High Molecular Weight Hyaluronic Acid Research Articles

Rheological Properties of Hyaluronic Acid Diluted Solutions as Components of Cosmetics

Rheological measurements were carried out on dilute aqueous solutions of high (HMW-HA, 1150 kDa) and low molecular weight hyaluronic acids (LMW-HA, 8 kDa) along with their mixtures to determine the relationship between the viscosity and concentration of the samples. Molecular weight and polydispersity of low molecular HA have been determined by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). HA diluted solutions were found to be weakly structured liquids with a slight viscosity anomaly. Critical values of concentration were determined at different ratios of HMW-HA and LMW-HA, leading to a sharp increase in the viscosity of solutions. Rheological studies have proved the pseudoplastic nature of the viscous flow of HMW-HA solutions. The possibility of using the Ostwald-de Waele equation for the mathematical description of a viscous flow was established. The results of the rheological analysis might be applied for the rational development of cosmetic formulations containing hyaluronic acid of various molecular weights.

Self-assembled hyaluronic acid nanoparticles for osteoarthritis treatment

Although osteoarthritis (OA) is the most prevalent degenerative joint disease, there is no effective disease-modifying therapy. We report an empty self-assembled hyaluronic acid nanoparticle (HA-NP) as a potential therapeutic agent for OA treatment. In mouse primary articular chondrocytes, HA-NPs blocked the receptor-mediated cellular uptake of free low-molecular-weight HA, and the cellular uptake of HA-NPs increased by ectopic expression of CD44, using an adenoviral delivery system (Ad-Cd44). HA-NP showed in vitro resistance to digestion with hyaluronidase and in vivo long-term retention ability in knee joint, compared with free high-molecular-weight (HMW) HA. CD44 expression increased in the damaged articular cartilage of patients and mice with OA. Ad-Cd44 infection and IL-1β treatment induced in vitro phenotypes of OA by enhancing catabolic gene expression in primary articular chondrocytes, and these effects were attenuated by HA-NP, but not HMW HA. Both Cd44 deficiency and intra-articular injection of HA-NP protected joint cartilage against OA development in the OA mouse model. NF-κB was found to mediate CD44-induced catabolic factor expression and HA-NP inhibited CD44-induced NF-κB activation in chondrocytes. Our results identify an empty HA-NP as a potential therapeutic agent targeting CD44 for OA treatment, and the CD44-NF-κB-catabolic gene axis as an underlying mechanism of destructive cartilage disorders.

Sodium hyaluronate supplemented culture medium combined with joint-simulating mechanical loading improves chondrogenic differentiation of human mesenchymal stem cells.

In vitro models aim to recapitulate the in vivo situation. To more closely mimic the knee joint environment, current in vitro models need improvements to reflect the complexity of the native tissue. High molecular weight hyaluronan (hMwt HA) is one of the most abundant bioactive macromolecules in healthy synovial fluid, while shear and dynamic compression are two joint-relevant mechanical forces. The present study aimed at investigating the concomitant effect of joint-simulating mechanical loading (JSML) and hMwt HA-supplemented culture medium on the chondrogenic differentiation of primary human bone-marrow-derived mesenchymal stem cells (hBM-MSCs). hBM-MSC chondrogenesis was investigated over 28 d at the gene expression level and total DNA, sulphated glycosaminoglycan, TGF-β1 production and safranin O staining were evaluated. The concomitant effect of hMwt HA culture medium and JSML significantly increased cartilage-like matrix deposition and sulphated glycosaminoglycan synthesis, especially during early chondrogenesis. A stabilisation of the hBM-MSC-derived chondrocyte phenotype was observed through the reduced upregulation of the hypertrophic marker collagen X and an increase in the chondrogenic collagen type II/X ratio. A combination of JSML and hMwt HA medium better reflects the complexity of the in vivo synovial joint environment. Thus, JSML and hMwt HA medium will be two important features for joint-related culture models to more accurately predict the in vivo outcome, therefore reducing the need for animal studies. Reducing in vitro artefacts would enable a more reliable prescreening of potential cartilage repair therapies.

A bioinspired synthetic soft hydrogel for the treatment of dry eye.

Natural soft hydrogels are unique elastic soft materials utilized by living organisms for protecting delicate tissues. Under a theoretical framework derived from the Blob model, we chemically crosslinked high molecular weight hyaluronic acid at a concentration close to its overlap concentration (c*), and created synthetic soft hydrogels that exhibited unique rheological properties similar to a natural soft hydrogel: being dominantly elastic under low shear stress while being viscous when the stress is above a small threshold. We explored a potential application of the hyaluronic acid‐based soft hydrogel as a long‐acting ocular surface lubricant and evaluated its therapeutic effects for dry eye. The soft hydrogel was found to be biocompatible after topical instillation on experimental animals' and companion dogs' eyes. In a canine clinical study, twice‐a‐day ocular instillation of the soft hydrogel in combination with cyclosporine for 1 month improved the clinical signs in more than 65% of dog patients previously unresponsive to cyclosporine treatment.

Downregulation of Hyaluronic acid-CD44 signaling pathway in cervical cancer cell by natural polyphenols Plumbagin, Pongapin and Karanjin.

Hyaluronic acid (HA)-CD44 pathway showed association with several malignancies. The natural polyphenols Plumbagin, Pongapin and Karanjin showed anti-cancer activities in different tumors including cervical carcinoma. To understand their mechanism of anti-cancer activity, the effect of the compounds on HA-CD44 pathway was analyzed in cervical cancer cell line HeLa. The mRNA expression of three different isoforms of CD44 i.e., CD44s, CD44v3, and CD44v6, was differentially downregulated by the compounds. This was validated by Western blot and immunocytochemical analysis of CD44s.The low molecular weight HA (LMW-HA) showed growth promoting activity in HeLa at low concentration, whereas high molecular weight HA (HMW-HA) had no such effect. The compounds could preferentially downregulate the LMW-HA level in HeLa, as evident in the cell as well as in the cell-free conditioned medium. Concentration-dependent upregulation of HA synthase-2 (HAS2) was seen in the cell by the compounds, whereas differential downregulation of hyalurinidases 1-4 (HYAL 1-4), predominantly HYAL1, were seen. The compounds could also downregulate the downstream target of the pathway p-AKT (T-308) in concentration-dependent manner. Thus, the compounds could attenuate the HA-CD44 pathway in HeLa cell to restrict the tumor growth.

Experience in the use of high-molecular-weight hyaluronic acid in the treatment of chronic generalized periodontitis

As a rule, periodontal diseases are accompanied by marginal recession of the gums, loss of attachment and exposure of the roots of the teeth. Traditional drugs for injection treatment are being replaced by modern drugs based on high molecular weight hyaluronic acid, which are successfully and highly efficiently used for local therapy of inflammatory and destructive periodontal diseases. In order to restore the volume of soft tissues in the interdental spaces, eliminate recessions and bleeding of the gingival margin, a preparation of high molecular weight hyaluronic acid “Revident +” was used, which was injected into the base of the gingival papilla at a distance of 2—3 mm from its top with the bevel of the needle upwards. To assess gingival bleeding, the PBI (papilla bleeding index) index was used, which is a sensitive indicator of the severity of gingival inflammation. The magnitude of gingival recession before and after treatment was assessed according to its severity: mild — up to 3 mm, moderate — 3—5 mm, and severe — 6 and more mm. Examination of periodontal patients before and 1.5 months after the application of high molecular weight hyaluronic acid in the composition of the Revident + preparation showed that the degree of gingival bleeding according to PBI decreased significantly after the third visit from 4 to 2 and from 3 to 1, respectively. The degree of gingival recession in the area of the anterior group of teeth decreased by an average of 2.1 mm, in the area of premolars — by 2.5 mm, and in the area of molars — by 2.8 mm.

Unsulfated biotechnological chondroitin by itself as well as in combination with high molecular weight hyaluronan improves the inflammation profile in osteoarthritis in vitro model.

Several studies suggest that inflammation has a pivotal role during the progression of osteoarthritis (OA) and cytokines have been identified as the main process mediators. This study aimed to explore the ability to modulate the main OA pro‐inflammatory biomarkers of novel gels (H‐HA/BC) based on high molecular weight hyaluronan (H‐HA) and unsulfated biotechnological chondroitin (BC). For the first time, BC was tested also in combination with H‐HA on human primary cells isolated from pathological knee joints. Specifically, the experiments were performed using an OA in vitro model based on human chondrocytes and synoviocytes. To evaluate the anti‐inflammatory effects of H‐HA/BC in comparison with H‐HA and BC single gels, NF‐kB, COMP‐2, MyD88, MMP‐13 and a wide range of cytokines, known to be specific biomarkers in OA (e.g., IL‐6, IL‐8, and TNF‐α), were evaluated. In addition, cell morphology and proliferation occurring in the presence of either H‐HA/BC or single components were assessed using time‐lapse video microscopy. It was shown that synovial fluids and cells isolated from OA suffering patients, presented a cytokine pattern respondent to an ongoing inflammation status. H‐HA and BC significantly reduced the levels of 23 biomarkers associated with cartilage damage. However, H‐HA/BC decreased significantly 24 biological mediators and downregulated 19 of them more efficiently than the single components. In synoviocytes cultures, cytokine analyses proved that H‐HA/BC gels re‐established an extracellular environment more similar to a healthy condition reducing considerably the concentration of 11 analytes. Instead, H‐HA and BC significantly modulated 7 (5 only with a longer treatment) and 8 biological cytokines, respectively. Our results suggest that H‐HA/BC beyond the viscosupplementation effect typical for HA‐based gels, can improve the inflammation status in joints and thus could be introduced as a valid protective and anti‐inflammatory intraarticular device in the field of Class III medical devices for OA treatments.

Estimation of the Effect of Accelerating New Bone Formation of High and Low Molecular Weight Hyaluronic Acid Hybrid: An Animal Study.

Osteoconduction is an important consideration for fabricating bio-active materials for bone regeneration. For years, hydroxyapatite and β-calcium triphosphate (β-TCP) have been used to develop bone grafts for treating bone defects. However, this material can be difficult to handle due to filling material sagging. High molecular weight hyaluronic acid (H-HA) can be used as a carrier to address this problem and improve operability. However, the effect of H-HA on bone formation is still controversial. In this study, low molecular weight hyaluronic acid (L-HA) was fabricated using gamma-ray irradiation. The viscoelastic properties and chemical structure of the fabricated hybrids were evaluated by a rheological analysis nuclear magnetic resonance (NMR) spectrum. The L-MH was mixed with H-HA to produce H-HA/L-HA hybrids at ratios of 80:20, 50:50 and 20:80 (w/w). These HA hybrids were then combined with hydroxyapatite and β-TCP to create a novel bone graft composite. For animal study, artificial bone defects were prepared in rabbit femurs. After 12 weeks of healing, the rabbits were scarified, and the healing statuses were observed and evaluated through micro-computer tomography (CT) and tissue histological images. Our viscoelastic analysis showed that an HA hybrid consisting 20% H-HA is sufficient to maintain elasticity; however, the addition of L-HA dramatically decreases the dynamic viscosity of the HA hybrid. Micro-CT images showed that the new bone formations in the rabbit femur defect model treated with 50% and 80% L-HA were 1.47 (p < 0.05) and 2.26 (p < 0.01) times higher than samples filled with HA free bone graft. In addition, a similar tendency was observed in the results of HE staining. These results lead us to suggest that the material with an H-HA/L-HA ratio of 50:50 exhibited acceptable viscosity and significant new bone formation. Thus, it is reasonable to suggest that it may be a potential candidate to serve as a supporting system for improving the operability of granular bone grafts and enhancing new bone formations.

Role of CD44 in increasing the potency of mesenchymal stem cell extracellular vesicles by hyaluronic acid in severe pneumonia

BackgroundAlthough promising, clinical translation of human mesenchymal stem or stromal cell-derived extracellular vesicles (MSC EV) for acute lung injury is potentially limited by significant production costs. The current study was performed to determine whether pretreatment of MSC EV with high molecular weight hyaluronic acid (HMW HA) would increase the therapeutic potency of MSC EV in severe bacterial pneumonia.MethodsIn vitro experiments were performed to determine the binding affinity of HMW HA to MSC EV and its uptake by human monocytes, and whether HMW HA primed MSC EV would increase bacterial phagocytosis by the monocytes. In addition, the role of CD44 receptor on MSC EV in the therapeutic effects of HMW HA primed MSC EV were investigated. In Pseudomonas aeruginosa (PA) pneumonia in mice, MSC EV primed with or without HMW HA were instilled intravenously 4 h after injury. After 24 h, the bronchoalveolar lavage fluid, blood, and lungs were analyzed for levels of bacteria, inflammation, MSC EV trafficking, and lung pathology.ResultsMSC EV bound preferentially to HMW HA at a molecular weight of 1.0 MDa compared with HA with a molecular weight of 40 KDa or 1.5 MDa. HMW HA primed MSC EV further increased MSC EV uptake and bacterial phagocytosis by monocytes compared to treatment with MSC EV alone. In PA pneumonia in mice, instillation of HMW HA primed MSC EV further reduced inflammation and decreased the bacterial load by enhancing the trafficking of MSC EV to the injured alveolus. CD44 siRNA pretreatment of MSC EV prior to incubation with HMW HA eliminated its trafficking to the alveolus and therapeutic effects.ConclusionsHMW HA primed MSC EV significantly increased the potency of MSC EV in PA pneumonia in part by enhancing the trafficking of MSC EV to the sites of inflammation via the CD44 receptor on MSC EV which was associated with increased antimicrobial activity.

B10 cells decrease fibrosis progression following cardiac injury partially by IL-10 production and regulating hyaluronan secretion.

B10 cells play negative roles in inflammatory disorders by producing IL-10. However, their effects on fibrosis have not been elucidated. Therefore, this study was conducted to examine the dynamic changes of B10 cell frequency and their potential role in cardiac fibrosis. We found that the frequency of B10 cells was significantly increased, and they participated in the regression of fibrosis via IL-10, particularly by accelerating hyaluronan secretion and inhibiting collagen deposition. In vivo, hyaluronan ablation or treatment significantly restricted cardiac fibrosis development. hyaluronan-induced conversion of M1/M2 Mc was dependent on the size of hyaluronan. Low molecular weight hyaluronan promoted the conversion to M1 Mϕ, whereas medium and high molecular weight hyaluronan accelerated Mϕ transdifferentiation into the M2 phenotype. Adoptive transfer of B10 cells significantly attenuated collagen deposition whereas CD19-/- mice with reduced B10 cells exacerbated fibrosis following cardiac injury. Our results provide new evidence suggesting that B10 cells exert antifibrotic effects by regulating the extracellular matrix composition during cardiac injury, and also highlight that B10 cells may serve as a promising therapeutic candidate for managing cardiac fibrosis-associated disorders.

Investigation of synovial fluid lubricants and inflammatory cytokines in the horse: a comparison of recombinant equine interleukin 1 beta-induced synovitis and joint lavage models

BackgroundLameness is a debilitating condition in equine athletes that leads to more performance limitation and loss of use than any other medical condition. There are a limited number of non-terminal experimental models that can be used to study early inflammatory and synovial fluid biophysical changes that occur in the equine joint. Here, we compare the well-established carpal IL-1β-induced synovitis model to a tarsal intra-articular lavage model, focusing on serial changes in synovial fluid inflammatory cytokines/chemokines and the synovial fluid lubricating molecules lubricin/proteoglycan 4 and hyaluronic acid. The objectives of this study were to evaluate clinical signs; synovial membrane and synovial fluid inflammation; and synovial fluid lubricants and biophysical properties in response to carpal IL-1β synovitis and tarsal intra-articular lavage.ResultsHyaluronic acid (HA) concentrations, especially high molecular weight HA, and synovial fluid viscosity decreased after both synovitis and lavage interventions. Synovial fluid lubricin concentrations increased 17–20-fold for both synovitis and lavage models, with similar changes in both affected and contralateral joints, suggesting that repeated arthrocentesis alone resulted in elevated synovial fluid lubricin concentrations. Synovitis resulted in a more severe inflammatory response based on clinical signs (temperature, heart rate, respiratory rate, lameness and joint effusion) and clinicopathological and biochemical parameters (white blood cell count, total protein, prostaglandin E2, sulfated glycosaminoglycans, tumor necrosis factor-α and CC chemokine ligands − 2, − 3, − 5 and − 11) as compared to lavage.ConclusionsSynovial fluid lubricin increased in response to IL-1β synovitis and joint lavage but also as a result of repeated arthrocentesis. Frequent repeated arthrocentesis is associated with inflammatory changes, including increased sulfated glycosaminoglycan concentrations and decreased hyaluronic acid concentrations. Synovitis results in more significant inflammatory changes than joint lavage. Our data suggests that synovial fluid lubricin, TNF-α, CCL2, CCL3, CCL5, CCL11 and sGAG may be useful biomarkers for synovitis and post-lavage joint inflammation. Caution should be exercised when performing repeated arthrocentesis clinically or in experimental studies due to the inflammatory response and loss of HA and synovial fluid viscosity.

RETRACTED ARTICLE: Effect of a single intra-articular high molecular weight hyaluronan in a naturally occurring canine osteoarthritis model: a randomized controlled trial

BackgroundOsteoarthritis (OA) is a complex joint disease and chronic pain source, affecting a patient’s quality of life and posing a financial burden. As the dog is considered a nearly ideal species for translation research of human OA and the most used model for research, exploring spontaneous dog OA under the One Health/One Medicine concept can improve both humans and dogs’ health and well-being.MethodsIn a clinical treatment experiment, forty (N=40) joints were selected and randomly assigned to a control group (CG), which received 0.9% NaCl or a treatment (HG), which received Hylan G-F 20. Evaluations were performed on treatment day (T0), 8, 15, 30, 90, and 180 days post-treatment. They consisted of four different Clinical Metrology Instruments (CMI), evaluation of weight distribution, joint range of motion, thigh girth, radiographic and digital thermography imaging, synovial fluid interleukin-1 (IL-1), and C-reactive protein concentrations. Results were compared with repeated measures ANOVA, with a Huynh-Feldt correction, Paired samples T-test, or Wilcoxon signed-ranks test, with p<0.05.ResultsPatients had a mean age of 6.5±2.4 years and a bodyweight of 26.6±5.2kg, and joints graded as mild (n=28, 70%), moderate (n=6, 15%), and severe OA (n=6, 15%). No differences were found between groups at T0. Symmetry index and deviation showed significant improvements in HG from 30 days (p<0.01) up to 180 days (p=0.01). Several CMI scores, particularly pain scores, improved from 90 to 180 days. Radiographic signs progressed in both groups. In both groups, increasing body weight and age corresponded to worse clinical presentation. IA hyaluronan administration produced increased lameness in six cases, which resolved spontaneously.ConclusionsThis study characterizes the response to treatment with Hylan G-F 20, which can produce significant functional and pain level improvements in patients with OA, even those with factors related to worse response to treatment.

Influence of high-molecular hyaluronic acid on MCF-7 breast cancer stem cells

In recent years, more and more data have been accumulating on the high radio- and chemo-resistance of tumor stem cells (CSCs), confirming the assumption that these cells play an important role in the recurrence of the tumor process in some cancer patients. Therefore it is of considerable interest to elucidate the patterns and mechanisms of the formation of the CSC pool under the influence of various factors, including one of the main components of the extracellular matrix, hyaluronic acid (HA). The purpose of the study was to elucidate the effects of HA with a molecular weight of (1-3) x 106 Dа on the amount of CSCs in MCF-7 breast cancer cell culture in vitro. Material and methods. Using the MTT test, the viability of MCF-7 cancer cells was determined after incubation with HA at a concentration of 0.3-5.0 mg/ml. Using flow cytometry, we evaluated the change in the relative and absolute amount of CSCs under the influence of HA (0.6 mg/ml). CSCs were detected by CD44+CD24-/low immunophenotype, as well as by their ability to efficiently efflux Hoechst 33342 fluorescent dye from cells and form so-called side population (SP). Results. Viability of cancer cells in the general population decreased with increasing concentration of HA (R=-0.94, p=0.006). At the same time the incubation of cells with HA led to an increase in both the relative and absolute amounts of CSCs (SP) compared with the control. Thus, the relative number of SP cells increased by 2.0 times (p = 0.002), CD44 + CD24- / low cells - by 6.1 times (p = 0.005). The absolute number of these cells changed to a lesser extent compared to the control: the increase was 1.6 (p = 0.004) and 2.9 times (p = 0.02), respectively. Conclusion. Thus, the effect of high-molecular weight HA on breast cancer cells of MCF-7 line leads to an increase in amount of CSCs, while the viability of non-stem cancer cells decreases under the same conditions.

Sexually Dimorphic Role of Toll-like Receptor 4 (TLR4) in High Molecular Weight Hyaluronan (HMWH)-induced Anti-hyperalgesia

High molecular weight hyaluronan (HMWH), a prominent component of the extracellular matrix binds to and signals via multiple receptors, including cluster of differentiation 44 (CD44) and toll-like receptor 4 (TLR4). We tested the hypothesis that, in the setting of inflammation, HMWH acts at TLR4 to attenuate hyperalgesia. We found that the attenuation of prostaglandin E2 (PGE2)-induced hyperalgesia by HMWH was attenuated by a TLR4 antagonist (NBP2-26245), but only in male and ovariectomized female rats. In this study we sought to evaluated the role of the TLR4 signaling pathway in anti-hyperalgesia induced by HMWH in male rats. Decreasing expression of TLR4 in nociceptors, by intrathecal administration of an oligodeoxynucleotide (ODN) antisense to TLR4 mRNA, also attenuated HMWH-induced anti-hyperalgesia, in male and ovariectomized female rats. Estrogen replacement in ovariectomized females reconstituted the gonad-intact phenotype. The administration of an inhibitor of myeloid differentiation factor 88 (MyD88), a TLR4 second messenger, attenuated HMWH-induced anti-hyperalgesia, while an inhibitor of the MyD88-independent TLR4 signaling pathway did not. Since it has previously been shown that HMWH-induced anti-hyperalgesia is also mediated, in part by CD44 we evaluated the effect of the combination of ODN antisense to TLR4 and CD44 mRNA. This treatment completely reversed HMWH-induced anti-hyperalgesia in male rats. Our results demonstrate a sex hormone-dependent, sexually dimorphic involvement of TLR4 in HMWH-induced anti-hyperalgesia, that is MyD88 dependent. PerspectiveThe role of TLR4 in anti-hyperalgesia induced by HMWH is a sexually dimorphic, TLR4 dependent inhibition of inflammatory hyperalgesia that provides a novel molecular target for the treatment of inflammatory pain.

619 IL-10 producing CD4+ T-cells mitigate dermal fibrosis

Background: CD4+ T-cells are essential in regulating dermal fibrosis and are a main source of IL-10. We have shown that IL-10 reduces dermal fibrosis by upregulating high molecular weight hyaluronan (HMW-HA). However, little of known the role of these cells in scarring. We hypothesize that IL-10 producing CD4+ cells attenuate dermal wound fibrosis via mediating inflammation and altering fibroblast extracellular matrix (ECM) production. Methods: C57BL/6J murine(6-10wk) splenocytes were enriched and sort into CD4+ IL-10 producing cells (Treg&Tr1). In vitro, fibroblasts were co-cultured with Treg or Tr1; fibrotic (Col1a1, aSMA) and ECM remodeling (HA synthases (HAS)1-3) markers were analyzed (qRT-PCR). In vivo, we performed bilateral 6mm dorsal full-thickness wounds on SCID mice (female,8-10wk), and adoptively transferred 106 CD4+, Treg, or Tr1 cells. Wounds were harvested at days 7/28 and analyzed for closure (H&E), fibrosis (trichrome), cell-cell spatial relationships (imaging mass cytometry) and inflammation panel (Luminex). Results: We confirmed the population (flow cytometry) and functionality (IL-10 ELISA) of Treg and Tr1. In the co-culture, Col1a1 in Tr1/Treg treated fibroblasts was reduced by 52.4% or 43.5%; and aSMA was reduced by 25.2% or 44.7%, respectively, compared to untreated fibroblasts. HAS2, a hyaluronan synthase which primarily produces HMW-HA, increased 3.11 or 2.95-fold with Tr1/Treg respectively. In vivo, Tr1 treated mice wound showed expedited wound closure at d7 and significantly greater aSMA (IHC), though both CD4+ and Tr1 treatments resulted in significantly reduced collagen content at d28 (trichrome). Reduced F4/80 were observed in all wounds treated with T cells (IHC). Luminex assay revealed wounds treated with Tr1 had decreased proinflammatory cytokines IL-6, MCP-1, and GM-CSF. Conclusions: IL-10 producing CD4+ cells regulate fibroblast ECM deposition and inflammatory cytokine balance to attenuate fibrosis. Promoting Tr1 recruitment, IL-10 production, and HMW-HA synthesis in wounds may a therapeutic target to improve wound healing.

Abundance and size of hyaluronan in naked mole-rat tissues and plasma

Large amounts of ultra-high molecular weight hyaluronan (HA) have been described as the main cause of cancer resistance in naked mole-rats (Heterocephalus glaber, NMR). Our work examined HA metabolism in these rodents more closely. HA was localized and quantified using HA binding proteins. Its molecular weight was determined using size exclusion chromatography and gel electrophoresis, HA family gene expression using RNAseq analysis, and hyaluronidase activity using zymography. Guinea pigs (Cavia porcellus) and mice (Mus musculus) were used as controls for some experiments. We found that HA localization was similar in NMR, guinea pig, and mouse tissues but NMR had larger amounts and higher molecular weight (maximum, around 2.5 MDa) of HA in serum and almost all tissues tested. We could not find ultra-high molecular weight HA (≥ 4 MDa) in NMR samples, in contrast to previous descriptions. Hyaluronidase-1 had lower expression and activity in NMR than mouse lymph nodes. RNAseq results showed that, among HA family genes, Tnfaip6 and hyaluronidase-3 (Hyal3) were systematically overexpressed in NMR tissues. In conclusion, NMR samples, contrary to expectations, do not harbor ultra-high molecular weight HA, although its amount and average molecular weight are higher in NMR than in guinea pig tissues and serum. Although hyaluronidase expression and activity are lower in NMR than mouse lymph nodes, this not sufficient to explain the presence of high molecular weight HA. A different activity of the NMR HA synthases remains possible. These characteristics, together with extremely high Hyal3 and Tnfaip6 expression, may provide the NMR with a bespoke, and perhaps protective, HA metabolism.

Strategies to manage anterior disc displacement without reduction of temporomandibular joint: a case report

Introduction Articular disc displacement is the most common temporomandibular joint (TMJ) arthropathy [1]. Disc displacement without reduction (DDwoR) is an intracapsular biomechanical disorder involving the condyle-disc complex [1] and can cause TMJ pain, limited mouth opening [2] and a change in the opening pattern of the patient. At first, the treatment for DDwoR should be reversible and conservative and include drugs, interocclusal devices and physiotherapy (PT) [3]. Moreover, minimally invasive techniques such as viscosupplementation (VS) seems to reduce pain and symptoms associated with internal derangement and improve quality of life [4]. The aim of this study is to report the efficacy of a combined protocol (PT and VS) in the control of signs and symptoms of a patient with temporomandibular disorder (TMD). Materials and methods Female patient, 38 years, with signs and symptoms of TMD presents a clinical diagnosis of right TMJ DDwoR and left TMJ subluxation, according with the Diagnostic Criteria for Temporomandibular Disorders protocol (DC/TMD). The initial pain free opening (PFO) was 31 mm with an uncorrected deviation to the right side in terms of opening pattern. Interdisciplinary team composed by two dentists and two physiotherapists decided the following strategy: assessment of PFO and opening pattern (DC/TMD examination form) before and after any intervention. After the initial assessment we had the first session of PT to prepare for the VS composed of behavioural and cognitive therapy, manual therapy, motor control exercises and prescription of home exercises. One week after we performed the first session of VS with 1 ml of high molecular weight hyaluronic acid bilaterally in the TMJ followed by another session of PT. Two sessions were performed, once a week, in two consecutive weeks. All the assumptions of the Helsinki Declaration have been fulfilled and an informed consent for clinical case of Clínica Dentária Egas Moniz approved by the ethic commission of Instituto Universitário Egas Moniz. Results Data was collected before and after any intervention. In first session of PT, PFO measurements increased from 31 mm to 38 mm and opening pattern remained a right uncorrected deviation. After the VS and second PT session the PFO increased from 35 mm at the beginning of the intervention to 45 mm at the end and the opening pattern changed to a straight opening pattern. Discussion and conclusions VS has been proven to be effective for knee and other large joints [4]. Studies suggest that adding VS to PT and therapeutic exercise may increase functionality [5]. No significant differences between non-invasive conservative interventions and minimally invasive or invasive surgical interventions for TMJ DDwoR [2] so primary treatment should consist of conservative strategies [6] carried out by a multidisciplinary team in order to improve range of motion, restore biomechanics, dynamic lubrification and function. This case report suggest the effectiveness of the combined protocol (PT and VS) in the control of signs and symptoms of TMD reinforcing the role of the interdisciplinary team. However, further studies should be done with an increased sample.

Wound Healing Promotion by Hyaluronic Acid: Effect of Molecular Weight on Gene Expression and In Vivo Wound Closure.

Hyaluronic acid (HA) has been known to play an important role in wound healing process. However, the effect of molecular weight (MW) of exogenously administered HA on the wound healing process has not been fully understood. In this study, we investigated HA with different MWs on wound healing process using human epidermal keratinocytes and dermal fibroblasts. Cell proliferation and migration ability were assessed by water soluble tetrazolium (WST) assay and wound scratch assay. We examined the effect of HA addition in a full-thickness wound model in mice and the gene expression related to wound healing. Proliferation and migration of HaCaT cells increased with the increase of MW and concentration of HA. Interleukin (IL-1β), IL-8 and vascular endothelial growth factor (VEGF) as well as matrix metalloproteinase (MMP)-9 and MMP-13 were significantly upregulated by high molecular weight (HMW) HA in keratinocytes. Together with VEGF upregulation and the observed promotion of HaCaT migration, HA with the MW of 2290 kDa may hold potential to improve re-epithelialization, a critical obstacle to heal chronic wounds.

Embryo biosensing by uterine natural killer cells determines endometrial fate decisions at implantation.

Decidualizing endometrial stromal cells (EnSC) critically determine the maternal response to an implanting conceptus, triggering either menstruation‐like disposal of low‐fitness embryos or creating an environment that promotes further development. However, the mechanism that couples maternal recognition of low‐quality embryos to tissue breakdown remains poorly understood. Recently, we demonstrated that successful transition of the cycling endometrium to a pregnancy state requires selective elimination of pro‐inflammatory senescent decidual cells by activated uterine natural killer (uNK) cells. Here we report that uNK cells express CD44, the canonical hyaluronan (HA) receptor, and demonstrate that high molecular weight HA (HMWHA) inhibits uNK cell‐mediated killing of senescent decidual cells. In contrast, low molecular weight HA (LMWHA) did not attenuate uNK cell activity in co‐culture experiments. Killing of senescent decidual cells by uNK cells was also inhibited upon exposure to medium conditioned by IVF embryos that failed to implant, but not successful embryos. Embryo‐mediated inhibition of uNK cell activity was reversed by recombinant hyaluronidase 2 (HYAL2), which hydrolyses HMWHA. We further report a correlation between the levels of HYAL2 secretion by human blastocysts, morphological scores, and implantation potential. Taken together, the data suggest a pivotal role for uNK cells in embryo biosensing and endometrial fate decisions at implantation.

The Association Between Plasma Hyaluronan Level and Plaque Types in ST-Segment–Elevation Myocardial Infarction Patients

Background: The metabolism of hyaluronan (HA) is widely known to be involved in the process of acute coronary syndrome, but it is unknown how circulating HA levels change in ST-Segment–Elevation Myocardial Infarction (STEMI) patients and whether HA is associated with plaque morphology, including rupture and erosion.Objectives: This study focused on the changes in the plasma levels of high molecular weight (HMW) HA (>35 kDa) and CD44 in STEMI patients and their relationship with plaque morphology evaluated by optical coherence tomography (OCT).Methods: We prospectively enrolled 3 cohorts in this study, including 162 patients with STEMI, 34 patients with stable coronary artery disease (S-CAD) and 50 healthy controls. Plaque morphology was detected by OCT analysis, and the plasma levels of HMW HA and CD44 were examined by enzyme-linked immunosorbent assay (ELISA). We compared plasma level of HMW HA and CD44 among STEMI patients, S-CAD patients and healthy controls, as well as in plaque rupture and plaque erosion.Results: The plasma levels of HMW HA and CD44 were significantly lower in STEMI patients than in healthy controls (p = 0.009 and p < 0.001, respectively). In addition, plasma level of HMW HA in plaque erosion was significantly lower than that in plaque rupture (p = 0.021), whereas no differences were found in plasma level of soluble CD44 between plaque rupture and erosion.Conclusions: Low levels of circulating HMW HA and CD44 were independently correlated with STEMI, and low levels of HMW HA were associated with plaque erosion compared with rupture. Moreover, plasma HMW HA might be a useful biomarker for identifying plaque erosion to improve the risk stratification and management of STEMI patients.