Hyaluronan And Proteoglycan Link Protein 1 Research Articles

The effects of hyaluronan and proteoglycan link protein 1 (HAPLN1) in ameliorating spinal cord injury mediated by Nrf2.

Excessive inflammatory response and oxidative stress (OS) play an important role in the pathogenesis of spinal cord injury (SCI). Balance of inflammation and prevention of OS have been considered an effective strategy for the treatment of SCI. Hyaluronan and proteoglycan link protein 1 (HAPLN1), also known as cartilage link protein, has displayed a wide range of biological and physiological functions in different types of tissues and cells. However, whether HAPLN1 regulates inflammation and OS during SCI is unknown. Therefore, we aimed to examine whether HAPLN1 can have a protective effect on SCI. In this study, both in vitro and in vivo SCI models were established. Nissl staining and terminal deoxynucleotidyl transferase dUTP nick end labeling staining assays were used. Western blotting and enzyme-linked immunosorbent assay were employed to assess the expression of proteins. Our results demonstrate that the administration of HAPLN1 promoted the recovery of motor neurons after SCI by increasing the Basso mouse scale score, increasing the numbers of motor neurons, and preventing apoptosis of spinal cord cells. Additionally, HAPLN1 mitigated OS in spinal cord tissue after SCI by increasing the content of superoxide dismutase SOD and the activity of glutathione peroxidase but reducing the levels of malondialdehyde. Importantly, we found that HAPLN1 stimulated the activation of the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway and stimulated the expression of heme oxygenase-1 and nicotinamide adenine dinucleotide phosphate quinone oxidoreductase-1, which mediated the attenuation of HAPLN1 in activation of the NOD-like receptor protein 3 (NLRP3) inflammasome by reducing the levels of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), caspase-1, and interleukin-1β. Correspondingly, in vitro experiments show that the presence of HAPLN1 suppressed the NLRP3 inflammasome and prevented cell injury against H2O2 in PC12 cells. These effects were mediated by the Nrf2/ARE pathway, and inhibition of Nrf2 with ML385 abolished the beneficial effects of HAPLN1. Based on these findings, we conclude that HAPLN1 inhibits the NLRP3 inflammasome through the stimulation of the Nrf2/ARE pathway, thereby suppressing neuroinflammation, enhancing motor neuronal survival, and improving the recovery of nerve function after SCI.

Comparison of sialylated and fucosylated N-glycans attached to Asn 6 and Asn 41 with different roles in hyaluronan and proteoglycan link protein 1 (HAPLN1)

Hyaluronan and proteoglycan link protein 1 (HAPLN1) is an extracellular matrix protein stabilizing interactions between hyaluronan and proteoglycan. Although HAPLN1 is being investigated for various biological roles, its N-glycosylation is poorly understood. In this study, the structure of N-glycopeptides of trypsin-treated recombinant human HAPLN1 (rhHAPLN1) expressed from CHO cells were identified by nano-liquid chromatography-tandem mass spectrometry. A total of 66 N-glycopeptides were obtained, including 16 and 12 N-glycans at sites Asn 6 (located in the N-terminal region) and Asn 41 (located in the Ig-like domain, which interacts with proteoglycan), respectively. The quantities (%) of each N-glycan relative to the totals (100 %) at each site were calculated. Tri- and tetra-sialylation (to resist proteolysis and extend half-life) were more abundant at Asn 6, and di- (core- and terminal-) fucosylation (to increase binding affinity and stability) and sialyl-Lewis X/a epitope (a major ligand for E-selectin) were more abundant at Asn 41. These results indicate that N-glycans attached to Asn 6 (protecting HAPLN1) and Asn 41 (supporting molecular interactions) play different roles in HAPLN1. This is the first study of site-specific N-glycosylation in rhHAPLN1, which will be useful for understanding its molecular interactions in the extracellular matrix.

Association of hyaluronan and proteoglycan link protein 1 gene with the need of home oxygen therapy in premature Japanese infants with bronchopulmonary dysplasia

Background Bronchopulmonary dysplasia (BPD) has a lasting effect on the respiratory function of infants, imposing chronic health burdens. BPD is influenced by various prenatal, postnatal, and genetic factors. This study explored the connection between BPD and home oxygen therapy (HOT), and then we examined the association between HOT and a specific single-nucleotide polymorphism (SNP) in the hyaluronan and proteoglycan link protein 1 (HAPLN1) gene among premature Japanese infants. Materials and methods Prenatal and postnatal data from 212 premature infants were collected and analyzed by four SNPs (rs975563, rs10942332, rs179851, and rs4703570) around HAPLN1 using the TaqMan polymerase chain reaction method. The clinical characteristics and genotype frequencies of HAPLN1 were assessed and compared between HOT and non-HOT groups. Results Individuals with AA/AC genotypes in the rs4703570 SNP exhibited significantly higher HOT rates at discharge than those with CC homozygotes (odds ratio, 1.20, 95% confidence interval, 1.07–1.35, p = .038). A logistic regression analysis determined that CC homozygotes in the rs4703570 SNP did not show a statistically significant independent association with HOT at discharge. Conclusions Although our study did not reveal a correlation between HAPLN1 and the onset of BPD, we observed that individuals with CC homozygosity at the rs4703570 SNP exhibit a reduced risk of HOT.

HAPLN1 matrikine: a bone marrow homing factor linked to poor outcomes in patients with MM

AbstractThe bone marrow (BM) microenvironment is critical for dissemination, growth, and survival of multiple myeloma (MM) cells. Homing of myeloma cells to the BM niche is a crucial step in MM dissemination, but the mechanisms involved are incompletely understood. In particular, any role of matrikines, neofunctional peptides derived from extracellular matrix proteins, remains unknown. Here, we report that a matrikine derived from hyaluronan and proteoglycan link protein 1 (HAPLN1) induces MM cell adhesion to the BM stromal components, such as fibronectin, endothelial cells, and stromal cells and, furthermore, induces their chemotactic and chemokinetic migration. In a mouse xenograft model, we show that MM cells preferentially home to HAPLN1 matrikine–conditioned BM. The transcription factor STAT1 is activated by HAPLN1 matrikine and is necessary to induce MM cell adhesion, migration, migration-related genes, and BM homing. STAT1 activation is mediated by interferon beta (IFN-β), which is induced by NF-κB after stimulation by HAPLN1 matrikine. Finally, we also provide evidence that higher levels of HAPLN1 in BM samples correlate with poorer progression-free survival of patients with newly diagnosed MM. These data reveal that a matrikine present in the BM microenvironment acts as a chemoattractant, plays an important role in BM homing of MM cells via NF-κB–IFN-β–STAT1 signaling, and may help identify patients with poor outcomes. This study also provides a mechanistic rationale for targeting HAPLN1 matrikine in MM therapy.

Recombinant Human HAPLN1 Mitigates Pulmonary Emphysema by Increasing TGF-β Receptor I and Sirtuins Levels in Human Alveolar Epithelial Cells.

Chronic obstructive pulmonary disease (COPD) will be the third leading cause of death worldwide by 2030. One of its components, emphysema, has been defined as a lung disease that irreversibly damages the lungs' alveoli. Treatment is currently unavailable for emphysema symptoms and complete cure of the disease. Hyaluronan (HA) and proteoglycan link protein 1 (HAPLN1), an HA-binding protein linking HA in the extracellular matrix to stabilize the proteoglycan structure, forms a bulky hydrogel-like aggregate. Studies on the biological role of the full-length HAPLN1, a simple structure-stabilizing protein, are limited. Here, we demonstrated for the first time that treating human alveolar epithelial type 2 cells with recombinant human HAPLN1 (rhHAPLN1) increased TGF-β receptor 1 (TGF-β RI) protein levels, but not TGF-β RII, in a CD44-dependent manner with concurrent enhancement of the phosphorylated Smad3 (p-Smad3), but not p-Smad2, upon TGF-β1 stimulation. Furthermore, rhHAPLN1 significantly increased sirtuins levels (i.e., SIRT1/2/6) without TGF-β1 and inhibited acetylated p300 levels that were increased by TGF-β1. rhHAPLN1 is crucial in regulating cellular senescence, including p53, p21, and p16, and inflammation markers such as p-NF-κB and Nrf2. Both senile emphysema mouse model induced via intraperitoneal rhHAPLN1 injections and porcine pancreatic elastase (PPE)-induced COPD mouse model generated via rhHAPLN1-containing aerosols inhalations showed a significantly potent efficacy in reducing alveolar spaces enlargement. Preclinical trials are underway to investigate the effects of inhaled rhHAPLN1-containing aerosols on several COPD animal models.

Novel Effect of Hyaluronan and Proteoglycan Link Protein 1 (HAPLN1) on Hair Follicle Cells Proliferation and Hair Growth.

Hair loss is a common condition that can have a negative impact on an individual's quality of life. The severe side effects and the low efficacy of current hair loss medications create unmet needs in the field of hair loss treatment. Hyaluronan and Proteoglycan Link Protein 1 (HAPLN1), one of the components of the extracellular matrix, has been shown to play a role in maintaining its integrity. HAPLN1 was examined for its ability to impact hair growth with less side effects than existing hair loss treatments. HAPLN1 was predominantly expressed in the anagen phase in three stages of the hair growth cycle in mice and promotes the proliferation of human hair matrix cells. Also, recombinant human HAPLN1 (rhHAPLN1) was shown to selectively increase the levels of transforming growth factor-β receptor II in human hair matrix cells. Furthermore, we observed concomitant activation of the ERK1/2 signaling pathway following treatment with rhHAPLN1. Our results indicate that rhHAPLN1 elicits its cell proliferation effect via the TGF-β2-induced ERK1/2 pathway. The prompt entering of the hair follicles into the anagen phase was observed in the rhHAPLN1-treated group, compared to the vehicle-treated group. Insights into the mechanism underlying such hair growth effects of HAPLN1 will provide a novel potential strategy for treating hair loss with much lower side effects than the current treatments.

HAPLN1 potentiates peritoneal metastasis in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) frequently metastasizes into the peritoneum, which contributes to poor prognosis. Metastatic spreading is promoted by cancer cell plasticity, yet its regulation by the microenvironment is incompletely understood. Here, we show that the presence of hyaluronan and proteoglycan link protein-1 (HAPLN1) in the extracellular matrix enhances tumor cell plasticity and PDAC metastasis. Bioinformatic analysis showed that HAPLN1 expression is enriched in the basal PDAC subtype and associated with worse overall patient survival. In a mouse model for peritoneal carcinomatosis, HAPLN1-induced immunomodulation favors a more permissive microenvironment, which accelerates the peritoneal spread of tumor cells. Mechanistically, HAPLN1, via upregulation of tumor necrosis factor receptor 2 (TNFR2), promotes TNF-mediated upregulation of Hyaluronan (HA) production, facilitating EMT, stemness, invasion and immunomodulation. Extracellular HAPLN1 modifies cancer cells and fibroblasts, rendering them more immunomodulatory. As such, we identify HAPLN1 as a prognostic marker and as a driver for peritoneal metastasis in PDAC.

Extremely low-frequency electromagnetic field (ELF-EMF) induces alterations in epigenetic regulation in the myometrium – An in vitro study

Previous research by the authors indicated that an extremely low-frequency electromagnetic field (ELF-EMF) evokes molecular alterations in the porcine myometrium. It was hypothesized that the ELF-EMF could induce alterations in the epigenetic regulation of gene expression in the myometrium. In the current study, slices of the porcine myometrium during the peri-implantation period (n = 4) were used for further in vitro exposition to ELF-EMF (50 Hz, 8 mT, 2 h treatment duration). The study tested whether the ELF-EMF may affect: 1/the expression of DNA (cytosine-5)-methyltransferase 1 (DNMT1) and DNA (cytosine-5)-methyltransferase 3a (DNMT3a), 2/the level of genomic DNA methylation, and 3/the level of amplification of methylated and unmethylated variants of promoter regions of selected genes with altered expression in response to ELF-EMF. It was found that ELF-EMF treatment increased DNMT1, decreased DNMT3a mRNA transcript and protein abundance, and increased the level of genomic DNA methylation. The direction of alterations in the level of amplification of methylated and unmethylated variants of the promoter region of selected genes with altered expression, i.e. prodynorphin (PDYN), interleukin 15 (IL15) signal transducer and activator of transcription 5A (STAT5A), tumor necrosis factor (TNF), and between down-regulated genes were early growth response 2 (EGR2), hyaluronan and proteoglycan link protein 1 (HAPLN1), and uteroferrin associated basic protein-2 (UABP2), mostly involving the direction of changes in their transcriptional activity, which was evaluated in a previous study by the authors. Thus, ELF-EMF radiation disturbs epigenetic mechanisms, which may underlay ELF-EMF-related transcriptomic alterations in the myometrium.

Hyaluronan and Proteoglycan Link Protein 1 Activates the BMP4/Smad1/5/8 Signaling Pathway to Promote Osteogenic Differentiation: an Implication in Fracture Healing.

Osteoblast regeneration, characterized by osteoblast differentiation, is the basis of fracture healing and accelerates fracture repair. It has been reported that hyaluronan and proteoglycan link protein 1 (HAPLN1) is overexpressed during osteoblast differentiation and regulates cartilage regeneration, but its function in fracture healing remains unclear. To elucidate this issue, we collected clinical blood samples of fracture healing, established a femoral fracture rat model, and induced an osteoblast differentiation cell model. We found that HAPLN1 was overexpressed in the serum of patients with fracture healing and the bone tissues of rats with fracture healing. Furthermore, the expression of HAPLN1 was increased time dependently during the osteogenic differentiation of MC3T3-E1 cells. HAPLN1 silencing prevented osteoblast differentiation and mineralization in MC3T3-E1 cells as evidenced by decreased osteoblast differentiation-related factors, suppressed alkaline phosphatase activities, and reduced alizarin red positive staining. Mechanically, the bone morphogenic protein 4 (BMP4)/Smad1/5/8 pathway, a facilitator of osteoblastic differentiation, was found to be inhibited by HAPLN1 knockdown, and inhibition of BMP4/Smad1/5/8 signaling enhanced the effects caused by HAPLN1 silencing. These findings demonstrated that HAPLN1 might promote fracture healing by facilitating osteogenic differentiation through the BMP4/Smad1/5/8 pathway, indicating that targeting HAPLN1 may be a feasible therapeutic candidate for fracture repair.

Ectopic CH60 mediates HAPLN1-induced cell survival signaling in multiple myeloma.

Multiple myeloma (MM), the second most common hematological malignancy, is generally considered incurable because of the development of drug resistance. We previously reported that hyaluronan and proteoglycan link protein 1 (HAPLN1) produced by stromal cells induces activation of NF-κB, a tumor-supportive transcription factor, and promotes drug resistance in MM cells. However, the identity of the cell surface receptor that detects HAPLN1 and thereby engenders pro-tumorigenic signaling in MM cells remains unknown. Here, we performed an unbiased cell surface biotinylation assay and identified chaperonin 60 (CH60) as the direct binding partner of HAPLN1 on MM cells. Cell surface CH60 specifically interacted with TLR4 to evoke HAPLN1-induced NF-κB signaling, transcription of anti-apoptotic genes, and drug resistance in MM cells. Collectively, our findings identify a cell surface CH60-TLR4 complex as a HAPLN1 receptor and a potential molecular target to overcome drug resistance in MM cells.

HAPLN1 confers multiple myeloma cell resistance to several classes of therapeutic drugs.

Multiple myeloma (MM), a malignant plasma cell infiltration of the bone marrow, is generally considered incurable: resistance to multiple therapeutic drugs inevitably arises from tumor cell-intrinsic and tumor microenvironment (TME)-mediated mechanisms. Here we report that the proteoglycan tandem repeat 1 (PTR1) domain of the TME matrix protein, hyaluronan and proteoglycan link protein 1 (HAPLN1), induces a host of cell survival genes in MM cells and variable resistance to different classes of clinical drugs, including certain proteasome inhibitors, steroids, immunomodulatory drugs, and DNA damaging agents, in several MM cell lines tested. Collectively, our study identifies HAPLN1 as an extracellular matrix factor that can simultaneously confer MM cell resistance to multiple therapeutic drugs.

The Implication of Serum Autoantibodies in Prognosis of Canine Mammary Tumors.

Simple SummaryCanine mammary tumor (CMT) is prevalent in female dogs. As tumor recurrence and metastasis occur in malignant CMT (MMT) dogs after surgery, serum prognostic biomarkers are needed to facilitate prediction of disease outcomes. We have identified CMT-associated autoantibodies, namely TYMS-AAb, IGFBP5-AAb, HAPLN1-AAb, and AGR2-AAb, which are present in serum of CMT dogs. In this study, we demonstrated that the serum AAb levels decreased at 3- and 12-months post-surgery in 11 MMT dogs. We also evaluated the correlation between the presurgical AAb level and overall survival (OS) of 90 CMT dogs after surgery. Data reveal that higher levels of IGFBP5-AAb and TYMS-AAb are significantly correlated with worse OS. On the contrary, a lower level of AGR2-AAb is correlated with poorer OS. Notably, MMT dogs presenting higher levels of TYMS-AAb and IGFBP5-AAb plus a lower level of AGR2-AAb have worst OS. This is the first study revealing an association between serum AAb levels and clinical outcomes of CMT and provides a starting point to verify the validity of utilizing this AAb panel in prediction of tumor relapse and therapy responses.Canine mammary tumor (CMT) is the most prevalent neoplasm in female dogs. Tumor recurrence and metastasis occur in malignant CMT (MMT) dogs after surgery. Identification of serum prognostic biomarkers holds the potential to facilitate prediction of disease outcomes. We have identified CMT-associated autoantibodies against thymidylate synthetase (TYMS), insulin-like growth factor-binding protein 5 (IGFBP5), hyaluronan and proteoglycan link protein 1 (HAPLN1), and anterior gradient 2 (AGR2), i.e., TYMS-AAb, IGFBP5-AAb, HAPLN1-AAb, and AGR2-AAb, respectively, by conducting serological enzyme-linked immunosorbent assays (ELISA). Herein we assessed serum AAb levels in 11 MMT dogs before and after surgery, demonstrating that IGFBP5-AAb and HAPLN1-AAb significantly decrease at 3- and 12-months post-surgery (p < 0.05). We evaluated the correlation between the presurgical AAb level and overall survival (OS) of 90 CMT dogs after surgery. Kaplan-Meier survival analysis reveals that IGFBP5-AAbHIgh and TYMS-AAbHigh are significantly correlated with worse OS (p = 0.017 and p = 0.029, respectively), while AGR2-AAbLow is correlated with somewhat poorer OS (p = 0.086). Areas under a time-dependent receiver operating characteristic curve (AUC) of IGFBP5-AAb and TYMS-AAb in predicting OS of MMT dogs are 0.611 and 0.616, respectively. Notably, MMT dogs presenting TYMS-AAbHigh/IGFBP5-AAbHigh/AGR2-AAbLow have worst OS (p = 0.0004). This study reveals an association between the serum AAb level and CMT prognosis.

Selected Articles from This Issue

Ceramide kinase (CERK) and its enzymatic product, ceramide-1-phosphate (C1P), have been implicated in oncogenesis, but molecular mechanisms underlying CERK/C1P-mediated oncogenesis have not been elucidated. While investigating CERK functionality in non–small cell lung cancer (NSCLC), Vu and colleagues discovered that CERK is more abundant in KRASG12 mutant NSCLC tumor samples. Further interrogation revealed that CERK inhibitor NVP-231 increases reactive oxygen species levels and ferroptotic cell death uniquely in KRASG12 mutant NSCLC cells. Accordingly, an in vivo model in which the authors used CRISPR/Cas9 to generate NSCLC cells with single CERK alleles demonstrated that limiting CERK abundance sensitizes KRASG12 mutant NSCLC cells to cisplatin. Voltage-dependent anion channel 1 (VDAC1) abrogation using siRNA reverses CERK inhibition-driven cytotoxicity and cisplatin sensitivity in vitro. Mechanistically, the authors found that CERK inhibition prevents AKT mitochondrial localization, reducing AKT-mediated VDAC1 phosphorylation and subsequent β-tubulin/VDAC1 interactions on mitochondrial outer membranes. Overall, this study demonstrates that KRASG12 mutant NSCLC survival is reliant on CERK, and that CERK dependence may be therapeutically targetable using existing chemotherapeutics.While increased Ecdysoneless (ECD) mRNA and protein abundance has been observed in breast cancer and other tumor types, molecular mechanisms by which ECD might promote breast cancer tumorigenesis have not been fully clarified. To query how ECD functions in breast cancer, Mohapatra and colleagues generated a mouse model in which an ECD transgene is overexpressed specifically in mammary epithelium (ECDTg). Mammary ECD overexpression produces mammary tumors with heterogeneous histological characteristics that occasionally metastasize to the lungs. Transcriptomic analyses of ECDTg and control tumors revealed that ECD overexpression enhances c-MYC transcriptional programming, particularly augmenting metabolic c-MYC target gene transcription. The authors demonstrated that ECD increases c-MYC abundance by facilitating c-MYC mRNA splicing and maturation. Furthermore, doxycycline disrupts ECD and c-MYC expression, unveiling a potential therapeutic vulnerability in ECD-overexpressing tumors. Taken together, this study defines novel, physiologically relevant ECD functions in mammary cancer and presents potential ECD-driven therapeutic targets.Small cell lung cancer (SCLC) is an aggressive disease for which current therapeutic options provide limited benefits, necessitating therapeutic target discovery. While it is known that MUC1-C facilitates tumorigenesis in several cancers, it has not been studied in SCLC. To assess the role of MUC1-C in SCLC, Fushimi and colleagues abrogated MUC1-C expression in classic, variant, and non-neuroendocrine SCLC cell lines using doxycycline-inducible shRNA and performed transcriptomic analyses. The authors found that MUC1-C enhances MYC transcriptional programming in each SCLC subtype. Further studies revealed that MUC1-C is required for MYC localization to the NOTCH2 promoter and enhancer, and that ablating MUC1-C or MYC expression decreases expression of NOTCH2 and master transcription factors that dictate SCLC subtypes. Genetic and pharmacological disruption of MUC1-C, as well as CRISPR-Cas9-mediated NOTCH2 elimination, inhibit SCLC cell tumorsphere formation in vitro and tumor growth in vivo, suggesting the MUC1-C/MYC/NOTCH2 axis drives stemness and tumor progression in SCLC. In sum, this study defines a novel, potentially therapeutically targetable molecular mechanism underlying SCLC tumor progression.Proteosome inhibitor bortezomib demonstrates effectiveness in many multiple myeloma patients upon initial treatment. However, patients often relapse after initial therapy and develop drug resistance. Previously, Shigeki Miyamoto's group discovered that bone marrow stromal cells (BMSC) produce cleaved forms of hyaluronan and proteoglycan link protein 1 (HAPLN1) that activate NF-κB to engender bortezomib resistance. How cleaved HAPLN1 matrikines are generated in multiple myeloma remains unknown. To test if BMSC-derived HAPLN matrikines might derive from proteolytic cleavage, Miyamoto and co-authors performed a qRT-PCR–based matrix metalloproteinase (MMP) screen in BMSC derived from healthy donors and multiple myeloma patients. The screen revealed heightened MMP2 expression in multiple myeloma patient BMSC, and gelatin zymography activity assays demonstrated increased MMP2 activity in multiple myeloma patient BMSC. Subsequent in vitro assays showed that MMP2 cleaves HAPLN1 into products similar in size to the previously discovered matrikines. Abrogating HAPLN1 and MMP2 expression via shRNA-expressing lentivirus transduction in multiple myeloma patient BMSC decreases NF-κB activation and fosters bortezomib sensitivity in multiple myeloma cells. Altogether, this study unveils a novel molecular mechanism by which BMSC support multiple myeloma cell bortezomib resistance.

Abstract 960: HAPLN1 increases peritoneal carcinomatosis by inducing tumor cell hyperplasticity

Abstract Pancreatic Ductal Adenocarcinoma (PDAC) frequently metastasizes into the peritoneum forming peritoneal carcinomatosis, which are so far not treatable effectively. Metastasis-initiating cells need to acquire beneficial traits including cell plasticity, immune evasion, dormancy state control and organ colonization. These characteristics can be summarized in broad terms into two main processes, epithelial-to-mesenchymal transition (EMT) and stemness. Hyaluronic acid (HA), an extracellular matrix component, is a crucial factor in regulating these processes in PDAC, but it is so far not successfully targetable. Analyzing publicly available databases by gene set enrichment analysis (GSEA), a signature related to HA binding was enriched in tumor samples compared to normal tissue. Hyaluronan And Proteoglycan Link Protein 1 (HAPLN1) was the top contributor to the enrichment score, being the 8th most enriched gene overall. We found that higher HAPLN1 expression correlated with shorter overall survival and that HAPLN1high patients had both, basal subtype and EMT signatures enriched. Moreover, these patients had a signature for peritoneal metastasis significantly enriched, suggesting a higher risk for peritoneal carcinomatosis. To study the role of HAPLN1 on PDAC in vitro, we stably overexpressed HAPLN1 in the murine PDAC cell line KPC. KPC-HAPLN1 cells expressed more EMT markers, more stem-related genes and changed the proteoglycan production from Aggrecan to Versican, which is known to be pro-metastatic. We found that spheroid formation, a feature of stemness, was improved in KPC-HAPLN1 vs KPC. Additionally, embedding these spheroids into matrigel led to an increased invasion of KPC-HAPLN1 cells. KPC-HAPLN1 cells improved KPC cell invasion capacities when co-cultured, indicating a paracrine effect. In vivo, intraperitoneal injection of luciferase expressing KPC cells resulted in higher luciferase activity when tumor cells expressed HAPLN1. Analyzing the peritoneal lavage (PL) from these mice, we obtained significantly more tumor cells in KPC-HAPLN1 injected mice. RNAseq data of tumor cells isolated from tumor nodules and PL showed that KPC-HAPLN1 cells acquired an increased metastatic potential and a strong immunomodulatory phenotype. Thus, we evaluated the immune cell composition of the PL by flow cytometry. Neutrophil and monocyte percentages were drastically reduced in KPC-HAPLN1 bearing mice. On the contrary, these mice had a significant increase in macrophages, which showed a reduction in pro-inflammatory gene expression. We conclude that HAPLN1 expression in tumor cells promotes a hyperplastic phenotype that facilitates invasion and colonization of the peritoneum, among others by creation of a pro-tumoral immune microenvironment. Citation Format: Lena Wiedmann, Francesca De Angelis Rigotti, Nuria Vaquero-Siguero, Elisa Donato, Elisa Espinet, Andreas Trumpp, Andreas Fischer, Juan Rodriguez-Vita. HAPLN1 increases peritoneal carcinomatosis by inducing tumor cell hyperplasticity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 960.

A Hyaluronan and Proteoglycan Link Protein 1 Matrikine: Role of Matrix Metalloproteinase 2 in Multiple Myeloma NF-κB Activation and Drug Resistance.

HAPLN1 and MMP2 produced by BMSCs obtained from patients with multiple myeloma promote NF-κB activity and resistance to bortezomib toxicity in multiple myeloma cells, uncovering their potential as biomarkers or therapeutic targets to address bortezomib resistance in patients with multiple myeloma.

The Effects of TNF-α Inhibition on the Metabolism of Cartilage: Relationship between KS, HA, HAPLN1 and ADAMTS4, ADAMTS5, TOS and TGF-β1 Plasma Concentrations in Patients with Juvenile Idiopathic Arthritis.

We assessed the effect of 24-month anti-tumor necrosis factor alpha (TNF-α) treatment on the remodeling of the cartilage extracellular matrix (ECM) in patients with juvenile idiopathic arthritis (JIA). Methods: Quantitative evaluation of keratan sulfate (KS), hyaluronic acid (HA), hyaluronan and proteoglycan link protein 1 (HAPLN1), as potential biomarkers of joint dysfunction, and the levels of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 4 and 5, total oxidative status (TOS) and transforming growth factor (TGF-β1) was performed (using immunoenzymatic methods) in blood obtained from patients before and after 24 months of etanercept (ETA) treatment. Results: When compared to the controls, KS, HA and HAPLN1 levels were significantly higher in patients with an aggressive course of JIA qualified for ETA treatment. An anti-cytokine therapy leading to clinical improvement promotes the normalization only of the HA level. Proteolytic and pro-oxidative factors, present in high concentrations in patients before the treatment, correlated with HAPLN1, but not with KS and HA levels. In these patients, negative correlations were found between the levels of TGF-β1 and KS, HA and HAPLN1. Conclusion: The anti-TNF-α therapy used in patients with JIA has a beneficial effect on ECM cartilage metabolism, but it does not completely regenerate it. The changes in the plasma HA level during the anti-cytokine therapy suggest its potential diagnostic utility in monitoring of disease activity and may be used to assess the efficacy of ETA treatment.

Loss of Hyaluronan and Proteoglycan Link Protein-1 Induces Tumorigenesis in Colorectal Cancer.

Colorectal cancer (CRC) is the third most common diagnosed cancer worldwide, but there are no effective cures for it. Hyaluronan and proteoglycan link protein-1 (HAPLN1) is a component of the extracellular matrix (ECM) proteins and involved in the tumor environment in the colon. Transforming growth factor (TGF)-β is a key cytokine that regulates the deposition of ECM proteins in CRC. However, the role of HAPLN1 in TGF-β contributions to CRC remains unknown. We found that the mRNA expression of HAPLN1 was decreased in tumors from CRC patients compared with healthy controls and normal tissue adjacent to the tumor using two existing microarray datasets. This was validated at the protein level by tissue array from CRC patients (n = 59). HAPLN1 protein levels were also reduced in human CRC epithelial cells after 24 h of TGF-β stimulation, and its protein expression correlated with type I collagen alpha-1 (COL1A1) in CRC. Transfection of HAPLN1 overexpression plasmids into these cells increased protein levels but reduced COL1A1 protein, tumor growth, and cancer cell migration. TGF-β stimulation increased Smad2/3, p-Smad2/3, Smad4, and E-adhesion proteins; however, HAPLN1 overexpression restored these proteins to baseline levels in CRC epithelial cells after TGF-β stimulation. These findings suggest that HAPLN1 regulates the TGF-β signaling pathway to control collagen deposition via the TGF-β signaling pathway and mediates E-adhesion to control tumor growth. Thus, treatments that increase HAPLN1 levels may be a novel therapeutic option for CRC.

Cancer-associated fibroblasts-derived HAPLN1 promotes tumour invasion through extracellular matrix remodeling in gastric cancer

BackgroundCancer-associated fibroblasts (CAFs) are the most principal cells of depositing and remodeling extracellular matrix (ECM) within solid tumours. Both CAFs and ECM have been demonstrated to play critical roles in tumour development. However, the functional roles of CAFs-associated ECM or ECM remodeling in the pathogenesis of gastric cancer remain unclear.MethodsBioinformatics analysis of the differentially expressed genes between CAFs and corresponding normal fibroblasts (NFs) in gastric cancer was performed. The clinical relevance of hyaluronan and proteoglycan link protein 1 (HAPLN1) was investigated using TCGA data and human gastric cancer specimens. Spheroid cell invasion assay and nude mouse xenograft model were introduced to assay cell invasion. Second harmonic generation (SHG) was used to image and analyze the changes of collagen fibers in ECM.ResultsHAPLN1 was identified as the most significantly up-regulated gene in CAFs of gastric cancer, and higher HAPLN1 levels were associated with shorter overall survival. HAPLN1 was prominently produced by CAFs, and its levels were correlated positively with tumor T staging (P < 0.0001), lymph node metastasis (P = 0.0006) and TNM stage (P = 0.0063). Mechanically, gastric cancer cells activate fibroblasts to up-regulate HAPLN1 expression via activation of TGF-β1/Smad2/3 signaling, which in turn promotes tumour migration and invasion. Importantly, SHG assays with mouse xenograft models and human samples further demonstrated CAFs-derived HAPLN1 increased tumour invasiveness through ECM remodeling.ConclusionsThis study sheds light on the role of CAFs-derived HAPLN1 in the pathogenesis of gastric cancer, and provides insights for the development of novel strategies for prevention and treatment of gastric carcinoma.

Hyaluronan and proteoglycan link protein1 exhibits chondroregenerative ability in injury-induced osteoarthritic animals through ALK5-SMAD2 signaling in articular chondrocytes

Purpose: Hyaluronan and proteoglycan link protein 1 (HAPLN1) has been known to play a role in the extracellular matrix (ECM) integrity by stabilizing the physicochemical interaction between aggrecan and hyaluronan chain. Our research group has previously identified a novel function of HAPLN1 which restores skin collagen and hyaluronan levels reduced during aging through the heterochronic parabiosis and aptamer-based proteomic analysis. Chondrocytes intimately communicate with their ECM by means of biochemical cues as well as mechanical intermediators.

Significant association of serum autoantibodies to TYMS, HAPLN1 and IGFBP5 with early stage canine malignant mammary tumours.

Canine mammary tumours (CMTs) are the most prevalent neoplasms in female dogs. Despite the high incidence of such tumours, a lack of easily accessible biomarkers still impedes early diagnosis of malignant CMTs. Herein we identify thymidylate synthetase (TYMS), hyaluronan and proteoglycan link protein 1 (HAPLN1) and insulin-like growth factor-binding protein 5 (IGFBP5) as CMT antigens eliciting corresponding autoantibodies in CMT cases. We establish enzyme-linked immunosorbent assays (ELISAs) to detect autoantibodies to TYMS (TYMS-AAb), HAPLN1 (HAPLN1-AAb) and IGFBP5 (IGFBP5-AAb) in sera from 81 dogs with malignant CMTs (41 in Stage I), 24 with benign CMTs and 35 healthy controls. Levels of all the three autoantibodies are elevated in the malignant group compared with the healthy or the benign group; notably, the elevated autoantibody levels significantly correlate with the stage-I CMTs. For discriminating malignant CMTs from healthy control, the area under curve (AUC) of TYMS-AAb is 0.694 with specificity of 82.9% and sensitivity of 50.6%. The AUC of utilising HAPLN1-AAb for distinguishing the stage-I CMTs from healthy controls is 0.711 with specificity of 77.1% and sensitivity of 58.5%. In differentiating malignant CMTs from the benign, the AUC of IGFBP5-AAb reaches 0.696 with specificity of 70.8% and sensitivity of 67.9%, and a combination of IGFBP5-AAb and TYMS-AAb increases the AUC to 0.72. Finally, the AUC of combined HAPLN1-AAb and IGFBP5-AAb in discriminating the stage-I CMTs from the benign achieves 0.731. Collectively, this study highlights a significant association of the three serum autoantibodies with early stage malignant CMTs.