Phosphorylation at the disordered N-end makes HuR accumulate and dimerize in the cytoplasm.

Human antigen R (HuR) is an RNA binding protein mainly involved in maintaining the stability and controlling the translation of mRNAs, critical for immune response, cell survival, proliferation and apoptosis. Although HuR is a nuclear protein, its mRNA translational-related function occurs at the cytoplasm, where the oligomeric form of HuR is more abundant. However, the regulation of nucleo-cytoplasmic transport of HuR and its connection with protein oligomerization remain unclear. In this work, we describe the phosphorylation of Tyr5 as a new hallmark for HuR activation. Our biophysical, structural and computational assays using phosphorylated and phosphomimetic HuR proteins demonstrate that phosphorylation of Tyr5 at the disordered N-end stretch induces global changes on HuR dynamics and conformation, modifying the solvent accessible surface of the HuR nucleo-cytoplasmic shuttling (HNS) sequence and releasing regions implicated in HuR dimerization. These findings explain the preferential cytoplasmic accumulation of phosphorylated HuR in HeLa cells, aiding to comprehend the mechanisms underlying HuR nucleus-cytoplasm shuttling and its later dimerization, both of which are relevant in HuR-related pathogenesis.

Biochemical and structural impact of two novel missense mutations in cystathionine ß-synthase gene associated with homocystinuria.

Homocystinuria is a rare disease caused by mutations in the CBS gene that results in a deficiency of cystathionine ß-synthase (CBS). CBS is an essential pyridoxal 5'-phosphate (PLP)-dependent enzyme in the transsulfuration pathway, responsible for combining serine with homocysteine to produce cystathionine, whose activity is enhanced by the allosteric regulator S-adenosylmethionine (SAM). CBS also plays a role in generating hydrogen sulfide (H2S), a gaseous signaling molecule with diverse regulatory functions within the vascular, nervous, and immune systems. In this study, we present the clinical and biochemical characterization of two novel CBS missense mutations that do not respond to pyridoxine treatment, namely c.689T > A (L230Q) and 215A > T (K72I), identified in a Chinese patient. We observed that the disease-associated K72I genetic variant had no apparent effects on the spectroscopic and catalytic properties of the full-length enzyme. In contrast, the L230Q variant expressed in Escherichia coli did not fully retain heme and when compared with the wild-type enzyme, it exhibited more significant impairments in both the canonical cystathionine-synthesis and the alternative H2S-producing reactions. This reduced activity is consistent with both in vitro and in silico evidence, which indicates that the L230Q mutation significantly decreases the overall protein's stability, which in turn, may represent the underlying cause of its pathogenicity.

The outcome of boosting mitochondrial activity in alcohol-associated liver disease is organ-dependent.

BACKGROUND AND AIMS: Alcohol-associated liver disease (ALD) accounts for 70% of liver-related deaths in Europe, with no effective approved therapies. Although mitochondrial dysfunction is one of the earliest manifestations of alcohol-induced injury, restoring mitochondrial activity remains a problematic strategy due to oxidative stress. Here, we identify methylation-controlled J protein (MCJ) as a mediator for ALD progression and hypothesize that targeting MCJ may help in recovering mitochondrial fitness without collateral oxidative damage. APPROACH AND RESULTS: C57BL/6 mice [wild-type (Wt)] Mcj knockout and Mcj liver-specific silencing (MCJ-LSS) underwent the NIAAA dietary protocol (Lieber-DeCarli diet containing 5% (vol/vol) ethanol for 10 days, plus a single binge ethanol feeding at day 11). To evaluate the impact of a restored mitochondrial activity in ALD, the liver, gut, and pancreas were characterized, focusing on lipid metabolism, glucose homeostasis, intestinal permeability, and microbiota composition. MCJ, a protein acting as an endogenous negative regulator of mitochondrial respiration, is downregulated in the early stages of ALD and increases with the severity of the disease. Whole-body deficiency of MCJ is detrimental during ALD because it exacerbates the systemic effects of alcohol abuse through altered intestinal permeability, increased endotoxemia, and dysregulation of pancreatic function, which overall worsens liver injury. On the other hand, liver-specific Mcj silencing prevents main ALD hallmarks, that is, mitochondrial dysfunction, steatosis, inflammation, and oxidative stress, as it restores the NAD + /NADH ratio and SIRT1 function, hence preventing de novo lipogenesis and improving lipid oxidation. CONCLUSIONS: Improving mitochondrial respiration by liver-specific Mcj silencing might become a novel therapeutic approach for treating ALD.

Trainable Reference Spikes Improve Temporal Information Processing of SNNs With Supervised Learning.

Spiking neural networks (SNNs) are the next-generation neural networks composed of biologically plausible neurons that communicate through trains of spikes. By modifying the plastic parameters of SNNs, including weights and time delays, SNNs can be trained to perform various AI tasks, although in general not at the same level of performance as typical artificial neural networks (ANNs). One possible solution to improve the performance of SNNs is to consider plastic parameters other than just weights and time delays drawn from the inherent complexity of the neural system of the brain, which may help SNNs improve their information processing ability and achieve brainlike functions. Here, we propose reference spikes as a new type of plastic parameters in a supervised learning scheme in SNNs. A neuron receives reference spikes through synapses providing reference information independent of input to help during learning, whose number of spikes and timings are trainable by error backpropagation. Theoretically, reference spikes improve the temporal information processing of SNNs by modulating the integration of incoming spikes at a detailed level. Through comparative computational experiments, we demonstrate using supervised learning that reference spikes improve the memory capacity of SNNs to map input spike patterns to target output spike patterns and increase classification accuracy on the MNIST, Fashion-MNIST, and SHD data sets, where both input and target output are temporally encoded. Our results demonstrate that applying reference spikes improves the performance of SNNs by enhancing their temporal information processing ability.

Natural and Synthetic Flavylium-Based Dyes: The Chemistry Behind the Color.

Flavylium compounds are a well-known family of pigments because they are prevalent in the plant kingdom, contributing to colors over a wide range from shades of yellow-red to blue in fruits, flowers, leaves, and other plant parts. Flavylium compounds include a large variety of natural compound classes, namely, anthocyanins, 3-deoxyanthocyanidins, auronidins, and their respective aglycones as well as anthocyanin-derived pigments (e.g., pyranoanthocyanins, anthocyanin-flavan-3-ol dimers). During the past few decades, there has been increasing interest among chemists in synthesizing different flavylium compounds that mimic natural structures but with different substitution patterns that present a variety of spectroscopic characteristics in view of their applications in different industrial fields. This Review provides an overview of the chemistry of flavylium-based compounds, in particular, the synthetic and enzymatic approaches and mechanisms reported in the literature for obtaining different classes of pigments, their physical-chemical properties in relation to their pH-dependent equilibria network, and their chemical and enzymatic degradation. The development of flavylium-based systems is also described throughout this Review for emergent applications to explore some of the physical-chemical properties of the multistate of species generated by these compounds.

Chitosan/Polyvinyl Alcohol-Based Biofilms Using Ternary Deep Eutectic Solvents towards Innovative Color-Stabilizing Systems for Anthocyanins.

Anthocyanins are amazing plant-derived colorants with highly valuable properties; however, their chemical and color instability issues limit their wide application in different food industry-related products such as active and intelligent packaging. In a previous study, it was demonstrated that anthocyanins could be stabilized into green plasticizers namely deep eutectic solvents (DESs). In this work, the fabrication of edible films by integrating anthocyanins along with DESs into biocompatible chitosan (CHT)-based formulations enriched with polyvinyl alcohol (PVA) and PVA nanoparticles was investigated. CHT/PVA-DES films' physical properties were characterized by scanning electron microscopy, water vapor permeability, swelling index, moisture sorption isotherm, and thermogravimetry analysis. Innovative red-to-blue formulation films were achieved for CHT/PVA nanoparticles (for 5 min of sonication) at a molar ratio 1:1, and with 10% of ternary DES (TDES)-containing malvidin-3-glucoside (0.1%) where the physical properties of films were enhanced. After immersion in solutions at different pH values, films submitted to pHs 5-8 were revealed to be more color stable and resistant with time than at acidic pH values.

Key substrate recognition residues in the active site of cystathionine beta-synthase from Toxoplasma gondii.

Cystathionine ß-synthase (CBS) catalyzes the condensation of l-serine and l-homocysteine to give l-cystathionine in the transsulfuration pathway. Recently, a few O-acetylserine (l-OAS)-dependent CBSs (OCBSs) have been found in bacteria that can exclusively function with l-OAS. CBS from Toxoplasma gondii (TgCBS) can efficiently use both l-serine and l-OAS to form l-cystathionine. In this work, a series of site-specific variants substituting S84, Y160, and Y246 with hydrophobic residues found at the same positions in OCBSs was generated to explore the roles of the hydroxyl moieties of these residues as determinants of l-serine/l-OAS preference in TgCBS. We found that the S84A/Y160F/Y246V triple mutant behaved like an OCBS in terms of both substrate requirements, showing ß-replacement activity only with l-OAS, and pH optimum, which is decreased by ~1 pH unit. Formation of a stable aminoacrylate upon reaction with l-serine is prevented by the triple mutation, indicating the importance of the H-bonds between the hydroxyl groups of Y160, Y246, and S84 with l-serine in formation of the intermediate. Analysis of the independent effect of each mutation on TgCBS activity and investigation of the protein-aminoacrylate complex structure allowed for the conclusion that the hydroxyl group of Y246 has a major, but not exclusive, role in controlling the l-serine preference by efficiently stabilizing its leaving group. These studies demonstrate that differences in substrate specificity of CBSs are controlled by natural variations in as few as three residue positions. A better understanding of substrate specificity in TgCBS will facilitate the design of new antimicrobial compounds.

Subjective Quality Assessment of V-PCC-Compressed Dynamic Point Clouds Degraded by Packet Losses.

This article describes an empirical exploration on the effect of information loss affecting compressed representations of dynamic point clouds on the subjective quality of the reconstructed point clouds. The study involved compressing a set of test dynamic point clouds using the MPEG V-PCC (Video-based Point Cloud Compression) codec at 5 different levels of compression and applying simulated packet losses with three packet loss rates (0.5%, 1% and 2%) to the V-PCC sub-bitstreams prior to decoding and reconstructing the dynamic point clouds. The recovered dynamic point clouds qualities were then assessed by human observers in experiments conducted at two research laboratories in Croatia and Portugal, to collect MOS (Mean Opinion Score) values. These scores were subject to a set of statistical analyses to measure the degree of correlation of the data from the two laboratories, as well as the degree of correlation between the MOS values and a selection of objective quality measures, while taking into account compression level and packet loss rates. The subjective quality measures considered, all of the full-reference type, included point cloud specific measures, as well as others adapted from image and video quality measures. In the case of image-based quality measures, FSIM (Feature Similarity index), MSE (Mean Squared Error), and SSIM (Structural Similarity index) yielded the highest correlation with subjective scores in both laboratories, while PCQM (Point Cloud Quality Metric) showed the highest correlation among all point cloud-specific objective measures. The study showed that even 0.5% packet loss rates reduce the decoded point clouds subjective quality by more than 1 to 1.5 MOS scale units, pointing out the need to adequately protect the bitstreams against losses. The results also showed that the degradations in V-PCC occupancy and geometry sub-bitstreams have significantly higher (negative) impact on decoded point cloud subjective quality than degradations of the attribute sub-bitstream.

Lossy Image Compression in a Preclinical Multimodal Imaging Study.

The growing use of multimodal high-resolution volumetric data in pre-clinical studies leads to challenges related to the management and handling of the large amount of these datasets. Contrarily to the clinical context, currently there are no standard guidelines to regulate the use of image compression in pre-clinical contexts as a potential alleviation of this problem. In this work, the authors study the application of lossy image coding to compress high-resolution volumetric biomedical data. The impact of compression on the metrics and interpretation of volumetric data was quantified for a correlated multimodal imaging study to characterize murine tumor vasculature, using volumetric high-resolution episcopic microscopy (HREM), micro-computed tomography (µCT), and micro-magnetic resonance imaging (µMRI). The effects of compression were assessed by measuring task-specific performances of several biomedical experts who interpreted and labeled multiple data volumes compressed at different degrees. We defined trade-offs between data volume reduction and preservation of visual information, which ensured the preservation of relevant vasculature morphology at maximum compression efficiency across scales. Using the Jaccard Index (JI) and the average Hausdorff Distance (HD) after vasculature segmentation, we could demonstrate that, in this study, compression that yields to a 256-fold reduction of the data size allowed to keep the error induced by compression below the inter-observer variability, with minimal impact on the assessment of the tumor vasculature across scales.

Effects of Fructose and Palmitic Acid on Gene Expression in Drosophila melanogaster Larvae: Implications for Neurodegenerative Diseases.

One of the largest health problems worldwide is the development of chronic noncommunicable diseases due to the consumption of hypercaloric diets. Among the most common alterations are cardiovascular diseases, and a high correlation between overnutrition and neurodegenerative diseases has also been found. The urgency in the study of specific damage to tissues such as the brain and intestine led us to use Drosophila melanogaster to study the metabolic effects caused by the consumption of fructose and palmitic acid in specific tissues. Thus, third instar larvae (96 ± 4 h) of the wild Canton-S strain of D. melanogaster were used to perform transcriptomic profiling in brain and midgut tissues to test for the potential metabolic effects of a diet supplemented with fructose and palmitic acid. Our data infer that this diet can alter the biosynthesis of proteins at the mRNA level that participate in the synthesis of amino acids, as well as fundamental enzymes for the dopaminergic and GABAergic systems in the midgut and brain. These also demonstrated alterations in the tissues of flies that may help explain the development of various reported human diseases associated with the consumption of fructose and palmitic acid in humans. These studies will not only help to better understand the mechanisms by which the consumption of these alimentary products is related to the development of neuronal diseases but may also contribute to the prevention of these conditions.

Inhibiting thyroid activation in aged human explants prevents mechanical induced detrimental signalling by mitigating metabolic processes.

OBJECTIVES: To investigate whether the deiodinase inhibitor iopanoic acid (IOP) has chondroprotective properties, a mechanical stress induced model of human aged explants was used to test both repeated dosing and slow release of IOP. METHODS: Human osteochondral explants subjected to injurious mechanical stress (65%MS) were treated with IOP or IOP encapsulated in poly lactic-co-glycolic acid-polyethylene glycol nanoparticles (NP-IOP). Changes to cartilage integrity and signalling were determined by Mankin scoring of histology, sulphated glycosaminoglycan (sGAG) release and expression levels of catabolic, anabolic and hypertrophic markers. Subsequently, on a subgroup of samples, RNA sequencing was performed on 65%MS (n = 14) and 65%MS+IOP (n = 7) treated cartilage to identify IOP's mode of action. RESULTS: Damage from injurious mechanical stress was confirmed by increased cartilage surface damage in the Mankin score, increased sGAG release, and consistent upregulation of catabolic markers and downregulation of anabolic markers. IOP and, though less effective, NP-IOP treatment, reduced MMP13 and increased COL2A1 expression. In line with this, IOP and NP-IOP reduced cartilage surface damage induced by 65%MS, while only IOP reduced sGAG release from explants subjected to 65%MS. Lastly, differential expression analysis identified 12 genes in IOP's mode of action to be mainly involved in reducing metabolic processes (INSIG1, DHCR7, FADS1 and ACAT2) and proliferation and differentiation (CTGF, BMP5 and FOXM1). CONCLUSION: Treatment with the deiodinase inhibitor IOP reduced detrimental changes of injurious mechanical stress. In addition, we identified that its mode of action was likely on metabolic processes, cell proliferation and differentiation.

Molecular Changes in the Dorsal Root Ganglion during the Late Phase of Peripheral Nerve Injury-induced Pain in Rodents: A Systematic Review.

The dorsal root ganglion is widely recognized as a potential target to treat chronic pain. A fundamental understanding of quantitative molecular and genomic changes during the late phase of pain is therefore indispensable. The authors performed a systematic literature review on injury-induced pain in rodent dorsal root ganglions at minimally 3 weeks after injury. So far, slightly more than 300 molecules were quantified on the protein or messenger RNA level, of which about 60 were in more than one study. Only nine individual sequencing studies were performed in which the most up- or downregulated genes varied due to heterogeneity in study design. Neuropeptide Y and galanin were found to be consistently upregulated on both the gene and protein levels. The current knowledge regarding molecular changes in the dorsal root ganglion during the late phase of pain is limited. General conclusions are difficult to draw, making it hard to select specific molecules as a focus for treatment.

Evidence of Anti-Inflammatory Effect of Transcranial Direct Current Stimulation in a CFA-Induced Chronic Inflammatory Pain Model in Wistar Rats.

INTRODUCTION: Given that chronic inflammatory pain is highly prevalent worldwide, it is important to study new techniques to treat or relieve this type of pain. The present study evaluated the effect of transcranial direct current stimulation (tDCS) in rats submitted to a chronic inflammatory model by nociceptive response, biomarker levels (brain-derived neurotrophic factor [BDNF] and interleukin [IL]-6 and IL-10), and by histological parameters. METHODS: Sixty-day-old male Wistar rats were used in this study and randomized by weight into 6 major groups: total control, control + sham-tDCS, control + active tDCS, total CFA, CFA + sham-tDCS, and CFA + active tDCS. After inflammatory pain was established, the animals were submitted to the treatment protocol for 8 consecutive days, according to the experimental group. The nociceptive tests (von Frey and hot plate) were assessed, and euthanasia by decapitation occurred at day 8 after the end of tDCS treatment, and the blood serum and central nervous structures were collected for BDNF and IL measurements. All experiments and procedures were approved by the Institutional Committee for Animal Care and Use (UFPel #4538). RESULTS: The tDCS treatment showed a complete reversal of the mechanical allodynia induced by the pain model 24 h and 8 days after the last tDCS session, and there was partial reversal of the thermal hyperalgesia at all time points. Serum BDNF levels were decreased in CFA + sham-tDCS and CFA + tDCS groups compared to the control + tDCS group. The control group submitted to tDCS exhibited an increase in serum IL-6 levels in relation to the other groups. In addition, there was a significant decrease in IL-10 striatum levels in control + tDCS, CFA, and CFA + sham-tDCS groups in relation to the control group, with a partial tDCS effect on the CFA pain model. Local histology demonstrated tDCS effects in decreasing lymphocytic infiltration and neovascularization and tissue regeneration in animals exposed to CFA. CONCLUSION: tDCS was able to reverse the mechanical allodynia and decrease thermal hyperalgesia and local inflammation in a chronic inflammatory pain model, with a modest effect on striatum IL-10 levels. As such, we suggest that analgesic tDCS mechanisms may be related to tissue repair by modulating the local inflammatory process.

M1-derived extracellular vesicles enhance photodynamic therapy and promote immunological memory in preclinical models of colon cancer.

Extracellular vesicles (EVs) are promising drug carriers of photosensitizers for photodynamic therapy (PDT) in cancer treatment, due to their ability to circulate in blood and enter cells efficiently. The therapeutic potential of EVs has been suggested to depend on the type and physiological state of their cell of origin. However, the effects of deriving EVs from various cells in different physiological states on their antitumor capacity are rarely evaluated. In the present study, we compared the antitumor efficacy of EV-mediated PDT by incorporating the photosensitizer Zinc Phthalocyanine (ZnPc) into EVs from multiple cells sources. ZnPc was incorporated by a direct incubation strategy into EVs derived from immune cells (M1-like macrophages and M2-like macrophages), cancer cells (B16F10 melanoma cancer cells) and external sources (milk). Our data show that all EVs are suitable carriers for ZnPc and enable efficient PDT in vitro in co-culture models and in vivo. We observed that EV-mediated PDT initiates immunogenic cell death through the release and exposure of damage associated molecular patterns (DAMPs) on cancer cells, which subsequently induced dendritic cell (DC) maturation. Importantly, of all ZnPc-EVs tested, in absence of light only M1-ZnPc displayed toxicity to MC38, but not to DC, in monoculture and in co-culture, indicating specificity for cancer over immune cells. In MC38 tumor-bearing mice, only M1-ZnPc induced a tumor growth delay compared to control in absence of light. Interestingly, M1- but not M2-mediated PDT, induced complete responses against MC38 tumors in murine models (100% versus 38% of cases, respectively), with survival of all animals up to at least 60 days post inoculation. Finally, we show that all cured animals are protected from a rechallenge with MC38 cells, suggesting the induction of immunological memory after EV-mediated PDT. Together, our data show the importance of the cell type from which the EVs are obtained and highlight the impact of the immunological state of these cells on the antitumor efficacy of EV-mediated PDT.

ARL15 modulates magnesium homeostasis through N-glycosylation of CNNMs.

Cyclin M (CNNM1-4) proteins maintain cellular and body magnesium (Mg2+) homeostasis. Using various biochemical approaches, we have identified members of the CNNM family as direct interacting partners of ADP-ribosylation factor-like GTPase 15 (ARL15), a small GTP-binding protein. ARL15 interacts with CNNMs at their carboxyl-terminal conserved cystathionine-ß-synthase (CBS) domains. In silico modeling of the interaction between CNNM2 and ARL15 supports that the small GTPase specifically binds the CBS1 and CNBH domains. Immunocytochemical experiments demonstrate that CNNM2 and ARL15 co-localize in the kidney, with both proteins showing subcellular localization in the endoplasmic reticulum, Golgi apparatus and the plasma membrane. Most importantly, we found that ARL15 is required for forming complex N-glycosylation of CNNMs. Overexpression of ARL15 promotes complex N-glycosylation of CNNM3. Mg2+ uptake experiments with a stable isotope demonstrate that there is a significant increase of 25Mg2+ uptake upon knockdown of ARL15 in multiple kidney cancer cell lines. Altogether, our results establish ARL15 as a novel negative regulator of Mg2+ transport by promoting the complex N-glycosylation of CNNMs.

Targeting circulating monocytes with CCL2-loaded liposomes armed with an oncolytic adenovirus.

Oncolytic viruses (OVs) selectively replicate in and destroy cancer cells resulting in anti-tumor immunity. However, clinical use remains a challenge because of virus clearance upon intravenous delivery. OV packaging using a nanomedicine approach could overcome this. Here we encapsulate an oncolytic adenovirus (Ad[I/PPT-E1A]) into CCL2-coated liposomes in order to exploit recruitment of CCR2-expressing circulating monocytes into tumors. We demonstrate successful encapsulation of Ad[I/PPT-E1A] into CCL2-coated liposomes that were preferentially taken up by CCR2-expressing monocytes. No complex-related toxicities were observed following incubation with prostate tumor cells and the encapsulation did not affect virus oncolytic activity in vitro. Furthermore, intravenous administration of our nanomedicine resulted in a significant reduction in tumor size and pulmonary metastasis in prostate cancer-bearing mice whereby a 1000-fold less virus was needed compared to Ad[I/PPT-E1A] alone. Taken together our data provide an opportunity to target OVs via circulation to inaccessible tumors using liposome-assisted drug delivery.

Upconversion nanoparticle platform for efficient dendritic cell antigen delivery and simultaneous tracking.

Upconversion nanoparticles (UCNPs) represent a group of NPs that can convert near-infrared (NIR) light into ultraviolet and visible light, thus possess deep tissue penetration power with less background fluorescence noise interference, and do not induce damage to biological tissues. Due to their unique optical properties and possibility for surface modification, UCNPs can be exploited for concomitant antigen delivery into dendritic cells (DCs) and monitoring by molecular imaging. In this study, we focus on the development of a nano-delivery platform targeting DCs for immunotherapy and simultaneous imaging. OVA 254-267 (OVA24) peptide antigen, harboring a CD8 T cell epitope, and Pam3CysSerLys4 (Pam3CSK4) adjuvant were chemically linked to the surface of UCNPs by amide condensation to stimulate DC maturation and antigen presentation. The OVA24-Pam3CSK4-UCNPs were thoroughly characterized and showed a homogeneous morphology and surface electronegativity, which promoted a good dispersion of the NPs. In vitro experiments demonstrated that OVA24-Pam3CSK4-UCNPs induced a strong immune response, including DC maturation, T cell activation, and proliferation, as well as interferon gamma (IFN-γ) production. In vivo, highly sensitive upconversion luminescence (UCL) imaging of OVA24-Pam3CSK4-UCNPs allowed tracking of UCNPs from the periphery to lymph nodes. In summary, OVA24-Pam3CSK4-UCNPs represent an effective tool for DC-based immunotherapy.

Point Cloud Compression: Impact on Object Detection in Outdoor Contexts.

Increasing demand for more reliable and safe autonomous driving means that data involved in the various aspects of perception, such as object detection, will become more granular as the number and resolution of sensors progress. Using these data for on-the-fly object detection causes problems related to the computational complexity of onboard processing in autonomous vehicles, leading to a desire to offload computation to roadside infrastructure using vehicle-to-infrastructure communication links. The need to transmit sensor data also arises in the context of vehicle fleets exchanging sensor data, over vehicle-to-vehicle communication links. Some types of sensor data modalities, such as Light Detection and Ranging (LiDAR) point clouds, are so voluminous that their transmission is impractical without data compression. With most emerging autonomous driving implementations being anchored on point cloud data, we propose to evaluate the impact of point cloud compression on object detection. To that end, two different object detection architectures are evaluated using point clouds from the KITTI object dataset: raw point clouds and point clouds compressed with a state-of-the-art encoder and three different compression levels. The analysis is extended to the impact of compression on depth maps generated from images projected from the point clouds, with two conversion methods tested. Results show that low-to-medium levels of compression do not have a major impact on object detection performance, especially for larger objects. Results also show that the impact of point cloud compression is lower when detecting objects using depth maps, placing this particular method of point cloud data representation on a competitive footing compared to raw point cloud data.

Multifunctional Role of Lipids in Modulating the Tumorigenic Properties of 4T1 Breast Cancer Cells.

Tumor growth and progression are linked to an altered lipid metabolism in the tumor microenvironment (TME), including tumor cells and tumor-associated macrophages (TAMs). A growing number of lipid metabolism targeting drugs have shown efficacy in anti-tumor therapy. In addition, exogenously applied lipids and lipid analogues have demonstrated anti-tumor activities in several cancers, including breast cancer. In this study, we investigated the anti-tumor efficacies of the natural lipids palmitic acid (PA), sphingomyelin (SM), ceramide (Cer) and docosahexaenoic acid (DHA) on breast cancer cells. All tested lipids reduced the malignancy of breast cancer cells in vitro by impairing cell proliferation, migration and invasiveness. PA showed superior anti-tumor properties, as it additionally impaired cancer cell viability by inducing apoptosis, without affecting healthy cells. Co-culture experiments further demonstrated that Cer and PA reduced the immunosuppressive phenotype of M2 macrophages and the M2 macrophage-promoted the epithelial-mesenchymal transition (EMT) and migration of breast cancer cells. At the molecular level, this coincided with the up-regulation of E-cadherin. Our results highlight a powerful role for exogenously applied PA and Cer in reducing breast cancer tumorigenicity by simultaneously targeting cancer cells and M2 macrophages. Our findings support the notion that lipids represent alternative biocompatible therapeutic agents for breast cancer.

Insights into Domain Organization and Regulatory Mechanism of Cystathionine Beta-Synthase from Toxoplasma gondii.

Cystathionine beta-synthase (CBS) is a key regulator of homocysteine metabolism. Although eukaryotic CBS have a similar domain architecture with a catalytic core and a C-terminal Bateman module, their regulation varies widely across phyla. In human CBS (HsCBS), the C-terminus has an autoinhibitory effect by acting as a cap that avoids the entry of substrates into the catalytic site. The binding of the allosteric modulator AdoMet to this region alleviates this cap, allowing the protein to progress from a basal toward an activated state. The same activation is obtained by artificial removal or heat-denaturation of the Bateman module. Recently, we reported the crystal structure of CBS from Toxoplasma gondii (TgCBS) showing that the enzyme assembles into basket-like dimers similar to the basal conformers of HsCBS. These findings would suggest a similar lid function for the Bateman module which, as in HsCBS, should relax in the absence of the C-terminal module. However, herein we demonstrate that, in contrast with HsCBS, removal of the Bateman module in TgCBS through deletion mutagenesis, limited proteolysis, or thermal denaturation has no effects on its activity, oligomerization, and thermal stability. This opposite behavior we have now found in TgCBS provides evidence of a novel type of CBS regulation.