Nandrolone Supplementation Promotes AMPK Activation and Divergent 18[FDG] PET Brain Connectivity in Adult and Aged Mice.

Decreased anabolic androgen levels are followed by impaired brain energy support and sensing with loss of neural connectivity during physiological aging, providing a neurobiological basis for hormone supplementation. Here, we investigated whether nandrolone decanoate (ND) administration mediates hypothalamic AMPK activation and glucose metabolism, thus affecting metabolic connectivity in brain areas of adult and aged mice. Metabolic interconnected brain areas of rodents can be detected by positron emission tomography using 18FDG-mPET. Albino CF1 mice at 3 and 18 months of age were separated into 4 groups that received daily subcutaneous injections of either ND (15 mg/kg) or vehicle for 15 days. At the in vivo baseline and on the 14th day, brain 18FDG-microPET scans were performed. Hypothalamic pAMPKT172/AMPK protein levels were assessed, and basal mitochondrial respiratory states were evaluated in synaptosomes. A metabolic connectivity network between brain areas was estimated based on 18FDG uptake. We found that ND increased the pAMPKT172/AMPK ratio in both adult and aged mice but increased 18FDG uptake and mitochondrial basal respiration only in adult mice. Furthermore, ND triggered rearrangement in the metabolic connectivity of adult mice and aged mice compared to age-matched controls. Altogether, our findings suggest that ND promotes hypothalamic AMPK activation, and distinct glucose metabolism and metabolic connectivity rearrangements in the brains of adult and aged mice.

Nasal Administration of Cationic Nanoemulsions as CD73-siRNA Delivery System for Glioblastoma Treatment: a New Therapeutical Approach.

Glioblastoma is the most devastating primary brain tumor. Effective therapies are not available, mainly due to high tumor heterogeneity, chemoresistance, and the difficulties imposed by blood-brain barrier. CD73, an enzyme responsible for adenosine (ADO) production, is overexpressed in cancer cells and emerges as a target for glioblastoma treatment. Indeed, ADO causes a variety of tumor-promoting actions, particularly by inducing tumor immune escape, whereas CD73 inhibition impairs tumor progression. Here, a cationic nanoemulsion to deliver CD73siRNA (NE-siRNA CD73R) via nasal route aiming glioblastoma treatment was developed. NE-siRNA CD73R was uptaken by glioma cells in culture, resulting in a parallel 60-80% decrease in AMPase activity and 30-50% in cell viability. Upon nasal delivery, NE-siRNA CD73R was detected in rat brain and serum. Notably, treatment with CD73siRNA complexes of glioma-bearing Wistar rats reduced tumor growth by 60%. Additionally, NE-siRNA CD73R treatment decreased 95% ADO levels in liquor and tumor CD73 expression, confirming in vivo CD73 silencing. Finally, no toxicity was observed in either primary astrocytes or rats with this cationic nanoemulsion. These results suggest that nasal administration of cationic NE as CD73 siRNA delivery system represents a novel potential treatment for glioblastoma. Graphical Abstract Glioblastoma is the most common and devastating form of primary brain tumor. CD73, a protein involved in cell-cell adhesion and migration processes and also responsible for extracellular adenosine (ADO) production, is overexpressed by glioma cells and emerges as an important target for glioma treatment. Indeed, ADO participates in tumor immune escape, cell proliferation, and angiogenesis, and CD73 inhibition impairs those processes. Here, a cationic nanoemulsion to deliver CD73 siRNA (NE-siRNA CD73R) via nasal route aiming glioblastoma treatment was developed. NE-siRNA CD73R knockdown in vitro and in vivo CD73. Upon nasal delivery of NE-siRNA CD73R, the treatment markedly reduced tumor volume by 60% in a rat preclinical glioblastoma model. The treatment was well tolerated, and did not induce kidney, liver, lung, olfactory, bone marrow, or behavior alterations. These results indicate that the nasal administration of NE as a CD73 siRNA delivery system offered an efficient means of gene knockdown and may represent a potential alternative for glioblastoma treatment.

Induction of haem oxygenase-1 increases infection of dog macrophages by L. infantum.

We aimed to induce and inhibit HO-1, ascertaining its effect on infection rate, parasite load and the levels of superoxide, reactive oxygen species (ROS), nitric oxide (NO), TNF-alpha and IL-10 in cultured macrophages from healthy dogs infected by Leishmania infantum. Macrophages obtained from 15 healthy dogs were cultured alone or infected with L. infantum, with or without association of HO-1 inducer and inhibitor. The infection rate and the parasite load were determined by the number of infected macrophages and number of promastigotes per macrophage, respectively. HO-1 levels and gene expression, as well as IL-10 and TNF-alpha levels were also measured in these cultures. Superoxide, ROS and NO levels in macrophages were measured through flow cytometry. Induction of HO-1 increased the infection rate and parasite load, while its inhibition decreased the infection rate and IL-10 production. There was a positive correlation between HO-1 and infection rate or parasite load. Increased infection rate was associated with decreased superoxide, ROS and NO levels. Induction of HO-1 metabolism in dogs infected by L. infantum is possibly one of the mechanisms responsible for increasing the infection of macrophages, mainly through reduction in the oxidative and nitrosative metabolisms of these cells.

M1 polarization and the effect of PGE2 on TNF-α production by lymph node cells from dogs with visceral leishmaniasis.

Canine visceral leishmaniasis (CVL) is caused by the intracellular parasite Leishmania infantum. Increased levels of arginase, nitric oxide (NO2 ) and prostaglandin E2 (PGE2 ) can play a regulatory role regarding the immune response in CVL cases. This study aimed to evaluate the arginase activity in adherent macrophages cultured from the lymph nodes of healthy and naturally infected dogs and to examine the NO2 and PGE2 levels in the supernatant of these cultures. In addition, the regulatory effect of PGE2 on the production of tumour necrosis factor (TNF-α) and interleukin-10 (IL-10) in supernatants from the total lymph node was observed in leucocyte cultures. The arginase activity was lower in the adherent macrophages cultured from the lymph nodes of naturally infected dogs and there were higher concentrations of NO2 and PGE2 in the supernatants of these cultures. Higher TNF-α and IL-10 concentrations were observed in supernatants from total lymph node leucocytes cultures, from infected dogs, and the presence of indomethacin only decreased TNF-α in the supernatant of these cultures. We conclude that the low arginase activity in macrophages suggested that M1 polarization and PGE2 were participating in the immune response and were increasing TNF-α in CVL.

Recombinant K28 antigen in ELISA in the diagnosis of canine visceral leishmaniosis.

Crude total antigen (CTA) from Leishmania infantum and recombinant antigen K39 (rK39) and recombinant antigen K28 (rK28) were compared using an ELISA for the diagnosis of canine visceral leishmaniosis (CVL). Forty-two blood samples from healthy dogs from a nonendemic area and 80 blood samples from an endemic area for dogs with visceral leishmaniosis (VL), confirmed with positive parasitological tests for Leishmania spp., were used in an ELISA. The parasitological diagnosis was chosen as a gold standard. The ELISA with rK28 antigen showed sensitivity of 100% and specificity of 100%, high agreement with CTA and rK39, indicating that the rK28 antigen is useful for ELISA serological diagnosis of CVL.