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Biodegradable plastics (BPs) have lately received attention as possible solutions to the problem of plastic pollution. Plastics have brought numerous benefits to human society, but their misuse and mismanagement have also brought environmental issues. For this reason, BPs have been proposed as alternative materials in specific applications (e.g. mulch films, fishing gears, packaging, disposable bags). In 2021, the global production capacity for BPs was 1.55 million tonnes and is foreseen to almost reach 5.29 million tonnes in 2026. However, the kinetics of degradation and potential environmental effects of BPs are still poorly understood. Biodegradation is a system property, meaning that biodegradation depends on both the specific material properties and the conditions of the environment receiving it. Hence the same material can biodegrade differently in different types of environments. In this work, we studied biodegradation of commercially available products made of biodegradable polymers (i.e. PLA, PBAT, starch blends) in three different environments (i.e. air, soil, seawater) for up to 1 year of exposure. To describe biodegradation rate and the physical-chemical mechanisms involved, several characterization techniques were applied, including Pyr-GC/MS, GPC, FTIR and SEM. Also see: https://micro2022.sciencesconf.org/427216/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

Primary microplastics, such as glitter, are being replaced with natural and/or biodegradable alternatives. When microplastics enter the environment, their physical presence and chemical leachate may alter the physiology of primary producers. Three experiments were set up to separate chemical and physical effects of different types of glitter: polyethylene terephthalate (PET), biodegradable modified regenerated cellulose (MRC) and synthetic mica, as well as a natural particle control (kaolinite) on the growth and physiology of Lemna minor (common duckweed) and freshwater microalga Chlorella vulgaris. Plants and algae were exposed to either fresh (chemical and physical effects), leachate from glitter (chemical) or aged glitter (physical). Overall, there was little impact of PET, synthetic mica or kaolinite. High concentrations of fresh MRC glitters, however, decreased root length, biomass and chlorophyll content of L. minor and decreased the growth of C. vulgaris. Some of these effects were also present when exposed to leachate from MRC glitters, but were less pronounced. Aged glitters of any type elicited almost no response in L. minor. Elemental analysis revealed high concentrations of metals in MRC glitter which may explain these responses. Short-term impacts of biodegradable glitters can arise due to a combination of their physical and chemical properties, but may lessen over time as their surface coating leaches. Understanding the impacts of primary microplastics labelled as biodegradable and environmentally safe is important in the context of current microplastics legislation especially regarding derogations for biodegradable microplastics. Also see: https://micro2022.sciencesconf.org/427308/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

Wet wipes are spunlace nonwoven fabrics obtained through the binding of fibers with water jets [1], used to delivery and apply skin-touching personal care products. Wet wipes are commonly composed of cellulose fibers, synthetic fibers, or blends of the two [1]. The intensive usage of wet wipes has increased the concern of the scientific community about microfiber pollution [2,3] and the release of additives in the environment [4]. We investigated different classes of wet wipes in commerce in UK: flushable according to UK certification, biodegradable but not flushable, and conventional. Evolved Gas Analysis-Mass Spectrometry (EGA-MS) allowed us to study the thermal profile of the materials constituting the wet wipes, while their composition and the presence of additives were assessed by multi-shot Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC-MS). Moreover, the samples were immersed in distilled water and subjected to artificial photoageing to simulate their behaviour in the environment. The photoaged tissues and the microfibers released in the water were analyzed by Py-GC-MS. All the samples showed significant releases of microfibers and, in the case of the blend composed of cellulose and polypropylene, a tendency to release preferentially cellulose microfibers was observed. [1] Y. Zhang, Z. Wen, W. Lin, V. Kosajan, T. Zhang, Resour. Conserv. Recycl, 174, (2021) 105803. [2] O. O Briain, A.R. Marquez Mendes, S. McCarron, M.G. Healy, L. Morrison, Water Res. 182, (2020) 116021. [3] J. Lee, S. Jeong, K. Chae, Sci. Total Environ. 784, (2021) 147144. [4] E.C. Pack, H.G. Lee, D.Y. Jang, H.S. Sin, T.Y. Kim, H.S. Kim, K.M. Lim, D.W. Choi, Sci. Total Environ. 782, (2021) 146829. Also see: https://micro2022.sciencesconf.org/427014/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

Plastic is widely acknowledged as a pressing global issue capable of detrimentally impacting the environment. Biodegradable polymers are often proposed as a solution to conventional plastics due to their properties to degrade over time. The global production of biodegradable polymers has increased over the last decade, and they are widely used in applications where there are substantive pathways to the environment, including agricultural and fishery products, tree shelters, textiles, and non-woven wet wipes. Yet their fate and degradation behaviour within different environments is poorly understood and is influenced by the interplay between the intrinsic properties of the plastic and the characteristics of the surrounding environment. Questions also remain around the individual- and ecosystem- level impacts of biodegradable plastics, and their degradation products. The interdisciplinary "Bio Plastic Risk" project aims to address these knowledge gaps, by establishing the rates of deterioration, pathways and environmental accumulation of plastic (and their breakdown products) in marine and terrestrial environments. Additionally, the direct effects of biodegradable plastic deterioration on marine and terrestrial organisms and indirect consequences on ecological and biogeochemical processes will be examined. The information gained during this project will be used to develop environmental risk assessments and guide the future development and use of biodegradable plastics. Also see: https://micro2022.sciencesconf.org/426929/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

Persistent infection and tumorigenesis by papillomaviruses (PVs) require viral manipulation of various cellular processes, including those involved in innate immune responses. The cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes (cGAS-STING) pathway has emerged as an essential innate immune sensing system, that recognizes DNA and trigger potent antiviral effector responses. In this study, we found that bovine PV (BPV) E5 protein, the major oncoprotein of bovine delta PVs, interacts with STING but not with cGAS in a spontaneous BPV infection of neoplastic urothelial cells of cattle. Real-time RT-PCR revealed a significant reduction in both cGAS and STING transcripts in E5-expressing cells. Furthermore, western blot (WB) analysis failed to detect any variation in the expression of interferon-inducible protein 16 (IFI16), an upstream effector of the STING pathway. A ternary complex composed of E5/STING/IFI16 was also observed. Co-immunoprecipitation studies showed that STING interacts with a protein network composed of total and phosphorylated TANK-binding kinase 1 (TBK1), total and phosphorylated interferon regulatory factor 3 (IRF3), IRF7, IKKα, IKKβ, IKKϵ, ELKS, MEKK3, and TAK1. RT-qPCR revealed a significant reduction in TBK1 mRNA levels in BPV-infected cells. WB analysis revealed significantly reduced expression levels of pTBK1, which is essential for the activation and phosphorylation of IRF3, a prerequisite for the latter to enter the nucleus to activate type 1 IFN genes. WB also revealed significantly down-expression of IKKα, IKKβ, IKKϵ, and overexpression of IRF7, ELKS, MEKK3, and TAK1in BPV-positive urothelial cells compared with that in uninfected healthy cells. Phosphorylated p65 (p-p65) was significantly reduced in both the nuclear and cytosolic compartments of BPV-infected cells compared with that in uninfected urothelial cells. Our results suggest that the innate immune signaling pathway mediated by cGAS-STING is impaired in cells infected with BPV. Therefore, effective immune responses are not elicited against these viruses, which facilitates persistent viral infection and subsequent tumorigenesis.

Ovine papillomavirus (OaPV) comprises four genotypes; OaPV1, OaPV2, and OaPV4 are fibropapillomaviruses within the genus Delta-papillomavirus ( Delta-PV ), whereas OaPV3 is an epitheliotropic virus that belongs to the genus Dyokappa-papillomavirus ( Dyokappa-PV ). To date, all of them have been known to infect sheep only. OaPV1, OaPV2, and OaPV4 have been associated with ovine cutaneous and mucosal fibropapillomas, while OaPV3 is a key factor in the squamous cell carcinoma (SCC) pathway of the sheep skin. Peripheral blood mononuclear cell (PBMC) samples obtained from 128 cattle at public slaughterhouses were investigated using droplet digital polymerase chain reaction (ddPCR). ddPCR is a new-generation PCR technique that enables accurate and absolute quantification of target molecules with high sensitivity and specificity. All OaPVs were detected by identification and quantification of nucleic acids using specific fluorescent probes. Of 128 PBMC samples, 100 (~78%) showed OaPV infections. Further, 42, 35, and 23 PBMC samples showed single, double, and triple OaPV infections, respectively. OaPV1 was responsible for 22 single infections, OaPV2 caused 16 single infections, and OaPV3 and OaPV4 caused two single infections each. OaPV1 and OaPV2 were the most frequent ovine viruses in dual and triple infections. In many PBMC samples, both ovine Delta-PV and Dyokappa-PV were found to be transcriptionally active, as shown by the detection and quantification of E5 oncogene transcripts for OaPV1, L1 transcripts for OaPV2, E6 and E7 transcripts for OaPV3, and E6 for OaPV4. OaPVs were found in the blood samples from cattle that shared grasslands rich in bracken ferns known to contain immunosuppressant substances. Furthermore, OaPVs were also found in cattle from intensive livestock farming without any contact with sheep. Because OaPV DNA was detected in both grass hay and corn silage, it is conceivable that these feed may be the viral sources.

ERas is a new gene of the Ras family found in murine embryonic stem (ES) cells. Its human ortholog is not expressed in human ES cells. So far ERas gene has only been found to be expressed in the tissues of adult cynomolgus monkeys and cattle; however, information about ERAS expression or its potential functions in equine tissues is lacking. This study was performed to investigate whether Eras is an equine functional gene and whether ERAS is expressed in the tissues of adult horses and determine its potential physiological role. Expression of the ERas gene was detected in all examined adult tissues, and the RT-PCR assay revealed ERAS transcripts. Protein expression was also detected by Western blot analysis. Quantitative real time RT-qPCR analysis revealed that different expression levels of ERAS transcripts were most highly expressed in the testis. Immunohistochemically, ERAS was found to be localized prevalently in the plasmatic membrane as well as cytoplasm of the cells. ERAS was a physical partner of activated PDGFβR leading to the AKT signaling. ERAS was found to interact with a network of proteins (BAG3, CHIP, Hsc70/Hsp70, HspB8, Synpo2, and p62) known to play a role in the chaperone-assisted selective autophagy (CASA), which is also known as BAG3-mediated selective macroautophagy, an adaptive mechanism to maintain cellular homeostasis. Furthermore, ERAS was found to interact with parkin. PINK1, BNIP3, laforin. All these proteins are known to play a role in parkin-dependent and -independent mitophagy. This is the first study demonstrating that Eras is a functional gene, and that ERAS is constitutively expressed in the tissues of adult horses. ERAS appears to play a physiological role in cellular proteostasis maintenance, thus mitigating the proteotoxicity of accumulated misfolded proteins and contributing to protection against disease. Finally, it is conceivable that activation of AKT pathway by PDGFRs promotes actin reorganization, directed cell movements, stimulation of cell growth.