Deposition Of Hyaluronic Acid Research Articles

Knockdown of Hyaluronan synthase 2 suppresses liver fibrosis in mice via induction of transcriptomic changes similar to 4MU treatment.

Hepatic fibrosis remains a significant clinical challenge due to ineffective treatments. 4-methylumbelliferone (4MU), a hyaluronic acid (HA) synthesis inhibitor, has proven safe in phase one clinical trials. In this study, we aimed to ameliorate liver fibrosis by inhibiting HA synthesis. We compared two groups of mice with CCl4-induced fibrosis, treated with 4-methylumbelliferone (4MU) and hyaluronan synthase 2 (HAS2) targeting siRNA (siHAS2). The administration of 4MU and siHAS2 significantly reduced collagen and HA deposition, as well as biochemical markers of hepatic damage induced by repeated CCl4 injections. The transcriptomic analysis revealed converging pathways associated with downstream HA signalling. 4MU- and siHAS2-treated fibrotic livers shared 405 upregulated and 628 downregulated genes. These genes were associated with xenobiotic and cholesterol metabolism, mitosis, endoplasmic reticulum stress, RNA processing, and myeloid cell migration. The functional annotation of differentially expressed genes (DEGs) in siHAS2-treated mice revealed attenuation of extracellular matrix-associated pathways. In comparison, in the 4MU-treated group, DEGs were related to lipid and bile metabolism pathways and cell cycle. These findings confirm that HAS2 is an important pharmacological target for suppressing hepatic fibrosis using siRNA.

Liver-Targeting Composite Nanocarrier Delivery System Based on Chitosan Nanoparticles and Phospholipid Complexes.

Liver fibrosis is mainly caused by excessive accumulation of extracellular matrix and structural changes in the liver, ultimately leading to cirrhosis if left untreated. Reducing hyaluronan synthesis by inhibiting hyaluronic acid deposition or regulating the expression of hyaluronic synthase can ameliorate liver fibrosis symptoms. In this study, we aimed to improve the bioavailability and liver-targeting capacity of hydroxymethyl coumarin (4-MU) using a newly developed phospholipid complex chitosan nanoparticle (4-MU PC/CNP) optimized using the Box-Behnken design. The composite nanocarrier delivery system was formulated using solvent evaporation technology, and formulation and process parameters were evaluated. Furthermore, 4-MU PC/CNPs and their pharmacokinetics were characterized. The established 4-MU PC/CNPs had an average particle size of 153.07 ± 0.29 nm, a polydispersity index value of 0.383, and a positive zeta potential of ∼35.4 mV. Compared with 4-MUs, 4-MU PC/CNPs exhibited significantly improved water solubility, faster plasma clearance and tissue distribution, and better liver targeting. Pharmacokinetic analysis showed that the oral bioavailability of 4-MU in 4-MU PC/CNPs was significantly higher than that of simple 4-MU. In conclusion, 4-MU PC improved drug lipid (oil-water distribution coefficient of 1.31 ± 0.03) and water solubilities (2.05 times the drug substance). 4-MU PC/CNPs significantly improved 4-MU oral bioavailability, representing a promising approach for enhancing drug solubility. This study demonstrates that the targeting parameters of 4-MU PC/CNPs in the liver were all greater than 1, indicating that they specifically targeted the liver, thereby potentially alleviating liver fibrosis.

Brazilian hug lips: a new approach to treating inverted and atrophic lips with hyaluronic acid

Background: Inverted and atrophic lips are always a major challenge when we opt for treatment with hyaluronic acid. In most cases, the correct indication would be surgical correction (Liplifting). However, we bring a new technique to provide improved lip inversion with aesthetically natural results. Methods: Six female patients aged between 30-80 years old and without any previous lip treatment were selected. The application of hyaluronic acid was carried out following the criteria developed by the authors, and deposition of hyaluronic acid using the C-shaped technique or "embrace" technique (HUG lips). Results: By following the technique and quantities (ml) of hyaluronic acid described, we achieve natural and satisfactory results for lip eversion. Conclusion: According to our study, we observed an improvement in lip definition, correcting atrophic lips, without the need for surgery, with a high level of satisfaction among treated patients.

Effects of hepatocyte growth factor-transfected mesenchymal stem cell transplantation in canine injured vocal folds

This study aimed to assess the efficacy of hepatocyte growth factor (HGF)-transfected adipose-derived mesenchymal stem cell (ADSC) transplantation in the injured vocal folds (VFs) of canines. A lentiviral vector encoding HGF was successfully produced via Gateway cloning, which was used to infect ADSCs. Four weeks after transoral laser microsurgery (type II) with CO2 laser, the beagles of each group were injected with HGF-transfected ADSCs or uninfected ADSCs into VFs. The results showed that the retention of HGF-transfected ADSCs in the VFs persisted about three months post-injection. The VFs in the HGF-transfected ADSCs group exhibited a closer-to-normal structure with less collagen deposition and higher amounts of hyaluronic acid (HA) in the third month. The short microvilli in the HGF-transfected ADSCs group showed a dense and uniform distribution. These results revealed that HGF-transfected ADSC is a potential treatment option for injured VFs.

Targeting MFAP5 in cancer-associated fibroblasts sensitizes pancreatic cancer to PD-L1-based immunochemotherapy via remodeling the matrix

Highly desmoplastic and immunosuppressive tumor microenvironment (TME) in pancreatic ductal adenocarcinoma (PDAC) contributes to tumor progression and resistance to current therapies. Clues targeting the notorious stromal environment have offered hope for improving therapeutic response whereas the underlying mechanism remains unclear. Here, we find that prognostic microfibril associated protein 5 (MFAP5) is involved in activation of cancer-associated fibroblasts (CAFs). Inhibition of MFAP5highCAFs shows synergistic effect with gemcitabine-based chemotherapy and PD-L1-based immunotherapy. Mechanistically, MFAP5 deficiency in CAFs downregulates HAS2 and CXCL10 via MFAP5/RCN2/ERK/STAT1 axis, leading to angiogenesis, hyaluronic acid (HA) and collagens deposition reduction, cytotoxic T cells infiltration, and tumor cells apoptosis. Additionally, in vivo blockade of CXCL10 with AMG487 could partially reverse the pro-tumor effect from MFAP5 overexpression in CAFs and synergize with anti-PD-L1 antibody to enhance the immunotherapeutic effect. Therefore, targeting MFAP5highCAFs might be a potential adjuvant therapy to enhance the immunochemotherapy effect in PDAC via remodeling the desmoplastic and immunosuppressive microenvironment.

Glioblastoma extracellular vesicles influence glial cell hyaluronic acid deposition to promote invasiveness.

Infiltration of glioblastoma (GBM) throughout the brain leads to its inevitable recurrence following standard-of-care treatments, such as surgical resection, chemo-, and radiotherapy. A deeper understanding of the mechanisms invoked by GBM to infiltrate the brain is needed to develop approaches to contain the disease and reduce recurrence. The aim of this study was to discover mechanisms through which extracellular vesicles (EVs) released by GBM influence the brain microenvironment to facilitate infiltration, and to determine how altered extracellular matrix (ECM) deposition by glial cells might contribute to this. CRISPR was used to delete genes, previously established to drive carcinoma invasiveness and EV production, from patient-derived primary and GBM cell lines. We purified and characterized EVs released by these cells, assessed their capacity to foster pro-migratory microenvironments in mouse brain slices, and evaluated the contribution made by astrocyte-derived ECM to this. Finally, we determined how CRISPR-mediated deletion of genes, which we had found to control EV-mediated communication between GBM cells and astrocytes, influenced GBM infiltration when orthotopically injected into CD1-nude mice. GBM cells expressing a p53 mutant (p53R273H) with established pro-invasive gain-of-function release EVs containing a sialomucin, podocalyxin (PODXL), which encourages astrocytes to deposit ECM with increased levels of hyaluronic acid (HA). This HA-rich ECM, in turn, promotes migration of GBM cells. Consistently, CRISPR-mediated deletion of PODXL opposes infiltration of GBM in vivo. This work describes several key components of an EV-mediated mechanism though which GBM cells educate astrocytes to support infiltration of the surrounding healthy brain tissue.

Effects of pharmacological inhibition of hyaluronic acid synthesis on experimental endometriosis.

Dysregulated hyaluronic acid (HA) metabolism has been shown to be implicated in several pathologies including endometriosis. 4-Methylumbelliferone (4MU) is an HA synthesis inhibitor with proven antitumour activity. In this study, we aim to evaluate the effect of 4MU on endometriosis development both in vivo and in vitro. Endometriosis was surgically induced by uterine tissue auto-transplantation in 32 two-month-old BALB/c mice. Animals were designated into the early or late starting treatment group, which initiated on day 2 or day 15 after surgery, respectively. Within each group, 4MU 200 mg/kg/day or vehicle (Control) were administered by oesophageal gavage for 28 days. After sacrifice, the percentage of developed lesions, lesion size, cell proliferation, vascularization and HA deposition within the endometriotic-like lesions were evaluated. Cell viability was assessed in endometrial epithelial cells (ECC-1) and in endometrial stromal cells (t-HESC); and migration was evaluated in t-HESC. There was a significant reduction in the percentage of developed lesions in mice that started the 4MU treatment on day 2 compared with its respective control group, and compared with those that started treatment on day 15. However, no significant changes were found when analysing endometriotic-like lesion's cell proliferation, vascularization and HA deposition. In vitro, both cell viability and migration were inhibited by 4MU treatment. The inhibition of HA synthesis could be a beneficial and alternative option to treat endometriosis at the early stage of the disease. Further research is necessary to elucidate 4MU's mechanism of action and better strategies for delivering this promising drug.

5-Aminolevulinic Acid-Mediated Photodynamic Therapy Improves Vocal Fold Wound Healing in Rats.

Studies showed that photodynamic therapy (PDT) might be able to prevent vocal fold scar formation when treating laryngeal lesions. We aim to investigate if PDT improves vocal wound healing and reduces scar formation in both prophylactic and remodeling procedures performed in vivo. In vivo. Vocal fold stripping was performed in Sprague-Dawley rats. PDT was performed with intraperitoneal injection of 100 mg/kg 5-Aminolevulinic Acid (5-ALA) and 635 nm laser irradiation of 20, 40, and 60 J/cm2 . PDT was performed immediately after surgery to study the prophylactic effect and 4 weeks after surgery to study the remodeling effect. Gene expression was evaluated with real-time PCR at 1 week after PDT. Histologic evaluations were performed 12 weeks after PDT, including hematoxylin-eosin, Masson, Alcian blue staining, and immunohistochemical staining of collagen I and III. PDT induced similar effects on the vocal fold wound healing outcomes in both prophylactic and remodeling procedures. Expression of MMP8, MMP13, HAS2, and TGFβ1 was significantly elevated. Histologic evaluation revealed significantly increased thickness, decreased density of collagen, and increased deposition of hyaluronic acid in the lamina propria. Immunohistochemistry also revealed better distribution and reduced density of collagen I and III. The most obvious changes were seen in the 60 J/cm2 PDT group. PDT could significantly improve vocal wound healing by providing both prophylactic effects and remodeling effects. It may be a minimally invasive treatment for vocal fold lesions with slight vocal scarring, and may be used to treat acute or chronic vocal injury to reduce vocal scarring. N/A Laryngoscope, 133:1943-1951, 2023.

Use of radiolabeled hyaluronic acid for preclinical assessment of inflammatory injury and acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is accompanied by a dramatic increase in lung hyaluronic acid (HA), leading to a dose-dependent reduction of pulmonary oxygenation. This pattern is associated with severe infections, such as COVID-19, and other important lung injury etiologies. HA actively participates in molecular pathways involved in the cytokine storm of COVID-19-induced ARDS. The objective of this study was to evaluate an imaging approach of radiolabeled HA for assessment of dysregulated HA deposition in mouse models with skin inflammation and lipopolysaccharide (LPS)-induced ARDS using a novel portable intensified Quantum Imaging Detector (iQID) gamma camera system. MethodsHA of 10 kDa molecular weight (HA10) was radiolabeled with 125I and 99mTc respectively to produce [125I]I-HA10 and [99mTc]Tc-HA10, followed by comparative studies on stability, in vivo biodistribution, and uptake at inflammatory skin sites in mice with 12-O-tetradecanoylphorbol-13-acetate (TPA)-inflamed ears. [99mTc]Tc-HA10 was used for iQID in vivo dynamic imaging of mice with ARDS induced by intratracheal instillation of LPS. Results[99mTc]Tc-HA10 and [125I]I-HA10 had similar biodistribution and localization at inflammatory sites. [99mTc]Tc-HA10 was shown to be feasible in measuring skin injury and monitoring skin wound healing. [99mTc]Tc-HA10 dynamic pulmonary images yielded good visualization of radioactive uptake in the lungs. There was significantly increased lung uptake and slower lung washout in mice with LPS-induced ARDS than in control mice. Postmortem biodistribution measurement of [99mTc]TcHA10 (%ID/g) was 11.0 ± 3.9 vs. 1.3 ± 0.3 in the ARDS mice (n = 6) and controls (n = 6) (P < 0.001), consistent with upregulated HA expression as determined by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC) staining. Conclusions[99mTc]Tc-HA10 is promising as a biomarker for evaluating HA dysregulation that contributes to pulmonary injury in ARDS. Rapid iQID imaging of [99mTc]Tc-HA10 clearance from injured lungs may provide a functional template for timely assessment and quantitative monitoring of pulmonary pathophysiology and intervention in ARDS.

A Multistep Tumor Growth Model of High-Grade Serous Ovarian Carcinoma Identifies Hypoxia-Associated Signatures

High-grade serous ovarian carcinoma (HGSC) is associated with late-stage disease presentation and poor prognosis, with a limited understanding of early transformation events. Our study analyzes HGSC tumor progression and organ-specific metastatic dissemination to identify hypoxia-associated molecular, cellular, and histological alterations. Clinical characteristics of the HGSC were replicated in orthotopic xenografts, which involve metastatic dissemination and the prevalence of group B tumors (volume: >0.0625 ≤ 0.5 cm³). Enhanced hyaluronic acid (HA) deposition, expanded tumor vasculature, and increased necrosis contributed to the remodeling of tumor tissue architecture. The proliferative potential of tumor cells and the ability to form glands were also altered during tumor growth. Flow cytometry and label chase-based molecular profiling across the tumor regenerative hierarchy identified the hypoxia-vasculogenic niche and the hybrid epithelial-mesenchymal tumor-cell state as determinants of self-renewal capabilities of progenitors and cancer stem cells. A regulatory network and mathematical model based on tumor histology and molecular signatures predicted hypoxia-inducible factor 1-alpha (HIF1A) as a central node connecting HA synthesis, epithelial-mesenchymal transition, metabolic, vasculogenic, inflammatory, and necrotic pathways in HGSC tumors. Thus, our findings provide a temporal resolution of hypoxia-associated events that sculpt HGSC tumor growth; an in-depth understanding of it may aid in the early detection and treatment of HGSC.

Hapln1 Defines an Epicardial Cell Subpopulation Required for Cardiomyocyte Expansion During Heart Morphogenesis and Regeneration.

Certain nonmammalian species such as zebrafish have an elevated capacity for innate heart regeneration. Understanding how heart regeneration occurs in these contexts can help illuminate cellular and molecular events that can be targets for heart failure prevention or treatment. The epicardium, a mesothelial tissue layer that encompasses the heart, is a dynamic structure that is essential for cardiac regeneration in zebrafish. The extent to which different cell subpopulations or states facilitate heart regeneration requires research attention. To dissect epicardial cell states and associated proregenerative functions, we performed single-cell RNA sequencing and identified 7 epicardial cell clusters in adult zebrafish, 3 of which displayed enhanced cell numbers during regeneration. We identified paralogs of hapln1 as factors associated with the extracellular matrix and largely expressed in cluster 1. We assessed HAPLN1 expression in published single-cell RNA sequencing data sets from different stages and injury states of murine and human hearts, and we performed molecular genetics to determine the requirements for hapln1-expressing cells and functions of each hapln1 paralog. A particular cluster of epicardial cells had the strongest association with regeneration and was marked by expression of hapln1a and hapln1b. The hapln1 paralogs are expressed in epicardial cells that enclose dedifferentiated and proliferating cardiomyocytes during regeneration. Induced genetic depletion of hapln1-expressing cells or genetic inactivation of hapln1b altered deposition of the key extracellular matrix component hyaluronic acid, disrupted cardiomyocyte proliferation, and inhibited heart regeneration. We also found that hapln1-expressing epicardial cells first emerge at the juvenile stage, when they associate with and are required for focused cardiomyocyte expansion events that direct maturation of the ventricular wall. Our findings identify a subset of epicardial cells that emerge in postembryonic zebrafish and sponsor regions of active cardiomyogenesis during cardiac growth and regeneration. We provide evidence that, as the heart achieves its mature structure, these cells facilitate hyaluronic acid deposition to support formation of the compact muscle layer of the ventricle. They are also required, along with the function of hapln1b paralog, in the production and organization of hyaluronic acid-containing matrix in cardiac injury sites, enabling normal cardiomyocyte proliferation and muscle regeneration.

Inhibition of Angiogenesis and Extracellular Matrix Remodeling: Synergistic Effect of Renin-Angiotensin System Inhibitors and Bevacizumab.

Bevacizumab (Bev) is a humanized vascular endothelial growth factor monoclonal antibody that is used with chemotherapeutic drugs for the treatment of metastatic colorectal cancer (mCRC). Bev-induced hypertension (HT) is the most common adverse reaction during clinical practice. However, at present, appropriate antihypertensive agents for Bev-induced HT are unavailable. In this study, retrospective analysis of clinical data from mCRC patients who received renin-angiotensin system inhibitors (RASIs) showed significant survival benefits of overall survival (OS) and progression-free survival (PFS) over patients who received calcium channel blockers (CCBs) and patients who received no antihypertensive drug (NO: Y2020046 retrospectively registered). An experiment of HCT116 colon cancer cell xenografts in mice confirmed that combined treatment of Bev and lisinopril (Lis), a RASI, synergistically inhibited subcutaneous tumor growth and enhanced the concentration of 5-fluorouracil (5-Fu) in tumor tissues. Our results showed that the addition of Lis did not interfere with the vascular normalization effect promoted by Bev, but also inhibited collagen and hyaluronic acid (HA) deposition and significantly downregulated the expression of TGF-β1 and downstream SMAD signaling components which were enhanced by Bev, ultimately remodeling primary extracellular matrix components. In conclusion, RASIs and Bev have synergistic effect in the treatment of colorectal cancer and RASIs might be an optimal choice for the treatment of Bev-induced HT.

The extracellular matrix maintained by hypodermal macrophages via IGF1 is a niche for Staphylococcus aureus infection

Abstract Macrophages (MΦ) play a vital role in tissue homeostasis, but their functions in skin hypodermis, a common site of Staphylococcus aureus (S. aureus) infection, remains largely unexplored. Using flow-cytometry, bulk RNA-seq and single-cell RNA-seq, two MΦ subsets with distinct transcriptomes were uncovered. Both MΦ subsets relied on colony stimulating factor 1 (CSF1) receptor signaling for their survival. Single-cell RNA-seq of non-immune cells identified fibroblasts (FB) as a major source of dermal and hypodermal CSF1. Analysis of dermal and hypodermal stromal cells transcriptomes revealed Tek (encoding Tie2) in hypodermal FB as a potential driver for skin layer-specific ablation of CSF1. Tek-cre x Csf1-floxed mice (Csf1ΔTek) displayed a striking post-natal ablation of hypodermal MΦ associated with an alteration of the collagen network and increased accumulation of hyaluronic acid (HA). Generation of a ligand-receptor map identified candidate genes involved in hypodermal MΦ-FB crosstalk. Among which, depletion of insulin-like growth factor 1 (IGF1) from MΦ in Csf1r-cre x Igf1-floxed (Igf1ΔCsf1r) recapitulated the alteration of the ECM observed in absence of hypodermal MΦ. Interestingly, upon injecting S. aureus into the hypodermis, Csf1ΔTek and Igf1ΔCsf1r mice displayed striking reduction of the cellulitis phenotype as compared to WT mice. Pre-injection of HA attenuated cellulitis in WT mice, suggesting that deposition of HA in the absence of MΦ or MΦ-derived IGF1 conferred host protection against S. aureus. Thus, while hypodermal MΦ critically maintained ECM homeostasis, this provided a niche for S. aureus infection, highlighting implications for novel therapeutic strategies in S. aureus soft-tissue infections.

Effects of Repeated Intracordal Glucocorticoid Injection on the Histology and Gene Expression of Rat Vocal Folds

Local injection of glucocorticoids (GCs) into the vocal folds has been used for treating the vocal fold lesions. While the positive effects on vocal fold nodules, polyps, or scarring have been clinically reported, some concern remains around the potential adverse effects such as vocal fold atrophy, and the mechanisms remain unclear. The present study examined the histology and gene expression of locally injected GC into the vocal folds in rats. Thirteen-week-old male Sprague-Dawley rats were used in the experiments. Triamcinolone acetonide (TAA) or saline were administered repeatedly to the right vocal folds at a weekly interval, and rats were euthanized one week after the last administration for histological examination. Genetic examination was assessed hyaluronic acid (HA) metabolism at 1 or 3 days after a single TAA injection by quantitative real-time polymerase chain reaction (qRT-PCR). The group which underwent four TAA injections showed a significant decrease in HA in the lamina propria (LP), thickness of the LP and total cell numbers of the LP compared with the saline group. In contrast, there was no significant difference in the area of collagen accumulation and the thyroarytenoid muscle, although there was a tendency of atrophy of the muscle. After single injection of TAA, qRT-PCR showed a significant decrease in the expression of HA synthases, Has2 and Has3. The current animal study first demonstrates that repeated intracordal injection of GCs may lead to atrophy of vocal folds caused by decrease of deposition of HA in the LP and decrease of gene expression of Has.

A cyclic nano-reactor achieving enhanced photodynamic tumor therapy by reversing multiple resistances

BackgroundPhotodynamic therapy (PDT) is a clinically implemented modality to combat malignant tumor, while its efficacy is largely limited by several resistance factors from tumor microenvironment (TME), such as hypoxia, anti-oxidant systems, and ATP-dependent tumor adaptive resistances. The aim of this work is to construct a multifunctional nanoplatform to remodel multiple resistant TME for enhanced PDT.ResultsHere, a targeting nano-reactor was facilely constructed to reverse the multiple resistances of PDT by incorporating glucose oxidase (GOx) and chlorin e6 (Ce6) into poly (D, L-lactic-co-glycolic acid) (PLGA)/ metal–organic framework (MOF) core–shell nanoassembly, with surface deposition of hyaluronic acid (HA) stabilized MnO2. The nano-reactor could selectively target tumor cells by virtue of surface HA modification, and once internalization, a few reactions were initiated to modulate TME. Glucose was consumed by GOx to inhibit ATP generation, and the produced H2O2 was catalyzed by MnO2 to generate O2 for tumor hypoxia alleviation and photodynamic sensitization, and glutathione (GSH) was also effectively depleted by MnO2 to suppress the tumor antioxidant defense. Consequently, the nano-reactor achieved robust PDT with amplified tumor therapy via intravenous injection.ConclusionsThis nano-reactor offers a multifunctional nanoplatform to sensitize TME-limited tumor treatment means via reversing multiple resistances.Grpahic abstract

Inhibition of hyaluronan secretion by novel coumarin compounds and chitin synthesis inhibitors.

Elevated plasma levels of hyaluronic acid (HA) is a disease marker in liver pathology and other inflammatory disorders. Inhibition of HA synthesis with coumarin 4-methylumbelliferone (4MU) has a beneficial effect in animal models of fibrosis, inflammation, cancer and metabolic syndrome. 4MU is an active compound of approved choleretic drug hymecromone with low bioavailability and a broad spectrum of action. New, more specific and efficient inhibitors of hyaluronan synthases (HAS) are required. We have tested several newly synthesized coumarin compounds and commercial chitin synthesis inhibitors to inhibit HA production in cell culture assay. Coumarin derivative compound VII (10′-methyl-6′-phenyl-3′H-spiro[piperidine-4,2′-pyrano[3,2-g]chromene]-4′,8′-dione) demonstrated inhibition of HA secretion by NIH3T3 cells with the half-maximal inhibitory concentration (IC50) = 1.69 ± 0.75 μΜ superior to 4MU (IC50 = 8.68 ± 1.6 μΜ). Inhibitors of chitin synthesis, etoxazole, buprofezin, triflumuron, reduced HA deposition with IC50 of 4.21 ± 3.82 μΜ, 1.24 ± 0.87 μΜ and 1.48 ± 1.44 μΜ, respectively. Etoxazole reduced HA production and prevented collagen fibre formation in the CCl4 liver fibrosis model in mice similar to 4MU. Bioinformatics analysis revealed homology between chitin synthases and HAS enzymes, particularly in the pore-forming domain, containing the proposed site for etoxazole binding.

Synthesis and anti-fibrotic effects of santamarin derivatives as cytotoxic agents against hepatic stellate cell line LX2

Liver fibrosis is a final result of extensive deposition of extracellular matrix (ECM) and starts with the activation and proliferation of hepatic stellate cells (HSCs). Our previous study showed that eudesmane sesquiterpenoid santamarin had cytotoxicity against hepatic stellate cell line LX2 (HSC-LX2) with IC50 values of 16.5 ± 0.7 μM. To explore the structure–activity relationships, twenty-six derivatives were synthesized by modifying the hydroxyl group, double-bond and unsaturated lactone. Cytotoxicity evaluation suggested that eight derivatives (6, 9, 13, 17, 20 and 25–27) increased activity against HSC-LX2. Especially, derivatives 17, 20 and 25 displayed obvious cytotoxicity with IC50 values of 6.4 ± 0.4, 4.6 ± 0.1, and 3.5 ± 0.1 μM, which were 3 to 5-fold higher than santamarin. Preliminary mechanisms study revealed that the active compound 20 exhibited more than 8-fold and 6-fold enhancement of inhibitory effect on the deposition of human hyaluronic acid (HA) and human laminin (HL) with IC50 values of 7.6 ± 0.6 and 3.3 ± 1.2 μM.

Mechanical Stress Induce PG-E2 in Murine Synovial Fibroblasts Originating from the Temporomandibular Joint.

Genetic predisposition, traumatic events, or excessive mechanical exposure provoke arthritic changes in the temporomandibular joint (TMJ). We analysed the impact of mechanical stress that might be involved in the development and progression of TMJ osteoarthritis (OA) on murine synovial fibroblasts (SFs) of temporomandibular origin. SFs were subjected to different protocols of mechanical stress, either to a high-frequency tensile strain for 4 h or to a tensile strain of varying magnitude for 48 h. The TMJ OA induction was evaluated based on the gene and protein secretion of inflammatory factors (Icam-1, Cxcl-1, Cxcl-2, Il-1ß, Il-1ra, Il-6, Ptgs-2, PG-E2), subchondral bone remodelling (Rankl, Opg), and extracellular matrix components (Col1a2, Has-1, collagen and hyaluronic acid deposition) using RT-qPCR, ELISA, and HPLC. A short high-frequency tensile strain had only minor effects on inflammatory factors and no effects on the subchondral bone remodelling induction or matrix constituent production. A prolonged tensile strain of moderate and advanced magnitude increased the expression of inflammatory factors. An advanced tensile strain enhanced the Ptgs-2 and PG-E2 expression, while the expression of further inflammatory factors were decreased. The tensile strain protocols had no effects on the RANKL/OPG expression, while the advanced tensile strain significantly reduced the deposition of matrix constituent contents of collagen and hyaluronic acid. The data indicates that the application of prolonged advanced mechanical stress on SFs promote PG-E2 protein secretion, while the deposition of extracellular matrix components is decreased.

The use of high-frequency ultrasonography for the diagnosis of palpable nodules after the administration of dermal fillers.

IntroductionEsthetic medicine is a buoyant field of medicine. As the number of performed procedures – mainly injections of botulin toxin and dermal fillers – is increasing, the number of complications is rising as well. The most popular dermal filler is hyaluronic acid. Injection of hyaluronic acid dermal fillers is considered a minimally invasive procedure, but complications in the form of skin nodules and lumps are being encountered more and frequently. Esthetic medicine does not currently offer its own diagnostic methods that would allow one to diagnose complications. In these circumstances, the implementation of objective diagnostic methods from other fields of medicine becomes significant. High-frequency ultrasound is one of such methods.Aim of the studyThe aim of this study was to implement high-frequency ultrasound for the diagnosis of palpable nodules after the administration of dermal fillers.Material and methodThe study group included 15 women who developed palpable nodules in the region of hyaluronic acid injection. The study includes both early and late complications. An EPIQ 5 (Philips, Bothell, USA) ultrasound machine and a L5–18 transducer were used to examine the nodules. Ultrasound images were evaluated qualitatively by 2 independent investigators.ResultsUltrasound enabled the diagnosis of hyaluronic acid deposition in 9 women, granulomas in 3 women, fibrosis in 2 women and a deposition with inflammation in 1 case. Each of the diagnosed structures presented a typical ultrasound appearance.ConclusionsHigh-frequency ultrasound is a useful diagnostic method that has a chance to become a widespread tool to diagnose and treat complications. Because of a low number of study reports in this area, continued research is warranted.

Interplay of Hydrogel Composition and Geometry on Human Mesenchymal Stem Cell Osteogenesis.

Microgels are emerging as an outstanding platform for tissue regeneration because they overcome issues associated with conventional bulk/macroscopic hydrogels such as limited cell-cell contact and cell communication and low diffusion rates. Owing to the enhanced mass transfer and injectability via a minimally invasive procedure, these microgels are becoming a promising approach for bone regeneration applications. Nevertheless, there still remains a huge gap between the understanding of how the hydrogel matrix composition can influence cell response and overall tissue formation when switching from bulk formats to microgel format, which is often neglected or rarely studied. Here, we fabricated polyethylene glycol-based microgels and bulk hydrogels incorporating gelatin and hyaluronic acid (HA), either individually or together, and assessed the impact of both hydrogel composition and format upon the osteogenic differentiation of encapsulated human bone marrow-derived mesenchymal stem cells (hBMSCs). Osteogenesis was significantly greater in microgels than bulk hydrogels for both gelatin alone (Gel) and gelatin HA composite (Gel:HA) hydrogels, as determined by the expression of Runt-related transcription factor (Runx2) and alkaline phosphatase (ALP) genes and mineral deposition. Interestingly, Gel and Gel:HA hydrogels behaved differently between bulk and microgel format. In bulk format, overall osteogenic outcomes were better in Gel:HA hydrogels, but in microgel format, while the level of osteogenic gene expression was equivalent between both compositions, the degree of mineralization was reduced in Gel:HA microgels. Investigation into the affinity of hydroxyapatite for the different matrix compositions indicated that the decreased mineralization of Gel:HA microgels was likely due to a low affinity of hydroxyapatite to bind to HA and support mineral deposition, which has a greater impact on microgels than bulk hydrogels. Together, these findings suggest that both hydrogel composition and format can determine the success of tissue formation and that there is a complex interplay of these two factors on both cell behavior and matrix deposition. This has important implications for tissue engineering, showing that hydrogel composition and geometry must be evaluated together when optimizing conditions for cell differentiation and tissue formation.