Kaempferol Treatment after Traumatic Brain Injury during Early Development Mitigates Brain Parenchymal Microstructure and Neural Functional Connectivity Deterioration at Adolescence

Targeting mitochondrial ion homeostasis using Kaempferol, a mitochondrial Ca2+ uniporter channel activator, improves energy metabolism and behavior soon after a traumatic brain injury (TBI) in developing rats. Because of broad TBI pathophysiology and brain mitochondrial heterogeneity, Kaempferol-mediated early-stage behavioral and brain metabolic benefits may accrue from diverse sources within the brain. We hypothesized that Kaempferol influences TBI outcome by differentially impacting the neural, vascular, and synaptic/axonal compartments. After TBI at early development (P31), functional magnetic resonance imaging and diffusion tensor imaging (DTI) were applied to determine imaging outcomes at adolescence (2 months post-injury). Vehicle and Kaempferol treatments were made at 1, 24, and 48 h post-TBI, and their effects were assessed at adolescence. A significant increase in neural connectivity was observed after Kaempferol treatment as assessed by the spatial extent and strength of the somatosensory cortical and hippocampal resting-state functional connectivity (RSFC) networks. However, no significant RSFC changes were observed in the thalamus. DTI measures of fractional anisotropy (FA) and apparent diffusion coefficient, representing synaptic/axonal and microstructural integrity, showed significant improvements after Kaempferol treatment, with highest changes in the frontal and parietal cortices and hippocampus. Kaempferol treatment also increased corpus callosal FA, indicating measurable improvement in the interhemispheric structural connectivity. TBI prognosis was significantly altered at adolescence by early Kaempferol treatment, with improved neural connectivity, neurovascular coupling, and parenchymal microstructure in select brain regions. However, Kaempferol failed to improve vasomotive function across the whole brain, as measured by cerebrovascular reactivity. The differential effects of Kaempferol treatment on various brain functional compartments support diverse cellular-level mitochondrial functional outcomes in vivo.

Intranasal instillation of distilled water, hypertonic saline and sodium bicarbonate promotes redox imbalance and acute lung inflammation in adult mice

Bronchial obstruction, caused by retained secretions, is often treated by the administration of mucoactive agents including distilled water, saline, hypertonic saline, and sodium bicarbonate. However, the inflammatory effect of these solutions on the lungs remains unclear. This study evaluated the instillation effects of different solutions on oxidative stress and lung inflammatory response in C57BL/6 mice. Fifty C57BL/6 mice were divided into 5 groups: control (CG); distilled water (DWG), hypertonic saline (HSG), saline (SG) and sodium bicarbonate (SBG). CG was exposed to ambient air while DWG, HSG, SG and SBG had 50 μl of respective solutions administered intranasally for 5 consecutive days. Twenty-four hours after the last intranasal instillation, all animals were euthanized for subsequent analysis. All solutions promoted increased recruitment of inflammatory cells to the lung compared to controls. Superoxide dismutase activity was lower in HSG compared to all other groups; catalase activity was reduced in SG, while it increased in SBG and DWG compared to CG. Finally, there was an increase in the inflammatory markers TNF-α, CCL2 and IFN-γ in DWG compared to CG, SG and HSG. In conclusions, the intranasal instillation of different solutions promotes redox imbalance and inflammation on lungs of adult mice.

Vesicular acetylcholine transport deficiency potentiates some inflammatory responses induced by diesel exhaust particles

Endogenous acetylcholine (ACh), which depends of the levels of vesicular ACh transport (VAChT) to be released, is the central mediator of the cholinergic anti-inflammatory system. ACh controls the release of cytokine in different models of inflammation. Diesel exhaust particles (DEP) are one of the major environmental pollutants produced in large quantity by automotive engines in urban center. DEP bind the lung parenchyma and induce inflammation. We evaluated whether cholinergic dysfunction worsens DEP-induced lung inflammation. Male mice with decreased ACh release due to reduced expression of VAChT (VAChT-KD mice) were submitted to DEP exposure for 30 days (3 mg/mL of DEP, once a day, five days a week) or saline. Pulmonary function and inflammation as well as extracellular matrix fiber deposition were evaluated. Additionally, airway and nasal epithelial mucus production were quantified. We found that DEP instillation worsened lung function and increased lung inflammation. Higher levels of mononuclear cells were observed in the peripheral blood of both wild-type (WT) and VAChT-KD mice. Also, both wild-type (WT) and VAChT-KD mice showed an increase in macrophages in bronchoalveolar lavage fluid (BALF) as well as increased expression of IL-4, IL-6, IL-13, TNF-α, and NF-κB in lung cells. The collagen fiber content in alveolar septa was also increased in both genotypes. On the other hand, we observed that granulocytes were increased only in VAChT-KD peripheral blood. Likewise, increased BALF lymphocytes and neutrophils as well as increased elastic fibers in alveolar septa, airway neutral mucus, and nasal epithelia acid mucus were observed only in VAChT-KD mice. The cytokines IL-4 and TNF-α were also higher in VAChT-KD mice compared with WT mice. In conclusion, decreased ability to release ACh exacerbates some of the lung alterations induced by DEP in mice, suggesting that VAChT-KD animals are more vulnerable to the effects of DEP in the lung.

Semi-Mechanistic Population Pharmacokinetic Modeling of L-Histidine Disposition and Brain Uptake in Wildtype and Pht1 Null Mice

PURPOSE

To develop a semi-mechanistic population pharmacokinetic (PK) model to quantitate the disposition kinetics of L-histidine, a peptide-histidine transporter 1 (PHT1) substrate, in the plasma, cerebrospinal fluid and brain parenchyma of wildtype (WT) and Pht1 knockout (KO) mice.

METHODS

L-[¹⁴C]Hisidine (L-His) was administrated to WT and KO mice via tail vein injection, after which plasma, cerebrospinal fluid (CSF) and brain parenchyma samples were collected. A PK model was developed using non-linear mixed effects modeling (NONMEM). The disposition of L-His between the plasma, brain, and CSF was described by a combination of PHT1-mediated uptake, CSF bulk flow and first-order micro-rate constants.

RESULTS

The PK profile of L-His was best described by a four-compartment model. A more rapid uptake of L-His in brain parenchyma was observed in WT mice due to PHT1-mediated uptake, a process characterized by a Michaelis-Menten component (V_max = 0.051 nmoL/min and K_m = 34.94 μM).

CONCLUSIONS

A semi-mechanistic population PK model was successfully developed, for the first time, to quantitatively characterize the disposition kinetics of L-His in brain under in vivo conditions. This model may prove a useful tool in predicting the uptake of L-His, and possibly other PHT1 peptide/mimetic substrates, for drug delivery to the brain.

Impact of NKT Cells and LFA-1 on Liver Regeneration under Subseptic Conditions

Background

Activation of the immune system in terms of subseptic conditions during liver regeneration is of paramount clinical importance. However, little is known about molecular mechanisms and their mediators that control hepatocyte proliferation. We sought to determine the functional role of immune cells, especially NKT cells, in response to partial hepatectomy (PH), and to uncover the impact of the integrin lymphocyte function-associated antigen-1 (LFA-1) on liver regeneration in a subseptic setting.

Methods

Wild-type (WT) and LFA-1^-/- mice underwent a 2/3 PH and low-dose lipopolysaccharid (LPS) application. Hepatocyte proliferation, immune cell infiltration, and cytokine profile in the liver parenchyma were determined.

Results

Low-dose LPS application after PH results in a significant delay of liver regeneration between 48h and 72h, which is associated with a reduced number of CD3⁺ cells within the regenerating liver. In absence of LFA-1, an impaired regenerative capacity was observed under low-dose LPS application. Analysis of different leukocyte subpopulations showed less CD3⁺NK1.1⁺ NKT cells in the liver parenchyma of LFA-1^-/- mice after PH and LPS application compared to WT controls, while CD3^-NK1.1⁺ NK cells markedly increased. Concordantly with this observation, lower levels of NKT cell related cytokines IL-12 and IL-23 were expressed in the regenerating liver of LFA-1^-/- mice, while the expression of NK cell-associated CCL5 and IL-10 was increased compared to WT mice.

Conclusion

A subseptic situation negatively alters hepatocyte proliferation. Within this scenario, we suggest an important impact of NKT cells and postulate a critical function for LFA-1 during processes of liver regeneration.

Natural carcinogenic fiber and pleural plaques assessment in a general population: A cross-sectional study

Natural carcinogenic fibers are asbestos and asbestiform fibers present as a natural component of soils or rocks. These fibers are released into the environment resulting in exposure of the general population. Environmental contamination by fibers are those cases occurred in: rural regions of Turkey, in Mediterranean countries and in other sites of the world, including northern Europe, USA and China. Fluoro-edenite(FE) is a natural mineral species first isolated in Biancavilla, Sicily. The fibers are similar in size and morphology to some amphibolic asbestos fibers, whose inhalation can cause chronic inflammation and cancer. The aim of the current study is to assess the presence and features of pleural plaques (PPs) in Biancavilla's general population exposed to FE through a retrospective cross-sectional study. All High-Resolution Computed Tomography (HRCT) chest scans carried out between June 2009 and June 2015 in Biancavilla municipality hospital site (exposed subjects) were reviewed. The exposed groups were 1:1 subjects, matched according to age and sex distributions, with unexposed subjects (n.1.240) randomly selected among HRCT chest scans carried out in a Hospital 30km away from Biancavilla. Subjects from Biancavilla with PPs were significantly more numerous than the control group ones (218 vs 38). Average age of either group was >60 years; the age of exposed subjects was significantly (p=0.0312) lesser than the unexposed group. In exposed subjects, in most PPs thickness ranged between 2 and 4.9cm(38%, n=83); while in unexposed ones PPs thickness was less than 2cm (55%, n=21). As to the size of PPs in exposed subjects, in most cases it ranged between 1cm and 24% of chest wall (53%, n=116); while in unexposed ones the size of PPs was lesser than 1cm (23%, n=58). Among exposed subjects, 36 cases (17%) PPs were detected with calcification, whereas in unexposed ones only three (8%) presented calcification. 137 lung parenchymal abnormalities were observed in exposed group; whereas, 12 lung parenchymal involvement were registered in unexposed subjects. The RR for PPs is 6,74 CI 95% (4,47-9,58) p<0,0001 in the exposed population. These findings, suggested the urge to extend the screening on the possible involvement of the respiratory tract to all Biancavilla's population, particularly in those aged more than 30. Besides, it seems essential to start indoor monitoring Biancavilla's municipality.