Soluble ACE2 (sACE2) decoys are promising agents to inhibit SARS-CoV-2, as their efficiency is unlikely to be affected by escape mutations. However, their success is limited by their relatively poor potency. To address this challenge, multimeric sACE2 consisting of SunTag or MoonTag systems is developed. These systems are extremely effective in neutralizing SARS-CoV-2 in pseudoviral systems and in clinical isolates, perform better than the dimeric or trimeric sACE2, and exhibit greater than 100-fold neutralization efficiency, compared to monomeric sACE2. SunTag or MoonTag fused to a more potent sACE2 (v1) achieves a sub-nanomolar IC50 , comparable with clinical monoclonal antibodies. Pseudoviruses bearing mutations for variants of concern, including delta and omicron, are also neutralized efficiently with multimeric sACE2. Finally, therapeutic treatment of sACE2(v1)-MoonTag provides protection against SARS-CoV-2 infection in an in vivo mouse model. Therefore, highly potent multimeric sACE2 may offer a promising treatment approach against SARS-CoV-2 infections.

In this study, we characterized the fatty acid production in Neochloris aquatica at transcriptomics and biochemical levels under limiting, normal, and excess nitrate concentrations in different growth phases. At the stationary phase, N. aquatica mainly produced saturated fatty acids such as stearic acid under the limiting nitrate concentration, which is suitable for biodiesel production. However, it produced polyunsaturated fatty acids such as α-linolenic acid under the excess nitrate concentration, which has nutritional values as food supplements. In addition, RNA-seq was employed to identify genes and pathways that were being affected in N. aquatica for three growth phases in the presence of the different nitrate amounts. Genes that are responsible for the production of saturated fatty acids were upregulated in the cells grown under a limiting nitrogen amount while genes that are responsible for the production of polyunsaturated fatty acid were upregulated in the cells grown under excess nitrogen amount. Further analysis showed more genes differentially expressed (DEGs) at the logarithmic phase in all conditions while a relatively steady trend was observed during the transition from the logarithmic phase to the stationary phase under limiting and excess nitrogen. Our results provide a foundation for identifying developmentally important genes and understanding the biological processes in the different growth phases of the N. aquatica in terms of biomass and lipid production.

Soluble ACE2 (sACE2) decoy receptors are promising agents to inhibit SARS-CoV-2 as they are not affected by common escape mutations in viral proteins. However, their success may be limited by their relatively poor potency. To address these challenges, we developed a highly active multimeric sACE2 decoy receptor via a SunTag system that could neutralize both pseudoviruses bearing SARS-CoV-2 spike protein and SARS-CoV-2 clinical isolates. This fusion protein demonstrated a neutralization efficiency nearly 250-fold greater than monomeric sACE2. SunTag in combination with a more potent version of sACE2 achieved near complete neutralization at a sub-nanomolar range, which is comparable with clinical monoclonal antibodies. We demonstrate that this activity is due to greater occupancy of the multimeric decoy receptors on Spike protein as compared to monomeric sACE2. Overall, these highly potent multimeric sACE2 decoy receptors offer a promising treatment approach against SARS-CoV-2 infections including its novel variants.

BACKGROUND:Metabolic syndrome, obesity and type 2 diabetes are metabolic disorders characterized by the insulin resistance and the impairment in the insulin secretion. Since impairment in the oxidative stress and adipocyte metabolism contribute to the formation of obesity and diabetes, targeting adipose tissue can be considered as an effective approach to fight against them. Rosiglitazone is used for treatment for patients with type 2 diabetes via inducing lipogenesis and transdifferentiation of white adipose tissue into brown adipose tissue. Since the development of such therapeutics is required to control the formation and function of brown fat cells, we aimed to reveal possible molecular mechanisms behind rosiglitazone induced biochemical changes in the adipose tissue.METHODS:Cells were expanded in the adipocyte culture medium supplemented with 5 µg/mL insulin following 2 days' induction. After those cells were treated with rosiglitazone 0, 0.13 mol/L and 10 µmol/L rosiglitazone for 48 hours and at 8th day, cells were collected and stored at -80 °C. Then the cells were used to evaluate antioxidant enzyme activities, mineral and trace element levels and fatty acid composition.RESULTS:Glucose-6-phosphate dehydrogenase and glutathione reductase significantly reduced in rosiglitazone-treated groups compared to the control. Na, Mg, K, Ca, Cr, Fe, Ni, Cu, Zn, Rb, Sr, Cs, Ba and Pb were determined in the cell lysates via ICP-MS. Also, relative FAME content decreased in the rosiglitazone-treated groups compared to the control.CONCLUSIONS:Rosiglitazone treatment at low doses showed promising results which may promote brown adipose tissue formation.

Upgrading of bitumen blended with microalgae Chlorella vulgaris was investigated in supercritical water (SCW) at 440 degrees C and 30 MPa in a home-made batch type bomb reactor. The effects of the water/feed ratio ranging from 2 to 10 and the effects of microalgae fraction in the feeds ranging from 0 (pure bitumen) to 100 wt.% (pure microalgae) were investigated. Pyrolysis experiments in the absence of water were also performed at the same conditions. SCW was found to suppress the coke formation. 25 wt.% microalgae addition to bitumen increased VR conversion 20% with a considerable increase in gas content and diesel yield. Increasing microalgae fraction in the feed to 50 wt.% resulted in increased light liquid yields due to increasing conversion of VR and also led to undesired increases in coke and gas formation. Water/feed ratio of 10 led to increased gas yields with a lower VR conversion.

In this study, we applied a second round of random mutagenesis using ethyl methanesulfonate to further increase the lipid productivity of a Chlorella vulgaris mutant strain. We generated a mutant (UV715-EMS25) with a lipid content and biomass that were respectively 67% and 35% higher than those of the wild type (WT). The highest achieved lipid productivity in UV715-EMS25 was 91 mg L-1 day(-1). Gas chromatography-mass spectrophotometric analysis revealed that the fatty acid methyl ester content of the mutant was 3.9-fold higher compared with that of WT cells. Amounts of saturated and monounsaturated fatty acids were also higher in the mutant, while the total amounts of polyunsaturated fatty acids were lower. Finally, the mutant displayed superior lipid productivity compared with the WT during pilot-scale cultivation in a flat panel photobioreactor. All these results demonstrate that UV715-EMS25 is highly suitable for biodiesel production.

In this study, physical and chemical mutagenesis methods were applied to enhance lipid productivity in Chlorella vulgaris. Then, de novo RNA-seq was performed to observe lipid metabolism changes at the genome-wide level. Characterization of two mutants, UV-715 and EMS-25, showed marked increases in lipid contents, i.e., 42% and 45%, respectively. In addition, the biomass productivity of the UV-715 cells was 9% higher than that of wild-type cells. Furthermore, gas chromatography-mass spectrophotometry analysis showed that both mutants have higher fatty acid methyl ester (FAME) contents than wild-type cells. To understand the effect of mutations that caused yield changes in UV-715 and EMS-25 cells at a genome-wide level, we carried out de novo RNA-seq. As expected, the transcriptional levels of the lipid biosynthesis genes were up-regulated, while the transcriptional levels of genes involved in lipid catabolism were down-regulated. Surprisingly, the transcriptional levels of the genes involved in nitrate assimilation and detoxification of reactive oxygen species (ROS) were significantly increased in the mutants. The genome-wide analysis results highlight the importance of nitrate metabolism and detoxification of ROS for high biomass and lipid productivity.