Design of customized coronavirus receptors.

Although coronaviruses use diverse receptors, the characterization of coronaviruses with unknown receptors has been impeded by a lack of infection models1,2. Here we introduce a strategy to engineer functional customized viral receptors (CVRs). The modular design relies on building artificial receptor scaffolds comprising various modules and generating specific virus-binding domains. We identify key factors for CVRs to functionally mimic native receptors by facilitating spike proteolytic cleavage, membrane fusion, pseudovirus entry and propagation for various coronaviruses. We delineate functional SARS-CoV-2 spike receptor-binding sites for CVR design and reveal the mechanism of cell entry promoted by the N-terminal domain-targeting S2L20-CVR. We generated CVR-expressing cells for 12 representative coronaviruses from 6 subgenera, most of which lack known receptors, and show that a pan-sarbecovirus CVR supports propagation of a propagation-competent HKU3 pseudovirus and of authentic RsHuB2019A3. Using an HKU5-specific CVR, we successfully rescued wild-type and ZsGreen-HiBiT-incorporated HKU5-1 (LMH03f) and isolated a HKU5 strain from bat samples. Our study demonstrates the potential of the CVR strategy for establishing native receptor-independent infection models, providing a tool for studying viruses that lack known susceptible target cells.

Late lactation in small mammals is a critically sensitive window of vulnerability to elevated ambient temperature.

Predicted increases in global average temperature are physiologically trivial for most endotherms. However, heat waves will also increase in both frequency and severity, and these will be physiologically more important. Lactating small mammals are hypothesized to be limited by heat dissipation capacity, suggesting high temperatures may adversely impact lactation performance. We measured reproductive performance of mice and striped hamsters (Cricetulus barabensis), including milk energy output (MEO), at temperatures between 21 and 36 °C. In both species, there was a decline in MEO between 21 and 33 °C. In mice, milk production at 33 °C was only 18% of that at 21 °C. This led to reductions in pup growth by 20% but limited pup mortality (0.8%), because of a threefold increase in growth efficiency. In contrast, in hamsters, MEO at 33 °C was reduced to 78.1% of that at 21 °C, yet this led to significant pup mortality (possibly infanticide) and reduced pup growth by 12.7%. Hamster females were more able to sustain milk production as ambient temperature increased, but they and their pups were less capable of adjusting to the lower supply. In both species, exposure to 36 °C resulted in rapid catastrophic lactation failure and maternal mortality. Upper lethal temperature was lowered by 3 to 6 °C in late lactation, making it a critically sensitive window to high ambient temperatures. Our data suggest future heat wave events will impact breeding success of small rodents, but this is based on animals with a long history in captivity. More work should be performed on wild rodents to confirm these impacts.

The less weight loss due to modest food restriction drove more fat accumulation in striped hamsters refed with high-fat diet.

Food restriction (FR) has been commonly used to decrease body fat, reducing the risk of overweight in humans and animals. However, the lost weight has been shown to be followed by overweight when food restriction ends. It remains uncertain whether the weight loss drives the overweight, or not. In the present study, striped hamsters were restricted by 15%, 30% and 40% of ad libitum food intake for 2 weeks, followed by high-fat refeeding for 6 weeks (FR15%-Re, FR30%-Re and FR40%-Re). The hamsters in FR15%, FR30% and FR40% groups decreased by 21.1%, 37.8% and 50.0% in fat mass (P < 0.01), and 16.8%, 42.8% and 53.4% in leptin levels (P < 0.01) compared with the hamsters fed ad libitum. The FR15%-Re, FR30%-Re and FR40%-Re groups showed 77.0%, 37.2% and 23.7% more body fat than ad libitum group (P < 0.01). The FR15%-Re group showed considerable decreases in gene expression of arcuate nucleus co-expressing proopiomelanocortin (POMC), cocaine - and amphetamineregulated transcript (CART) and the long isoform of leptin receptor (LepRb) in the hypothalamus and of several genes associated with fatty acid transport to mitochondria and ß-oxidation in brown adipose tissue and liver. It suggests that less weight loss is likely to drive more fat accumulation when food restriction ends, in which the impaired function of LepRb, POMC and CART in the brain and fatty acid oxidation in brown adipose tissue and liver may be involved.

The roles of metabolic thermogenesis in body fat regulation in striped hamsters fed high-fat diet at different temperatures.

The metabolic thermogenesis plays important roles in thermoregulation, and it may be also involved in body fat regulation. The thermogenesis of brown adipose tissue (BAT) is largely affected by ambient temperature, but it is unclear if the roles in body fat regulation are dependent on the temperature. In the present study, uncoupling protein 1 (ucp1)-based BAT thermogenesis, energy budget and body fat content were examined in the striped hamsters fed high fat diet (HF) at cold (5°C) and warm (30°C) temperatures. The effect of 2, 4-dinitrophenol (DNP), a chemical uncoupler, on body fat was also examined. The striped hamsters showed a notable increase in body fat following the HF feeding at 21°C. The increased body fat was markedly elevated at 30°C, but was significantly attenuated at 5°C compared to that at 21°C. The hamsters significantly increased energy intake at 5°C, but consumed less food at 30°C relative to those at 21°C. Metabolic thermogenesis, indicated by basal metabolic rate, UCP1 expression and/or serum triiodothyronine levels, significantly increased at 5°C, but decreased at 30°C compared to that at 21°C. A significant decrease in body fat content was observed in DNP-treated hamsters relative to the controls. These findings suggest that the roles of metabolic thermogenesis in body fat regulation largely depend on ambient temperature. The cold-induced enhancement of BAT thermogenesis may contribute the decreased body fat, resulting in a lean mass. Instead, the attenuation of BAT thermogenesis at the warm may result in notable obesity.

The increase in fat content in the warm-acclimated striped hamsters is associated with the down-regulated metabolic thermogenesis.

It has been well known that metabolic thermogenesis plays an important role in the thermoregulation of small mammals under different temperatures, while its role in fat accumulation is far from clear. In the present study, several physiological, hormonal, and biochemical measures indicative of metabolic thermogenesis were measured in the weaning striped hamsters after acclimated to a warm condition (30°C) for 1, 3 and 4months. The warm-acclimated groups significantly decreased energy intake, and simultaneously decreased nonshivering thermogenesis compared to those housed at 21°C. Body fat content increased by 29.9%, 22.1% and 19.6% in the hamsters acclimated to 1, 3 or 4months, respectively relative to their counterparts maintain at 21°C (P<0.05). The cytochrome c oxidase (COX) activity of brain, liver, heart and skeletal muscle, and the ratio of serum tri-iodothyronine to thyroxine significantly decreased in warm-acclimated groups compared with 21°C group. COX activity and uncoupling protein 1 (UCP1) mRNA expression of brown adipose tissue (BAT) were significantly down-regulated under the warm conditions. COX activity of BAT, liver, heart and muscle were significantly negatively correlated with body fat content, and the correlation between UCP1 expression and body fat content tended to be negative. These findings suggest that the decrease in the energy spent on metabolic thermogenesis plays an important role in the fat accumulation. The attenuation of COX and UCP1-based BAT activity may be involved in body fat accumulation in animals under warm conditions.

Sarbecovirus RBD indels and specific residues dictating multi-species ACE2 adaptiveness.

Our comprehensive understanding of the multi-species ACE2 adaptiveness of sarbecoviruses remains elusive, particularly for those with various receptor binding motif (RBM) insertions/deletions (indels). Here, we analyzed RBM sequences from 268 sarbecoviruses categorized into four RBM indel types. We examined the ability of 20 representative sarbecovirus Spike glycoproteins (S) and derivatives in utilizing ACE2 from various bats and several other mammalian species. We reveal that sarbecoviruses with long RBMs (type-I) can achieve broad ACE2 tropism, whereas viruses with single deletions in Region 1 (type-II) or Region 2 (type-III) exhibit narrower ACE2 tropism. Sarbecoviruses with double region deletions (type-IV) completely lost ACE2 usage, which is restricted by clade-specific residues within and outside RBM. Lastly, we propose the evolution of sarbecovirus RBM indels and illustrate how loop lengths, disulfide, and residue determinants shape multi-species ACE2 adaptiveness. This study provides profound insights into the mechanisms governing ACE2 usage and spillover risks of sarbecoviruses.

Postoperative urinary leakage after bilateral totally extraperitoneal herniorrhaphy in a patient with a healed cystostomy and appendectomy: A case report.

We report a case of postoperative urinary leakage after bilateral laparoscopic totally extraperitoneal (TEP) herniorrhaphy. A man in his upper 80s with a healed cystostomy and appendectomy underwent bilateral TEP herniorrhaphy. Urinary leakage was noted by ultrasound examination 4 days after bilateral TEP. Cystography and computed tomography conclusively confirmed a 6-mm extraperitoneal fistula at the site of the previous cystostomy. The fistula involved the anterior bladder wall and was associated with an extended urinoma. The patient was treated by indwelling catheterization using a Foley catheter and repeated ultrasound-guided puncture and aspiration of the inguinal effusion at the bedside. The patient was completely healed 69 days after the operation with no mesh infection or bladder dysfunction. We believe that urinary leakage is possible after TEP herniorrhaphy in patients with a healed suprapubic cystostomy. Therefore, indwelling catheterization using a Foley catheter should be implemented before surgery, and the Foley catheter can be removed within 1 week after surgery if no postoperative urinary leakage is observed. A history of suprapubic cystotomy should not be regarded as a contraindication for TEP surgery. This is the first report of urinary leakage after bilateral TEP herniorrhaphy in a patient with a healed cystostomy and appendectomy.

Polysaccharide ORP-1 isolated from Oudemansiella raphanipes ameliorates age-associated intestinal epithelial barrier dysfunction in Caco-2 cells monolayer.

Age-associated increase in intestinal permeability is known to relate with gut microbiota dysbiosis and loss of epithelial tissue integrity. To improve healthy aging and prevent age-associated chronic disabilities, the protective potential of polysaccharides from Oudemansiella raphanipes (ORP-1) against age-associated intestinal epithelial barrier dysfunction in d-galactose-induced Caco-2 cells monolayer was investigated. In-vitro results demonstrated that ORP-1 can restore a healthy gut microbial population to handle age-related gut microbiota dysbiosis mainly by facilitating the proliferation and adhesion of probiotics Lactobacillus acidophilus (L. acidophilus) and Bifidobacterium bifidum (B. bifidum) to compete with intestinal pathogenic Escherichia coli (E. coli) for ecological niches and nutrition. Meanwhile, ORP-1 strengthened the intestinal structural integrity primarily by abolishing the aggravation of apoptosis and the age-associated alterations of tight junction (TJ) proteins expression in intestine. These findings highlighted that ORP-1 could be a potential functional food component with preventive utility against age-associated intestinal barrier injury.

An unusual porous cationic metal-organic framework based on a tetranuclear hydroxyl-copper(ii) cluster for fast and highly efficient dichromate trapping through a single-crystal to single-crystal process.

An unusual porous cationic metal-organic framework based on a tetranuclear hydroxy-copper(ii) cluster displays fast and highly efficient dichromate trapping through a single-crystal to single-crystal process.

A new strategy to obtain tetranuclear cobalt(ii) metal-organic frameworks based on the [Co4(µ3-OH)2] cluster: synthesis, structures and properties.

Three metal-organic frameworks (MOFs) {[Co4(OH)2(adc)6(H2O)5][Co2(OH)(btrb)]2·8H2O}n (1), {[Co4(OH)2(btrb)(nip)3(H2O)3]·4H2O}n (2·4H2O) and {[Co4(OH)2(btrb)(btc)2(H2O)2]·9H2O}n (3·9H2O) (btrb = 1,4-bis(1,2,4-triazol-4-ylmethyl)benzene, H2adc = 1,3-adamantanedicarboxylic acid, H2nip = 5-nitroisophthalic acid and H3btc = 1,3,5-benzenetricarboxylic acid) were synthesized by a hydrothermal method. 1 shows an unusual (3,4)-connected 2D network with a point symbol of (4·62)2(42·62·82) based on [Co4(µ3-OH)2] and [Co2(µ3-OH)] units. 2 is a 6-connected pcu topology based on the [Co4(µ3-OH)2] unit. 3 is a rare (3,8)-connected 3D framework with a rare point symbol of (4·5·6)2(42·56·616·72·82) based on the [Co4(µ3-OH)2] unit. The magnetic measurements reveal that 1-3 exhibit antiferromagnetic interactions between the adjacent cobalt(ii) centers. 1-3 are good photocatalysts for the degradation of methylene blue (MB). The 1,2-position nitrogen atoms of the 4-substituted 1,2,4-triazole ligand act as strong σ-donators to form a quite stable coordination quadrangle with two metal ions. The btrb ligand containing two 4-substituted 1,2,4-triazole rings is favorable to form tetranuclear metal units. By the regulation of the multicarboxylate ligands, the connection number of [Co4(µ3-OH)2] clusters increases from 4 in 1 to 6 in 2 and then 8 in 3. This work presents a novel but effective method to design and regulate the connection number (4, 6 and 8 connected in this work) of MOFs with 4-substituted 1,2,4-triazole and rigid multicarboxylate ligands.