Peripheral endocannabinoids in major depressive disorder and alcohol use disorder: a systematic review.

BACKGROUND: Major Depressive Disorder (MDD) and Alcohol Use Disorder (AUD) are two high-prevalent conditions where the Endocannabinoid system (ECS) is believed to play an important role. The ECS regulates how different neurotransmitters interact in both disorders, which is crucial for controlling emotions and responses to stress and reward stimuli. Measuring peripheral endocannabinoids (eCBs) in human serum and plasma can help overcome the limitations of detecting endocannabinoid levels in the brain. This systematic review aims to identify levels of peripheral eCBs in patients with MDD and/or AUD and find eCBs to use as diagnostic, prognostic biomarkers, and potential therapeutic targets. METHODS: We conducted a systematic literature search according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines from the earliest manuscript until October 22, 2023, in three electronic databases. We included studies of human adults who had a current diagnosis of AUD and/or MDD and evaluated plasma or serum endocannabinoids. We carefully considered known variables that may affect endocannabinoid levels. RESULTS: We included 17 articles in this systematic review, which measured peripheral eCBs in 170 AUD and 359 MDD patients. Stressors increase peripheral 2-arachidonyl-glycerol (2-AG) concentrations, and 2-AG may be a particular feature of depression severity and chronicity. Anxiety symptoms are negatively correlated with anandamide (AEA) concentrations, and AEA significantly increases during early abstinence in AUD. Studies suggest a negative correlation between Oleoylethanolamide (OEA) and length of abstinence in AUD patients. They also show a significant negative correlation between peripheral levels of AEA and OEA and fatty acid amide hydrolase (FAAH) activity. Eicosapentaenoylethanolamide (EPEA) is correlated to clinical remission rates in depression. Included studies show known variables such as gender, chronicity, symptom severity, comorbid psychiatric symptoms, length of abstinence in the case of AUD, and stress-inducibility that can affect peripheral eCBs. CONCLUSIONS: This systematic review highlights the important role that the ECS plays in MDD and AUD. Peripheral eCBs appear to be useful biomarkers for these disorders, and further research may identify potential therapeutic targets. Using accessible biological samples such as blood in well-designed clinical studies is crucial to develop novel therapies for these disorders.

Effects of atrazine on ovarian growth, in the estuarine crab Neohelice granulata.

Atrazine, a herbicide that is intensively used in Argentina, was assayed to evaluate the alteration of reproduction in a wild species of crustaceans. Adult females of the estuarine crab Neohelice granulata were exposed to formulated atrazine during the 3-month pre-reproductive period. Three atrazine concentrations (0.03, 0.3 and 3mg/L) were assayed, together with a water dilution control. At the end of the exposure period, several variables concerning the energetic status of animals were measured, such as weight gain, glycemia, and energy reserves in both muscle and hepatopancreas. The gonadosomatic index (GSI) was also determined, as well as the proportion and relative area of each oocyte type in histological sections. Besides, the total content of vitellogenin proteins (Vg) in both ovary and hepatopancreas was measured. A significant (p<0.05) decrease of glycogen content was observed in muscle, while a significant (p<0.05) lower area of both previtellogenic and vitellogenic oocytes was verified in the ovary by effect of atrazine, in correspondence with a Vg content significantly (p<0.05) diminished in the ovary and augmented in the hepatopancreas. Besides, a higher proportion of previtellogenic oocytes were seen by effect of atrazine. Taken together, these results indicate a clear reduction and delay in the ovarian growth of the studied species, during the period at which the ovary normally grows up prior to spawning. On the other hand, a decrease of Vg content was observed at 0.3 and 3mg/L of atrazine after 24-h in vitro assays carried out with ovarian explants, providing additional evidence about the inhibitory role of this herbicide on the ovarian growth. These results encourage future research on deleterious effects of atrazine on crustacean reproduction.

Site-specific recombination in gram-positive theta-replicating plasmids.

This review summarises current information on the site-specific recombinases encoded by the plasmids of the Gram-positive bacteria that have low guanine and cytosine content in their DNA. It focuses on the peculiar biological features of the recombination systems encoded by the theta-replicating plasmids and compares them with the site-specific recombinases encoded by transposons or plasmids originally isolated from Gram-negative bacteria.

Role of the alternative sigma factor sigmaS in expression of the AlkS regulator of the Pseudomonas oleovorans alkane degradation pathway.

The AlkS protein activates transcription from the PalkB promoter, allowing the expression of a number of genes required for the assimilation of alkanes in Pseudomonas oleovorans. We have identified the promoter from which the alkS gene is transcribed, PalkS, and analyzed its expression under different conditions and genetic backgrounds. Transcription from PalkS was very low during the exponential phase of growth and increased considerably when cells reached the stationary phase. The PalkS -10 region was similar to the consensus described for promoters recognized by Escherichia coli RNA polymerase bound to the alternative sigma factor sigmaS, which directs the expression of many stationary-phase genes. Reporter strains containing PalkS-lacZ transcriptional fusions showed that PalkS promoter is very weakly expressed in a Pseudomonas putida strain bearing an inactivated allele of the gene coding for sigmaS, rpoS. When PalkS was transferred to E. coli, transcription started at the same site and expression was higher in stationary phase only if sigmaS-RNA polymerase was present. The low levels of AlkS protein generated in the absence of sigmaS were enough to support a partial induction of the PalkB promoter. The -10 and -35 regions of PalkS promoter also show some similarity to the consensus recognized by sigmaD-RNA polymerase, the primary form of RNA polymerase. We propose that in exponential phase PalkS is probably recognized both by sigmaD-RNA polymerase (inefficiently) and by sigmaS-RNA polymerase (present at low levels), leading to low-level expression of the alkS gene. sigmaS-RNA polymerase would be responsible for the high level of activity of PalkS observed in stationary phase.

Carbon-source-dependent expression of the PalkB promoter from the Pseudomonas oleovorans alkane degradation pathway.

Pseudomonas oleovorans GPo1 can metabolize medium-chain-length alkanes by means of an enzymatic system whose induction is regulated by the AlkS protein. In the presence of alkanes, AlkS activates the expression of promoter PalkB, from which most of the genes of the pathway are transcribed. In addition, expression of the first enzyme of the pathway, alkane hydroxylase, is known to be influenced by the carbon source present in the growth medium, indicating the existence of an additional overimposed level of regulation associating expression of the alk genes with the metabolic status of the cell. Reporter strains bearing PalkB-lacZ transcriptional fusions were constructed to analyze the influence of the carbon source on induction of the PalkB promoter by a nonmetabolizable inducer. Expression was most efficient when cells grew at the expense of citrate, decreasing significantly when the carbon source was lactate or succinate. When cells were grown in Luria-Bertani rich medium, PalkB was strongly down-regulated. This effect was partially relieved when multiple copies of the gene coding for the AlkS activator were present and was not observed when the promoter was moved to Escherichia coli, a heterologous genetic background. Possible mechanisms responsible for PalkB regulation are discussed.

Site-specific recombination by the beta protein from the streptococcal plasmid pSM19035: minimal recombination sequences and crossing over site.

The beta recombinase from the broad host range Grampositive plasmid pSM19035 catalyzes intramolecular site-specific recombination between two directly or inversely oriented recombination sites in the presence of a chromatin-associated protein (Hbsu). The recombination site had been localized to a 447 bp DNA segment from pSM19035. This segment includes a 90 bp region that contains two adjacent binding sites (I and II) for beta protein dimers. Using in vitro recombination assays, we show that this 90 bp region is necessary and sufficient for beta protein-mediated recombination; this defines the six site as the region required for beta protein binding. The point of crossing over has been localized to the center of site I. Hbsu has a strong binding affinity for an unknown site located within the 447 bp segment containing the six site. We discuss the possibility that Hbsu recognizes an altered DNA structure, rather than a specific sequence, generated in the synaptic complex.

beta Recombinase catalyzes inversion and resolution between two inversely oriented six sites on a supercoiled DNA substrate and only inversion on relaxed or linear substrates.

The beta recombinase, in the presence of a chromatin-associated protein such as Hbsu, catalyzes DNA resolution or DNA inversion on supercoiled substrates containing two directly or inversely oriented six sites. Hbsu stabilizes the formation of the recombination complex (Alonso, J. C., Weise, F., and Rojo, F. (1995) J. Biol. Chem. 270, 2938-2945). In this study we show that resolution by beta recombinase strictly requires supercoiled DNA, but inversion does not. On a substrate with two inversely oriented six sites, beta recombinase catalyzed both resolution and inversion if the DNA was supercoiled but only inversion if the substrate was relaxed or linear. Hbsu was critical for the formation of synaptic complexes; its concentration relative to that of the supercoiled DNA substrate determined whether resolution or inversion products were preferentially formed. The results suggest that the beta recombinase forms unproductive short-lived synaptic complexes between two juxtaposed inversely oriented six sites; the presence of 3 to 13 Hbsu dimers per supercoiled DNA molecule would stabilize a synaptic complex with a relative geometry of the six sites allowing beta recombinase preferentially to achieve resolution. Supercoiling probably helps to overcome an energetic barrier, since resolution does not occur in relaxed DNA. The presence of >30 Hbsu dimers per DNA molecule probably favors the formation of a recombination complex with a different geometry since the reaction is directed preferentially toward DNA inversion.

Mutational analysis of a site-specific recombinase: characterization of the catalytic and dimerization domains of the beta recombinase of pSM19035.

The beta recombinase encoded by the streptococcal plasmid pSM19035, which shows 28 to 34% identity with DNA resolvases and DNA invertases, can catalyze formation of deletions or inversions between properly oriented target sites. We have constructed a number of site-directed mutations at residues that are conserved between the beta protein and other DNA recombinases of the resolvase/invertase family. The analysis of the recombination and DNA-binding ability of each mutant protein shows that the mutations affect the catalytic activity and, in two cases, the dimerization of the protein. The results suggest that the beta protein probably mediates recombination by a catalytic mechanism similar to that proposed for the resolvase/invertase family. Since the beta recombinase differs from DNA resolvases and DNA invertases in its lack of bias towards either of these reactions, the results presented support the hypothesis that its unique properties might depend on details of the architecture or assembly of the recombination complex. In addition, two beta protein mutants that can no longer form dimers in solution have provided new insights into the way the protein binds to DNA.

Dislocation of the shoulder with ipsilateral humeral shaft fracture.

Dislocation of the shoulder with ipsilateral shaft fracture is an uncommon, but serious injury. I present one case report and the guidelines used for treatment. The method employed was Hackethal's pins through open reduction. The dislocation was reduced during surgery. The fracture and dislocation healed without any problems, and there was no damage to the radial nerve. After a recent follow-up, the patient was allowed to return to work without restrictions, and he has regained normal mobility.

A positive feedback mechanism controls expression of AlkS, the transcriptional regulator of the Pseudomonas oleovorans alkane degradation pathway.

The AlkS regulator, encoded by the alkS gene of the Pseudomonas oleovorans OCT plasmid, activates the expression of a set of enzymes that allow assimilation of alkanes. We show that the AlkS protein regulates, both negatively and positively, the expression of its own gene. In the absence of alkanes, alkS is expressed from promoter PalkS1, which is recognized by sigmaS-RNA polymerase, and whose activity is very low in the exponential phase of growth and considerably higher in stationary phase. AlkS was found to downregulate this promoter, limiting expression of alkS in stationary phase when alkanes were absent. In the presence of alkanes, AlkS repressed PalkS1 more strongly and simultaneously activated a second promoter for alkS, named PalkS2, located 38 bp downstream from PalkS1. Activation of PalkS2 allowed efficient transcription of alkS when alkanes were present. Transcription from PalkS2 was modulated by catabolite repression when cells were provided with a preferred carbon source. We propose that the expression of alkS is regulated by a positive feedback mechanism, which leads to a rapid increase in alkS transcription when alkanes are present. This mechanism should allow a rapid induction of the pathway, as well as a fast switch-off when alkanes are depleted. An improved model for the regulation of the pathway is proposed.