Metabolic Stimulation-Elicited Transcriptional Responses and Biosynthesis ofAcylated Triterpenoids in the Medicinal Plant Helicteres Angustifolia

Helicteres angustifolia has long been used in Chinese traditional medicine. It has multiple pharmacological benefits, including anti-inflammatory, anti-viral and anti-tumor effects. Its main active chemicals include betulinic acid, oleanolic acid, helicteric acid, helicterilic acid, and other triterpenoid sapions. It is worth noting that the acylation of triterpenoids, such as helicteric acid and helicterilic acid, are characteristic components of Helicteres and are relatively rare among other plants. However, reliance on natural plants as the only sources of these restricts the potential use of H. angustifolia. Therefore, engineering of its metabolic pathway is of high research value for enhancing the production of secondary metabolites. Unfortunately, little is known of the biosynthesis of acylated triterpenoids, hindering its further investigation. Here, the RNAs of different groups treated by metabolic stimulation were sequenced with an Illumina high-throughput sequencing platform, resulting in 121 gigabases of data. A total of 424,824 unigenes were obtained after the trimming and assembly of the raw data, and 22,430 unigenes were determined to be differentially expressed. In addition, three oxidized squalene cyclases (OSCs) and four Cytochrome P450 (CYP450s) were screened, of which one OSC (HaOSC1) and one CYP450 (HaCYPi3) achieved functional verification, suggesting that they could catalyze the production of lupeol and oleanolic acid, respectively. At the same time, we also screened two triterpenoid acetyl transferases (TATs) and one triterpenoid benzoyl transferase (TBT), as subsequent structural modificatory genes, their preliminary study laid a foundation for the acylation of triterpenoids. In a nutshell, these results shed light on the regulation of acylated triterpenoids biosynthesis.

In vivo O2 imaging in hepatic tissues by phosphorescence lifetime imaging microscopy using Ir(III) complexes as intracellular probes

Phosphorescence lifetime imaging microscopy (PLIM) combined with an oxygen (O2)-sensitive luminescent probe allows for high-resolution O2 imaging of living tissues. Herein, we present phosphorescent Ir(III) complexes, (btp)2Ir(acac-DM) (Ir-1) and (btp-OH)3Ir (Ir-2), as useful O2 probes for PLIM measurement. These small-molecule probes were efficiently taken up into cultured cells and accumulated in specific organelles. Their excellent cell-permeable properties allowed for efficient staining of three-dimensional cell spheroids, and thereby phosphorescence lifetime measurements enabled the evaluation of the O2 level and distribution in spheroids, including the detection of alterations in O2 levels by metabolic stimulation with an effector. We took PLIM images of hepatic tissues of living mice by intravenously administrating these probes. The PLIM images clearly visualized the O2 gradient in hepatic lobules with cellular-level resolution, and the O2 levels were derived based on calibration using cultured cells; the phosphorescence lifetime of Ir-1 gave reasonable O2 levels, whereas Ir-2 exhibited much lower O2 levels. Intravenous administration of NH4Cl to mice caused the hepatic tissues to experience hypoxia, presumably due to O2 consumption to produce ATP required for ammonia detoxification, suggesting that the metabolism of the probe molecule might affect liver O2 levels.

The effects of calcium–silicate–hydrate (C–S–H) seeds on reference microorganisms

Building materials are constantly improved with various additives and admixtures in order to achieve goals ranging from obtaining increased durability or antimicrobial activity up to reducing the carbon footprint left by the cement production. Since nanomaterials were proposed for cement products, many studies explored the possibilities for their incorporation. One of the novel trends in studying these materials is evaluating their impact on living organisms, with the focus not only on toxicology but also on the application potential. Therefore, in this study, we investigated the effects of three types of calcium–silicate–hydrate (C–S–H) seeds on reference microorganisms in the scope of their basic physiology and primary metabolism. Shape, size and elemental composition of C–S–H seeds were also evaluated. The tests on the reference microorganisms have shown that the reaction to these nanomaterials can be specific and depends on the strain as well as the type of used nanomaterial. Furthermore, the presence of C–S–H seeds in the growth environment led to metabolic stimulation that resulted in faster growth, higher biochemical activity, and increased biofilm formation. Based on our findings, we conclude that even though C–S–H seeds have antimicrobial potential, they can be potentially used to promote the growth of selected microbial strains. This phenomenon could be further investigated towards the formation of beneficial biofilms on building materials.

Successful Emergency Treatment in Bradypus variegatus following Non-Hemorrhagic Hypovolemic Shock

Background: The brown-throated sloth (Bradypus variegatus) occurs from the Nicaragua to Brazil. In brazilian amazonian, these animals are rescued with illnesses caused by anthropic actions. Emergencial treatment of sloths is complex because is a lack of specie-specific information allied to a particularly physiology. They have low metabolism and physiological parameters during resting time is 4-7 breaths/min, 40-100 heartbeats/min and temperature between 32-35ºC. They are also folivores, predisposing cases of dehydration and even hypovolemic shock. This study aimed to report the emergency treatment performed on a specimen of Bradypus variegatus affected by hypovolemic shock due to dehydration.Case: A male sloth weighing 2.7 kg was attended at the Veterinary Hospital-Wild Animals Sector of the Federal University of Pará (HVSAS-UFPA), victim of untreated hypovolemic shock due three days of forced eating with inadequate food, which resulted in dehydration, non-hemorrhagic hypovolemic shock, and severe apathy. Physiological parameters were 8 breaths/min, heart rate 90/min and rectal temperature of 33°C. Treatment begun with fluid therapy taking account of 10% of body dehydration (270 mL Ringer lactate, 8 mL vitamin complex and 2 mL glucose), for respiratory decompensation nebulization was conducted with epinephrine (0.5 mL/kg), and intramuscular administration of vitamin B complex (1 mg/kg), metoclopramide (0.2 mg/kg), ranitidine (0.5 mg/kg), and dexamethasone (0.3 mg/kg) to metabolic stimulation improvement. Physiological parameters were monitored every 10 min for the first 12 h of hospitalization. The management were gradually established as the clinical conditions were improved, including forced feeding, daily walks, and enclosure adapted for the minimal behavioral and biological requirements. After 14 days of intensive treatment, the animal was considered ready for release.Discussion: Treatment of critically ill and unnourishment patients requires prompt interventions. Animals with low metabolism potentially have reduced chances of success, therefore, a prompt establishment of viable airways and body temperature maintenance would allow the efficient drugs metabolization. Severe dehydration can lead to animal death by hypovolemic shock, as a consequence of low blood volume, diminish in blood pressure and in the amount of oxygen in body supply, so fluid replacement is essential, as well as stimulating respiratory compensation through bronchodilator drugs. Furthermore, metabolic stimulation is important in cases to prevent numbness, which is common in very weak sloths. The constant monitoring of physiological parameters since at first moment of hospitalization provided parameter to decide about particular needs adaptations during the animal recovery time. Such protocols described for the brown-throated sloth was absent in the literature. In conclusion, the therapeutic and management protocol implemented and adapted to a particular patience, as brown-throated sloth, resulted in a gradual clinical improvement and allowed to its return for the natural environment.

Textile waste and microplastic induce activity and development of unique hydrocarbon-degrading marine bacterial communities

ABSTRACTBiofilm-forming microbial communities on plastics and textile fibers are of growing interest since they have potential to contribute to disease outbreaks and material biodegradability in the environment. Knowledge on microbial colonization of pollutants in the marine realm is expanding, but metabolic responses during substrate colonization remains poorly understood. Here, we assess the metabolic response in marine microbial communities to three different micropollutants, virgin high-density polyethylene (HDPE) microbeads, polysorbate-20 (Tween), and textile fibers. Intertidal textile fibers, mainly cotton, virgin HDPE, and Tween induced variable levels of microbial growth, respiration, and community assembly in controlled microcosm experiments. RAMAN characterization of the chemical composition of the textile waste fibers and high-throughput DNA sequencing data shows how the increased metabolic stimulation and biodegradation is translated into selection processes ultimately manifested in different communities colonizing the different micropollutant substrates. The composition of the bacterial communities colonizing the substrates were significantly altered by micropollutant substrate type and light conditions. Bacterial taxa, closely related to the well-known hydrocarbonoclastic bacteria Kordiimonas spp. and Alcanivorax spp., were enriched in the presence of textile-waste. The findings demonstrate an increased metabolic response by marine hydrocarbon-degrading bacterial taxa in the presence of microplastics and textile waste, highlighting their biodegradation potential. The metabolic stimulation by the micropollutants was increased in the presence of light, possibly due to photochemical dissolution of the plastic into smaller bioavailable compounds. Our results suggest that the development and increased activity of these unique microbial communities likely play a role in the bioremediation of the relatively long lived textile and microplastic pollutants in marine habitats.Graphical Abstract

The carotid baroreflex modifies the pressor threshold of the muscle metaboreflex in humans

The purpose of the present study was to test our hypothesis that unloading the carotid baroreceptors alters the threshold and gain of the muscle metaboreflex in humans. Ten healthy subjects performed a static handgrip exercise at 50% of maximum voluntary contraction. Contraction was sustained for 15, 30, 45, and 60 s and was followed by 3 min of forearm circulatory arrest, during which forearm muscular pH is known to decrease linearly with increasing contraction time. The carotid baroreceptors were unloaded by applying 0.1-Hz sinusoidal neck pressure (oscillating from +15 to +50 mmHg) during ischemia. We estimated the threshold and gain of the muscle metaboreflex by analyzing the relationship between the cardiovascular responses during ischemia and the amount of work done during the exercise. In the condition with unloading of the carotid baroreceptors, the muscle metaboreflex thresholds for mean arterial blood pressure (MAP) and total vascular resistance (TVR) corresponded to significantly lower work levels than the control condition (threshold for MAP: 795 ± 102 vs. 662 ± 208 mmHg and threshold for TVR: 818 ± 213 vs. 572 ± 292 kg·s, P < 0.05), but the gains did not differ between the two conditions (gain for MAP: 4.9 ± 1.7 vs. 4.4 ± 1.6 mmHg·kg·s−1·100 and gain for TVR: 1.3 ± 0.8 vs. 1.3 ± 0.7 mmHg·l−1·min−1·kg·s−1·100). We conclude that the carotid baroreflex modifies the muscle metaboreflex threshold in humans. Our results suggest the carotid baroreflex brakes the muscle metaboreflex, thereby inhibiting muscle metaboreflex-mediated pressor and vasoconstriction responses. NEW & NOTEWORTHY We found that unloading the carotid baroreceptors shifts the pressor threshold of the muscle metaboreflex toward lower metabolic stimulation levels in humans. This finding indicates that, in the normal loading state, the carotid baroreflex inhibits the muscle metaboreflex pressor response by shifting the reflex threshold to higher metabolic stimulation levels.