Hypoxia contributes to galectin-3 expression in renal carcinoma cells

Effect and potential mechanism of modified citrus pectin in 3D printing-based cartilage tissue engineering

Modified citrus pectin (MCP) is widely used as a dietary supplement in the food and pharmaceutical industries with pleiotropic bioactivities. Particularly, MCP has effects on chondroprotection and phenotype maintenance of chondrocyte. Here, after confirming its chondroprotective effect in a partial-thickness articular cartilage (AC) defect, the distributions of MCP in cartilage and chondrocytes were investigated using fluorescence labeled-MCP. Then the potential of it in cartilage tissue engineering (CTE) was studied using 3D-printed scaffolds of hybrid hydrogel (GelMA/HAMA/MCP) of MCP, methacryloydylated-gelatin (GelMA) and hyaluronic acid (HAMA). Finally, the mechanism of the scaffolds on chondrogenesis were analyzed through transcriptome sequencing. It was found that MCP could penetrate cartilage, enter chondrocytes and accumulate in lysosome by binding with Gal-3. MCP could promote the proliferation and maintain the phenotype of chondrocytes in continuous passage culture. Mechanistically, MCP-based scaffold could upregulate the expression of genes of chondrogenic markers and growth factors, downregulate genes related to inflammation or degeneration mediators, and modulate autophagy pathways to maintain homeostasis of chondrocytes. Ultimately, MCP-based scaffolds could support chondrocytes adhesion, proliferation, ECM deposition, and enhance the chondrogenesis of the engineered cartilage. Together, our results demonstrate that MCP has great potential in three-dimensional bioprinting (3DBP)-based CTE to enhance the cartilage regeneration.

Lactococcus petauri LZys1 modulates gut microbiota, diminishes ileal FXR-FGF15 signaling, and regulates hepatic function

Recent studies have indicated that Lactococcus petauri LZys1 (L. petauri LZys1), isolated from healthy human feces, exhibits a promising probiotic profile in vitro. However, its impact on the physiological status of the host in vivo remains uncertain. The objective of our study was to investigate the effects and mechanisms of orally administering L. petauri LZys1 on gut microbiota and liver function in mice. We administered L. petauri LZys1 through daily oral gavage to C57BL/6 male mice. Subsequently, we analyzed changes in gut microbiota composition using 16S rRNA sequencing and quantified alterations in hepatic-intestinal bile acid (BA) profile. Serum biochemical parameters were assessed to evaluate liver function. Our findings revealed that L. petauri LZys1 led to an increase in body weight, liver mass, and serum aminotransferase levels. Oral administration altered the gut microbiota composition, resulting in reduced diversity and abundance of intestinal bacteria. Additionally, the profiles of BAs were suppressed across organs, associated with the downregulation of the ileum's farnesoid X receptor (FXR)/fibroblast growth factor 15 (FGF15) signaling pathway. The decrease in circulating FGF15 mediated the downregulation of hepatic fibroblast growth factor receptor 4 (FGFR4)/FXR, disrupting BA metabolism and fatty acid oxidation. Our findings suggest that L. petauri LZys1 may impact liver function by influencing the gut microbiota-mediated ileal FXR-FGF15 axis and inhibiting hepatic bile acid metabolism.

IMPORTANCE

This work elucidated the impact of L. petauri LZys1 on host gut microbiota metabolism and hepatic physiological metabolism. We observed that L. petauri LZys1 administration induced liver weight gain and biochemical parameters changes, in addition to a altered gut microbiota and suppressed bile acid (BA) profiles. Furthermore, we propose that changes in liver status are related to the enterohepatic farnesoid X receptor-fibroblast growth factor axis, which alters bile acid metabolism and disrupts liver function. The above findings suggest that attention should be paid to the effect of probiotics on liver function.

Involvement of Lgals3/Galectin-3 in Choroidal Neovascularization and Subretinal Fibrosis Formation

Background:Lgals3/galectin-3 plays a pivotal role in many vascular diseases. However, the involvement of Lgals3/galectin-3 in eyes with neovascular age-related macular degeneration (nAMD) remains unknown. Methods: In the laser-induced CNV model, a whole mount retina stained with Isolectin B4 and collagen type I revealed the vascular bed and CNV-associated subretinal fibrosis on day 7 after laser treatment. Results: We show that the expression levels of Lgals3/galectin-3 were significantly increased in the RPE/choroidal complex of CNV mice. An intravitreal injection of Lgals3-siRNA significantly suppressed the area of CNV and subretinal fibrosis, together with Mcp-1 decline. The mixture of Lgals3-siRNA and Ranibizumab showed more efficiency than each drug used separately. Hypoxia induced Lgals3/galectin-3 production in ARPE-19 cells, which was reduced by the silencing hypoxia-inducible factor -1α (Hif-1a). Conclusions: Our data indicated that Lgals3/galectin-3 is involved in the pathogenesis of CNV and subretinal fibrosis, and Lgals3/galectin-3 could be a potential therapeutic target for nAMD.

Galectin-3: action and clinical utility in chronic kidney disease

Chronic kidney disease is a significant cause of morbidity and mortality worldwide. In recent years, Galectin-3 has been put forward as a potential biomarker of chronic kidney disease progression. This review aims to assess the clinical utility of Galectin-3 in various pathological processes leading up to chronic kidney disease such as diabetes and lupus nephritis. We conducted a systematic search on PubMed from inception to September 2023, using the search term ("Galectin-3" OR "gal-3") AND ("renal" OR "kidney"). Galectin-3 has been shown to be both pro-fibrotic and protective against renal fibrosis through various mechanisms such as apoptotic body clearance and modulation of the Wnt pathway. Studies have found associations between raised Galectin-3, incidence and progression of chronic kidney disease. In lupus nephritis, Galectin-3 may serve as a biomarker for lupus nephritis activity. Although Galectin-3 inhibits cystogenesis, there is no correlation between total kidney volume and Galectin-3 in polycystic kidney disease. The role of Galectin-3 in staging and prognostication of renal cell carcinoma is yet to be determined. Galectin-3 has potential in predicting chronic kidney disease progression, in combination with other biomarkers. However, more trials are required given that present studies demonstrate conflicting results on the relationship between Galectin-3 and clinical outcomes in chronic kidney disease patients of varying aetiologies.

On Whether Ca-125 Is the Answer for Diagnosing Overhydration, Particularly in End-Stage Kidney Disease Patients-A Systematic Review

Overhydration (OH) is a prevalent medical problem that occurs in patients with kidney failure, but a specific marker has still not been found. Patients requiring kidney replacement therapy suffer from a water imbalance, which is correlated with mortality rates in this population. Currently, clinicians employ techniques such as bioimpedance spectroscopy (BIS) and ultrasound (USG) markers of overhydration or markers of heart and kidney function, namely NT-pro-BNP, GFR, or creatinine levels. New serum markers, including but not limited to Ca-125, galectin-3 (Gal-3), adrenomedullin (AMD), and urocortin-2 (UCN-2), are presently under research and have displayed promising results. Ca-125, which is a protein mainly used in ovarian cancer diagnoses, holds great potential to become an OH marker. It is currently being investigated by cardiologists as it corresponds to the volume status in heart failure (HF) and ventricular hypertrophy, which are also associated with OH. The need to ascertain a more precise marker of overhydration is urgent mainly because physical examinations are exceptionally inaccurate. The signs and symptoms of overhydration, such as edema or a gradual increase in body mass, are not always present, notably in patients with chronic kidney disease. Metabolic disruptions and cachexia can give a false picture of the hydration status. This review paper summarizes the existing knowledge on the assessment of a patient's hydration status, focusing specifically on kidney diseases and the role of Ca-125.

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.

Plasma galectins and metabolites in advanced head and neck carcinomas: evidence of distinct immune characteristics linked to hypopharyngeal tumors

Extra-cellular galectins 1, 3 and 9 (gal-1, -3 and -9) are known to act as soluble immunosuppressive agents in various malignancies. Previous publications have suggested that their expression is dependent on the metabolic status of producing cells and reciprocally that they can influence metabolic pathways in their target cells. Very little is known about the status of gal-1, -3 and -9 in patients bearing head and neck squamous cell carcinomas (HNSCC) and about their relationships with the systemic metabolic condition. This study was conducted in plasma samples from a prospective cohort of 83 HNSCC patients with advanced disease. These samples were used to explore the distribution of gal-1, -3 and -9 and simultaneously to profile a series of 87 metabolites assessed by mass spectrometry. We identified galectin and metabolic patterns within five disease categories defined according to the primary site and human papillomavirus (HPV) status (HPV-positive and -negative oropharyngeal carcinomas, carcinomas of the oral cavity, hypopharynx and larynx carcinomas). Remarkably, samples related to hypopharyngeal carcinomas displayed the highest average concentration of gal-9 (p = .017) and a trend toward higher concentrations of kynurenine, a potential factor of tumor growth and immune suppression. In contrast, there was a tendency toward higher concentrations of fatty acids in samples related to oral cavity. These observations emphasize the diversity of HPV-negative HNSCCs. Depending on their primary site, they evolve into distinct types of immune and metabolic landscapes that seem to be congruent with specific oncogenic mechanisms.

The hypoxia-driven crosstalk between tumor and tumor-associated macrophages: mechanisms and clinical treatment strategies

Given that hypoxia is a persistent physiological feature of many different solid tumors and a key driver for cancer malignancy, it is thought to be a major target in cancer treatment recently. Tumor-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment (TME), which have a large impact on tumor development and immunotherapy. TAMs massively accumulate within hypoxic tumor regions. TAMs and hypoxia represent a deadly combination because hypoxia has been suggested to induce a pro-tumorigenic macrophage phenotype. Hypoxia not only directly affects macrophage polarization, but it also has an indirect effect by altering the communication between tumor cells and macrophages. For example, hypoxia can influence the expression of chemokines and exosomes, both of which have profound impacts on the recipient cells. Recently, it has been demonstrated that the intricate interaction between cancer cells and TAMs in the hypoxic TME is relevant to poor prognosis and increased tumor malignancy. However, there are no comprehensive literature reviews on the molecular mechanisms underlying the hypoxia-mediated communication between tumor cells and TAMs. Therefore, this review has the aim to collect all recently available data on this topic and provide insights for developing novel therapeutic strategies for reducing the effects of hypoxia.

Galectin expression detected by 68Ga-galectracer PET as a predictive biomarker of radiotherapy resistance

PURPOSE

Hypoxia is a hallmark of solid tumors that is related to radiotherapy resistance. As galectin members, such as galectin-1 and galectin-3, are associated with tumor hypoxia, herein we aimed to investigate whether positron emission tomography (PET) imaging of galectin expression can be employed to effectively pinpoint tumor hypoxia, and to predict radiotherapy resistance.

METHODS

We synthesized a galectin-targeting radiotracer, designated ⁶⁸Ga-galectracer, by radiolabeling a thiodigalactoside derivative. The properties of ⁶⁸Ga-galectracer for PET imaging of tumor hypoxia were characterized in three tumor hypoxia mouse models. Additionally, preliminary PET/CT was performed in two patients with lung cancer to investigate the potential application of ⁶⁸Ga-galectracer for clinical imaging.

RESULTS

High-contrast imaging was achieved in the murine acute hypoxia tumor model, A549 natural hypoxia model, and sorafenib treatment-induced hypoxic 4T1 tumor model by PET using ⁶⁸Ga-galectracer. In fact, ⁶⁸Ga-galectracer exhibited superior hypoxia detection to that of ¹⁸F-misonidazole in the 4T1 tumors. Moreover, tumors with high galectin expression levels, as detected by ⁶⁸Ga-galectracer PET, exhibited significantly lower responses to subsequent radiotherapy compared to those with low galectin expression levels. In patients with lung cancer, PET imaging using ⁶⁸Ga-galectracer provided data that were complementary to that of the glucose metabolic PET radiotracer ¹⁸F-fluorodeoxyglucose.

CONCLUSION

⁶⁸Ga-galectracer is a promising radiotracer for PET-based imaging of tumor hypoxia in vivo. Thus, hypoxia PET with ⁶⁸Ga-galectracer could provide a noninvasive approach to proactively predict radiotherapy efficacy.

TRIAL REGISTRATION

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Targeting galectins in T cell-based immunotherapy within tumor microenvironment

Over the past few years, tumor immunotherapy has emerged as an innovative tumor treatment and owned incomparable advantages over other tumor therapy. With unique complexity and uncertainty, immunotherapy still need helper to apply in the clinic. Galectins, modulated in tumor microenvironment, can regulate the disorders of innate and adaptive immune system resisting tumor growth. Considering the role of galectins in tumor immunosuppression, combination therapy of targeted anti-galectins and immunotherapy may be a promising tumor treatment. This brief review summarizes the expression and immune functions of different galectins in tumor microenvironment and discusses the potential value of anti-galectins in combination with checkpoint inhibitors in tumor immunotherapy.