Inositol-Related Gene Knockouts Mimic Lithium's Effect on Mitochondrial Function

The inositol-depletion hypothesis proposes that lithium attenuates phosphatidylinositol signaling. Knockout (KO) mice of two genes (IMPA1 or Slc5a3), each encoding for a protein related to inositol metabolism, were studied in comparison with lithium-treated mice. Since we previously demonstrated that these KO mice exhibit a lithium-like neurochemical and behavioral phenotype, here we searched for pathways that may mediate lithium''s/the KO effects. We performed a DNA-microarray study searching for pathways affected both by chronic lithium treatment and by the KO of each of the genes. The data were analyzed using three different bioinformatics approaches. We found upregulation of mitochondria-related genes in frontal cortex of lithium-treated, IMPA1 and Slc5a3 KO mice. Three out of seven genes differentially expressed in all three models, Cox5a, Ndufs7, and Ndufab, all members of the mitochondrial electron transfer chain, have previously been associated with bipolar disorder and/or lithium treatment. Upregulation of the expression of these genes was verified by real-time PCR. To further support the link between mitochondrial function and lithium''s effect on behavior, we determined the capacity of chronic low-dose rotenone, a mitochondrial respiratory chain complex I inhibitor, to alter lithium-induced behavior as measured by the forced-swim and the amphetamine-induced hyperlocomotion paradigms. Rontenone treatment counteracted lithium''s effect on behavior, supporting the proposition suggested by the bioinformatics analysis for a mitochondrial function involvement in behavioral effects of lithium mediated by inositol metabolism alterations.The results provide support for the notion that mitochondrial dysfunction is linked to bipolar disorder and can be ameliorated by lithium. The phenotypic similarities between lithium-treated wild-type mice and the two KO models suggest that lithium may affect behavior by altering inositol metabolism.     

A Contemporary 20-Year Cleveland Clinic Experience of Nonbacterial Thrombotic Endocarditis: Etiology,Echocardiographic Imaging,Management, and Outcomes

BackgroundNonbacterial thrombotic endocarditis, or marantic endocarditis, is rare. Contemporary data on the etiology, echocardiographic evaluation, and management of nonbacterial thrombotic endocarditis are limited.MethodsA single-center retrospective cohort study was performed. Electronic medical records and echocardiographic records were searched for patients ages ≥18 years with a confirmed diagnosis of nonbacterial thrombotic endocarditis between January 1999 and November 2019. Demographic, echocardiographic, and management data were collected.ResultsOf 600,577 transthoracic echocardiograms (TTEs) and 89,264 transesophageal echocardiograms (TEEs), 42 patients had nonbacterial thrombotic endocarditis (mean age: 54 ± 14.5 years; 66.7% were female). The median duration of follow-up was 8.2 (interquartile range 3.3-24.4) months. Seventeen patients (40.5%) had malignancy, 33.3% had systemic lupus erythematosus, and 35.7% had antiphospholipid antibody syndrome. Stroke was the most common presentation (59.5%).TTE enabled the diagnosis in 19 cases (45.2%), compared with TEE, which identified the condition in 33 of 34 (97.1%) cases in which it was utilized. Three-dimensional echocardiography was performed in 17 TEEs. The most common valves involved were mitral (61.9%), and aortic (23.8%) valves. Thirty-two patients were managed with anticoagulation. Ten patients underwent surgery. Sixteen (38.1%) patients died, most of whom had a diagnosis of advanced malignancy.ConclusionIn a contemporary 20-year cohort, TTE and TEE played important roles in diagnosis, with superior diagnostic performance of TEE for nonbacterial thrombotic endocarditis. Mortality was high, and advanced malignancy portended a worse prognosis. Management in most cases was therapeutic anticoagulation. In select cases, surgery provided favorable outcomes.     

Chronic Lithium Treatment Enhances the Number of Quiescent Neural Progenitors but Not the Number of DCX-Positive Immature Neurons

Background:

The term adult neurogenesis constitutes a series of developmental steps including the birth, survival, differentiation, maturation, and even death of newborn progenitor cells within neurogenic niches. Within the hippocampus progenitors reside in the neurogenic niche of the subgranular zone in the dentate gyrus subfield. At the different stages, designated type-I, type-IIa, type-IIb, type-III, and granule cell neurons, the cells express a series of markers enabling their identification and visualization. Lithium has been shown to increase hippocampal cell proliferation in the subgranular zone of the hippocampal dentate gyrus subfield of adult rodents and to stimulate the proliferation of hippocampal progenitor cells in vitro, but data regarding lithium’s ability to increase neuronal differentiation and survival is equivocal.

Methods:

To clarify the effect of lithium on adult hippocampal neurogenesis, we identified the effect of chronic lithium treatment on distinct stages of hippocampal progenitor development using adult Nestin-green fluorescent protein transgenic mice and immunofluorescent techniques.

Results:

The present observations confirm that lithium targets the initial stages of progenitor development enhancing the turnover of quiescent neural progenitors/putative stem-cells, corroborating previous reports. However, the enhanced quiescent neural progenitor-turnover does not translate into an increased number of immature neurons. We also observed a steep decline in the number of type-III immature neurons with complex tertiary-dendrites, suggesting that lithium alters the morphological maturation of newborn neurons.

Conclusions:

Our results do not corroborate previous reports of lithium-induced enhanced numbers of newly generated neurons.     

A Qualitative Inquiry About Pruno,an Illicit Alcoholic Beverage Linked to Botulism Outbreaks in United States Prisons

Objectives. Since 2011, 3 outbreaks of botulism in US prisons have been attributed to pruno, which is an alcoholic beverage made by inmates. Following 1 outbreak, we conducted a qualitative inquiry to understand pruno brewing and its social context to inform outbreak prevention measures.Methods. We interviewed staff, inmates, and parolees from 1 prison about pruno production methods, the social aspects of pruno, and strategies for communicating the association between botulism and pruno.Results. Twenty-seven inmates and parolees and 13 staff completed interviews. Pruno is fermented from water, fruit, sugar, and miscellaneous ingredients. Knowledge of pruno making was widespread among inmates; staff were familiar with only the most common ingredients and supplies inmates described. Staff and inmates described inconsistent consequences for pruno possession and suggested using graphic health messages from organizations external to the prison to communicate the risk of botulism from pruno.Conclusions. Pruno making was frequent in this prison. Improved staff recognition of pruno ingredients and supplies might improve detection of brewing activities in this and other prisons. Consistent consequences and clear messages about the association between pruno and botulism might prevent outbreaks.Botulism is a rare but serious illness that can lead to respiratory failure and death. Botulism patients may initially present with blurred or double vision, drooping eyelids, slurred speech, and difficulty swallowing before developing more severe signs and symptoms, such as paralysis and difficulty breathing. In the United States, an average of 145 confirmed botulism cases are reported each year, of which approximately 15% are attributable to foodborne botulism.1 Foodborne botulism is caused by ingestion of botulinum toxin, a bacterial toxin that is produced under the following rarely attained conditions: an anaerobic environment with warm temperatures and low acid, salt, and sugar concentrations.2 Alaska Native foods and home-canned vegetables are the food items most commonly associated with foodborne botulism3,4; however, in the past decade, 5 foodborne botulism outbreaks have been attributed to pruno, an illicit alcoholic beverage made in prisons.5 Pruno was initially recognized as a botulism vehicle after it was implicated in 2 outbreaks in California in 2004 and 2005; these outbreaks resulted in confirmed botulism in 5 inmates, 3 of whom were critically ill and mechanically ventilated.6 No additional outbreaks were reported until 2011, when 8 maximum security inmates in Utah developed botulism after drinking pruno. Three were mechanically ventilated, and most reported persistent symptoms, such as weakness, 11 months after the outbreak.7 The following year, 12 Arizona inmates were sickened in 2 outbreaks of botulism associated with pruno consumption; 8 were mechanically ventilated.5 In all 5 outbreaks, pruno was made with potatoes,5 an uncommon pruno ingredient according to online sources, and a food historically associated with botulism.8,9 Because of these outbreaks, pruno-related botulism accounted for 40% and 48% of foodborne botulism cases in the United States in 2011 and 2012, respectively (Centers for Disease Control and Prevention, unpublished data).Internet sources indicate that pruno is common in US prisons.10–12 Although recent trends suggest future pruno-related botulism outbreaks are likely to occur,5,7 there is a dearth of information about how pruno is made and distributed in prisons, and the social and entrepreneurial aspects of its production and use. To address these gaps and inform botulism outbreak prevention measures, 4 months after the Utah outbreak, we conducted a qualitative inquiry in the affected prison to better understand the brewing process, social context of pruno, and communication strategies for informing inmates about the risk of botulism from pruno.     

Multistage antiplasmodial activity of hydroxyethylamine compounds,in vitro and in vivo evaluations

Malaria, a global threat to the human population, remains a challenge partly due to the fast-growing drug-resistant strains of Plasmodium species. New therapeutics acting against the pathogenic asexual and sexual stages, including liver-stage malarial infection, have now attained more attention in achieving malaria eradication efforts. In this paper, two previously identified potent antiplasmodial hydroxyethylamine (HEA) compounds were investigated for their activity against the malaria parasite''s multiple life stages. The compounds exhibited notable activity against the artemisinin-resistant strain of P. falciparum blood-stage culture with 50% inhibitory concentrations (IC₅₀) in the low micromolar range. The compounds'' cytotoxicity on HEK293, HepG2 and Huh-7 cells exhibited selective killing activity with IC₅₀ values > 170 μM. The in vivo efficacy was studied in mice infected with P. berghei NK65, which showed a significant reduction in the blood parasite load. Notably, the compounds were active against liver-stage infection, mainly compound 1 with an IC₅₀ value of 1.89 μM. Mice infected with P. berghei sporozoites treated with compound 1 at 50 mg kg⁻¹ dose had markedly reduced liver stage infection. Moreover, both compounds prevented ookinete maturation and affected the developmental progression of gametocytes. Further, systematic in silico studies suggested both the compounds have a high affinity towards plasmepsin II with favorable pharmacological properties. Overall, the findings demonstrated that HEA and piperidine possessing compounds have immense potential in treating malarial infection by acting as multistage inhibitors.

Malaria, a global threat to the human population, remains a challenge partly due to the fast-growing drug-resistant strains of Plasmodium species.     

Lithium,Inositol and Mitochondria

Our recent DNA-microarray and proteomics studies searching for pathways affected both by chronic lithium treatment and by knockout of each of two genes (IMPA1 or Slc5a3) encoding for proteins related to inositol metabolism, indicated up-regulation of mitochondria-related genes and autophagy-related proteins in the frontal cortex. Differently from previously reported observations of aberrant mitochondrial function in bipolar patients which leave a causality relationship between mitochondrial dysfunction and bipolar disorder an open question, the behavioral results of our recent report following rotenone treatment tempt us to speculate that mitochondrial dysfunction predisposes manic behavior and that drugs targeted to ameliorate mitochondrial function are potential preventers of bursting manic episodes. However, the promiscuity of the involvement of mitochondrial dysfunction and impaired autophagy in the pathophysiology of psychiatric and neurodegenerative disorders raises questions regarding the credibility and relevance of these findings.     

Lack of lithium-like behavioral and molecular effects in IMPA2 knockout mice.

Lithium is a potent mood-stabilizing medication in bipolar disorder. Despite 50 years of clinical use, the mechanism of action is unknown. Multiple effects have been attributed to lithium including the uncompetitive inhibition of inositol monophosphatase (IMPase). IMPA2, one of the genes that encode IMPase, is located in a region with linkage to bipolar disorder. Owing to the role of IMPase in cell signaling and the possibility that this enzyme is a target for mood-stabilizing drugs, we generated IMPA2(-/-) mice. Possible involvement of IMPase in complex behaviors related to affective disorders was assessed by monitoring the behavior of the IMPA2(-/-) mice in the forced swim test, the tail suspension test (TST), the elevated zero-maze and open field test. It has been described that chronically lithium-treated mice exhibit reduced immobility time in the forced swim test and decreased exploratory behavior. We found increased rearing of IMPA2(-/-) mice in the open field, suggesting an increased exploratory behavior. Although immobility time of IMPA2(-/-) female but not male mice in the forced swim test was reduced, no difference was found between male and female IMPA2(-/-) and IMPA2(+/+) mice in the TST and overall there was no clear effect of the deletion of IMPA2 on depression-like behavior. Frontal cortex IMPase activity and inositol levels in the IMPA2(-/-) mice did not differ from IMPA2(+/+) mice, but kidney inositol levels were reduced. In conclusion, phenotypic characterization of the IMPA2(-/-) mouse indicates that deleting IMPA2 does not mimic the effects of lithium treatment.