Measuring flow-mediated protein drift across stationary supported lipid bilayers.

Fluid flow near biological membranes influences cell functions such as development, motility, and environmental sensing. Flow can laterally transport extracellular membrane proteins located at the cell-fluid interface. To determine whether this transport contributes to flow signaling in cells, quantitative knowledge of the forces acting on membrane proteins is required. Here, we demonstrate a method for measuring flow-mediated lateral transport of lipid-anchored proteins. We rupture giant unilamellar vesicles to form discrete patches of supported membrane inside rectangular microchannels and then allow proteins to bind to the upper surface of the membrane. While applying flow, we observe the formation of protein concentration gradients that span the membrane patch. By observing how these gradients dynamically respond to changes in applied shear stress, we determine the flow mobility of the lipid-anchored protein. We use simplified model membranes and proteins to demonstrate our method's sensitivity and reproducibility. Our intention was to design a quantitative, reliable method and analysis for protein mobility that we will use to compare flow transport for a variety of proteins, lipid anchors, and membranes in model systems and on living cells.

An innate pathogen sensing strategy involving ubiquitination of bacterial surface proteins.

Sensing of pathogens by ubiquitination is a critical arm of cellular immunity. However, universal ubiquitination targets on microbes remain unidentified. Here, using in vitro, ex vivo, and in vivo studies, we identify the first protein-based ubiquitination substrates on phylogenetically diverse bacteria by unveiling a strategy that uses recognition of degron-like motifs. Such motifs form a new class of intra-cytosolic pathogen-associated molecular patterns (PAMPs). Their incorporation enabled recognition of nonubiquitin targets by host ubiquitin ligases. We find that SCFFBW7 E3 ligase, supported by the regulatory kinase, glycogen synthase kinase 3ß, is crucial for effective pathogen detection and clearance. This provides a mechanistic explanation for enhanced risk of infections in patients with chronic lymphocytic leukemia bearing mutations in F-box and WD repeat domain containing 7 protein. We conclude that exploitation of this generic pathogen sensing strategy allows conservation of host resources and boosts antimicrobial immunity.

Molecular Mechanism of Hydrotropic Properties of GTP and ATP.

Hydrotropes are small amphiphilic compounds that increase the aqueous solubility of hydrophobic molecules. Recent evidence suggests that adenosine triphosphate (ATP), which is the primary energy carrier in cells, also assumes hydrotropic properties to prevent the aggregation of hydrophobic proteins, but the mechanism of hydrotropy is unknown. Here, we compare the hydrotropic behavior of all four biological nucleoside triphosphates (NTPs) using molecular dynamics (MD) simulations. We launch all atom MD simulations of aqueous solutions of NTPs [ATP, guanosine triphosphate (GTP), cytidine triphosphate (CTP), and uridine triphosphate (UTP)] with pyrene, which acts both as a model hydrophobic compound and as a spectroscopic reporter for aggregation. GTP prevents pyrene aggregation effectively. Dissolution is not achieved in the presence of CTP and UTP. The higher stability of the base stacking in guanine is responsible for the higher hydrotropic efficiency of GTP. Consistent with the simulations, spectroscopic measurements also suggest that the hydrotropic activity of GTP is higher than ATP. Stacking of aromatic pyrene with the aromatic base of NTPs is a characteristic feature of this hydrotropic property. Both ATP and GTP also dissolve clusters of di- and tripeptides containing tryptophan but with equal potency. Importantly, the presence of aromatic amino acids is a necessary condition for the hydrotropic potency of ATP and GTP. Our results can have broad implications for hydrotrope design in the pharmaceutical industry, as well as the possibility of cells employing GTP as a hydrotrope to regulate the hydrophobic protein aggregation in membrane-less biological condensates.

Antioxidant and Antivenom Potential of an Essential Oil, 4-(2-Oxo-propyl)-cyclopentane-1,3-dione, and Allantoin Derived from the Polyherbal Combination of Aristolochia indica L. and Piper nigrum L.

The goal of this study was to identify new compounds from a methanol extract of a polyherbal combination of Aristolochia indica L. and Piper nigrum L. (MECAIPN), two traditional medicinal plants used to cure envenomation, as well as to assess their antioxidant and antivenom properties. MECAIPN yielded EA1 (an essential oil), AA2 (4-(2-oxo-propyl)-cyclopentane-1,3-dione), and W3 ((2,5-dioxo-imidazolidin-4-yl)-urea) (Allantoin). Although EA1 had stronger radical scavenging activity, AA2 had higher DPPH and ferric ion radical scavenging activity, and W3 had higher molybdenum ion radical scavenging activity due to being a single molecule, the binding investigation revealed that EA1 has a greater Stern-Volmer quenching constant (Ksv) than AA2 and W3. Synchronous measurements indicated that EA1, AA2, and W3 bind to tryptophan and tyrosine residues in venom, causing denaturation of the secondary structure of the residue. Finally, the current study concludes that EA1 has more therapeutic antivenom potential, which could be related to the synergism of chemicals found in it. When it came to single compounds, AA2 had stronger antioxidant and antivenom capabilities than W3. To understand the mechanism of action and manufacture the green antivenom medication, more testing of the EA1 and compounds remains required.

Can platelet-rich plasma injections provide better pain relief and functional outcomes in persons with common shoulder diseases: a meta-analysis of randomized controlled trials.

BACKGROUND: To evaluate the efficacy of autologous platelet-rich plasma (PRP) injections in the treatment of common shoulder diseases. METHODS: The PubMed, Medline, and Central databases and trial registries were searched from their inception to October 2020 for randomized controlled trials of autologous PRP injections for shoulder diseases versus placebo or any control intervention. Preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed in the selection, analysis, and reporting of findings. The primary outcome was pain intensity (visual analog scale), and secondary outcomes were changes in function and quality of life (QoL). RESULTS: A total of 17 randomized controlled trials of PRP versus control were analyzed. From 8-12 weeks to ≥1 year, PRP injections were associated with better pain relief and functional outcomes than control interventions. PRP injections were also associated with greater QoL, with an effect size of 2.61 (95% confidence interval, 2.01-14.17) at medium-term follow-up. Compared with placebo and corticosteroid injections, PRP injections provided better pain relief and functional improvement. In subgroup analyses, trials in which PRP was prepared by the double centrifugation technique, the platelet concentration in the PRP was enriched ≥5 times, leucocyte-rich PRP was used, or an activating agent was used before application reported the most effective pain relief at 6-7 months. CONCLUSIONS: PRP injections could provide better pain relief and functional outcomes than other treatments for persons presenting with common shoulder diseases. PRP injections have a greater capacity to improve shoulder-related QoL than other interventions.

A concise review of mushrooms antiviral and immunomodulatory properties that may combat against COVID-19.

The World Health Organization (WHO) declared COVID-19 as a pandemic on March 11, 2020, because of its widespread transmission and infection rates. The unique severe disease was found in Wuhan, China, since December 2019, and swiftly spread throughout the world. Natural chemicals derived from herbal medicines and medicinal mushrooms provide a significant resource for the development of novel antiviral drugs. Many natural drugs have been proven to have antiviral properties against a variety of virus strains, such as the coronavirus and the herpes simplex virus (HSV).. In this research, successful dietary treatments for different COVID illnesses were compared to potential of mushroom products in its therapy. In Google Scholar, Science Direct, PubMed, and Scopus, search keywords like COVID, COVID-19, SARS, MERS, mushrooms, and their compounds were utilized. In this review of the literature we foucsed popular mushrooms such as Agaricus subrufescens Peck, Agaricus blazei Murill, Cordyceps sinensis (Berk.) Sacc., Ganoderma lucidum (Curtis.) P. Karst., Grifola frondosa (Dicks.) Gray, Hericium erinaceus (Bull.) Pers., Inonotus obliquus (Arch. Ex Pers.) Pilát., Lentinula edodes (Berk.) Pegler, Pleurotus ostreatus (Jacq.) P. Kumm., Poria cocos F.A. Wolf, and Trametes versicolor (L.) Lloyd.,. Changed forms of ß-Glucan seem to have a good impact on viral replication suppression and might be used in future studies. However, the results seems terpenoids, lectins, glycoproteins, lentinan, galactomannan, and polysaccharides from mushrooms are promising prophylactic or therapeutic agents against COVID-19.

Clinical features and prognosis of COVID-19/SARS-CoV-2 infections in persons with spinal cord injury: a review of current literature.

STUDY DESIGN: Focused literature review. OBJECTIVES: Objective of the study was to perform a literature search and summarise the clinical features and prognosis of persons with spinal cord injury (SCI) infected with COVID-19 from the published articles. SETTING: India. METHODS: PubMed, CENTRAL and MEDLINE were systematically searched using specific keywords. The study assessed 2747 scientific studies involving COVID-19 and SCI for possible inclusion in a meta-analysis of SCI and SARS-COV-2. Studies involving persons with SCI who were tested positive for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in the nasopharyngeal or throat swab polymerase chain reaction were included. RESULTS: Out of 2747 articles, 11 articles (206 participants), including six case reports, were included in this review. Fever was the most frequently observed symptom of COVID-19 infection in the SCI population. C-reactive protein (CRP) and lymphocytopenia were common abnormal laboratory parameters. The most common radiological finding in COVID-19 infection was ground glass opacities in lung fields. Prophylactic/therapeutic anticoagulation was given in a significant number of SCI persons infected with COVID-19. Persons with SCI who were diagnosed early showed good outcomes. CONCLUSIONS: Based on the few studies published on COVID-19 and SCI populations since 2019, this study determined fever, elevated CRP, lymphocytopenia and ground glass opacities, which indicated inflammation, compromised immune response, and lung edema, as the main clinical features of COVID-19 infection in SCI population. Though COVID-19 infection reported an increased number of deaths in few studies, a significant number of SCI populations with positive RT-PCR were treated successfully and discharged at home.

Effect of pH on the phase behavior of DMPC bilayers.

We have studied the effect of acidic pH on the phase behavior of the zwitterionic lipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) using differential scanning calorimetry and x-ray scattering. Dispersions of DMPC in HCl solutions of pH = 4 and 3 behave identical to dispersions in water. The main transition temperature increases sharply and the pre-transition disappears at lower pH. An untilted gel phase is observed at pH = 2 and 1, in contrast to the tilted gel phase found at higher pH. The relatively large periodicity of the untilted gel phase, in comparison to that of the tilted gel phase occurring near neutral pH, clearly demonstrates the simultaneous charging and dehydration of the headgroups as the pH approaches the pK of the phosphate group. Headgroup dehydration at low pH also leads to the formation of DMPC crystallites and the inverted hexagonal phase at low and high temperatures, respectively, after a few days of incubation. These results show the significant effect of acidic pH on the phase behavior of zwitterionic lipids.

Interaction of the mononucleotide UMP with a fluid phospholipid bilayer.

Interaction between mononucleotides and lipid membranes is believed to have played an important role in the origin of life on Earth. Studies on mononucleotide-lipid systems hitherto have focused on the influence of the lipid environment on the organization of the mononucleotide molecules, and the effect of the latter on the confining medium has not been investigated in detail. We have probed the interaction of the mononucleotide, uridine 5'-monophosphate (UMP), and its disodium salt (UMPDSS) with fluid dimyristoylphosphatidylcholine (DMPC) membranes, using small-angle X-ray scattering (SAXS), cryogenic scanning electron microscopy (cryo-SEM) and computer simulations. UMP adsorbs and charges the lipid membrane, resulting in the formation of unilamellar vesicles in dilute solutions. Adsorption of UMP reduces the bilayer thickness of DMPC. UMPDSS has a much weaker effect on interbilayer interactions. These observations are in very good agreement with the results of an all-atom molecular dynamics simulation of these systems. In the presence of counterions, such as Na+, UMP forms small aggregates in water, which bind to the bilayer without significantly perturbing it. The phosphate moiety in the lipid headgroup is found to bind to the hydrogens from the sugar ring of UMP, while the choline group tends to bind to the two oxygens from the nucleotide base. These studies provide important insights into lipid-nucleotide interactions and the effect of the nucleotide on lipid membranes.

Evaluation of Aristolochia indica L. and Piper nigrum L. methanol extract against centipede Scolopendra moristans L. using Wistar albino rats and screening of bioactive compounds by high pressure liquid chromatography: a polyherbal formulation.

The present study was aimed to explore the anti-venom activity of Aristolochia indica and Piper nigrum plants against the centipede (Scolopendra moristans) envenomation in animal model. In vtiro phytochemical, antioxidant and blocking of proteolysis were carried out by using standard spectrophotometric methods. In vivo anti-venom activity of methanol extracts was determined using Wistar albino rats after fixing lethal and effective doses. The electrolytes, lipid, liver, kidney, hematological parameters were analyzed and histopathology of skin and liver were also examined. Anti-skin cancer by MTT method and HPLC analysis were also carried out. The CAIPN extract showed higher total phenolics (150.65 ± 0.08 mg GAE/g extract) and flavonoids (158.97 ± 0.93 mg RE/g extract) content. Further, the same extract revealed the higher molybdenum reducing, inhibition of lipid peroxidation (80.08 ± 0.22%), DPPH radical scavenging (3.05 µg/mL), and blocking of proteolysis activities (96.45 ± 0.04%). The parameters like hypersensitivity, electrolytes, lipids, blood components, liver and kidney marker of the CAIPN methanol extract (200 mg/kg) treated envenomated rats was remarkable and same as in the normal animals. Such status was also achieved by RBAI and SPN at 600 mg/kg. The histopathological scoring of skin and liver confirmed the venom neutralizing activity of CAIPN. Also, the CAIPN methanol extract was notable in anti-skin cancer activity (208 µg/mL). The presence of the ferulic acid (04 ± 0.09 µg/mg) and quercetin (35.30 ± 0.30 µg/mg) like compounds was confirmed by HPLC analysis. Hence, the present investigation results conclude that the CAIPN was significant in their action and this polyherbal formulation could be considered as a new source for the pharmaceutical industries to develop a new effective, ecofriendly anti-venom drug.

Chemical profiling of Pterolobium hexapetalum leaves by HPLC analysis and its productive wound healing activities in rats.

Research on wound healing agents is one of the developing areas in modern biomedical sciences. Several drugs have been used in the management of wounds and a large variety of treatment modalities are available for wound repair. Among these medicines, herbal origin has been the basis of treatment and cure for healing of wounds. Pterolobium hexapetalum is well known medicinal plant of Caesalpiniaceae family was used by many tribal groups for wound treatment in India. Different extracts of P. hexapetalum leaves are evaluated for its antiradical activity and in vivo wound healing activity by excision, incision, and dead space wound models in Wistar rats, further respective phyto constituents are profiled using High Performance Liquid Chromatography. In this present study methanol extract of leaves depicted the maximum amount of phenolics and flavonoids content and also registered highest DPPH (IC50: 3.40µg/mL), ABTS+(8869.36µM TE/g extract) and Superoxide (87.72%) radical scavenging activity. Methanolic leaf extract are further studied for wound healing property, highest wound contraction percentage and lowest epithelialization period (16.33days) of 5% methanolic extract treated group exhibits highest wound healing activity compare to control group and it was confirmed by histopathology results and scoring analysis. Maximum tensile strain (110.69%) of incision and highest hydroxyproline (16.28mg/g) content of dead space wound model are comparable with standard 5% Neomycin. HPLC employed quantification of phyto constituents explores the presence of catechin (367.54µg/mg), caffeic acid (87µg/mg), rutin (289.20µg/mg), quercetin (239.39µg/mg) and naringenin (24.42µg/mg). From the results leaves of P. hexapetalum significantly stimulate wound contraction, braking strength and hydroxyproline content of treated group. It showed remarkable wound healing activity and may be recommended for treating various type of wound.