Autodisplay of Human Hyaluronidase Hyal-1 on Escherichia coli and Identification of Plant-Derived Enzyme Inhibitors

Fine-tuning of liposome integrity for differentiated transcytosis and enhanced antitumor efficacy

Transcytosis-inducing nanomedicines have been developed to improve tumor extravasation. However, the fate during transcytosis across multicell layers and the structural integrity of the nanomedicines before reaching tumor cells could impact antitumor therapy. Here, a BAY 87-2243 (a hypoxia-inducible factor-1 inhibitor)-loaded liposomal system (HA-P-LBAY) modified by low molecular weight protamine (LMWP) and crosslinked by hyaluronic acid (HA) was constructed. This system could accomplish differentiate cellular transport in endothelial and tumor cells by fine-tuning its structural integrity, i.e. transcytosis across the endothelial cells while preserving structural integrity, facilitating subsequent retention and drug release within tumor cells via degradation-induced aggregation. In vitro cellular uptake and transwell studies demonstrated that HA-P-LBAY were internalized by endothelial cells (bEnd.3) via an active, caveolin and heparin sulfate proteoglycan (HSPG)-mediated endocytosis, and subsequently achieved transcytosis mainly through the ER/Golgi pathway. Moreover, the fluorescence resonance energy transfer (FRET) study showed that HA-crosslinking maintained higher integrity of HA-P-LBAY after transcytosis, more efficiently than electrostatic coating of HA (HA/P-LBAY). In addition, more HA-P-LBAY was retained in tumor cells (4T1) compared to HA/P-LBAY corresponding to its enhanced in vitro cytotoxicity. This may be attributed to better integrity of HA-P-LBAY post endothelial transcytosis and more degradation of HA in tumor cells, leading to more liposome aggregation and inhibition of their transcytosis, which was inferred by both TEM images and the HAase responsiveness assay proved by FRET. In vivo, HA-P-LBAY exhibited more potency in tumor suppression than the other formulations in both low and high permeability tumor models. This highlighted that fine-tuning of structural integrity of nanocarriers played a key role no matter whether the transcytosis of nanocarriers contributed to cellular transport. Collectively, this study provides a promising strategy for antitumor therapies by fine-tuning liposome integrity to achieve active trans-endothelial transport with structural integrity and selective aggregation for prolonged tumor retention.

Proposed mechanisms of action of herbal drugs and their biologically active constituents in the treatment of coughs: an overview

Various medicinal plants find their use in cough treatment, based on traditions and long-term experience. Pharmacological principles of their action, however, are much less known. Herbal drugs usually contain a mixture of potentially active compounds, which can manifest diverse effects. Expectorant or antitussive effects, which can be accompanied by others, such as anti-inflammatory or antibacterial, are probably the most important in the treatment of coughs. The aim of this review is to summarize the current state of knowledge of the effects of medicinal plants or their constituents on cough, based on reliable pharmacological studies. First, a comprehensive description of each effect is provided in order to explain the possible mechanism of action in detail. Next, the results related to individual plants and substances are summarized and critically discussed based on pharmacological in vivo and in vitro investigation.

Exploring opportunities for drug repurposing and precision medicine in cannabis use disorder using genetics

Cannabis use disorder (CUD) remains a significant public health issue globally, affecting up to one in five adults who use cannabis. Despite extensive research into the molecular underpinnings of the condition, there are no effective pharmacological treatment options available. Therefore, we sought to further explore genetic analyses to prioritise opportunities to repurpose existing drugs for CUD. Specifically, we aimed to identify druggable genes associated with the disorder, integrate transcriptomic/proteomic data and estimate genetic relationships with clinically actionable biochemical traits. Aggregating variants to genes based on genomic position, prioritised the phosphodiesterase gene PDE4B as an interesting target for drug repurposing in CUD. Credible causal PDE4B variants revealed by probabilistic finemapping in and around this locus demonstrated an association with inflammatory and other substance use phenotypes. Gene and protein expression data integrated with the GWAS data revealed a novel CUD associated gene, NPTX1, in whole blood and supported a role for hyaluronidase, a key enzyme in the extracellular matrix in the brain and other tissues. Finally, genetic correlation with biochemical traits revealed a genetic overlap between CUD and immune-related markers such as lymphocyte count, as well as serum triglycerides.

ANTIAGE-DB: A Database and Server for the Prediction of Anti-Aging Compounds Targeting Elastase, Hyaluronidase, and Tyrosinase

Natural products bear a multivariate biochemical profile with antioxidant, anti-inflammatory, antibacterial, and antitumoral properties. Along with their natural sources, they have been widely used both as anti-aging and anti-melanogenic agents due to their effective contribution in the elimination of reactive oxygen species (ROS) caused by oxidative stress. Their anti-aging activity is mainly related to their capacity of inhibiting enzymes like Human Neutrophil Elastase (HNE), Hyaluronidase (Hyal) and Tyrosinase (Tyr). Herein, we accumulated literature information (covering the period 1965–2020) on the inhibitory activity of natural products and their natural sources towards these enzymes. To navigate this information, we developed a database and server termed ANTIAGE-DB that allows the prediction of the anti-aging potential of target compounds. The server operates in two axes. First a comparison of compounds by shape similarity can be performed against our curated database of natural products whose inhibitory potential has been established in the literature. In addition, inverse virtual screening can be performed for a chosen molecule against the three targeted enzymes. The server is open access, and a detailed report with the prediction results is emailed to the user. ANTIAGE-DB could enable researchers to explore the chemical space of natural based products, but is not limited to, as anti-aging compounds and can predict their anti-aging potential. ANTIAGE-DB is accessed online.

Autodisplay of human PIP5K1α lipid kinase on Escherichia coli and inhibitor testing

The human phosphatidylinositol 4-phosphate 5-kinase type I α (hPIP5K1α) plays a major role in the PI3K/AKT/mTOR signaling pathway. As it has been shown before that hPIP5K1α is involved in the development of different types of cancer in particular prostate cancer, inhibitors of the enzyme might be a new option for the treatment of this disease. Here we report on the expression of hPIP5K1α on the surface of E. coli using Autodisplay. Autodisplay is defined as the surface display of a recombinant protein on a gramnegative bacterium by the autotransporter secretion pathway. After verification of surface expression, enzyme activity of whole cells displaying hPIP5K1α was determined by a capillary electrophoresis based assay. When using cells at an OD₅₇₈ of 2.5, the artificial substrate phosphatidylinositol4-phosphate (PI(4)P) fluorescein was converted by a rate of 10.7 ± 0.2 fmol/min. Using this substrate inhibition of three pyranobenzoquinone type compounds was tested. The most active compound was 4-(2-amino-3-cyano-6-hydroxy-5,8-dioxo-7-undecyl-5,8-dihydro-4H-chromen-4-yl) benzoic acid with an IC₅₀ value of 8.6 μM. Because until now, all attempts to purify hPIP5K1α failed, we suggest the use of whole cells of E. coli displaying the enzyme as a convenient tool for inhibitor identification.

Improved Surface Display of Human Hyal1 and Identification of Testosterone Propionate and Chicoric Acid as New Inhibitors

Degradation of high molecular weight hyaluronic acid (HA) in humans is mainly catalyzed by hyaluronidase Hyal1. This enzyme is involved in many pathophysiological processes and therefore appears an interesting target for drug discovery. Until now, only a few inhibitors of human Hyal1 are known due to obstacles in obtaining active enzymes for inhibitor screening. The aim of the present work was to provide a convenient enzyme activity assay and show its feasibility by the identification of new inhibitors. By autodisplay, Escherichia coli F470 can present active Hyal1 on its surface. In this study, the inducible expression of Hyal1 on the cell surface of E. coli under the control of a rhamnose-dependent promoter (Prha) was performed and optimized. Enzyme activity per single cell was increased by a factor of 100 compared to the constitutive Hyal1 surface display, as described before. An activity of 6.8 × 10-4 mU per single cell was obtained under optimal reaction conditions. By this modified activity assay, two new inhibitors of human Hyal1 were identified. Chicoric acid, a natural compound belonging to the phenylpropanoids, showed an IC50 value of 171 µM. The steroid derivative testosterone propionate showed and IC50 value of 124 ± 1.1 µM. Both values were in the same order of magnitude as the IC50 value of glycyrrhizic acid (177 µM), one of the best known inhibitors of human Hyal1 known so far. In conclusion, we established a new enzyme activity assay for human Hyal1 and identified new inhibitors with this new assay method.

Hyaluronidase-Expressing Salmonella Effectively Targets Tumor-Associated Hyaluronic Acid in Pancreatic Ductal Adenocarcinoma

In pancreatic ductal adenocarcinoma (PDAC), the extracellular matrix (ECM) surrounding cancer cells forms a barrier that often limits the ability of chemotherapeutic drugs and cytotoxic immune subsets to penetrate and eliminate tumors. The dense stromal matrix protecting cancer cells, also known as desmoplasia, results from the overproduction of major ECM components such as collagens and hyaluronic acid (HA). Although candidate drugs targeting ECM components have shown promise in increasing penetration of chemotherapeutic agents, severe adverse effects associated with systemic depletion of ECM in peripheral healthy tissues limits their use at higher, more effective doses. Currently, few strategies exist that preferentially degrade ECM in tumor tissue over healthy tissues. In light of this, we have developed an attenuated, tumor-targeting Salmonella typhimurium (ST) expressing functional bacterial hyaluronidase (bHs-ST), capable of degrading human HA deposited within PDAC tumors. Our data show that bHs-ST (i) targets and colonizes orthotopic human PDAC tumors following systemic administration and (ii) is efficiently induced in vivo to deplete tumor-derived HA, which in turn (iii) significantly increases diffusion of Salmonella typhimurium within desmoplastic tumors. BHs-ST represents a promising new tumor ECM-targeting strategy that may be instrumental in minimizing off-tumor toxicity while maximizing drug delivery into highly desmoplastic tumors.

Hyal-1 inhibitors from the leaves of Phyllanthus muellerianus (Kuntze) Excell

ETHNOPHARMACOLOGICAL RELEVANCE

Leaves and twigs from Phyllanthus muellerianus Kuntze Excell are known to exert anti-inflammatory and antipyretic properties as well as wound healing properties. During a wide screening for human hyaluronidase-1 inhibitors from natural sources leaf extracts from P. muellerianus turned out to show basic anti-hyaluronidase activity. A detailed investigation of this effect should rationalize the potential anti-inflammatory activity of the extract for improved wound healing.

AIM OF THE STUDY

The following study aimed to characterize the anti-Hyal-1 activity of the extract from P. muellerianus and to pinpoint the responsible natural products responsible for this bioactivity.

MATERIALS AND METHODS

Using cell surface displayed human Hyal-1 on Escherichia coli, the activity of inhibitors was determined by the stains-all assay method. A hydroalcoholic extract PWE from P. muellerianus was subjected to bioactivity-guided fractionation. Active compounds were characterized by means of mass spectrometry and NMR.

RESULTS

PWE exerts a concentration dependent inhibition of Hyal-1 with an IC₅₀ of 80 μg/mL. Bioassay-guided fractionation revealed 13 compounds from the two most active fractions, mainly ellagitannins and flavonoid glycosides. The most activeHyal-1 inhibitor was found to be the ellagitannin chebulanin 10 (IC₅₀ 132 μM). This represents the first description of chebulanin in P. muellerianus.

CONCLUSIONS

The hydroalcoholic extract of P. muellerianus, as well as several subfractions obtained during bioassay-guided fractionation showed strong activity against Hyal-1. The main activity can be correlated to the ellagitanin chebulanin. Additionally, also synergistic effects are observed, indicating that the traditional use of aqueous extracts of P. muellerianus is justified, rather than the use of the isolated tannins. The traditional use of the plant as an anti-inflammatory agent for improved wound-healing can be rationalized by the anti-Hyal-1 activities of its constituents.

Isoflavonoids with inhibiting effects on human hyaluronidase-1 and norneolignan clitorienolactone B from Ononis spinosa L. root extract

Human hyaluronidase-1 (Hyal-1) is one of the main enzymes in the homeostasis of hyaluronic acid (HA), the main polysaccharide of extracellular matrix. Development of specific Hyal-1 inhibitors might be a promising target for improved wound healing, tissue regeneration, and looking at renal function for diuresis. By using surface-displayed Hyal-1 on Escherichia coli F470 cells, HA as substrate and stains-all method for quantification of undegraded HA, the respective enzyme activity can be determined easily. Based on the traditional use of extracts from the roots from Ononis spinosa L. (Restharrow root) as a weak diuretic to achieve flushing of the urinary tract and as an adjuvant in minor urinary complaints the herbal material was selected for bioactivity guided fractionation for compounds with Hyal-1 inhibition activity. Hot water and hydroalcoholic extracts showed moderate inhibiting effects (IC₅₀ 1.36 resp. 0.73 mg/mL) while dichloromethane extract exerted an IC₅₀ of 190 μg/mL. Bioassay guided fractionation of the dichloromethane extract yielded four isoflavonoids with anti Hyal-1 activity: onogenin 1, sativanone 2, medicarpin 3 and calycosin-D 4 with inhibition rates of 25.4, 61.2, 22.4 and 23.0%, respectively at test concentration level of 250 μM. The norneolignan clitorienolactone B 5, the first time described for the genus Ononis, was inactive. The IC₅₀ of sativanone, the most active compound was determined with 1501 μM, which was better than that of the positive control glycyrrhizinic acid (177 μM). Thus, a possible explanation for diuretic properties of Ononis spinosa L. root extract may be postulated from the results so far obtained.

Phytochemical Characterization of Low Molecular Weight Constituents from Marshmallow Roots (Althaea officinalis) and Inhibiting Effects of the Aqueous Extract on Human Hyaluronidase-1

Extract RE was obtained from the roots of Althaea officinalis in a yield of 8.1%, related to the dried plant material, by extraction with MeOH-H₂O (1:1), followed by precipitation with EtOH to remove high molecular weight constituents. Phytochemical investigation of RE revealed the presence of N-phenylpropenoyl-l-amino acid amides 1-5, 8% glycine betaine 6, about 9% total amino acids with proline as the main compound, and about 61% mono- and oligomeric carbohydrates with sucrose as the main compound. Further fractionation revealed the presence of a hypolaetin diglycoside (12) and four hypolaetin glycosides (7-9 and 11) with O-sulfocarbohydrate moieties; additionally, 4'-O-methylisoscutellarein-8-O-β-d-(3″-O-sulfo)glucuronopyranoside (10) and the diglycosylated coumarin haploperoside D (13) were identified. The hypolaetin-O-sulfoglycosides 7-10 are new natural products. RE inhibited the enzymatic activity of surface-displayed human hyaluronidase-1 on Escherichia coli F470 cells with an IC₅₀ of 7.7 mg/mL. RE downregulated mRNA expression of hyal-1 in HaCaT keratinocytes at 125 and 250 μg/mL, respectively. These data contribute to a deeper phytochemical understanding of marshmallow root extracts and to the positive influence of extracts used for therapy of irritated and inflamed buccal tissue and cough.

Carbohydrate-Processing Enzymes of the Lysosome: Diseases Caused by Misfolded Mutants and Sugar Mimetics as Correcting Pharmacological Chaperones

Lysosomal storage diseases are hereditary disorders caused by mutations on genes encoding for one of the more than fifty lysosomal enzymes involved in the highly ordered degradation cascades of glycans, glycoconjugates, and other complex biomolecules in the lysosome. Several of these metabolic disorders are associated with the absence or the lack of activity of carbohydrate-processing enzymes in this cell compartment. In a recently introduced therapy concept, for susceptible mutants, small substrate-related molecules (so-called pharmacological chaperones), such as reversible inhibitors of these enzymes, may serve as templates for the correct folding and transport of the respective protein mutant, thus improving its concentration and, consequently, its enzymatic activity in the lysosome. Carbohydrate-processing enzymes in the lysosome, related lysosomal diseases, and the scope and limitations of reported reversible inhibitors as pharmacological chaperones are discussed with a view to possibly extending and improving research efforts in this area of orphan diseases.

In silico approach to explore the disruption in the molecular mechanism of human hyaluronidase 1 by mutant E268K that directs Natowicz syndrome

Natowicz syndrome (mucopolysaccharidoses type 9) is a lysosomal storage disorder caused by deficient or defective human hyaluronidase 1. The disorder is not well studied at the molecular level. Therefore, a new in silico approach was proposed to study the molecular basis on which one clinically observed mutation, Glu268Lys, results in a defective enzyme. The native and mutant structures were subjected to comparative analyses using a conformational sampling approach for geometrical variables viz, RMSF, RMSD, and Ramachandran plot. In addition, the strength of a Cys207-Cys221 disulfide bond and electrostatic interaction between Arg265 and Asp206 were studied, as they are known to be involved in the catalytic activity of the enzyme. Native and mutant E268K showed statistically significant variations with p < 0.05 in RMSD, Ramachandran plot, strengths of disulfide bond, and electrostatic interactions. Further, single model analysis showed variations between native and mutant structures in terms of intra-protein interactions, hydrogen bond dilution, secondary structure, and dihedral angles. Docking analysis predicted the mutant to have a less favorable substrate binding energy compared to the native protein. Additionally, steered MD analysis indicated that the substrate should have more affinity to the native than mutant enzymes. The observed changes theoretically explain the less favorable binding energy of substrate towards mutant E268K, thereby providing a structural basis for its reduced catalytic activity. Hence, our study provides a basis for understanding the disruption in the molecular mechanism of human hyaluronidase 1 by mutation E268K, which may prove useful for the development of synthetic chaperones as a treatment option for Natowicz syndrome.