KYP-2047, an Inhibitor of Prolyl-Oligopeptidase, Reduces GlioBlastoma Proliferation through Angiogenesis and Apoptosis Modulation

Biotinylated polyaminoacid-based nanoparticles for the targeted delivery of lenvatinib towards hepatocarcinoma

In this work, we describe the development of targeted polymeric nanoparticles loaded with lenvatinib for the treatment of hepatocellular carcinoma (HCC). A synthetic brush copolymer (PHEA-g-BIB-pButMA-g-PEG-biotin) was synthesized from α-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) by a three-step reaction involving atom transfer radical polymerisation (ATRP) to graft hydrophobic polybutylmethacrylate pendant groups and further conjugation with biotinylated polyethylene glycol via carbonate ester. Subsequently, lenvatinib-loaded nanoparticles were obtained and characterized demonstrating colloidal size, negative zeta potential, biotin exposure on the surface and the ability to release lenvatinib in a sustained manner. Lenvatinib-loaded nanoparticles were tested in vitro on HCC cells to evaluate their anticancer efficacy compared to free drug. Furthermore, the enhanced in vivo efficacy of lenvatinib-loaded nanoparticles on nude mice HCC xenograft models was demonstrated by evaluating tumor burdens, apoptotic markers and histological scores after administration of lenvatinib-nanoparticles via intraperitoneal or oral route. Finally, in vivo biodistribution studies were performed, demonstrating the ability of the prepared drug delivery systems to significantly accumulate in the solid tumor by active targeting, due to the presence of biotin on the nanoparticle surface.

EZH2 Inhibition to Counteract Oral Cancer Progression through Wnt/β-Catenin Pathway Modulation

Oral squamous cell carcinoma (OSCC) is one of the most common human malignancies worldwide. The molecular mechanisms of OSCC pathogenesis are still unknown; however, in recent years, several reports have focused on the role of enhancer of zeste homolog 2 (EZH2) in OSCC. Therefore, in this study we aimed to investigate the effects of GSK343, a selective EZH2 inhibitor, and its impact on the signaling pathways in OSCC, using an in vitro and in vivo orthotopic model. In the in vitro model, GSK343 (1, 10, and 25 μM) significantly decreased OSCC cell viability and cell migration through EZH2 inhibition, modulating NF-κB/IκBα pathway activation and eNOS, VEGF, and TGFβ expression, important markers of angiogenesis. In the in vivo model, GSK343 (5 mg/kg and 10 mg/kg) restored tongue tissue architecture and reduced tumor progression through EZH2 inhibition and Wnt/β-catenin signaling pathway modulation. Moreover, GSK343 reduced the expression of inflammatory mediators; eNOS and TGFβ, markers of angiogenesis; and CD31 and CD34, markers of micro vessel density, respectively. In conclusion, our data demonstrate that GSK343 counteracts oral cancer progression through EZH2/Wnt/β-catenin pathway modulation, suggesting that it could be a promising therapeutic approach for OSCC management.

Signaling Pathways of AXL Receptor Tyrosine Kinase Contribute to the Pathogenetic Mechanisms of Glioblastoma

Brain tumors are a diverse collection of neoplasms affecting the brain with a high prevalence rate in people of all ages around the globe. In this pathological context, glioblastoma, a form of glioma that belongs to the IV-grade astrocytoma group, is the most common and most aggressive form of the primary brain tumors. Indeed, despite the best treatments available including surgery, radiotherapy or a pharmacological approach with Temozolomide, glioblastoma patients' mortality is still high, within a few months of diagnosis. Therefore, to increase the chances of these patients surviving, it is critical to keep finding novel treatment opportunities. In the past, efforts to treat glioblastoma have mostly concentrated on customized treatment plans that target specific mutations such as epidermal growth factor receptor (EGFR) mutations, Neurotrophic Tyrosine Receptor Kinase (NTRK) fusions, or multiple receptors using multi-kinase inhibitors like Sunitinib and Regorafenib, with varying degrees of success. Here, we focused on the receptor tyrosine kinase AXL that has been identified as a mediator for tumor progression and therapy resistance in various cancer types, including squamous cell tumors, small cell lung cancer, and breast cancer. Activated AXL leads to a significant increase in tumor proliferation, tumor cell migration, and angiogenesis in different in vitro and in vivo models of cancer since this receptor regulates interplay with apoptotic, angiogenic and inflammatory pathways. Based on these premises, in this review we mainly focused on the role of AXL in the course of glioblastoma, considering its primary biological mechanisms and as a possible target for the application of the most recent treatments.

Prolyl oligopeptidase inhibition ameliorates experimental pulmonary fibrosis both in vivo and in vitro

BACKGROUND

Pulmonary fibrosis is a progressive disease characterized by lung remodeling due to excessive deposition of extracellular matrix. Although the etiology remains unknown, aberrant angiogenesis and inflammation play an important role in the development of this pathology. In this context, recent scientific research has identified new molecules involved in angiogenesis and inflammation, such as the prolyl oligopeptidase (PREP), a proteolytic enzyme belonging to the serine protease family, linked to the pathology of many lung diseases such as pulmonary fibrosis. Therefore, the aim of this study was to investigate the effect of a selective inhibitor of PREP, known as KYP-2047, in an in vitro and in an in vivo model of pulmonary fibrosis.

METHODS

The in vitro model was performed using human alveolar A549 cells. Cells were exposed to lipopolysaccharide (LPS) 10 μg/ml and then, cells were treated with KYP-2047 at the concentrations of 1 μM, 10 μM and 50 μM. Cell viability was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) bromide colorimetric assay, while inflammatory protein expression was assessed by western blots analysis. The in vivo model was induced in mice by intra-tracheal administration of bleomycin (1 mg/kg) and then treated intraperitoneally with KYP-2047 at doses of 1, 2.5 and 5 mg/kg once daily for 12 days and then mice were sacrificed, and lung tissues were collected for analyses.

RESULTS

The in vitro results demonstrated that KYP-2047 preserved cell viability, reduced inflammatory process by decreasing IL-18 and TNF-α, and modulated lipid peroxidation as well as nitrosative stress. The in vivo pulmonary fibrosis has demonstrated that KYP-2047 was able to restore histological alterations reducing lung injury. Our data demonstrated that KYP-2047 significantly reduced angiogenesis process and the fibrotic damage modulating the expression of fibrotic markers. Furthermore, KYP-2047 treatment modulated the IκBα/NF-κB pathway and reduced the expression of related pro-inflammatory enzymes and cytokines. Moreover, KYP-2047 was able to modulate the JAK2/STAT3 pathway, highly involved in pulmonary fibrosis.

CONCLUSION

In conclusion, this study demonstrated the involvement of PREP in the pathogenesis of pulmonary fibrosis and that its inhibition by KYP-2047 has a protective role in lung injury induced by BLM, suggesting PREP as a potential target therapy for pulmonary fibrosis. These results speculate the potential protective mechanism of KYP-2047 through the modulation of JAK2/STAT3 and NF-κB pathways.

An RNAi-Mediated Reduction in Transcription Factor Nrf-2 Blocks the Positive Effects of Dimethyl Fumarate on Metabolic Stress in Alzheimer's Disease

The prevalence of obesity is rapidly rising around the world, and this will have a significant impact on our society as it is believed to be one of the leading causes of death. One of the main causes of these occurrences is added sugar consumption, which is associated with a higher risk of obesity, heart disease, diabetes, and brain illnesses such as Alzheimer's disease (AD). To this purpose, excess sugar might worsen oxidative damage and brain inflammation: two neuropathological signs of AD. Dimethyl fumarate (DMF) is an orally accessible methyl ester of fumaric acid with putative neuroprotective and immunomodulatory properties. In addition, DMF stimulates the nuclear factor erythroid 2-related factor 2 (Nrf-2), a key regulator of the antioxidant response mechanism in cells. The aim of the current study was to assess the potential therapeutic benefits of DMF in an in vitro model of metabolic stress induced by high and low sugar levels. We discovered that DMF reversed the negative impacts of high and low glucose exposure on the viability and oxidative stress of SH-SY5Y cells. Mechanistically, DMF's actions were mediated by Nrf-2. To this end, we discovered that DMF boosted the expression of the Nrf-2-regulated genes heme-oxygenase-1 (HO1) and manganese superoxide dismutase (MnSOD). More importantly, we found that inhibiting Nrf-2 expression prevented DMF's positive effects. Our combined findings suggest that DMF may be a valuable support for treatments for metabolic diseases.

Recent Emerging Immunological Treatments for Primary Brain Tumors: Focus on Chemokine-Targeting Immunotherapies

Primary brain tumors are a leading cause of death worldwide and are characterized by extraordinary heterogeneity and high invasiveness. Current drug and radiotherapy therapies combined with surgical approaches tend to increase the five-year survival of affected patients, however, the overall mortality rate remains high, thus constituting a clinical challenge for which the discovery of new therapeutic strategies is needed. In this field, novel immunotherapy approaches, aimed at overcoming the complex immunosuppressive microenvironment, could represent a new method of treatment for central nervous system (CNS) tumors. Chemokines especially are a well-defined group of proteins that were so named due to their chemotactic properties of binding their receptors. Chemokines regulate the recruitment and/or tissue retention of immune cells as well as the mobilization of tumor cells that have undergone epithelial–mesenchymal transition, promoting tumor growth. On this basis, this review focuses on the function and involvement of chemokines and their receptors in primary brain tumors, specifically examining chemokine-targeting immunotherapies as one of the most promising strategies in neuro-oncology.

Sodium Propionate Contributes to Tumor Cell Growth Inhibition through PPAR-γ Signaling

New therapeutic approaches are needed to improve the outcome of patients with glioblastoma (GBM). Propionate, a short-chain fatty acid (SCFA), has a potent antiproliferative effect on various tumor cell types. Peroxisome proliferator-activated receptor (PPAR) ligands possess anticancer properties. We aimed to investigate the PPAR-γ/SCFAs interaction in in vitro and in vivo models of GBM. The U87 cell line was used in the in vitro study and was treated with sodium propionate (SP). U87 cells were silenced by using PPAR-γ siRNA or Ctr siRNA. In the in vivo study, BALB/c nude mice were inoculated in the right flank with 3 × 10⁶ U-87 cells. SP (doses of 30 and 100 mg/kg) and GW9662 (1 mg/kg) were administered. In vitro exposure of GBM to SP resulted in prominent apoptosis activation while the autophagy pathway was promoted by SP treatments by influencing autophagy-related proteins. Knockdown of PPAR-γ sensitized GBM cells and blocked the SP effect. In vivo, SP was able to decrease tumor growth and to resolve GBM tissue features. SP promoted apoptosis and autophagy pathways and tumor cell proliferation leading to cell cycle arrest through a PPAR-γ-dependent mechanism suggesting that the PPAR-γ/SCFAs axis could be targeted for the management of GBM.

The Pivotal Role of Protein Phosphatase 2A (PP2A) in Brain Tumors

Protein phosphatase 2A (PP2A) is a highly complex heterotrimeric Ser/Thr phosphatase that regulates many cellular processes. PP2A is dysregulated in several human diseases, including oncological pathology; interestingly, PP2A appears to be essential for controlling cell growth and may be involved in cancer development. The role of PP2A as a tumor suppressor has been extensively studied and reviewed. To leverage the potential clinical utility of combination PP2A inhibition and radiotherapy treatment, it is vital that novel highly specific PP2A inhibitors be developed. In this review, the existing literature on the role of PP2A in brain tumors, especially in gliomas and glioblastoma (GBM), was analyzed. Interestingly, the review focused on the role of PP2A inhibitors, focusing on CIP2A inhibition, as CIP2A participated in tumor cell growth by stimulating cell-renewal survival, cellular proliferation, evasion of senescence and inhibition of apoptosis. This review suggested CIP2A inhibition as a promising strategy in oncology target therapy.

GSK343, an Inhibitor of Enhancer of Zeste Homolog 2, Reduces Glioblastoma Progression through Inflammatory Process Modulation: Focus on Canonical and Non-Canonical NF-κB/IκBα Pathways

Glioblastoma (GB) is a tumor of the central nervous system characterized by high proliferation and invasiveness. The standard treatment for GB includes radiotherapy and chemotherapy; however, new therapies are needed. Particular attention was given to the role of histone methyltransferase enhancer of zeste-homolog-2 (EZH2) in GB. Recently, several EZH2-inhibitors have been developed, particularly GSK343 is well-known to regulate apoptosis and autophagy processes; however, its abilities to modulate canonical/non-canonical NF-κB/IκBα pathways or an immune response in GB have not yet been investigated. Therefore, this study investigated for the first time the effect of GSK343 on canonical/non-canonical NF-κB/IκBα pathways and the immune response, by an in vitro, in vivo and ex vivo model of GB. In vitro results demonstrated that GSK343 treatments 1, 10 and 25 μM significantly reduced GB cell viability, showing the modulation of canonical/non-canonical NF-κB/IκBα pathway activation. In vivo GSK343 reduced subcutaneous tumor mass, regulating canonical/non-canonical NF-κB/IκBα pathway activation and the levels of reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD). Ex vivo results confirmed the anti-proliferative effect of GSK343 and also demonstrated its ability to regulate immune response through CXCL9, CXCL10 and CXCL11 expression in GB. Thus, GSK343 could represent a therapeutic strategy to counteract GB progression, thanks to its ability to modulate canonical/non-canonical NF-κB/IκBα pathways and immune response.

Adenosine Targeting as a New Strategy to Decrease Glioblastoma Aggressiveness

Simple Summary

Given the rising mortality rate caused by GBM, current therapies do not appear to be effective in counteracting tumor progression. The role of adenosine and its interaction with specific receptor subtypes in various physiological functions has been studied for years. Only recently, adenosine has been defined as a tumor-protective target because of its accumulation in the tumor microenvironment. Current knowledge of the adenosine pathway and its involvement in brain tumors would support research in the development of adenosine receptor antagonists that could represent alternative treatments for glioblastoma, used either alone and/or in combination with chemotherapy, immunotherapy, or both.

Abstract

Glioblastoma is the most commonly malignant and aggressive brain tumor, with a high mortality rate. The role of the purine nucleotide adenosine and its interaction with its four subtypes receptors coupled to the different G proteins, A1, A2A, A2B, and A3, and its different physiological functions in different systems and organs, depending on the active receptor subtype, has been studied for years. Recently, several works have defined extracellular adenosine as a tumoral protector because of its accumulation in the tumor microenvironment. Its presence is due to both the interaction with the A2A receptor subtype and the increase in CD39 and CD73 gene expression induced by the hypoxic state. This fact has fueled preclinical and clinical research into the development of efficacious molecules acting on the adenosine pathway and blocking its accumulation. Given the success of anti-cancer immunotherapy, the new strategy is to develop selective A2A receptor antagonists that could competitively inhibit binding to its endogenous ligand, making them reliable candidates for the therapeutic management of brain tumors. Here, we focused on the efficacy of adenosine receptor antagonists and their enhancement in anti-cancer immunotherapy.

SUN11602, a bFGF mimetic, modulated neuroinflammation, apoptosis and calcium-binding proteins in an in vivo model of MPTP-induced nigrostriatal degeneration

Background

Parkinson’s disease (PD) is the second most frequent neurodegenerative disease. PD etiopathogenesis is multifactorial and not yet fully known, however, the scientific world advised the establishment of neuroinflammation among the possible risk factors. In this field, basic fibroblast growth factor/fibroblast growth factor receptor-1 (bFGF/FGFR1) could be a promising way to treat CNS-mediated inflammation; unfortunately, the use of bFGF as therapeutic agent is limited by its side effects. The novel synthetic compound SUN11602 exhibited neuroprotective activities like bFGF. With this perspective, this study aimed to evaluate the effect of SUN11602 administration in a murine model of MPTP-induced dopaminergic degeneration.

Methods

Specifically, nigrostriatal degeneration was induced by intraperitoneal injection of MPTP (80 mg/kg). SUN11602 (1 mg/kg, 2.5 mg/kg, and 5 mg/kg) was administered daily by oral gavage starting from 24 h after the first administration of MPTP. Mice were killed 7 days after MPTP induction.

Results

The results obtained showed that SUN11602 administration significantly reduced the alteration of PD hallmarks, attenuating the neuroinflammatory state via modulation of glial activation, NF-κB pathway, and cytokine overexpression. Furthermore, we demonstrated that SUN11602 treatment rebalanced Ca²⁺ overload in neurons by regulating Ca²⁺-binding proteins while inhibiting the apoptotic cascade.

Conclusion

Therefore, in the light of these findings, SUN11602 could be considered a valuable pharmacological strategy for PD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02457-3.

Effect of Melatonin on Psoriatic Phenotype in Human Reconstructed Skin Model

Psoriasis is an inflammatory and auto-immune skin-disease characterized by uncontrolled keratinocyte proliferation. Its pathogenesis is not still fully understood; however, an aberrant and excessive inflammatory and immune response can contribute to its progression. Recently, more attention has been given to the anti-inflammatory and immunomodulators effects of melatonin in inflammatory diseases. The aim of this paper was to investigate the effect of melatonin on psoriatic phenotype and also in S. aureus infection-associated psoriasis, with an in vitro model using Skinethic Reconstructed Human Epidermis (RHE). An in vitro model was constructed using the RHE, a three-dimensional-model obtained from human primary-keratinocytes. RHE-cells were exposed to a mix of pro-inflammatory cytokines, to induce a psoriatic phenotype; cells were also infected with S. aureus to aggravate psoriasis disease, and then were treated with melatonin at the concentrations of 1 nM, 10 nM, and 50 nM. Our results demonstrated that melatonin at higher concentrations significantly reduced histological damage, compared to the cytokine and S. aureus groups. Additionally, the treatment with melatonin restored tight-junction expression and reduced pro-inflammatory cytokine levels, such as interleukin-1β and interleukin-12. Our results suggest that melatonin could be considered a promising strategy for psoriasis-like skin inflammation, as well as complications of psoriasis, such as S. aureus infection.

Therapeutic Effect of Novel Cyanopyrrolidine-Based Prolyl Oligopeptidase Inhibitors in Rat Models of Amnesia

Prolyl oligopeptidase (POP) is a large cytosolic serine peptidase that is altered in patients with Alzheimer’s disease, Parkinsonian syndrome, muscular dystrophies, and other denervating diseases. Thus, POP may represent a relevant therapeutic target for treatment of neuropsychiatric disorders and neurodegenerative diseases. Here, we report the characterization of five novel cyanopyrrolidine-based compounds (BocTrpPrdN, BocGlyPrdN, CbzMetPrdN, CbzGlnPrdN, and CbzAlaPrdN) and show that they are potent inhibitors of POP and are predicted to penetrate the blood-brain barrier (BBB). Indeed, we show that CbzMetPrdN penetrates the rat BBB and effectively inhibits POP in the brain when administered intraperitoneally. Furthermore, molecular modeling confirmed these compounds likely inhibit POP via interaction with the POP catalytic site. We evaluated protective effects of the cyanopyrrolidine-based POP inhibitors using scopolamine- and maximal electroshock-induced models of amnesia in rats and showed that BocTrpPrdN, BocGlyPrdN, CbzMetPrdN, and CbzGlnPrdN significantly prolonged conditioned passive avoidance reflex (CPAR) retention time when administered intraperitoneally (1 and 2 mg/kg) before evaluation in both models of amnesia, although CbzAlaPrdN was not effective in scopolamine-induced amnesia. Our data support previous reports on the antiamnesic effects of prolinal-based POP inhibitors and indicate an important role of POP in the regulation of learning and memory processes in the CNS.

Beneficial effect of KYP-2047, a propyl-oligopeptidase inhibitor, on oral squamous cell carcinoma

Oral squamous cell-carcinoma (OSCC) is a common cancer which arises from the alveolar ridge, buccal mucosa, and tongue. Among OSCC, the incidence of tongue squamous cell-carcinoma (TSCC) is growing all over the world. Oral carcinogenesis has been linked to genetic mutations, chromosomal aberrations and viral factors. Apoptosis and angiogenesis play a key role in the development of oral cancer. Therefore, it is very important discover new therapeutic strategies to counteract oral cancer progression. This study aimed to investigate the effect of KYP-2047 in an in vitro model of TSCC and in vivo CAL27-xenograft model. Our results demonstrated that KYP-2047 was able to reduce TSCCs cell viability at the concentrations of 50 μM and 100 μM. Additionally, KYP-2047 was able to increase Bax, Bad and caspase-3 expression, whereas Bcl-2 and p53 expression were reduced. Moreover, KYP-2047 significantly reduced vascular-endothelial-growth-factor (VEGF) and endothelial-nitric-oxide-synthase (eNOS) expression. In the vivo xenograft model, KYP-2047 at doses of 1 and 5 mg/kg significantly reduced tumor burden and tumor weight, decreasing also angiogenesis markers VEGF and eNOS. Moreover, KYP-2047 increased Bax and reduced Bcl2 expressions. Thus, KYP-2047 could represent a potential therapeutic treatment to counteract tongue oral-cancer growth, thanks its abilities to modulate angiogenesis and apoptosis pathways.

Novel Treatment Strategies for Glioblastoma-A Summary

Glioblastoma (GBM) is the most common primary central nervous system tumor in adults, accounting for approximately 80% of all brain-related malignancies [...].

The Protective Role of Prolyl Oligopeptidase (POP) Inhibition in Kidney Injury Induced by Renal Ischemia-Reperfusion

Ischemia/reperfusion injury (IRI) is a complex pathophysiological process characterized by blood circulation disorder caused by various factors, such as traumatic shock, surgery, organ transplantation, and thrombus. Severe metabolic dysregulation and tissue structure destruction are observed upon restoration of blood flow to the ischemic tissue. The kidney is a highly perfused organ, sensitive to ischemia and reperfusion injury, and the incidence of renal IRI has high morbidity and mortality. Several studies showed that infiltration of inflammatory cells, apoptosis, and angiogenesis are important mechanisms involved in renal IRI. Despite advances in research, effective therapies for renal IRI are lacking. Recently it has been demonstrated the role of KYP2047, a selective inhibitor of prolyl oligopeptidase (POP), in the regulation of inflammation, apoptosis, and angiogenesis. Thus, this research focused on the role of POP in kidney ischemia/reperfusion (KI/R). An in vivo model of KI/R was performed and mice were subjected to KYP2047 treatment (intraperitoneal, 0.5, 1 and 5 mg/kg). Histological analysis, Masson's trichrome and periodic acid shift (PAS) staining, immunohistochemical and Western blots analysis, real-time PCR (RT-PCR) and ELISA were performed on kidney samples. Moreover, serum creatinine and blood urea nitrogen (BUN) were quantified. POP-inhibition by KYP2047 treatment, only at the doses of 1 and 5 mg/kg, significantly reduced renal injury and collagen amount, regulated inflammation through canonical and non-canonical NF-κB pathway, and restored renal function. Moreover, KYP2047 modulated angiogenesis markers, such as TGF-β and VEGF, also slowing down apoptosis. Interestingly, treatment with KYP2047 modulated PP2A activity. Thus, these findings clarified the role of POP inhibition in AKI, also offering novel therapeutic target for renal injury after KI/R.

NLRP3 Inflammasome Inhibitor BAY-117082 Reduces Oral Squamous Cell Carcinoma Progression

Oral cancer is one of the most common human malignancies, and its incidence is increasing worldwide. In particular, oral squamous cell carcinoma (OSCC) is characterized by high rates of proliferation, invasiveness, and metastasis. Currently, standard treatment for OSCC includes surgical removal, chemotherapy, and radiotherapy; however, the survival rate of patients with OSCC remains low, thus new therapies are needed. It has been proven that excessive NLRP3 inflammasome activation and apoptosis alteration may contribute to oral cancer progression. This study aimed to investigate the effect of BAY-117082, an NLRP3 inflammasome inhibitor, in an in vitro and in vivo xenograft model of oral cancer. In vitro results revealed that BAY-117082 at concentrations of 5, 10, and 30 µM was able to reduce OSCC cell viability. BAY-117082 at higher concentrations significantly reduced NLRP3, ASC, caspase-1, IL-1β, and IL-18 expression. Moreover, Bax, Bad, and p53 expression were increased, whereas Bcl-2 expression was reduced. Furthermore, the in vivo study demonstrated that BAY-117082 at doses of 2.5 and 5 mg/kg significantly decreased subcutaneous tumor mass, and also reduced NLRP3 inflammasome pathway activation. Therefore, based on these results, the use of BAY-117082 could be considered a promising strategy to counteract oral cancer progression, thanks its ability to modulate the NLRP3 inflammasome and apoptosis pathways.

Evaluating the Protective Properties of a Xyloglucan-Based Nasal Spray in a Mouse Model of Allergic Rhinitis

A breached nasal epithelial barrier plays an important role in driving allergic rhinitis (AR). Corticosteroids remain the standard of care (SoC) but come with side effects, thus alternative safe and effective treatments able to avoid inflammation and restore barrier integrity are needed. The aim of the present study is to evaluate the barrier-forming capacity of a xyloglucan-based nasal spray (XG) and compare its efficacy to several SoC treatments (corticosteroid spray, oral mast-cell stabilizer and oral antihistamine) in reducing allergic responses in addition to its effect when concomitantly administered with an antihistamine. An ovalbumin (OVA)-induced mouse AR model was used. XG shows a significant efficacy in reducing histological damage in AR mice; improves nasal rubbing and histamine-induced hyper-responsiveness. Total and OVA-specific IgE as well as pro-inflammatory cytokines are significantly reduced compared to OVA challenged-mice, with im-proved efficacy when used as an add-on treatment. However, XG reduces mucous secreting cells (PAS-positive) and mucin mRNA expression similar to the corticosteroid-treated mice. XG-spray maintains tight junction protein expression (ZO-1) and conversely decreases HDAC1 significantly; the latter being highly expressed in AR patients. Moreover, the concomitant treatment showed in all of the endpoints a similar efficacy to the corticosteroids. This innovative approach may represent a novel therapeutic strategy for nasal respiratory diseases like AR, reducing undesirable side effects and improving the quality of life in patients.