectins can serve as biomarkers in COVID-19: A comprehensive systematic review and meta-analysis

Background

Galectins are an eleven-member class of lectins in humans that function as immune response mediators and aberrancies in their expression are commonly associated with immunological diseases. Several studies have focused on galectins as they may represent an important biomarker and a therapeutic target in the fight against COVID-19. This systematic review and meta-analysis examined the usefulness of clinical assessment of circulating galectin levels in patients with COVID-19.

Methods

International databases including PubMed, Scopus, Web of Science, and Embase were systematically used as data sources for our analyses. The random-effect model was implemented to calculate the standardized mean difference (SMD) and a 95% confidence interval (CI).

Results

A total of 18 studies, comprising 2,765 individuals, were identified and used in our analyses. We found that Gal-3 is the most widely investigated galectin in COVID-19. Three studies reported significantly higher Gal-1 levels in COVID-19 patients. Meta-analysis revealed that patients with COVID-19 had statistically higher levels of Gal-3 compared with healthy controls (SMD 0.53, 95% CI 0.10 to 0.96, P=0.02). However, there was no significant difference between severe and non-severe cases (SMD 0.45, 95% CI -0.17 to 1.07, P=0.15). While one study supports lower levels of Gal-8 in COVID-19, Gal-9 was measured to be higher in patients and more severe cases.

Conclusion

Our study supports Gal-3 as a valuable non-invasive biomarker for the diagnosis and/or prognosis of COVID-19. Moreover, based on the evidence provided here, more studies are needed to confirm a similar diagnostic and prognostic role for Gal-1, -8, and -9.

Galectins Are Central Mediators of Immune Escape in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers and is highly immune tolerant. Although there is immune cell infiltration in PDAC tissues, most of the immune cells do not function properly and, therefore, the prognosis of PDAC is very poor. Galectins are carbohydrate-binding proteins that are intimately involved in the proliferation and metastasis of tumor cells and, in particular, play a crucial role in the immune evasion of tumor cells. Galectins induce abnormal functions and reduce numbers of tumor-associated macrophages (TAM), natural killer cells (NK), T cells and B cells. It further promotes fibrosis of tissues surrounding PDAC, enhances local cellular metabolism, and ultimately constructs tumor immune privileged areas to induce immune evasion behavior of tumor cells. Here, we summarize the respective mechanisms of action played by different Galectins in the process of immune escape from PDAC, focusing on the mechanism of action of Galectin-1. Galectins cause imbalance between tumor immunity and anti-tumor immunity by coordinating the function and number of immune cells, which leads to the development and progression of PDAC.

Prognostic Value and Biological Function of Galectins in Malignant Glioma

Malignant glioma is the most common solid tumor of the adult brain, with high lethality and poor prognosis. Hence, identifying novel and reliable biomarkers can be advantageous for diagnosing and treating glioma. Several galectins encoded by LGALS genes have recently been reported to participate in the development and progression of various tumors; however, their detailed role in glioma progression remains unclear. Herein, we analyzed the expression and survival curves of all LGALS across 2,217 patients with glioma using The Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA), and Rembrandt databases. By performing multivariate Cox analysis, we built a survival model containing LGALS1, LGALS3, LGALS3BP, LGALS8, and LGALS9 using TCGA database. The prognostic power of this panel was assessed using CGGA and Rembrandt datasets. ESTIMATE and CIBERSORT algorithms confirmed that patients in high-risk groups exhibited significant stromal and immune cell infiltration, immunosuppression, mesenchymal subtype, and isocitrate dehydrogenase 1 (IDH1) wild type. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), CancerSEA, and Gene Set Enrichment Analysis (GSEA) showed that pathways related to hypoxia, epithelial-to-mesenchymal transition (EMT), stemness, and inflammation were enriched in the high-risk group. To further elucidate the function of LGALS in glioma, we performed immunohistochemical staining of tissue microarrays (TMAs), Western blotting, and cell viability, sphere formation, and limiting dilution assays following lentiviral short hairpin RNA (shRNA)-mediated LGALS knockdown. We observed that LGALS expression was upregulated in gliomas at both protein and mRNA levels. LGALS could promote the stemness maintenance of glioma stem cells (GSCs) and positively correlate with M2-tumor-associated macrophages (TAMs) infiltration. In conclusion, we established a reliable survival model for patients with glioma based on LGALS expression and revealed the essential roles of LGALS genes in tumor growth, immunosuppression, stemness maintenance, pro-neural to mesenchymal transition, and hypoxia in glioma.

Design and synthesis of novel 3-triazolyl-1-thiogalactosides as galectin-1, -3 and -8 inhibitors

Galectins are galactoside-binding proteins that play a role in various pathophysiological conditions, making them attractive targets in drug discovery. We have designed and synthesised a focused library of aromatic 3-triazolyl-1-thiogalactosides targeting their core site for binding of galactose and a subsite on its non-reducing side. Evaluation of their binding affinities for galectin-1, -3, and -8N identified acetamide-based compound 36 as a suitable compound for further affinity enhancement by adding groups at the reducing side of the galactose. Synthesis of its dichlorothiophenyl analogue 59 and the thiodigalactoside analogue 62 yielded promising pan-galectin inhibitors.

A new series of potent galectin ligands based on the galactose and triazole moieties was designed and synthesised.

The role of galectins‑1, 3, 7, 8 and 9 as potential diagnostic and therapeutic markers in ovarian cancer (Review)

The incidence of ovarian cancer is increasing, particularly throughout the highly developed countries, while this cancer type remains a major diagnostic and therapeutic challenge. The currently poorly recognized lectins called galectins have various roles in interactions occurring in the tumor microenvironment. Galectins are involved in tumor-associated processes, including the promotion of growth, adhesion, angiogenesis and survival of tumor cells. Results of research studies performed so far point to a complex role of galectins-1, 3, −7, −8 and −9 in carcinogenesis of ovarian cancer and elucidation of the mechanisms may contribute to novel forms of therapies targeting the proteins. In particular, it appears important to recognize the reasons for changes in expression of galectins. Galectins also appear to be a useful diagnostic and prognostic tool to evaluate tumor progression or the efficacy of therapies in patients with ovarian cancer, which requires further study.

Gene set enrichment analysis and ingenuity pathway analysis to identify biomarkers in Sheng-ji Hua-yu formula treated diabetic ulcers

ETHNOPHARMACOLOGICAL RELEVANCE

Sheng-ji Hua-yu (SJHY) formula is a Chinese herbal prescription for diabetic ulcers (DUs) treatment, which can accelerate wound reconstruction and shorten the healing time. However, its mechanism role maintains unclear.

AIM OF THE STUDY

To elucidate the molecular mechanisms of SJHY application on DUs.

MATERIALS AND METHODS

To begin with, transcriptome sequencing was adopted to identified differentially expression mRNAs among normal ulcers, DUs, and DUs + SJHY treatment in vivo. Liquid chromatography-tandem mass spectrometry was applied for the quality control of SJHY formula. GO and KEGG enrichment analysis were used to identify the mechanisms underlying the therapeutic effect of SJHY formula, and then gene set enrichment analysis and ingenuity pathway analysis were conducted for functional analysis. Further, qPCR detection was performed in vivo for validation.

RESULTS

SJHY administration could regulate the glucose metabolic process, AMPK and HIF-1 pathway to accelerate healing processes of DUs. Besides, CRHR1, SHH, and GAL were identified as the critical targets, and SLC6A3, GRP, FGF23, and CYP27B1 were considered as the upstream genes of SJHY treatment. Combined with animal experiments, the prediction results were validated in DUs mice model.

CONCLUSIONS

This study used modular pharmacology analysis to identify the biomarkers of SJHY formula and provide the potential therapeutic targets for DUs treatment as well.

Molecular characterization and expression profiling of tandem-repeat galectin-8 from red-spotted grouper (Epinephelus akaara): Potential antibacterial, antiviral, and wound healing activities

Galectin-8 is a typical β-galactoside binding lectin, which primarily functions as a pattern recognition receptor and/or danger receptor that is engaged in pathogen recognition by the host innate immune system. Although several fish galectins have been identified, the role of galectin-8 in teleost immunity is still not fully understood. In this study, molecular, transcriptional, and immune-related functions of galectin-8 (EaGal8) from red-spotted grouper (Epinephelus akaara) were analyzed. The open reading frame of EaGal8 comprised 960 bp encoding 319 amino acids of a ∼35 kDa protein, composed of the N- and C-terminal carbohydrate recognition domains joined by a short hinge peptide. Phylogenetic analysis revealed that EaGal8 was closely related to the Epinephelus lanceolatus galectin-8-like protein. Although EaGal8 showed ubiquitous tissue expression, the highest expression level was observed in the blood. Immunostimulants, including lipopolysaccharide, poly(I:C), and nervous necrosis virus, significantly upregulated the EaGal8 transcription level in a time-dependent manner (p < 0.05). Furthermore, recombinant EaGal8 (rEaGal8) showed a binding affinity toward seven different carbohydrates in a concentration-dependent manner. In addition, rEaGal8 caused strong agglutination of fish red blood cells and several gram-positive and gram-negative bacteria, including Streptococcus iniae, Streptococcus parauberis, Lactococcus garvieae, Escherichia coli, Edwardsiella tarda, Vibrio alginolyticus, Vibrio parahaemolyticus, and Pseudomonas aeruginosa. For the first time in teleosts, we report the wound healing ability of galectin-8 in this study. At low concentrations, rEaGal8 showed potential wound healing responses in FHM cells, in vitro. Thus, this study reinforces the role of EaGal8 in innate immune responses against bacterial and viral infections and wound healing in red-spotted grouper.

Galectin-8, cytokines, and the storm

Galectin-8 (Gal-8) belongs to a family of animal lectins that modulate cell adhesion, cell proliferation, apoptosis, and immune responses. Recent studies have shown that mammalian Gal-8 induces in an autocrine and paracrine manner, the expression and secretion of cytokines and chemokines such as RANKL, IL-6, IL-1β, SDF-1, and MCP-1. This involves Gal-8 binding to receptor complexes that include MRC2/uPAR/LRP1, integrins, and CD44. Receptors ligation triggers FAK, ERK, Akt, and the JNK signaling pathways, leading to induction of NF-κB that promotes cytokine expression. Indeed, immune-competent Gal-8 knockout (KO) mice express systemic lower levels of cytokines and chemokines while the opposite is true for Gal-8 transgenic animals. Cytokine and chemokine secretion, induced by Gal-8, promotes the migration of cancer cells toward cells expressing this lectin. Accordingly, Gal-8 KO mice experience reduced tumor size and smaller and fewer metastatic lesions when injected with cancer cells. These observations suggest the existence of a ‘vicious cycle’ whereby Gal-8 expression and secretion promotes the secretion of cytokines and chemokines that further promote Gal-8 expression. This ‘vicious cycle’ could enhance the development of a ‘cytokine storm’ which is a key contributor to the poor prognosis of COVID-19 patients.

Selective Galectin-8N Ligands: The Design and Synthesis of Phthalazinone-d-Galactals

Ligand selectivity among the highly conserved galectins has been an ever-challenging objective. For galectin-8, a protein prevalent in both pathology and tissue distribution, we report phthalazinone-galactals that show excellent selectivity for the galectin-8N-terminal domain. A dissection of structure-activity relationships of the phthalazinone and an extensive molecular dynamics meta-analysis accompany the discovery of the selective galectin-8N ligands presented here. These selective compounds will facilitate the study of galectin-8 biology and may have pharmaceutical relevance in the wide range of galectin-8 associated pathologies.

A Neoglycoprotein-Immobilized Fluorescent Magnetic Bead Suspension Multiplex Array for Galectin-Binding Studies

Carbohydrate-protein conjugates have diverse applications. They have been used clinically as vaccines against bacterial infection and have been developed for high-throughput assays to elucidate the ligand specificities of glycan-binding proteins (GBPs) and antibodies. Here, we report an effective process that combines highly efficient chemoenzymatic synthesis of carbohydrates, production of carbohydrate-bovine serum albumin (glycan-BSA) conjugates using a squarate linker, and convenient immobilization of the resulting neoglycoproteins on carboxylate-coated fluorescent magnetic beads for the development of a suspension multiplex array platform. A glycan-BSA-bead array containing BSA and 50 glycan-BSA conjugates with tuned glycan valency was generated. The binding profiles of six plant lectins with binding preference towards Gal and/or GalNAc, as well as human galectin-3 and galectin-8, were readily obtained. Our results provide useful information to understand the multivalent glycan-binding properties of human galectins. The neoglycoprotein-immobilized fluorescent magnetic bead suspension multiplex array is a robust and flexible platform for rapid analysis of glycan and GBP interactions and will find broad applications.

Selective Monovalent Galectin-8 Ligands Based on 3-Lactoylgalactoside

Galectin-8 has gained attention as a potential new pharmacological target for the treatment of various diseases, including cancer, inflammation, and disorders associated with bone mass reduction. To that end, new molecular probes are needed in order to better understand its role and its functions. Herein we aimed to improve the affinity and target selectivity of a recently published galectin-8 ligand, 3-O-[1-carboxyethyl]-β-d-galactopyranoside, by introducing modifications at positions 1 and 3 of the galactose. Affinity data measured by fluorescence polarization show that the most potent compound reached a K_D of 12 μM. Furthermore, reasonable selectivity versus other galectins was achieved, making the highlighted compound a promising lead for the development of new selective and potent ligands for galectin-8 as molecular probes to examine the protein's role in cell-based and in vivo studies.

circHMGCS1-016 reshapes immune environment by sponging miR-1236-3p to regulate CD73 and GAL-8 expression in intrahepatic cholangiocarcinoma

Background

Accumulating evidence indicates that circRNAs may serve as essential regulators in the progression of several human cancers, but the function and mechanism of circRNAs in intrahepatic cholangiocarcinoma (ICC) are largely unknown.

Methods

RNA-seq was used to assess differentially expressed circRNAs between 4 ICC and peritumor tissues. Quantitative RT-PCR and in situ hybridization were used to determine the circHMGCS1–016 expression in ICC tissues. The function and mechanism of circHMGCS1–016 were further identified via in vivo experiments. The clinical characteristics and prognostic significance of circHMGCS1–016 were analyzed by a retrospective study. The functions of circHMGCS1–016 were assessed via modifying circRNA expression in ICC cells. Moreover, the molecular mechanisms of circHMGCS1–016 in ICC cells were explored by circRNA precipitation, miRNA immunoprecipitation, SILAC and luciferase reporter assays.

Results

We identified that compared with peritumor tissues, ICC tissues expressed hsa_circ_0008621 (circHMGCS1–016) high by RNA-seq, which was further identified by qRT-PCR and in situ hybridization. Moreover, the expression of circHMGCS1–016 was revealed to be associated with survival and recurrence of ICC patients. By regulating circHMGCS1–016 expression, we found that elevated circHMGCS1–016 promoted ICC development both in vitro and in vivo. By SILAC and circRNA-pull down, we demonstrated that circHMGCS1–016 induced ICC cell invasion and reshaped the tumor immune microenvironment via the miR-1236-3p/CD73 and GAL-8 axis. In ICC tissues, we uncovered that a high level of circHMGCS1–016 was positively associated with CD73 and GAL-8 expression and negatively related to the CD8⁺ T cells infiltration, which was further validated by establishing a humanized mouse tumor model. Importantly, we displayed that ICC patients with high levels of circHMGCS1–016 in tumor tissues benefited less from anti-PD1 treatment compared to those with low levels of circHMGCS1–016.

Conclusions

CircHMGCS1–016 is a forceful contributor in ICC development and immune tolerance via miR-1236-3p/CD73 and GAL-8 axis. CircHMGCS1–016 can be explored as a new potential biomarker and therapeutic target for PD1-resistant ICC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02095-2.

Benzimidazole-galactosides bind selectively to the Galectin-8 N-Terminal domain: Structure-based design and optimisation

We have obtained the X-ray crystal structure of the galectin-8 N-terminal domain (galectin-8N) with a previously reported quinoline-galactoside ligand at a resolution of 1.6 Å. Based on this X-ray structure, a collection of galactosides derivatised at O3 with triazole, benzimidazole, benzothiazole, and benzoxazole moieties were designed and synthesised. This led to the discovery of a 3-O-(N-methylbenzimidazolylmethyl)-galactoside with a K_d of 1.8 μM for galectin-8N, the most potent selective synthetic galectin-8N ligand to date. Molecular dynamics simulations showed that benzimidazole-galactoside derivatives bind the non-conserved amino acid Gln47, accounting for the higher selectivity for galectin-8N. Galectin-8 is a carbohydrate-binding protein that plays a key role in pathological lymphangiogenesis, modulation of the immune system, and autophagy. Thus, the benzimidazole-derivatised galactosides represent promising compounds for studies of the pathological implications of galectin-8, as well as a starting point for the development of anti-tumour and anti-inflammatory therapeutics targeting galectin-8.

N-Glycan profiling of chondrocytes and fibroblast-like synoviocytes: Towards functional glycomics in osteoarthritis

PURPOSE

N-Glycan profiling provides an indicator of the cellular potential for functional pairing with tissue lectins. Following the discovery of galectin expression by chondrocytes as a factor in osteoarthritis pathobiology, mapping of N-glycans upon their phenotypic dedifferentiation in culture and in fibroblast-like synoviocytes is a step to better understand glycobiological contributions to disease progression.

EXPERIMENTAL DESIGN

The profiles of cellular N-glycans of human osteoarthritic chondrocytes and fibroblast-like synoviocytes were characterized by mass spectrometry. RT-qPCR experiments determined mRNA levels of 16 glycosyltransferases. Responsiveness of cells to galectins was quantified by measuring the mRNA level for interleukin-1β.

RESULTS

The shift of chondrocytes to a fibroblastic phenotype (dedifferentiation) is associated with changes in N-glycosylation. The N-glycan profile of chondrocytes at passage 4 reflects characteristics of synoviocytes. Galectins-1 and -3 enhance expression of interleukin-1β mRNA in both cell types, most pronounced in primary culture. Presence of interleukin-1β leads to changes in sialylation in synoviocytes that favor galectin binding.

CONCLUSIONS AND CLINICAL RELEVANCE

N-Glycosylation reflects phenotypic changes of osteoarthritic cells in vitro. Like chondrocytes, fibroblast-like synoviocytes express N-glycans that are suited to bind galectins, and these proteins serve as inducers of pro-inflammatory markers in these cells. Synoviocytes can thus contribute to disease progression in osteoarthritis in situ.

A Fish Galectin-8 Possesses Direct Bactericidal Activity

Galectins are a family of animal lectins with high affinity for β-galactosides. Galectins are able to bind to bacteria, and a few mammalian galectins are known to kill the bound bacteria. In fish, no galectins with direct bactericidal effect have been reported. In the present study, we identified and characterized a tandem repeat galectin-8 from tongue sole Cynoglossus semilaevis (designated CsGal-8). CsGal-8 possesses conserved carbohydrate recognition domains (CRDs), as well as the conserved HXNPR and WGXEE motifs that are critical for carbohydrate binding. CsGal-8 was constitutively expressed in nine tissues of tongue sole and up-regulated in kidney, spleen, and blood by bacterial challenge. When expressed in HeLa cells, CsGal-8 protein was detected both in the cytoplasm and in the micro-vesicles secreted from the cells. Recombinant CsGal-8 (rCsGal-8) bound to lactose and other carbohydrates in a dose dependent manner. rCsGal-8 bound to a wide range of gram-positive and gram-negative bacteria and was co-localized with the bound bacteria in animal cells. Lactose, fructose, galactose, and trehalose effectively blocked the interactions between rCsGal-8 and different bacteria. Furthermore, rCsGal-8 exerted potent bactericidal activity against some gram-negative bacterial pathogens by directly damaging the membrane and structure of the pathogens. Taken together, these results indicate that CsGal-8 likely plays an important role in the immune defense against some bacterial pathogens by direct bacterial interaction and killing.

Galectin-8 Enhances T cell Response by Promotion of Antigen Internalization and Processing

Galectin-8 (Gal-8) is a mammalian lectin endowed with immunostimulatory ability. In the present work, we demonstrate that Gal-8-glycan interactions on the surface of antigen-presenting cells (APCs) promote antigen binding and internalization, independently from antigen nature. Both Gal-8 and antigen were together internalized and localized in early endosomes. Interestingly, antigen processing by APCs was also accelerated in the presence of Gal-8 as a separate mechanism, distinct from the increased antigen internalization. Moreover, APCs pulsed together with antigen and Gal-8 were able to activate cognate CD4+ T cells more efficiently than those pulsed with antigen alone. This enhanced antigen presentation was still evident in the absence of costimulatory signals and APCs-derived soluble mediators. Therefore, our results provide evidence for as yet unrecognized mechanism by which Gal-8 stimulates the elicitation of the immune response in a lectin-dependent manner, by inducing antigen uptake and processing upon lattice formation at APCs surface.

Anti-inflammatory Role of Galectin-8 During Trypanosoma cruzi Chronic Infection

Galectins are animal lectins with high affinity for β-galactosides that drive the immune response through several mechanisms. In particular, the role of galectin-8 (Gal-8) in inflammation remains controversial. To analyze its role in a chronic inflammatory environment, we studied a murine model of Trypanosoma cruzi infection. The parasite induces alterations that lead to the development of chronic cardiomyopathy and/or megaviscera in 30% of infected patients. The strong cardiac inflammation along with fibrosis leads to cardiomyopathy, the most relevant consequence of Chagas disease. By analyzing infected wild-type (iWT) and Gal-8-deficient (iGal-8KO) C57BL/6J mice at the chronic phase (4–5 months post-infection), we observed that the lack of Gal-8 favored a generalized increase in heart, skeletal muscle, and liver inflammation associated with extensive fibrosis, unrelated to tissue parasite loads. Remarkably, increased frequencies of neutrophils and macrophages were observed within cardiac iGal-8KO tissue by flow cytometry. It has been proposed that Gal-8, as well as other galectins, induces the surface expression of the inner molecule phosphatidylserine on activated neutrophils, which serves as an “eat-me” signal for macrophages, favoring viable neutrophil removal and tissue injury protection, a process known as preaparesis. We found that the increased neutrophil rates could be associated with the absence of Gal-8-dependent preaparesis, leading to a diminished neutrophil-clearing capability in macrophages. Thus, our results support that Gal-8 exerts an anti-inflammatory role in chronic T. cruzi infection.

Full-length galectin-8 and separate carbohydrate recognition domains: the whole is greater than the sum of its parts?

Galectin-8 (Gal-8) is a tandem-repeat type galectin with affinity for β-galactosides, bearing two carbohydrate recognition domains (CRD) connected by a linker peptide. The N- and C-terminal domains (Gal-8N and Gal-8C) share 35% homology, and their glycan ligand specificity is notably dissimilar: while Gal-8N shows strong affinity for α(2-3)-sialylated oligosaccharides, Gal-8C has higher affinity for non-sialylated oligosaccharides, including poly-N-acetyllactosamine and/ or A and B blood group structures. Particularly relevant for understanding the biological role of this lectin, full-length Gal-8 can bind cell surface glycoconjugates with broader affinity than the isolated Gal-8N and Gal-8C domains, a trait also described for other tandem-repeat galectins. Herein, we aim to discuss the potential use of separate CRDs in modelling tandem-repeat galectin-8 and its biological functions. For this purpose, we will cover several aspects of the structure-function relationship of this protein including crystallographic structures, glycan specificity, cell function and biological roles, with the ultimate goal of understanding the potential role of each CRD in predicting full-length Gal-8 involvement in relevant biological processes.

Plasma proteomic signature of the risk of developing mobility disability: A 9-year follow-up

INTRODUCTION

Mobility disability is a powerful indicator of poor health in older adults. The biological and pathophysiological mechanism underlying the development of mobility disability remains unknown. This study conducted a data-driven discovery phase investigation to identify plasma proteins that predict the incidence of mobility disability in community-dwelling older adults without mobility disability at baseline.

METHODS

We investigated 660 women and men, aged 71.9 ± 6.0 (60-94) years, who participated in the Invecchiare in Chianti, "Aging in the Chianti Area" study and completed the 400-m walk at fast pace (400-m walk) at enrollment. Median follow-up time was 8.57 [interquartile, 3.20-9.08] years. SOMAscan technology was used to measure 1,301 plasma proteins at enrollment. The incident of mobility disability was defined as inability to complete the 400-m walk. Protein-specific Cox proportional hazard model was adjusted for sex, age, and other important covariates.

RESULTS

Plasma levels of 75 proteins predicted mobility disability (p < .05). Significant proteins were enriched for the KEGG "PI3K-Akt signaling," "phagosomes," and "cytokine-cytokine receptor interaction" pathways. After multiple comparison adjustment, plasma cathepsin S (CTSS; hazard ratio [HR] 1.33, 95% CI: 1.17, 1.51, q = 0.007), growth/differentiation factor 15 (GDF15; HR: 1.45, 95% CI: 1.23, 1.72, q = 0.007), and thrombospondin-2 (THBS2; HR: 1.44, 95% CI: 1.22, 1.69, q = 0.007) remained significantly associated with high risk of losing mobility.

CONCLUSION

CTSS, GDF15, and THBS2 are novel blood biomarkers associated with new mobility disability in community-dwelling individuals. Overall, our analysis suggests that cellular senescence and inflammation should be targeted for prevention of mobility disability.