Conventionally, eukaryotic mRNAs were thought to be monocistronic, leading to the translation of a single protein. However, large-scale proteomics has led to a massive identification of proteins translated from mRNAs of alternative ORF (AltORFs), in addition to the predicted proteins issued from the reference ORF or from ncRNAs. These alternative proteins (AltProts) are not represented in the conventional protein databases and this “Ghost proteome” was not considered until recently. Some of these proteins are functional and there is growing evidence that they are involved in central functions in physiological and physiopathological context. Based on our experience with AltProts we have got interested in finding out their involvement in development of the SARS-CoV-2 virus, responsible for the 2020 Covid-19 outbreak. Thus, we have scrutinized the recently published data by Krogan and coworkers (2020) on the SARS-CoV-2 interactome with host cells by co-IP in the perspective of drug repurposing. The initial work has revealed the interaction between 332 human cellular RefProts with the 27 viral proteins. Re-interrogation of this data using 23 viral targets and including AltProts, followed by enrichment of the interaction networks, leads to identify 218 RefProts (in common to initial study) plus 56 AltProts involved in 93 interactions. This demonstrates the necessity to take into account the Ghost proteome for discovering new therapeutic targets and establish new therapeutic strategies. Missing the ghost proteome in the drug metabolism and pharmacokinetic (DMPK) drug development pipeline will certainly be a major limitation to the establishment of efficient therapies.

In the recent years, Cannabis and hemp-based products have become increasingly popular for various applications ranging from recreational use, edibles, beverages to health care products and medicines. The rapid detection and differentiation of phytocannabinoids is, therefore, essential to assess the potency, therapeutic and nutritional values of cannabis cultivars. Here, we implemented the SpiderMass technology for the in vivo detection of cannabidiol acid (CBDA) and tetrahydrocannabinol acid (THCA) and other endogenous organic plant compounds to access distribution gradients within the plants and differentiate cultivars. The SpiderMass system is composed of an IR- laser handheld microsampling probe connected to the mass spectrometer through a transfer tube. The analysis was performed in situ on different plant organs from freshly cultivated Cannabis plants in only a few seconds. SpiderMass analysis easily discriminated the two acid phytocannabinoid isomers by MS/MS and the built statistical models differentiated between four Cannabis cultivars. Different abundancies of acid phytocannabinoids were also found along the plant as well as between different cultivars. All together, these results introduce the direct analysis by SpiderMass as a compelling analytical alternative for forensic and hemp industrial analysis.

Using a combination of pan proteomic platform associated with systemic biology analyses, we demonstrate that neonatal microglial cells derived from cortex and spinal cord expressed different phenotypes upon the physiological or pathological conditions. They also highlight great variability in protein production on both cellular and exosome levels. Bioinformatics data indicate for the cortical microglia anti-inflammatory and neurogenesis/tumorigenesis characteristics, while for the spinal cord microglia involvement in the inflammatory response. We confirmed these results by performing functional testing including neurite outgrowth assays in DRGs cell line, and glioma proliferation analysis in 3D spheroid cultures. Results from these in vitro assays indicate that the microglia located at different CNS areas reveal differential biological functions. While both microglia sources enhanced growth of DRGs axons, only the spinal microglia significantly attenuated glioma proliferation. Overall these findings are pointing to the fact that the origin of neonatal microglia affects the physio-pathological function, which may address the prevalence of the glioma in the brain in comparison with the spinal cord in adult.