Environment, epigenetics and neurodegeneration: Focus on nutrition in Alzheimer's disease

Many different environmental factors (nutrients, pollutants, chemicals, physical activity, lifestyle, physical and mental stress) can modulate epigenetic markers in the developing and adult organism. Epigenetics, in turn, can cause and is associated with several neurodegenerative and aging-dependent human diseases. Alzheimer's disease certainly represents one of the most relevant neurodegenerative disorders due to its incidence and its huge socio-economic impact. Therefore, it is easy to understand why recent literature focuses on the epigenetic modifications associated with Alzheimer's disease and other neurodegenerative disorders. One of the most intriguing and, at the same time, worrying evidence is that even "mild" environmental factors (such as behavioral or physical stress) as well as the under-threshold exposure to pollutants and chemicals, can be effective. Finally, even mild nutrients disequilibria can result in long-lasting and functional alterations of many epigenetic markers, although they don't have an immediate acute effect. Therefore, we will probably have to re-define the current risk threshold for many factors, molecules and stresses. Among the many different environmental factors affecting the epigenome, nutrition represents one of the most investigated fields; the reasons are probably that each person interacts with nutrients and that, in turn, nutrients can modulate at molecular level the epigenetic biochemical pathways. The role that nutrition can exert in modulating epigenetic modifications in Alzheimer's disease will be discussed with particular emphasis on the role of B vitamins and DNA methylation

S-adenosylmethionine and superoxide dismutase 1 synergistically counteract Alzheimer's disease features progression in tgCRND8 mice

Recent evidence emphasizes the role of dysregulated one-carbon metabolism in Alzheimer's Disease (AD). Exploiting a nutritional B-vitamin deficiency paradigm, we have previously shown that PSEN1 and BACE1 activity is modulated by one-carbon metabolism, leading to increased amyloid production. We have also demonstrated that S-adenosylmethionine (SAM) supplementation contrasted the AD-like features, induced by B-vitamin deficiency. In the present study, we expanded these observations by investigating the effects of SAM and SOD (Superoxide dismutase) association. TgCRND8 AD mice were fed either with a control or B-vitamin deficient diet, with or without oral supplementation of SAM + SOD. We measured oxidative stress by lipid peroxidation assay, PSEN1 and BACE1 expression by Real-Time Polymerase Chain Reaction (PCR), amyloid deposition by ELISA assays and immunohistochemistry. We found that SAM + SOD supplementation prevents the exacerbation of AD-like features induced by B vitamin deficiency, showing synergistic effects compared to either SAM or SOD alone. SAM + SOD supplementation also contrasts the amyloid deposition typically observed in TgCRND8 mice. Although the mechanisms underlying the beneficial effect of exogenous SOD remain to be elucidated, our findings identify that the combination of SAM + SOD could be carefully considered as co-adjuvant of current AD therapies

Biotechnological and digital revolution for climate-smart plant breeding

Climate change, associated with global warming, extreme weather events, and increasing incidence of weeds, pests and pathogens, is strongly influencing major cropping systems. In this challenging scenario, miscellaneous strategies are needed to expedite the rate of genetic gains with the purpose of developing novel varieties. Large plant breeding populations, efficient high-throughput technologies, big data management tools, and downstream biotechnology and molecular techniques are the pillars on which next generation breeding is based. In this review, we describe the toolbox the breeder has to face the challenges imposed by climate change, remark on the key role bioinformatics plays in the analysis and interpretation of big “omics„ data, and acknowledge all the benefits that have been introduced into breeding strategies with the biotechnological and digital revolution

Terpenoid Transport in Plants: How Far from the Final Picture?

Contrary to the biosynthetic pathways of many terpenoids, which are well characterized and elucidated, their transport inside subcellular compartments and the secretion of reaction intermediates and final products at the short- (cell-to-cell), medium- (tissue-to-tissue), and long-distance (organ-to-organ) levels are still poorly understood, with some limited exceptions. In this review, we aim to describe the state of the art of the transport of several terpene classes that have important physiological and ecological roles or that represent high-value bioactive molecules. Among the tens of thousands of terpenoids identified in the plant kingdom, only less than 20 have been characterized from the point of view of their transport and localization. Most terpenoids are secreted in the apoplast or stored in the vacuoles by the action of ATP-binding cassette (ABC) transporters. However, little information is available regarding the movement of terpenoid biosynthetic intermediates from plastids and the endoplasmic reticulum to the cytosol. Through a description of the transport mechanisms of cytosol- or plastid-synthesized terpenes, we attempt to provide some hypotheses, suggestions, and general schemes about the trafficking of different substrates, intermediates, and final products, which might help develop novel strategies and approaches to allow for the future identification of terpenoid transporters that are still uncharacterized

P4‐181: Homocysteine, S‐adenosylmethionine/s‐adenosylhomocysteine ratio, glutathione and nitric oxide levels in TgCRDND8 mice fed with B vitamin‐deficient diet

n/

Establishment of a DNA-free genome editing and protoplast regeneration method in cultivated tomato (Solanum lycopersicum)

Key message We have established a DNA-free genome editing method via ribonucleoprotein-based CRISPR/Cas9 in cultivated tomato and obtained mutant plants regenerated from transfected protoplasts with a high mutation rate. The application of genome editing as a research and breeding method has provided many possibilities to improve traits in many crops in recent years. In cultivated tomato (Solanum lycopersicum), so far only stable Agrobacterium-mediated transformation carrying CRISPR/Cas9 reagents has been established. Shoot regeneration from transfected protoplasts is the major bottleneck in the application of DNA-free genome editing via ribonucleoprotein-based CRISPR/Cas9 method in cultivated tomato. In this study, we report the implementation of a transgene-free breeding method for cultivated tomato by CRISPR/Cas9 technology, including the optimization of protoplast isolation and overcoming the obstacle in shoot regeneration from transfected protoplasts. We have identified that the shoot regeneration medium containing 0.1 mg/L IAA and 0.75 mg/L zeatin was the best hormone combination with a regeneration rate of up to 21.3%. We have successfully obtained regenerated plants with a high mutation rate four months after protoplast isolation and transfection. Out of 110 regenerated M-0 plants obtained, 35 (31.8%) were mutated targeting both SP and SP5G genes simultaneously and the editing efficiency was up to 60% in at least one allele in either SP or SP5G genes

Mitochondrial DNA editing in potato through mitoTALEN and mitoTALECD: molecular characterization and stability of editing events

Background The aim of this study was to evaluate and characterize the mutations induced by two TALE-based approaches, double-strand break (DSB) induction by the FokI nuclease (mitoTALEN) and targeted base editing by the DddA cytidine deaminase (mitoTALECD), to edit, for the first time, the mitochondrial genome of potato, a vegetatively propagated crop. The two methods were used to knock out the same mitochondrial target sequence (orf125). Results Targeted chondriome deletions of different sizes (236–1066 bp) were induced by mitoTALEN due to DSB repair through ectopic homologous recombination of short direct repeats (11–12 bp) present in the target region. Furthermore, in one case, the induced DSB and subsequent repair resulted in the amplification of an already present substoichiometric molecule showing a 4288 bp deletion spanning the target sequence. With the mitoTALECD approach, both nonsense and missense mutations could be induced by base substitution. The deletions and single nucleotide mutations were either homoplasmic or heteroplasmic. The former were stably inherited in vegetative offspring. Conclusions Both editing approaches allowed us to obtain plants with precisely modified mitochondrial genomes at high frequency. The use of the same plant genotype and mtDNA region allowed us to compare the two methods for efficiency, accuracy, type of modifications induced and stability after vegetative propagation

HRV in active-duty special forces and public order military personnel

Heart rate variability (HRV) is a simple, non-invasive, real-time analyzable, and highly reproducible measurement that captures incidences for assessing a person’s health and physical condition. Public security jobs are characterized by major exposure to risk factors known to influence the cardiovascular response to stimuli, e.g., night shifts, highly physically demanding activity, and acute stress activity. This study aimed to evaluate the HRV parameters in a population of 112 male personnel of the special forces and public order of the Carabinieri, aged 25-59, when engaged in several duty tasks, such as paratroopers, night shift police station officers, night shift patrol, dynamic precision shooting evaluative team, dynamic precision shooting non-evaluative team, and office clerks (used as control group). During the specific task of each participant, the HRV parameters were collected with wearable devices and processed. The HRV parameters in the time and frequency domains collected were average heart rate, standard deviation of all normal RR intervals, root mean square of successive differences in adjacent normal-to-normal (NN) intervals, very-low-frequency power, low-frequency power, high-frequency power, stress index, parasympathetic nervous system activity index, and sympathetic nervous system activity index. Parametric tests for independent series to compare the HRV parameters by subgroups within the study subjects were used. A multivariate linear regression analysis was conducted to evaluate the association between the HRV parameters and some personal and organizational factors. The comparison between different subgroups showed that activities with a high demand for concentration and precision, as is the case with paratroopers and dynamic precision shooters, differ significantly from activities that can be defined as routine, such as office work. Other activities, such as patrolling or remote management from operations centers, although including critical elements, did not deviate significantly from the control group. The study of HRV parameters is therefore a useful tool for occupational physicians, both for addressing work suitability assessments and for better targeting health promotion campaigns, to be considered as being aimed at monitoring the subject’s physiological parameters, and not at the diagnosis of any pathological condition, which should always be carried out by the medical specialist

Generation and physiological characterization of genome-edited Nicotiana benthamiana plants containing zeaxanthin as the only leaf xanthophyll

Main conclusionSimultaneous genome editing of the two homeologousLCYeandZEPgenes ofNicotiana benthamianaresults in plants in which all xanthophylls are replaced by zeaxanthin.AbstractPlant carotenoids act both as photoreceptors and photoprotectants in photosynthesis and as precursors of apocarotenoids, which include signaling molecules such as abscisic acid (ABA). As dietary components, the xanthophylls lutein and zeaxanthin have photoprotective functions in the human macula. We developed transient and stable combinatorial genome editing methods, followed by direct LC-MS screening for zeaxanthin accumulation, for the simultaneous genome editing of the two homeologous Lycopene Epsilon Cyclase (LCYe) and the two Zeaxanthin Epoxidase (ZEP) genes present in the allopolyploid Nicotiana benthamiana genome. Editing of the four genes resulted in plants in which all leaf xanthophylls were substituted by zeaxanthin, but with different ABA levels and growth habits, depending on the severity of the ZEP1 mutation. In high-zeaxanthin lines, the abundance of the major photosystem II antenna LHCII was reduced with respect to wild-type plants and the LHCII trimeric state became unstable upon thylakoid solubilization. Consistent with the depletion in LHCII, edited plants underwent a compensatory increase in PSII/PSI ratios and a loss of the large-size PSII supercomplexes, while the level of PSI-LHCI supercomplex was unaffected. Reduced activity of the photoprotective mechanism NPQ was shown in high-zeaxanthin plants, while PSII photoinhibition was similar for all genotypes upon exposure to excess light, consistent with the antioxidant and photoprotective role of zeaxanthin in vivo

Mitochondrial gene editing and allotopic expression unveil the role of orf125 in the induction of male fertility in some Solanum spp. hybrids and in the evolution of the common potato

: Genic-cytoplasmic male sterility (CMS) due to interactions between nuclear and cytoplasmic genomes is a well-known phenomenon in some Solanum spp. hybrids, but genes involved are not known. In this study, the chondriomes of two isonuclear male-fertile and sterile somatic hybrids (SH9A and SH9B, respectively) between the common potato (S. tuberosum Group Tuberosum, tbr) and the wild species S. commersonii were sequenced and compared to those of parental species to identify mitochondrial genes involved in the expression of male sterility. A putative novel gene (orf125) was found only in tbr and in male-sterile hybrids. Physical or functional deletion of orf125 by mtDNA editing in SH9B and its allotopic expression in SH9A clearly demonstrated that orf125 affects male fertility. Besides knockout mutants induced by mitoTALEN and DddA-derived cytosine base editing, specific orf125 missense mutations generated by the latter approach also induced reversion to male fertility in edited SH9B plants, prompting further studies on ORF125 structure-function relationship. The organization of the mitochondrial genome region implicated in CMS was found to be conserved across all common potato accessions, while an identical copy of tbr orf125 was detected in accessions belonging to the S. berthaultii species complex (ber). Such findings corroborate the hypothesis that ber accessions with T/β cytoplasm outcrossed as female with Andean potato, giving rise to the differentiation of the Chilean potato, and highlight the origin of mitochondrial factors contributing to genic-cytoplasmic male sterility in some tuber-bearing Solanum hybrids. Our results contribute to the development of innovative breeding approaches in potato