Experimental Pulmonary Tuberculosis in the Absence of Detectable Brain Infection Induces Neuroinflammation and Behavioural Abnormalities in Male BALB/c Mice

Polyphyllin II inhibits NLPR3 inflammasome activation and inflammatory response of Mycobacterium tuberculosis-infected human bronchial epithelial cells

BACKGROUND

The bronchial infection by Mycobacterium tuberculosis (Mtb) is increasing in prevalence and severity worldwide. Despite appropriate tuberculosis treatment, most patients still develop bronchial stenosis, which often leads to disability. Polyphyllin II (PP2) is a steroidal saponin extracted from Rhizoma Paridis. In this study, we aimed to explore the effect of PP2 on the advancement of Mtb-induced bronchial infection.

METHOD

The effects of PP2 on cell viability were measured by using MTT and lactate dehydrogenase (LDH) kit. The mRNA and protein levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-8 were elucidated by RT-qPCR and ELISA, respectively. The expression of NLR family pyrin domain containing 3 (NLRP3) related inflammasome (NLRP3, IL-1β, and cleaved-caspase-1) and the activated degree of protein kinase B (AKT)/nuclear factor-kappa B (NF-kB; p-AKT and p-NF-κB) were detected by Western blotting.

RESULTS

PP2 at 0, 1, 5, and 10 μM had little cytotoxicity on 16HBE cells. PP2 inhibited Mtb-induced cell proliferation and decreased LDH levels. We further found that PP2 could suppress Mtb-induced inflammatory responses and activation of NLPR3 inflammasome. Additionally, the role of PP2 in Mtb is associated with the AKT/NF-kB signaling pathway.

CONCLUSION

PP2 inhibited Mtb infection in bronchial epithelial cells, by inhibiting Mtb-induced inflammatory reactions and activation of NLPR3 inflammasome. These effects may be exerted by suppressing the AKT/NF-kB pathway, which will provide a prospective treatment.

Gliosis, misfolded protein aggregation, and neuronal loss in a guinea pig model of pulmonary tuberculosis

Tuberculosis, caused by Mycobacterium tuberculosis infection, is an ongoing epidemic with an estimated ten million active cases of the disease worldwide. Pulmonary tuberculosis is associated with cognitive and memory deficits, and patients with this disease are at an increased risk for Parkinson's disease and dementia. Although epidemiological data correlates neurological effects with peripheral disease, the pathology in the central nervous system is unknown. In an established guinea pig model of low-dose, aerosolized Mycobacterium tuberculosis infection, we see behavior changes and memory loss in infected animals. We correlate these findings with pathological changes within brain regions related to motor, cognition, and sensation across disease progression. This includes microglial and astrocytic proliferation and reactivity. These cellular changes are followed by the aggregation of neurotoxic amyloid β and phosphorylated tau and, ultimately, neuronal degeneration in the hippocampus. Through these data, we have obtained a greater understanding of the neuropathological effects of a peripheral disease that affects millions of persons worldwide.

Regional homogeneity alterations in multifrequency bands in patients with extracranial multi-organ tuberculosis: a prospective cross-sectional study

Background

This study aimed to clarify the spontaneous neural activity in the conventional frequency band (0.01-0.08 Hz) and 2 subfrequency bands (slow-4: 0.027-0.073 Hz; slow-5: 0.01-0.027 Hz) in patients with extracranial multi-organ tuberculosis (EMTB) through regional homogeneity (ReHo) analysis.

Methods

In all, 32 patients with EMTB and 31 healthy controls (HCs) were assessed by resting-state functional magnetic resonance imaging (rs-fMRI) scans to clarify the abnormal spontaneous neural activity through ReHo analysis in the conventional frequency band and 2 subfrequency bands.

Results

Compared with the HCs, the patients with EMTB exhibited decreased ReHo in the left postcentral gyrus [t=-4.79; 95% confidence interval (CI): -0.79 to -0.31] and the left superior cerebellum (t=-4.45; 95% CI: -0.54 to -0.21) in the conventional band. Conversely, increased ReHo was observed in the right middle occipital gyrus (t=3.94; 95% CI: 0.18-0.53). In the slow-4 band, patients with EMTB only exhibited decreased ReHo in the superior cerebellum (t=-4.69; 95% CI: -0.54 to -0.22); meanwhile, in the slow-5 band, these patients exhibited decreased ReHo in the right postcentral gyrus (t=-3.76; 95% CI: -0.74 to -0.21) and the left superior cerebellum (t=-5.20, 95% CI: -0.72 to -0.31). After Bonferroni correction, no significant correlation was observed between the ReHo values in clusters showing significant between-group differences and cognitive test scores.

Conclusions

ReHo showed abnormal synchronous neural activity in patients with EMTB in different frequency bands, which provides a novel understanding of the pathological mechanism of EMTB.

New Drugs and Novel Cellular Targets against Tuberculosis

Mycobacterium tuberculosis (Mtb) is the etiological agent of tuberculosis (TB), one of the most life-threatening communicable diseases, which causes 10 million new cases each year and results in an estimated 1 [...].

Mycobacterium tuberculosis Infection Induces BCSFB Disruption but No BBB Disruption In Vivo: Implications in the Pathophysiology of Tuberculous Meningitis

Central nervous system (CNS) tuberculosis is the most lethal and devastating form among the diseases caused by Mycobacterium tuberculosis. The mechanisms by which M. tuberculosis bacilli enter the CNS are still unclear. However, the BBB and the BCSFB have been proposed as possible routes of access into the brain. We previously reported that certain strains of M. tuberculosis possess an enhanced ability to cause secondary CNS infection in a mouse model of progressive pulmonary tuberculosis. Here, we evaluated the morphostructural and molecular integrity of CNS barriers. For this purpose, we analyzed through transmission electron microscopy the ultrastructure of brain parenchymal microvessels and choroid plexus epithelium from animals infected with two mycobacterial strains. Additionally, we determined the expression of junctional proteins and cytokines by immunological techniques. The results showed that the presence of M. tuberculosis induced disruption of the BCSFB but no disruption of the BBB, and that the severity of such damage was related to the strain used, suggesting that variations in the ability to cause CNS disease among distinct strains of bacteria may also be linked to their capacity to cause direct or indirect disruption of these barriers. Understanding the pathophysiological mechanisms involved in CNS tuberculosis may facilitate the establishment of new biomarkers and therapeutic targets.

Development of Anxiolytic and Depression-like Behavior in Mice Infected with Mycobacterium lepraemurium

Murine leprosy is a systemic infectious disease of mice caused by Mycobacterium lepraemurium (MLM) in which the central nervous system (CNS) is not infected; nevertheless, diseased animals show measurable cognitive alterations. For this reason, in this study, we explored the neurobehavioral changes in mice chronically infected with MLM. BALB/c mice were infected with MLM, and 120 days later, the alterations in mice were evaluated based on immunologic, histologic, endocrine, neurochemical, and behavioral traits. We found increases in the levels of IL-4 and IL-10 associated with high bacillary loads. We also found increase in the serum levels of corticosterone, epinephrine, and norepinephrine in the adrenal gland, suggesting neuroendocrine deregulation. Mice exhibited depression-like behavior in the tail suspension and forced swimming tests and anxiolytic behavior in the open field and elevated plus maze tests. The neurobehavioral alterations of mice were correlated with the histologic damage in the prefrontal cortex, ventral hippocampus, and amygdala, as well as with a blood-brain barrier disruption in the hippocampus. These results reveal an interrelated response of the neuroimmune-endocrinological axis in unresolved chronic infections that result in neurocognitive deterioration.

Effect of Curcumin in Experimental Pulmonary Tuberculosis: Antimycobacterial Activity in the Lungs and Anti-Inflammatory Effect in the Brain

Tuberculosis (TB) is one of the ten leading causes of death worldwide. Patients with TB have been observed to suffer from depression and anxiety linked to social variables. Previous experiments found that the substantial pulmonary inflammation associated with TB causes neuroinflammation, neuronal death, and behavioral impairments in the absence of brain infection. Curcumin (CUR) is a natural product with antioxidant, anti-inflammatory and antibacterial activities. In this work, we evaluated the CUR effect on the growth control of mycobacteria in the lungs and the anti-inflammatory effect in the brain using a model of progressive pulmonary TB in BALB/c mice infected with drug-sensitive mycobacteria (strain H37Rv). The results have shown that CUR decreased lung bacilli load and pneumonia of infected animals. Finally, CUR significantly decreased neuroinflammation (expression of TNFα, IFNγ and IL12) and slightly increased the levels of nuclear factor erythroid 2-related to factor 2 (Nrf2) and the brain-derived neurotrophic factor (BDNF) levels, improving behavioral status. These results suggest that CUR has a bactericidal effect and can control pulmonary mycobacterial infection and reduce neuroinflammation. It seems that CUR has a promising potential as adjuvant therapy in TB treatment.

Effect of Big Data Analysis-Based Remote Management Combined with Yangyin Runfei Decoction on Coagulation Function, Pulmonary Function, and Quality of Life of Pulmonary Tuberculosis Patients

Objective

To explore the effect of big data analysis-based remote management combined with Yangyin Runfei decoction on coagulation function, pulmonary function, and quality of life (QOL) of pulmonary tuberculosis (PTB) patients.

Methods

A total of 90 PTB patients treated in our hospital from May 2019 to May 2020 were selected as the subjects and divided into the experimental group (EG) and control group (CG) according to their admission order, with 45 cases each. Patients in CG accepted routine management and treatments and those in EG received big data analysis-based remote management combined with Yangyin Runfei decoction, so as to compare the clinical indicators between the two groups.

Results

Compared with CG after treatment, EG presented an obviously higher total clinical effective rate, various pulmonary function indicators, and GQOLI-74 score (P < 0.001) and significantly lower various coagulation indicators and inflammatory factor indicators (P < 0.001).

Conclusion

Performing big data analysis-based remote management combined with Yangyin Runfei decoction to PTB patients can effectively improve their QOL and pulmonary function and present a higher application value compared to routine management and treatments. Further research will be conducive to establishing a better solution for patients. This trial is registered with Clinical Study Registration Number: https://clinicaltrials.gov/ct2/show/ChiCTR2200057257.

Increased survival in puppies affected by Canine Parvovirus type II using an immunomodulator as a therapeutic aid

Canine parvovirus type II (CPV-2) infection induces canine parvoviral enteritis (CPE), which in turn promotes sepsis and systemic inflammatory response syndrome (SIRS). Mortality in this disease is usually registered within 48-72 h post-hospitalization, the critical period of the illness. It has been recently described that the use of an immunomodulator, whose major component is monomeric ubiquitin (mUb) without the last two glycine residues (Ub∆GG), in pediatric human patients with sepsis augments survival. It is known that CXCR4 is the cell receptor of extracellular ubiquitin in humans. This work aimed to explore the effect of one immunomodulator (human Dialyzable Leukocyte Extract-hDLE) as a therapeutic auxiliary in puppies with sepsis and SIRS induced by CPE. We studied two groups of puppies with CPV-2 infection confirmed by polymerase chain reaction. The first group received conventional treatment (CT) and vehicle (V), while the second group received CT plus the immunomodulator (I). We assessed both groups' survival, clinical condition, number of erythrocytes, neutrophils, and lymphocytes during the hospitalization period. In addition, hematocrit, hemoglobin, plasma proteins and cortisol values, as well as norepinephrine/epinephrine and serotonin concentration were determined. Puppies treated with CT + I showed 81% survival, mild clinical signs, and a significant decrease in circulating neutrophils and lymphocytes in the critical period of the treatment. In contrast, the CT + V group presented a survival of 42%, severe clinical status, and no improvement of the parameters evaluated in the critical period of the disease. We determined in silico that human Ub∆GG can bind to dog CXCR4. In conclusion, the administration of a human immunomodulator (0.5 mg/day × 5 days) to puppies with CPE under six months of age reduces the severity of clinical signs, increases survival, and modulates inflammatory cell parameters. Further studies are necessary to take full advantage of these clinical findings, which might be mediated by the human Ub∆GG to canine CXCR4 interaction.

Behavioral and Neurochemical Shifts at the Hippocampus and Frontal Cortex Are Associated to Peripheral Inflammation in Balb/c Mice Infected with Brucella abortus 2308

Brucellosis is a zoonosis affecting 50,000,000 people annually. Most patients progress to a chronic phase of the disease in which neuropsychiatric symptoms upsurge. The biological processes underlying the progression of these symptoms are yet unclear. Peripheral inflammation mounted against Brucella may condition neurochemical shifts and hence unchained neuropsychiatric disorders. Our work aimed at establishing whether neurological, behavioral, and neurochemical disarrays are circumstantially linked to peripheral inflammation uprise secondary to Brucella abortus 2308 infections. We then evaluated, in control and Brucella-infected mice, skeletal muscle strength, movement coordination, and balance and motivation, as well as dopamine, epinephrine, norepinephrine, and serotonin availability in the cerebellum, frontal cortex, and hippocampus. Serum levels of proinflammatory cytokines and corticosterone in vehicle-injected and -infected mice were also estimated. All estimates were gathered at the infection acute and chronic phases. Our results showed that infected mice displayed motor disabilities, muscular weakness, and reduced motivation correlated with neurochemical and peripheral immunological disturbances that tended to decrease after 21 days of infection. The present observations support that disturbed peripheral inflammation and the related neurochemical disruption might lead to mood disorders in infected mice. Future experiments must be aimed at establishing causal links and to explore whether similar concepts might explain neurological and mood disorders in humans affected by brucellosis.

The Therapeutic Effect of Intranasal Administration of Dexamethasone in Neuroinflammation Induced by Experimental Pulmonary Tuberculosis

Tuberculosis (TB) is an important infectious disease and a public health problem. The organs most frequently affected by TB are the lungs; despite this, it has been reported that TB patients suffer from depression and anxiety, which have been attributed to social factors. In previous experimental work, we observed that the extensive pulmonary inflammation characteristic of TB with high cytokine production induces neuroinflammation, neuronal death and behavioral abnormalities in the absence of brain infection. The objective of the present work was to reduce this neuroinflammation and avoid the psycho-affective disorders showed during pulmonary TB. Glucocorticoids (GCs) are the first-line treatment for neuroinflammation; however, their systemic administration generates various side effects, mostly aggravating pulmonary TB due to immunosuppression of cellular immunity. Intranasal administration is a route that allows drugs to be released directly in the brain through the olfactory nerve, reducing their doses and side effects. In the present work, dexamethasone’s (DEX) intranasal administration was evaluated in TB BALB /c mice comparing three different doses (0.05, 0.25 and 2.5 mg/kg BW) on lung disease evolution, neuroinflammation and behavioral alterations. Low doses of dexamethasone significantly decreased neuroinflammation, improving behavioral status without aggravating lung disease.

A Preliminary Investigation on Plasma Cell Adhesion Molecules Levels by Protein Microarray Technology in Major Depressive Disorder

Objectives: Major depressive disorder (MDD) is a serious mental disorder, and there is a great difficulty to diagnose and treat. Hitherto, relatively few studies have explored the correlation between the levels of plasma cell adhesion molecules and MDD. Methods: Thirty outpatients with acute episodes of MDD in Shanghai Mental Health Center and 34 healthy volunteers from the community were recruited as subjects. Protein microarray technology was applied to compared the differences in plasma levels of 17 kinds of adhesion molecular proteins between the two groups. Meanwhile, the diagnostic value of different proteins in depression was discussed by using the receiver operating characteristic curve. Results: The levels of Carcinoembryonic Antigen Related Cell Adhesion Molecule-1(CEACAM-1) and Neural Cell Adhesion Molecule (NrCAM) in MDD patients were significantly higher than those in healthy controls (P < 0.05). The area under ROC curve of CEACAM-1 combined with NrCAM was 0.723, with the sensitivity 0.800 and the specificity 0.676. Conclusion: The plasma levels of CEACAM-1 and NrCAM were significantly up-regulated in MDD, and their combined application was of potential diagnostic value, deserving to expand the sample size for further verification.