Identification of hub genes associated with COVID-19 and idiopathic pulmonary fibrosis by integrated bioinformatics analysis.

INTRODUCTION: The coronavirus disease 2019 (COVID-19), emerged in late 2019, was caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The risk factors for idiopathic pulmonary fibrosis (IPF) and COVID-19 are reported to be common. This study aimed to determine the potential role of differentially expressed genes (DEGs) common in IPF and COVID-19. MATERIALS AND METHODS: Based on GEO database, we obtained DEGs from one SARS-CoV-2 dataset and five IPF datasets. A series of enrichment analysis were performed to identify the function of upregulated and downregulated DEGs, respectively. Two plugins in Cytoscape, Cytohubba and MCODE, were utilized to identify hub genes after a protein-protein interaction (PPI) network. Finally, candidate drugs were predicted to target the upregulated DEGs. RESULTS: A total of 188 DEGs were found between COVID-19 and IPF, out of which 117 were upregulated and 71 were downregulated. The upregulated DEGs were involved in cytokine function, while downregulated DEGs were associated with extracellular matrix disassembly. Twenty-two hub genes were upregulated in COVID-19 and IPF, for which 155 candidate drugs were predicted (adj.P.value < 0.01). CONCLUSION: Identifying the hub genes aberrantly regulated in both COVID-19 and IPF may enable development of molecules, encoded by those genes, as therapeutic targets for preventing IPF progression and SARS-CoV-2 infections.

Identification of Off-Patent Compounds That Present Antifungal Activity Against the Emerging Fungal Pathogen Candida auris.

Candida auris is an emerging fungal pathogen of great concern among the scientific community because it is causing an increasing number of hospital outbreaks of difficult management worldwide. In addition, isolates from this species frequently present reduced susceptibility to azole and echinocandin drugs. For this reason, it is necessary to develop new antifungal strategies to better control the disease caused by this yeast. In this work, we screened drugs from the Prestwick chemical library, which contains 1,280 off-patent compounds that are already approved by the Food and Drug Administration, with the aim of identifying molecules with antifungal activity against C. auris. In an initial screening, we looked for drugs that inhibited the growth of three different C. auris strains and found 27 of them which it did so. Ten active compounds were selected to test the susceptibility profile by using the EUCAST protocol. Antifungal activity was confirmed for seven drugs with MICs ranging from 0.5 to 64 mg/L. Some of these drugs were also tested in combination with voriconazole and anidulafungin at sub-inhibitory concentrations. Our results suggest synergistic interactions between suloctidil and voriconazole with fractional inhibitory concentration index (FICI) values of 0.11 to 0.5 and between ebselen and anidulafungin (FICI, 0.12 to 0.44). Our findings indicate that drug repurposing could be a viable alternative to managing infections by C. auris.

A repurposing approach identifies off-patent drugs with fungicidal cryptococcal activity, a common structural chemotype, and pharmacological properties relevant to the treatment of cryptococcosis.

New, more accessible therapies for cryptococcosis represent an unmet clinical need of global importance. We took a repurposing approach to identify previously developed drugs with fungicidal activity toward Cryptococcus neoformans, using a high-throughput screening assay designed to detect drugs that directly kill fungi. From a set of 1,120 off-patent medications and bioactive molecules, we identified 31 drugs/molecules with fungicidal activity, including 15 drugs for which direct antifungal activity had not previously been reported. A significant portion of the drugs are orally bioavailable and cross the blood-brain barrier, features key to the development of a widely applicable anticryptococcal agent. Structural analysis of this set revealed a common chemotype consisting of a hydrophobic moiety linked to a basic amine, features that are common to drugs that cross the blood-brain barrier and access the phagolysosome, two important niches of C. neoformans. Consistent with their fungicidal activity, the set contains eight drugs that are either additive or synergistic in combination with fluconazole. Importantly, we identified two drugs, amiodarone and thioridazine, with activity against intraphagocytic C. neoformans. Finally, the set of drugs is also enriched for molecules that inhibit calmodulin, and we have confirmed that seven drugs directly bind C. neoformans calmodulin, providing a molecular target that may contribute to the mechanism of antifungal activity. Taken together, these studies provide a foundation for the optimization of the antifungal properties of a set of pharmacologically attractive scaffolds for the development of novel anticryptococcal therapies.

A screen for drugs that protect against the cytotoxicity of polyglutamine-expanded androgen receptor.

Spinobulbar muscular atrophy is a neurodegenerative disorder caused by expansion of a CAG triplet repeat sequence encoding a polyglutamine tract in the androgen receptor. It has been shown that the mutant protein is toxic in cell culture and triggers an apoptotic cascade resulting in activation of caspase-3. We developed an assay of caspase-3 activation in cells expressing the mutant androgen receptor. This assay was used to screen 1040 drugs, most of which are approved for clinical use. Drugs that inhibit polyglutamine-dependent activation of caspase-3 were subjected to follow-up screens to identify compounds that reproducibly prevent polyglutamine-induced cytotoxicity. Four drugs satisfied these criteria. Three of these (digitoxin, nerifolin and peruvoside) are structurally and functionally related compounds of the cardiac glycoside class and known inhibitors of Na(+)K(+)-ATPase. The fourth compound, suloctidil, is a calcium channel blocker.

Glucose- and K(+)-induced acidification in different yeast species.

The process of acidification of the external medium after addition of glucose and subsequently of KCl to a suspension of yeast cells varies substantially from species to species. After glucose it is most pronounced in Saccharomyces cerevisiae and Schizosaccharomyces pombe but is very much lower in Lodderomyces elongisporus, Dipodascus magnusii and Rhodotorula gracilis. Both the buffering capacity and the varied effects of vanadate, suloctidil and erythrosin B indicate that the acidification is by about one-half due to the activity of plasma membrane H(+)-ATPase and by about one-half to the extrusion of acidic metabolites from cells. This is supported by the finding that a respiratory quotient greater than one (in various strains of S. cerevisiae and in S. pombe) is indicative of a greater buffering capacity and overall acidification of the medium. Taking into account the virtually negligible buffering capacity of the medium in the pH range where the effect of K+ is observed, the effect of K+ is generally of a similar magnitude as that of adding glucose. It is clearly dependent on (anaerobic) production of metabolic energy, quite distinct from the dependence of the H(+)-ATPase-caused acidification.

Different sources of acidity in glucose-elicited extracellular acidification in the yeast Saccharomyces cerevisiae.

Three wild-type strains of Saccharomyces cerevisiae, viz. K, Y55 and sigma 1278b, two mutants lacking one or both of the putative K+ transporters, trk1 delta and trk1 delta trk2 delta, and a mutant in the plasma membrane H(+)-ATPase, viz. pma1-105, were compared in their extracellular acidification following addition of glucose and subsequent addition of KCl; in ATPase activity in purified plasma membranes; and in respiration on glucose. The glucose-induced acidification was the greater the higher the respiratory quotient, i.e. the higher the anaerobic metabolism. A markedly lower acidification was found in the ATPase-deficient pma1-105 strain but also in the TRK-deficient double mutant. The acidification pattern after addition of KCl corresponds to expectations in the TRK mutants; however, a similarly decreased acid production was found in the ATPase-deficient mutant pma1-105. The highest rate of ATP hydrolysis in vitro was found with the trk1 delta trk2 delta mutant where glucose-, as well as KCl-induced acidification were lowest. Likewise, the pma1-105 mutant with extremely low acidification showed only a minutely lower ATP hydrolysis than did its parent Y55 strain. Apparently, several different sources of acidity are involved in the glucose-induced acidification (including extrusion of organic acids); in fact, contrary to the general belief, the H(+)-ATPase may play a minor role in this process in some strains.

1H-NMR study of suloctidil-A23187 calcium ionophore interaction.

Suloctidil is a molecule with calcium antagonist properties, whose anti-ionophoretic effect has previously been reported. In the presence of A23187 calcium ionophore free acid (A+), the NMR spectra of suloctidil (S +/-) are modified at the level of H-1 protons and to a lesser degree in the CH3-3 and aromatic regions. Experiments with one of the enantiomers of suloctidil and decoupling investigations led us to postulate the existence of diastereoisomers S+/A+, S-/A+ in the suloctidil +/-/A23187 + mixture. Moreover our results allow the hypothesis that suloctidil and calcium compete for the same binding site of the ionophore molecule.

[The effect of suloctidil and acetylsalicylic acid on eicosanoid synthesis in human platelets]. / Wplyw syloktydylu i kwasu acetylosalicylowego na synteze prostanoidów w krwinkach plytkowych czlowieka.

The study aimed at comparing an effect of suloctidil and acetylsalicylic acid on malonyldialdehyde levels resulting from the arachidonic acid metabolism in blood platelets. It was shown that inhibitory effect of suloctidil is more potent than that of acetylsalicylic acid. Therefore the first is more inhibitor of an enzymatic metabolism of arachidonate in blood platelets than the latter.

Are proton symports in yeast directly linked to H(+)-ATPase acidification?

Transport of amino acids in Saccharomyces cerevisiae is an H(+)-driven secondary active transport. Inhibitors of the plasma membrane H(+)-ATPase, particularly heavy water, diethylstilbestrol and suloctidil, were shown to affect the H(+)-extruding ATPase activity as well as the ATP-hydrolyzing activity, to a similar degree as they inhibited the transport of amino acids. The inhibitors had virtually no effect on the membrane electric potential or on the delta pH which constitute the thermodynamically relevant source of energy for these transports. Transport of acidic amino acids was affected much more than that of the neutral and especially of the basic ones. The effects were greater with higher amino acid concentrations. All this is taken as evidence that the amino acid carriers respond kinetically to the presence of protons directly at the membrane site where they are extruded by the H(+)-ATPase, rather than to the overall protonmotive force.

Suloctidil increases the rat brain cortex microvascular regeneration after a lesion.

A "cavity" lesion made by aspiration in the rat occipital cortex induces a parenchymal and a vascular reaction in its vicinity. The first was mainly characterized by cellular necrosis and gliosis, the second by an increase of the vascular network. In vehicle treated rats, a 50% significant increase of the vascular network was observed around the cavity 4 days after the lesion, in comparison to the uninjured contralateral cortex. The effects of a vasoactive substance, suloctidil, on the vascular reaction was studied in the brain cortex. A single oral dose of suloctidil (30 mg/kg; 2 hours before the sacrifice) gave the same effect as the vehicle group. After 8 days of suloctidil oral administration (30 mg/kg; twice daily: 4 days before lesion and 4 days after) a significant increase (123%) of the vascular network was observed around the cavity. The hypothetical ways by which a chronic treatment of suloctidil induces this increase of the neovascularization observed after cortical lesion are discussed.

Suloctidil-induced hepatotoxicity.

Suloctidil is a new drug that is currently being evaluated in many clinical trials for use in dementia and thrombotic disorders. Hepatotoxicity has to date been reported exclusively in the European literature, and the few available histologic descriptions have been reported in the French language. We report a case of suloctidil-induced hepatotoxicity documented by serum liver biochemical tests and liver biopsy. Histologic features included focal necrosis of hepatocytes, mild hyperplasia of Kupffer cells, and other features suggestive of mild acute hepatitis.

Effects of the antithrombotic drug suloctidil on low density lipoprotein processing and cholesterol metabolism in cultured human fibroblasts.

Human foetal lung fibroblasts were pretreated for 24 h with the antithrombotic drug, suloctidil (1 to 10 mumol/l), which induced a dose-dependent increase in LDL binding, uptake and degradation. At 10 mumol/l suloctidil, the respective increases in these parameters were 40%, 80% and 50%. The same treatment also resulted in increases of 1.5 to 2-fold in the synthesis of sterols, fatty acids and triacylglycerols from sodium acetate. In contrast, the esterification of cholesterol with oleic acid was specifically decreased by 35% by 24 h pretreatment of fibroblasts with 10 mumol/l suloctidil. A similar decrease of cholesterol esterification was observed in cholesterol-laden fibroblasts. It is suggested that these effects of suloctidil on LDL processing and cholesterol metabolism are related to the amphiphilic characteristics of the drug and to its calcium-blocking properties.

Stimulation of prostacyclin production in blood vessels by the antithrombotic drug suloctidil.

Suloctidil is a calcium antagonist with vascular relaxing activity and an antithrombotic agent: its antiplatelet action has been demonstrated in vivo, but is difficult to reproduce in vitro and the mechanism of this effect remains unknown. We have observed that suloctidil (10 microM) stimulated the release of prostacyclin (PGI2) from the rabbit aorta, the dog vena cava and the dog portal vein, in vitro. This effect could be explained by an increased mobilization of free arachidonic acid. Neither the inactive congener CP894S, nor the two calcium channel antagonists, verapamil and flunarizine, reproduced the stimulatory effect of suloctidil. Suloctidil acted selectively on the vascular endothelium: it stimulated the release of PGI2 from bovine aortic and human umbilical vein endothelial cells, but neither from the de-endothelialized rabbit aorta nor from the bovine aortic media. The stimulatory effect of suloctidil on the release of the platelet inhibitor PGI2 from the vascular endothelium might contribute to the known antiplatelet and antithrombotic activity of this drug.

Taurine interferes with spiperone binding in the striatum.

The effects of taurine and its structural analogues and two new anticonvulsant derivatives, taltrimide and MY-103, on the function of brain dopaminergic systems were studied by assessing their interference with the binding of [3H]spiperone to synaptic membranes isolated from rat striata. Two populations of binding sites were detected. The binding was effectively displaced by (+)butaclamol and dopamine, serotonin being less potent by one order of magnitude. Taurine, taltrimide and MY-103 inhibited spiperone binding moderately. The binding constants of both high- and low-affinity components and the maximal binding capacity of the low-affinity component decreased in the presence of taurine. The results show that taurine and its novel anticonvulsant derivates could modulate the function of striatal dopaminergic systems.

In vitro vasorelaxing activity of suloctidil.

The vasorelaxing effect of suloctidil was evaluated in isolated rat and rabbit aorta and in isolated rabbit mesenteric and saphenous artery. Suloctidil inhibited contractions induced by increasing extracellular calcium in depolarized arteries, mainly in a competitive way. In the rat aorta, the pA2 value was 7.50 for suloctidil, while pA2 values of 9.96, 7.90 and 8.10 were obtained for nifedipine, cinnarizine and verapamil, respectively. Suloctidil more potently inhibited calcium-induced contractions in small arteries (mesenteric and saphenous artery), than in the aorta. Suloctidil also reduced the tonic component of the responses to norepinephrine. In contrast to the effects on calcium-induced contractions, the effects of suloctidil on norepinephrine-induced responses was mainly noncompetitive. In addition, and unlike cinnarizine and verapamil, high concentration of suloctidil also reduced the phasic component of contractile responses to norepinephrine. Furthermore, unlike nifedipine, verapamil, diltiazem and cinnarizine, suloctidil was devoid of a negative inotropic effect in spontaneously beating guinea-pig atria. In conclusion, suloctidil behaves as a Ca2+-channel blocker in arteries and displays an additional mode of action that could include receptor-operated Ca2+-channels or an intracellular site of action. In addition, suloctidil was found to affect small arteries more than the aorta, and not to affect the atria.

Effect of suloctidil on tomographically quantitated platelet accumulation in Dacron aortic grafts.

Platelet deposition contributes to the thrombotic and embolic complications of prosthetic materials in man. To determine if the investigational platelet inhibitory drug suloctidil (200 mg 3 times daily) reduces platelet deposition on Dacron aortic grafts, a randomized, double-blind, crossover trial was conducted in 12 men with grafts that had been in place more than 9 months. Platelet deposition in the graft was assessed by quantitative analysis of planar images obtained at 24, 48 and 72 hours after injection of indium-111-labeled platelets. Also, a tomographic method of imaging and quantitating labeled platelet deposition in the graft was developed. Tomographic imaging was performed at 24 and 72 hours after platelet injection and was quantitated by a graft/blood ratio that compared indium-111 platelet activity in summed 1.8-cm-thick transaxial tomographic slices of the aortic graft to indium-111 platelet activity in well-counted whole blood. Compared with placebo, suloctidil failed to decrease the tomographic graft/blood ratio at 24 hours (6.2 +/- 1.3 vs 5.7 +/- 0.8) and 72 hours (11.4 +/- 2.9 vs 10.7 +/- 2.2). Similarly, the graft/blood ratio determined by planar imaging was not different between placebo and suloctidil therapy at 24 hours (1.7 +/- 0.3 vs 1.6 +/- 0.2), 48 hours (2.2 +/- 0.4 vs 2.4 +/- 0.4) or 72 hours (2.6 +/- 0.5 vs 2.8 +/- 0.5) after labeled platelet injection. Thus, suloctidil does not significantly reduce platelet deposition on chronically implanted Dacron grafts in humans.

Effect of suloctidil on rat liver.

The effect of suloctidil (120 mg/kg body weight PO for 3 weeks) on rat liver was investigated using biochemical and morphological methods: enzymatic activities characteristic of the main cellular compartments were used as biochemical markers of hepatocyte function and morphometry was applied to investigate morphological changes. No sign of hepatotoxicity was evidenced after suloctidil treatment (liver weight; cytochrome c oxidase; glucose 6-phosphatase; NADPH-cytochrome c reductase; D-amino acid oxidase; urate oxidase; fatty acid oxidation; peroxisomal number, volume and size distribution). Suloctidil increased catalase activity by 22% without morphologically detectable changes in the peroxisomes. After suloctidil treatment, slightly increased mitochondrial volume fraction and slightly decreased mitochondrial number were noted without significant changes in cytochrome c oxidase. Clofibrate, at the same dose, increased NADPH-cytochrome c reductase, catalase, acylCoA oxidase, mitochondrial and peroxisomal number and volume fraction, and decreased urate oxidase activity.