The strain SARS-CoV-2, newly emerged in late 2019, has been identified as the cause of COVID-19 and the pandemic declared by WHO in early 2020. Although lipids have been shown to possess antiviral ...efficacy, little is currently known about lipid compounds with anti-SARS-CoV-2 binding and entry properties. To address this issue, we screened, overall, 17 polyunsaturated fatty acids, monounsaturated fatty acids and saturated fatty acids, as wells as lipid-soluble vitamins. In performing target-based ligand screening utilizing the RBD-SARS-CoV-2 sequence, we observed that polyunsaturated fatty acids most effectively interfere with binding to hACE2, the receptor for SARS-CoV-2. Using a spike protein pseudo-virus, we also found that linolenic acid and eicosapentaenoic acid significantly block the entry of SARS-CoV-2. In addition, eicosapentaenoic acid showed higher efficacy than linolenic acid in reducing activity of TMPRSS2 and cathepsin L proteases, but neither of the fatty acids affected their expression at the protein level. Also, neither reduction of hACE2 activity nor binding to the hACE2 receptor upon treatment with these two fatty acids was observed. Although further in vivo experiments are warranted to validate the current findings, our study provides a new insight into the role of lipids as antiviral compounds against the SARS-CoV-2 strain.
In the pursuit of suitable and effective solutions to SARS-CoV-2 infection, we investigated the efficacy of several phenolic compounds in controlling key cellular mechanisms involved in its ...infectivity. The way the SARS-CoV-2 virus infects the cell is a complex process and comprises four main stages: attachment to the cognate receptor, cellular entry, replication and cellular egress. Since, this is a multi-part process, it creates many opportunities to develop effective interventions. Targeting binding of the virus to the host receptor in order to prevent its entry has been of particular interest. Here, we provide experimental evidence that, among 56 tested polyphenols, including plant extracts, brazilin, theaflavin-3,3'-digallate, and curcumin displayed the highest binding with the receptor-binding domain of spike protein, inhibiting viral attachment to the human angiotensin-converting enzyme 2 receptor, and thus cellular entry of pseudo-typed SARS-CoV-2 virions. Both, theaflavin-3,3'-digallate at 25 mug/ml and curcumin above 10 mug/ml concentration, showed binding with the angiotensin-converting enzyme 2 receptor reducing at the same time its activity in both cell-free and cell-based assays. Our study also demonstrates that brazilin and theaflavin-3,3'-digallate, and to a still greater extent, curcumin, decrease the activity of transmembrane serine protease 2 both in cell-free and cell-based assays. Similar pattern was observed with cathepsin L, although only theaflavin-3,3'-digallate showed a modest diminution of cathepsin L expression at protein level. Finally, each of these three compounds moderately increased endosomal/lysosomal pH. In conclusion, this study demonstrates pleiotropic anti-SARS-CoV-2 efficacy of specific polyphenols and their prospects for further scientific and clinical investigations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Polyphenols, found abundantly in plants, display many anticarcinogenic properties including their inhibitory effects on cancer cell proliferation, tumor growth, angiogenesis, metastasis, and ...inflammation as well as inducing apoptosis. In addition, they can modulate immune system response and protect normal cells against free radicals damage. Most investigations on anticancer mechanisms of polyphenols were conducted with individual compounds. However, several studies, including ours, have indicated that anti-cancer efficacy and scope of action can be further enhanced by combining them synergistically with chemically similar or different compounds. While most studies investigated the anti-cancer effects of combinations of two or three compounds, we used more comprehensive mixtures of specific polyphenols and mixtures of polyphenols with vitamins, amino acids and other micronutrients. The mixture containing quercetin, curcumin, green tea, cruciferex, and resveratrol (PB) demonstrated significant inhibition of the growth of Fanconi anemia head and neck squamous cell carcinoma and dose-dependent inhibition of cell proliferation, matrix metalloproteinase (MMP)-2 and -9 secretion, cell migration and invasion through Matrigel. PB was found effective in inhibition of fibrosarcoma HT-1080 and melanoma A2058 cell proliferation, MMP-2 and -9 expression, invasion through Matrigel and inducing apoptosis, important parameters for cancer prevention. A combination of polyphenols (quercetin and green tea extract) with vitamin C, amino acids and other micronutrients (EPQ) demonstrated significant suppression of ovarian cancer ES-2 xenograft tumor growth and suppression of ovarian tumor growth and lung metastasis from IP injection of ovarian cancer A-2780 cells. The EPQ mixture without quercetin (NM) also has shown potent anticancer activity in vivo and in vitro in a few dozen cancer cell lines by inhibiting tumor growth and metastasis, MMP-2 and -9 secretion, invasion, angiogenesis, and cell growth as well as induction of apoptosis. The presence of vitamin C, amino acids and other micronutrients could enhance inhibitory effect of epigallocatechin gallate (EGCG) on secretion of MMPs. In addition, enrichment of NM with quercetin (EPQ mix) enhanced anticancer activity of NM in vivo. In conclusion, polyphenols, especially in combination with other polyphenols or micronutrients, have been shown to be effective against multiple targets in cancer development and progression, and should be considered as safe and effective approaches in cancer prevention and therapy.
The ongoing rise in antibiotic resistance, and a waning of the introduction of new antibiotics, has resulted in limited treatment options for bacterial infections, including these caused by ...methicillin-resistant
Staphylococcus aureus
, leaving the world in a post-antibiotic era. Here, we set out to examine mechanisms by which theaflavin 3,3’-digallate (TF3) might act as an anti-hemolytic compound. In the presented study, we found that TF3 has weak bacteriostatic and bactericidal effects on
Staphylococcus aureus
, and strong inhibitory effect towards the hemolytic activity of its α-hemolysin (Hla) including its production and secretion. A supportive SPR assay reinforced these results and further revealed binding of TF3 to Hla with KD = 4.57×10
−5
M. Interestingly, TF3 was also able to protect human primary keratinocytes from Hla-induced cell death, being at the same time non-toxic for them. Further analysis of TF3 properties revealed that TF3 blocked Hla-prompting immune reaction by inhibiting production and secretion of IL1β, IL6, and TNFα
in vitro
and
in vivo
, through affecting NFκB activity. Additionally, we observed that TF3 also markedly attenuated
S
.
aureus
-induced barrier disruption, by inhibiting Hla-triggered E-cadherin and ZO-1 impairment. Overall, by blocking activity of Hla, TF3 subsequently subdued the inflammation and protected the epithelial barrier, which is considered as beneficial to relieving skin injury.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Fatty acids belong to a group of compounds already acknowledged for their broad antiviral efficacy. However, little is yet known about their effect on replication of human coronaviruses. To shed ...light on this subject, we first screened 15 fatty acids, three lipid-soluble vitamins, and cholesterol, on SARS-CoV-2 RdRp, and identified the four fatty acids with the highest RdRp inhibitory potential. Among them, linoleic acid was found to have the greatest interaction with SARS-CoV-2 RdRp, with its direct binding to the cavity formed by the RNA double helix and protein. Linoleic acid forms hydrophobic interactions with multiple residues, and at the same time forms electrostatic interactions including the hydrogen bond with Lys593 and Asp865. In line with these results, a dose-dependent inhibition of HCoV-OC43 replication in vitro was observed, additionally strengthened by data from in vivo study, which also confirmed anti-inflammatory potential of linoleic acid. Based on these results, we concluded that our study provides a new understanding of the antiviral properties of fatty acids against human coronaviruses including the SARS-CoV-2 strain. Particularly, they lays down a new prospect for linoleic acid's RdRp-inhibitory activity, as a candidate for further studies, which are warranted to corroborate the results presented here.
The cases of Lyme disease caused by Borrelia burgdorferi infection have been increasing throughout Northern America and Europe. This pathogen, if not treated in a timely manner with antibiotics, can ...cause persisting and debilitating health outcomes. In the search for novel agents against B. burgdorferi, we investigated a phenolic compound—gallic acid—for its anti-Borrelia and anti-inflammatory effects. Our results showed its biocidal effect starting from 100 μg/mL against active spirochetes, persisters/round-shaped bodies, and biofilm like aggregates of B. burgdorferi sensu stricto. Activation of macrophages by live B. burgdorferi also resulted in a robust NFκB-dependent proinflammatory responses seen in increased production of cytokines. Using human CD14+ macrophages in vitro, we showed that CD14+ adaptor and phosphorylated p65 molecule are impeded at nonbiocidal and noncytotoxic concentrations of gallic acid, resulting in the inhibition of both expression and secretion of cytokines IL1β, IL6, and TNFα. Our findings demonstrate efficacy of gallic acid against B. burgdorferi and provide potential mechanistic insight into its TLR2/CD14+-NFκB mediated mode of action. Further studies on the potential of gallic acid as a safe and effective compound against Borrelia-caused infection are warranted.
In the search for novel agents against oral pathogens in their planktonic and biofilm form, we have focused our attention on 10-undecynoic acid as the representative of the acetylenic fatty acids. ...Using macro-broth susceptibility testing method we first established MIC value. Next, the MBC value was determined from a broth dilution minimum inhibitory concentration test by sub-culturing it to BHI agar plates that did not contain the test agent. Anti-biofilm efficacy was tested in 96-well plates coated with saliva using BHI broth supplemented with 1% sucrose as a standard approach. Based on obtained results, MIC value for 10-undecynoic acid was established to be 2.5 mg/ml and the MBC value to be 5 mg/ml. The MBIC90 showed to be 2.5 mg/ml, however completed inhibition of biofilm formation was achieved at 5.0 mg/ml. MBBC concentration revealed to be the same as MBC value, causing approximately 30% reduction at the same time in biomass of pre-existing biofilm, whereas application of 7.0 mg/ml of 10-undecynoic acid crossed the 50% eradication mark. Strong anti-adherent effect was observed upon 10-undecynoic acid application at sub-MBC concentrations as well, complemented with suppression of acidogenicity and aciduricity. Thus, we concluded that 10-undecynoic acid might play an important role in the development of alternative or adjunctive antibacterial and anti-biofilm preventive and/or therapeutic approaches.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Modified interleukin-2 (IL-2) formulations are being tested in cancer patients. However, IL-2 immunotherapy damages IL-2 receptor (IL-2R)-positive endothelial cells and stimulates IL-2Rα ...(CD25)-expressing lymphocytes that curtail anti-tumor responses. A first generation of IL-2Rβ (CD122)-biased IL-2s addressed some of these drawbacks. Here, we present a second-generation CD122-biased IL-2, developed by splitting and permanently grafting unmutated human IL-2 (hIL-2) to its antigen-binding groove on the anti-hIL-2 monoclonal antibody NARA1, thereby generating NARA1leukin. In comparison to hIL-2/NARA1 complexes, NARA1leukin shows a longer in vivo half-life, completely avoids association with CD25, and more potently stimulates CD8
T and natural killer cells. These effects result in strong anti-tumor responses in various pre-clinical cancer models, whereby NARA1leukin consistently surpasses the efficacy of hIL-2/NARA1 complexes in controlling metastatic disease. Collectively, NARA1leukin is a CD122-biased single-molecule construct based on unmutated hIL-2 with potent efficacy against advanced malignancies.
Cerebral cavernous malformation (CCM) is a neurovascular disease that can lead to seizures and stroke-like symptoms. The familial form is caused by a heterozygous germline mutation in either the
,
or
...gene. While the importance of a second-hit mechanism in CCM development is well established, it is still unclear whether it immediately triggers CCM development or whether additional external factors are required. We here used RNA sequencing to study differential gene expression in
knockout induced pluripotent stem cells (
iPSCs), early mesoderm progenitor cells (eMPCs), and endothelial-like cells (ECs). Notably, CRISPR/Cas9-mediated inactivation of
led to hardly any gene expression differences in iPSCs and eMPCs. However, after differentiation into ECs, we found the significant deregulation of signaling pathways well known to be involved in CCM pathogenesis. These data suggest that a microenvironment of proangiogenic cytokines and growth factors can trigger the establishment of a characteristic gene expression signature upon
inactivation. Consequently,
precursor cells may exist that remain silent until entering the endothelial lineage. Collectively, not only downstream consequences of
ablation but also supporting factors must be addressed in CCM therapy development.
The strain in a fast spinning carbon fiber flywheel rotor is of great interest for condition monitoring, as well as for studying long-term aging effects in the carbon fiber matrix. Optoelectronic ...strain measurement is a contactless measurement principle where a special reflective pattern is applied to the rotor which is scanned by a stationary optical setup. It does not require any active electronic components on the rotor and is suited for operation in a vacuum. In this paper, the influences of the key parts comprising the optoelectronic strain measurement are analyzed. The influence of each part on the measurement result including the uncertainty is modeled. The total uncertainty, as well as each part's contribution is calculated. This provides a valuable assessment of requirements for component selection, as well as tolerances of mechanical parts and processes to reach a final target measurement uncertainty or to estimate the uncertainty of a given setup. We have shown that the edge quality of the special reflective pattern has the strongest influence, and how to improve it. Considering all influences, it is possible to measure strain with an uncertainty of less than 1% at a rotation speed of 500Hz.
PDF
