(Wh)olistic (E)ndocannabinoidome-Microbiome-Axis Modulation through (N)utrition (WHEN) to Curb Obesity and Related Disorders

The discovery of the endocannabinoidome (eCBome) is evolving gradually with yet to be elucidated functional lipid mediators and receptors. The diet modulates these bioactive lipids and the gut microbiome, both working in an entwined alliance. Mounting evidence suggests that, in different ways and with a certain specialisation, lipid signalling mediators such as N-acylethanolamines (NAEs), 2-monoacylglycerols (2-MAGs), and N-acyl-amino acids (NAAs), along with endocannabinoids (eCBs), can modulate physiological mechanisms underpinning appetite, food intake, macronutrient metabolism, pain sensation, blood pressure, mood, cognition, and immunity. This knowledge has been primarily utilised in pharmacology and medicine to develop many drugs targeting the fine and specific molecular pathways orchestrating eCB and eCBome activity. Conversely, the contribution of dietary NAEs, 2-MAGs and eCBs to the biological functions of these molecules has been little studied. In this review, we discuss the importance of (Wh) olistic (E)ndocannabinoidome-Microbiome-Axis Modulation through (N) utrition (WHEN), in the management of obesity and related disorders.

A positive feedback loop mediates crosstalk between calcium, cyclic nucleotide and lipid signalling in Toxoplasma gondii

Fundamental processes of obligate intracellular parasites, such as Toxoplasma gondii and Plasmodium falciparum are controlled by a set of plant-like calcium dependent kinases (CDPKs), the conserved cAMP- and cGMP-dependent protein kinases (PKA and PKG), secondary messengers and lipid signalling. While some major components of the signalling networks have been identified, how these are connected is largely not known. Here, we compare the phospho-signalling networks during Toxoplasma egress from its host cell by artificially raising cGMP or calcium levels to activate PKG or CDPKs, respectively. We show that both these inducers trigger near identical signalling pathways and provide evidence for a positive feedback loop involving CDPK3. We measure phospho- and lipid signalling in parasites treated with the Ca2+ ionophore A23187 in a sub-minute timecourse and show CDPK3-dependent regulation of diacylglycerol levels and increased phosphorylation of four phosphodiesterases (PDEs), suggesting their function in the feedback loop. Disruption of CDPK3 leads to elevated cAMP levels and inhibition of PKA signalling rescues the egress defect of ΔCDPK3 parasites treated with A23187. Biochemical analysis of the four PDEs identifies PDE2 as the only cAMP-specific PDE among these candidates while the other PDEs are cGMP specific; two of which are inhibited by the predicted PDE inhibitor BIPPO. Conditional deletion of the four PDEs supports an important, but non-essential role of PDE1 and PDE2 for growth, with PDE2 controlling A23187-mediated egress. In summary we uncover a positive feedback loop that potentiates signalling during egress and links several signalling pathways together.

Hormonal and environmental signaling pathways target membrane water transport

Plant water transport and its molecular components including aquaporins are responsive, across diverse time scales, to an extremely wide array of environmental and hormonal signals. These include water deficit and abscisic acid (ABA) but also more recently identified stimuli such as peptide hormones or bacterial elicitors. The present review makes an inventory of corresponding signalling pathways. It identifies some main principles, such as the central signalling role of ROS, with a dual function of aquaporins in water and hydrogen peroxide transport, the importance of aquaporin phosphorylation that is targeted by multiple classes of protein kinases, and the emerging role of lipid signalling. More studies including systems biology approaches are now needed to comprehend how plant water transport can be adjusted in response to combined stresses.

Fatty Acid Desaturases: Uncovering Their Involvement in Grapevine Defence against Downy Mildew

Grapevine downy mildew, caused by the biotrophic oomycete Plasmopara viticola, is one of the most severe and devastating diseases in viticulture. Unravelling the grapevine defence mechanisms is crucial to develop sustainable disease control measures. Here we provide new insights concerning fatty acid’s (FA) desaturation, a fundamental process in lipid remodelling and signalling. Previously, we have provided evidence that lipid signalling is essential in the establishment of the incompatible interaction between grapevine and Plasmopara viticola. In the first hours after pathogen challenge, jasmonic acid (JA) accumulation, activation of its biosynthetic pathway and an accumulation of its precursor, the polyunsaturated α-linolenic acid (C18:3), were observed in the leaves of the tolerant genotype, Regent. This work was aimed at a better comprehension of the desaturation processes occurring after inoculation. We characterised, for the first time in Vitis vinifera, the gene family of the FA desaturases and evaluated their involvement in Regent response to Plasmopara viticola. Upon pathogen challenge, an up-regulation of the expression of plastidial FA desaturases genes was observed, resulting in a higher content of polyunsaturated fatty acids (PUFAs) of chloroplast lipids. This study highlights FA desaturases as key players in membrane remodelling and signalling in grapevine defence towards biotrophic pathogens.

Divergent transcriptomic profiles in skeletal muscle of diabetics with and without heart failure

Funding Acknowledgements Type of funding sources: None. Background Patients with type 2 diabetes mellitus (DM) that have coexistent heart failure (HF) have exacerbated symptoms and prognosis, however beside cardiac dysfunction the mechanisms governing these features are incompletely understood. Evidence indicates abnormalities in the periphery could contribute to this worse clinical phenotype, including a role for skeletal muscle whereby disturbances in the transcriptome could disrupt muscle homeostasis/repair to offer a novel therapeutic approach. Purpose Is the skeletal muscle transcriptome distinguishable between DM patients with and without HF? Methods DM patients without (n = 11) or with HF with reduced left ventricular ejection fraction (LVEF) (n = 16) were included. Muscle biopsies were collected from the pectoralis major during pacemaker implantation. Following RNA extraction and cDNA synthesis, non-bias RNA sequencing (RNAseq) was performed (Cambridge Genomic Services, UK) followed by targeted RT-PCR gene expression of relevant targets. DESeq2 identified differentially expressed genes (DEGs) with a false discovery rate (p < 0.05). Gene enrichment analysis was performed with clusterProfiler v3.16.0 to interrogate the gene ontology database, while pathway analysis was conducted using ReactomePA v1.32.0 to interrogate the Reactome database, using an adjusted p value. Values of p < 0.05 were accepted as significant. Results Groups were not different (p > 0.05) for age (74 ± 11 vs. 66 ± 10 years), BMI (31 ± 7 vs 29 ± 6), sex (n = 2 females per group), or HbA1c (56 ± 10 vs. 57 ± 8 mmol/mol), although LVEF was lower in the group with HF (27 ± 8 vs. 54 ± 2%; p < 0.05). Of the 19,544 genes analysed, RNAseq identified 53 DEGs between DM patients with and without HF, with several relevant targets related to myofiber homeostasis such as autophagy (RUBCN), protein synthesis (DGKζ), and inflammation/apoptosis (TLE1). Follow-up RT-PCR analysis confirmed a trend towards upregulation of the autophagy-related machinery p62 (p = 0.043) and BNIP3 (p = 0.085) in the HF group, but not ubiquitin-proteasome (MuRF1, MAFbx; p > 0.05). Gene-enrichment analysis of DEGs identified 7 overrepresented terms (P < 0.05), including lipid metabolism/signalling alongside epigenetic modifications related to histone deacetylases (HDAC6/10). Furthermore, pathway analysis identified 4 terms (p < 0.05) related to NOTCH signalling and phosphatidyl inositol-bisphosphate (PIP2) hydrolysis thus indicating alterations to muscle repair and lipid signalling respectively. Conclusion(s): This study confirms that DM patients with and without HF demonstrate distinct skeletal muscle transcriptome profiles. Key differences related to skeletal muscle myogenesis, autophagy, epigenetic regulation, and lipid signalling were identified that could form part of important therapeutic targets. Whether these underlying muscle transcriptome differences contribute to poorer clinical outcomes in DM patients with HF remains to be determined.

Combinatorial analysis of phenotypic and clinical risk factors associated with hospitalized COVID-19 patients

1AbstractCharacterization of the risk factors associated with variability in the clinical outcomes of COVID-19 is important. Our previous study using genomic data identified a potential role of calcium and lipid homeostasis in severe COVID-19. This study aimed to identify similar combinations of features (disease signatures) associated with severe disease in a separate patient population with purely clinical and phenotypic data.The PrecisionLife combinatorial analytics platform was used to analyze features derived from de-identified health records in the UnitedHealth Group COVID-19 Data Suite. The platform identified and analyzed 836 disease signatures in two cohorts associated with increased risk of COVID-19 hospitalization. Cohort 1 was formed of cases hospitalized with COVID-19 and a set of controls who developed mild symptoms. Cohort 2 included Cohort 1 individuals for whom additional laboratory test data was available.We found several disease signatures where lower levels of lipids were found co-occurring with lower levels of serum calcium and leukocytes. Many of the low lipid signatures were independent of statin use and 50% of cases with hypocalcemia signatures were reported with vitamin D deficiency. These signatures may be attributed to similar mechanisms linking calcium and lipid signaling where changes in cellular lipid levels during inflammation and infection affect calcium signaling in host cells.This study and our previous genomics analysis demonstrate that combinatorial analysis can identify disease signatures associated with the risk of developing severe COVID-19 separately from genomic or clinical data in different populations. Both studies suggest associations between calcium and lipid signalling in severe COVID-19.

98 Peroxisome proliferator-activated receptor-gamma (PPARG) is dispensable for bovine blastocyst formation

Prostaglandins (PGs) are lipid signalling molecules that play critical roles in gestation by promoting corpus luteus maintenance or luteolysis, and have been suggested to play other roles in early pregnancy, including embryo–maternal crosstalk. The signalling roles of PGs and other lipids are often mediated by peroxisome proliferator-activated receptors (PPARs), transcription factors that regulate the expression of other genes through PPAR-responsive elements. PPARG is a PPAR expressed by bovine pre-implantation embryos whose inhibition by morpholino intrauterine infusion has been reported to impair embryo development. As this approach causes PPARG depletion in both conceptus and uterus, it is unknown whether PPARG-mediated signalling in the embryo is required for embryo development. The objective of this study was to determine whether PPARG is required for blastocyst formation. For that aim, we have evaluated embryo development in PPARG knockout (KO) bovine embryos generated by CRISPR-Cas9 technology. Invitro matured oocytes were allocated in two groups: one was injected with mRNA encoding for Cas9 and sgRNA against PPARG to generate KO embryos (C+G, n=191) and the other was injected with mRNA alone (C, n=148), serving as a microinjection control generating only wild-type embryos. Following fertilization, embryos were allowed to develop to Day 8 blastocysts invitro. No differences were found in cleavage and blastocyst rates between both groups (cleavage 78.5±3.4 vs. 78.4±4.2; Day 7 blastocyst 17.3±3.9 vs. 10.8±2.9; Day 8 blastocyst 20.4±6.2 vs. 16.9±4.7; C+G vs. C; mean±s.e.m.; ANOVA P>0.05). Blastocysts of the C+G group were genotyped by clonal sequencing to determine which embryos in the C+G group were KO (i.e. harboured only frame-disrupting, KO alleles). Twenty-eight out of the 32 blastocysts analysed were edited (87.5%), of which 6 (18.8%) were KO. These results show that PPARG is not required for blastocyst formation, because KO embryos develop to that stage, but do not rule out a possible role in further developmental stages.

The Emerging Role of the Double-Edged Impact of Arachidonic Acid- Derived Eicosanoids in the Neuroinflammatory Background of Depression.

: Eicosanoids are arachidonic acid (AA) derivatives belonging to a family of lipid signalling mediators that are engaged in both physiological and pathological processes in the brain. Recently, their implication in the prolonged inflammatory response has become a focus of particular interest because, in contrast to acute inflammation, chronic inflammatory processes within the central nervous system (CNS) are crucial for the development of brain pathologies including depression. The synthesis of eicosanoids is catalysed primarily by cyclooxygenases (COX), which are involved in the production of pro-inflammatory AA metabolites, including prostaglandins and thromboxanes. Moreover, eicosanoid synthesis is catalysed by lipoxygenases (LOXs), which generate both leukotrienes and anti-inflammatory derivatives such as lipoxins. Thus, AA metabolites have double- edged pro-inflammatory and anti-inflammatory, pro-resolving properties, and an imbalance between these metabolites has been proposed as a contributor or even the basis for chronic neuroinflammatory effects. This review focuses on important evidence regarding eicosanoid-related pathways (with special emphasis on prostaglandins and lipoxins) that has added a new layer of complexity to the idea of targeting the double-edged AA-derivative pathways for therapeutic benefits in depression. We also sought to explore future research directions that can support a pro-resolving response to control the balance between eicosanoids and thus to reduce the chronic neuroinflammation that underlies at least a portion of depressive disorders.