A narrative review of digital biomarkers in the management of major depressive disorder and treatment-resistant forms

IntroductionDepression is the leading cause of worldwide disability, until now only 3% of patients with major depressive disorder (MDD) experiences full recovery or remission. Different studies have tried to better understand MDD pathophysiology and its resistant forms (TRD), focusing on the identification of candidate biomarkers that would be able to reflect the patients’ state and the effects of therapy. Development of digital technologies can generate useful digital biomarkers in a real-world setting. This review aims to focus on the use of digital technologies measuring symptom severity and predicting treatment outcomes for individuals with mood disorders.MethodsTwo databases (PubMed and APA PsycINFO) were searched to retrieve papers published from January 1, 2013, to July 30, 2023, on the use of digital devices in persons with MDD. All papers had to meet specific inclusion criteria, which resulted in the inclusion of 12 articles.ResultsResearch on digital biomarkers confronts four core aspects: (I) predicting diagnostic status, (II) assessing symptom severity and progression, (III) identifying treatment response and (IV) monitoring real-word and ecological validity. Different wearable technologies have been applied to collect physiological, activity/sleep, or subjective data to explore their relationships with depression.DiscussionDepression’s stable rates and high relapse risk necessitate innovative approaches. Wearable devices hold promise for continuous monitoring and data collection in real world setting.ConclusionMore studies are needed to translate these digital biomarkers into actionable interventions to improve depression diagnosis, monitoring and management. Future challenges will be the applications of wearable devices routinely in personalized medicine

La protéine S1 chez Staphylococcus aureus, une protéine chaperonne de l’ARN impliquée dans l'initiation de la traduction et la régulation médiée par des ARN non codants

Even if translation initiation is a conserved process among bacteria, we have recently shown that low G+C content Gram-positive, such as Staphylococcus aureus, differ from E. coli on the mechanism by which structured mRNAs are recognized and adapted on the ribosome. One peculiarity of the S. aureus ribosome is the absence of ribosomal protein S1, which is shorter than E. coli S1 and has different domains organization. My work could demonstrate that S. aureus S1 (SauS1) specifically promotes translation initiation of the α-psm 1-4 operon by binding its highly structured mRNA. Moreover, it influences the expression and production of other exotoxins (α-haemolysin, δ-haemolysin and γ-haemolysins) and exoenzymes (proteases and lipases). Besides its role in translation, SauS1 could be implicated in other cellular processes such as RNA maturation/degradation and sRNA-mediated regulation. It forms in vivo complexes with several sRNAs whose level is affected in a strain deleted of rpsA gene, coding for S1. Preliminary results show that SauS1 has a chaperone activity promoting the kinetic of annealing of two model RNA molecules and at least in one case, we could demonstrate that it stimulates the recognition between a sRNA and its target RNA. Taken together, SauS1 belongs to a new class of RNA chaperones that play key roles in the regulation of S.aureus virulon.Bien que l'initiation de la traduction soit un processus conservé entre les bactéries, nous avons montré que le mécanisme par lequel les ARNm structurés sont reconnus et adaptés sur le ribosome diffère chez Staphylococcus aureus, un micro-organisme avec un bas taux de G+C et chez Escherichia coli. Une particularité du ribosome de S. aureus est l'absence de la protéine ribosomale S1, qui non seulement est plus courte que celle de E. coli mais qui possède également une organisation distincte des domaines. Mes expériences suggèrent que la protéine S1 (SauS1) favorise spécifiquement l'initiation de la traduction de l'opéron α-psm 1-4 en liant son ARNm hautement structuré. En outre, il influence aussi l'expression et la production de facteurs de virulence comme les exotoxines (α-haemolysine, δ-hémolysine et γ- hémolysine) et les exoenzymes (protéases et lipases). En plus de son rôle dans la traduction, SauS1 pourrait être impliquée dans d'autres processus cellulaires tels que le métabolisme de l'ARN et la régulation par des ARN non-codants (ARNnc). Elle forme des complexes in vivo avec plusieurs ARNnc dont la stabilité serait affectée dans la souche délétée du gène rpsA codant S1. SauS1 a donc une activité chaperonne favorisant la cinétique d’appariement entre deux molécules d'ARN et au moins dans un cas, elle stimule la reconnaissance entre un ARNnc et son ARN cible. Ainsi, SauS1 appartient à une nouvelle classe de chaperons d'ARN qui jouent un rôle clé dans la régulation du virulon de S. aureus

Site-Directed Chemical Probing to map transient RNA/protein interactions

International audienceRNA-protein interactions are at the bases of many biological processes, forming either tight and stable functional ribonucleoprotein (RNP) complexes (i.e. the ribosome) or transitory ones, such as the complexes involving RNA chaperone proteins. To localize the sites where a protein interacts on an RNA molecule, a common simple and inexpensive biochemical method is the footprinting technique. The protein leaves its footprint on the RNA acting as a shield to protect the regions of interaction from chemical modification or cleavages obtained with chemical or enzymatic nucleases. This method has proven its efficiency to study in vitro the organization of stable RNA-protein complexes. Nevertheless, when the protein binds the RNA very dynamically, with high off-rates, protections are very often difficult to observe. For the analysis of these transient complexes, we describe an alternative strategy adapted from the Site Directed Chemical Probing (SDCP) approach and we compare it with classical footprinting. SDCP relies on the modification of the RNA binding protein to tether an RNA probe (usually Fe-EDTA) to specific protein positions. Local cleavages on the regions of interaction can be used to localize the protein and position its domains on the RNA molecule. This method has been used in the past to monitor stable complexes; we provide here a detailed protocol and a practical example of its application to the study of Escherichia coli RNA chaperone protein S1 and its transitory complexes with mRNAs