Inorganic nitrate benefits contrast-induced nephropathy after coronary angiography for acute coronary syndromes: the NITRATE-CIN trial.

BACKGROUND AND AIMS: Contrast-induced nephropathy (CIN), also known as contrast-associated acute kidney injury (CA-AKI) underlies a significant proportion of the morbidity and mortality following coronary angiographic procedures in high-risk patients and remains a significant unmet need. In pre-clinical studies inorganic nitrate, which is chemically reduced in vivo to nitric oxide, is renoprotective but this observation is yet to be translated clinically. In this study, the efficacy of inorganic nitrate in the prevention of CIN in high-risk patients presenting with acute coronary syndromes (ACS) is reported. METHODS: NITRATE-CIN is a double-blind, randomized, single-centre, placebo-controlled trial assessing efficacy of inorganic nitrate in CIN prevention in at-risk patients presenting with ACS. Patients were randomized 1:1 to once daily potassium nitrate (12 mmol) or placebo (potassium chloride) capsules for 5 days. The primary endpoint was CIN (KDIGO criteria). Secondary outcomes included kidney function [estimated glomerular filtration rate (eGFR)] at 3 months, rates of procedural myocardial infarction, and major adverse cardiac events (MACE) at 12 months. This study is registered with ClinicalTrials.gov: NCT03627130. RESULTS: Over 3 years, 640 patients were randomized with a median follow-up of 1.0 years, 319 received inorganic nitrate with 321 received placebo. The mean age of trial participants was 71.0 years, with 73.3% male and 75.2% Caucasian; 45.9% had diabetes, 56.0% had chronic kidney disease (eGFR <60 mL/min) and the mean Mehran score of the population was 10. Inorganic nitrate treatment significantly reduced CIN rates (9.1%) vs. placebo (30.5%, P < .001). This difference persisted after adjustment for baseline creatinine and diabetes status (odds ratio 0.21, 95% confidence interval 0.13-0.34). Secondary outcomes were improved with inorganic nitrate, with lower rates of procedural myocardial infarction (2.7% vs. 12.5%, P = .003), improved 3-month renal function (between-group change in eGFR 5.17, 95% CI 2.94-7.39) and reduced 1-year MACE (9.1% vs. 18.1%, P = .001) vs. placebo. CONCLUSIONS: In patients at risk of renal injury undergoing coronary angiography for ACS, a short (5 day) course of once-daily inorganic nitrate reduced CIN, improved kidney outcomes at 3 months, and MACE events at 1 year compared to placebo.

Elevated expression of wildtype RhoC promotes ErbB2- and Pik3ca-induced mammary tumor formation.

Copy number gains in genes coding for Rho activating exchange factors as well as losses affecting genes coding for RhoGAP proteins are common in breast cancer (BC), suggesting that elevated Rho signaling may play an important role. Extra copies and overexpression of RHOC also occur, although a role for RhoC overexpression in driving tumor formation has not been assessed in vivo. To this end, we report on the development of a Rosa26 (R26)-targeted Cre-conditional RhoC overexpression mouse (R26RhoC). This mouse was crossed to two models for ERBB2/NEU+ breast cancer: one based on expression of an oncogenic ErbB2/Neu cDNA downstream of the endogenous ErbB2 promoter (FloxNeoNeuNT), the other, a metastatic model that is based on high-level expression from MMTV regulatory elements (NIC). RhoC overexpression dramatically enhanced mammary tumor formation in FloxNeoNeuNT mice but showed a more subtle effect in the NIC line, which forms multiple mammary tumors after a very short latency. RhoC overexpression also enhanced mammary tumor formation in an activated Pik3ca model for breast cancer (Pik3caH1047R). The transforming effect of RhoC was associated with epithelial/mesenchymal transition (EMT) in ErbB2/NeuNT and Pik3caH1047R systems. Thus, our study reveals the importance of elevated wildtype Rho protein expression as a driver of breast tumor formation and highlights the significance of Copy Number Abberations that affect Rho signalling.

Low-dose X-ray radiation induces an adaptive response: A potential countermeasure to galactic cosmic radiation exposure.

Space exploration involves many dangers including galactic cosmic radiation (GCR). This class of radiation includes high-energy protons and heavy ionizing ions. NASA has defined GCR as a carcinogenic risk for long-duration space missions. To date, no clear strategy has been developed to counter chronic GCR exposure. We hypothesize that preconditioning cells with low levels of radiation will be protective from subsequent higher radiation exposures. H9C2 cells were pretreated with 0.1 to 1.0 Gy X-rays. The challenge radiation exposure consisted of either 8 Gy X-rays or 75 cGy of GCR, using a five-ion GCRsim protocol. A cell doubling time assay was used to determine cell viability. An 8 Gy X-ray challenge alone significantly (P < 0.05) increased cell doubling time compared to the no-radiation control group. Low-dose radiation pre-treatment ameliorated the 8 Gy X-ray-induced increases in cell doubling time. A 75 cGy GCR challenge alone significantly increased cell doubling time compared to the no-radiation group. Following the 75 cGy challenge, only the 0.5 and 1.0 Gy pre-treatment ameliorated the 75 cGy-induced increases in cell doubling time. DNA damage or pathological oxidant stress will delay replicative functions and increase cell doubling time. Our results suggested that pretreatment with low-dose X-rays induced an adaptive response which offered a small but significant protection against a following higher radiation challenge. Although perhaps not a practical countermeasure, these findings may serve to offer insight into cell signalling pathways activated in response to low-dose irradiation and targeted for countermeasure development.

The green seaweed Ulva: tomorrow's "wheat of the sea" in foods, feeds, nutrition, and biomaterials.

Ulva, a genus of green macroalgae commonly known as sea lettuce, has long been recognized for its nutritional benefits for food and feed. As the demand for sustainable food and feed sources continues to grow, so does the interest in alternative, plant-based protein sources. With its abundance along coastal waters and high protein content, Ulva spp. have emerged as promising candidates. While the use of Ulva in food and feed has its challenges, the utilization of Ulva in other industries, including in biomaterials, biostimulants, and biorefineries, has been growing. This review aims to provide a comprehensive overview of the current status, challenges and opportunities associated with using Ulva in food, feed, and beyond. Drawing on the expertise of leading researchers and industry professionals, it explores the latest knowledge on Ulva's nutritional value, processing methods, and potential benefits for human nutrition, aquaculture feeds, terrestrial feeds, biomaterials, biostimulants and biorefineries. In addition, it examines the economic feasibility of incorporating Ulva into aquafeed. Through its comprehensive and insightful analysis, including a critical review of the challenges and future research needs, this review will be a valuable resource for anyone interested in sustainable aquaculture and Ulva's role in food, feed, biomaterials, biostimulants and beyond.

Learning in context: Undergraduate students' knowledge and the content retention of anatomy between discipline-specific and integrated course approaches.

Undergraduate introductory human anatomy and human physiology courses are either taught as discipline-specific or integrated anatomy and physiology (A&P) sequences. An institution underwent a curricular revision to change the course approach from discipline-specific Human Anatomy and Human Physiology to an integrated A&P I and II sequence, allowing the unique opportunity to explore the potential role of contextual learning in academic achievement and content retention. Mediation and moderation analysis was used to evaluate lecture examinations, laboratory practical examinations, and anatomical content retention between the different course approaches. Undergraduate students in the integrated A&P I course approach performed significantly better on lecture assessments and had a higher anatomy content retention rate at the end of the year than students enrolled in the standalone Human Anatomy course. The lecture examination averages between Human Physiology and A&P II (the second course in the sequence), as well as the anatomy laboratory practical examinations, were not significantly different between discipline-specific and integrated course approaches. The results suggest contextual learning-providing physiological context to anatomical structures-increases the anatomical content retention and academic achievement overall.

KIF3A tail domain phosphorylation is not required for ciliogenesis in mouse embryonic fibroblasts.

Primary cilia are essential signaling organelles that protrude from most cells in the body. Heterodimeric kinesin-2 (KIF3A/KIF3B/KAP3) powers several intracellular transport processes, including intraflagellar transport (IFT), essential for ciliogenesis. A long-standing question is how a motor protein is differentially regulated for specific cargos. Since phosphorylation of the KIF3A tail domain was suggested to regulate the activity of kinesin-2 for ciliogenesis, similarly as for the cytosolic cargo N-Cadherin, we set out to map the phosphosites involved in this regulation. Using well-characterized Kif3a-/-; Kif3b-/- mouse embryonic fibroblasts, we performed ciliogenesis rescue assays with a library of phosphomimetic mutants comprising all predicted phosphosites in the KIF3A tail domain. In contrast to previous reports, we found that KIF3A tail domain phosphorylation is dispensable for ciliogenesis in mammals. Thus, mammalian kinesin-2 is differently regulated for IFT than currently thought, consistent with the idea of differential regulation for ciliary and cytosolic cargo.

Characterization of the disease-causing mechanism of KIF3B mutations from ciliopathy patients.

The heterodimeric kinesin-2 motor (KIF3A/KIF3B with accessory protein KAP3) drives intraflagellar transport, essential for ciliogenesis and ciliary function. Three point mutations in the KIF3B subunit have recently been linked to disease in humans (E250Q and L523P) and Bengal cats (A334T) (Cogné et al., Am. J. Hum. Genet., 2020, 106, 893-904). Patients display retinal atrophy and, in some cases, other ciliopathy phenotypes. However, the molecular mechanism leading to disease is currently unknown. Here, we used Kif3a -/- ;Kif3b -/- (knockout) 3T3 cells, which cannot make cilia, to characterize these mutations. While reexpression of KIF3B(E250Q) and KIF3B(L523P) did not rescue ciliogenesis, reexpression of wildtype or KIF3B(A334T) restored ciliogenesis to wildtype levels. Fluorescent tagging revealed that the E250Q mutant decorated microtubules and thus is a rigor mutation. The L523P mutation, in the alpha-helical stalk domain, surprisingly did not affect formation of the KIF3A/KIF3B/KAP3 complex but instead impaired motility along microtubules. Lastly, expression of the A334T motor was reduced in comparison to all other motors, and this motor displayed an impaired ability to disperse the Golgi complex when artificially linked to this high-load cargo. In summary, this work uses cell-based assays to elucidate the molecular effects of disease-causing mutations in the KIF3B subunit on the kinesin-2 holoenzyme.

Induction of Meiosis from Human Pluripotent Stem Cells.

An in vitro model of human meiosis would accelerate research into this important reproductive process and development of therapies for infertility. We have developed a method to induce meiosis starting from male or female human pluripotent stem cells. We demonstrate that DNMT1 inhibition, retinoid signaling activation, and overexpression of regulatory factors (anti-apoptotic BCL2, and pro-meiotic HOXB5, BOLL, or MEIOC) rapidly activates meiosis, with leptonema beginning at 6 days, zygonema at 9 days, and pachynema at 12 days. Immunofluorescence microscopy shows key aspects of meiosis, including chromosome synapsis and sex body formation. The meiotic cells express genes similar to meiotic oogonia in vivo, including all synaptonemal complex components and machinery for meiotic recombination. These findings establish an accessible system for inducing human meiosis in vitro.

Biochemical characterisation of a PL24 ulvan lyase from seaweed-associated Vibrio sp. FNV38.

Ulvan is a green macroalgal cell wall polysaccharide that has tremendous potential for valorisation due to its unique composition of sulphated rhamnose, glucuronic acid, iduronic acid and xylose. Several potential applications such as production of biofuels, bioplastics and other value-added products necessitate the breakdown of the polysaccharide to oligomers or monomers. Research on ulvan saccharifying enzymes has been continually increasing over the last decade, with the increasing focus on valorisation of seaweed biomass for a biobased economy. Lyases are the first of several enzymes that are involved in saccharifying the polysaccharide and several ulvan lyases have been structurally and biochemically characterised to enable their effective use in the valorisation processes. This study investigates the whole genome of Vibrio sp. FNV38, an ulvan metabolising organism and biochemical characteristics of a PL24 ulvan lyase that it possesses. The genome of Vibrio sp. FNV38 has a diverse CAZy profile with several genes involved in the metabolism of ulvan, cellulose, agar, and alginate. The enzyme exhibits optimal activity at pH 8.5 in 100 mM Tris-HCl buffer and 30 °C. However, its thermal stability is poor with significant loss of activity after 2 h of incubation at temperatures above 25 °C. Breakdown product analysis reveals that the enzyme depolymerised the polysaccharide predominantly to disaccharides and tetrasaccharides. Supplementary Information: The online version contains supplementary material available at 10.1007/s10811-023-03136-3.