Mitotherapy prevents peripheral neuropathy induced by oxaliplatin in mice.

Oxaliplatin (OXA) is an antineoplastic agent used for the treatment of cisplatin-resistant tumours, presenting lower incidence of nephrotoxicity and myelotoxicity than other platinum-based drugs. However, OXA treatment is highly associated with painful peripheral neuropathy, a well-known and relevant side effect caused by mitochondrial dysfunction. The transfer of functional exogenous mitochondria (mitotherapy) is a promising therapeutic strategy for mitochondrial diseases. We investigated the effect of mitotherapy on oxaliplatin-induced painful peripheral neuropathy (OIPN) in male mice. OIPN was induced by i.p. injections of oxaliplatin (3 mg/kg) over 5 consecutive days. Mechanical (von Frey test) and cold (acetone drop test) allodynia were evaluated between 7 and 17 days after the first OXA treatment. Mitochondria was isolated from donor mouse livers and mitochondrial oxidative phosphorylation was assessed with high resolution respirometry. After confirming that the isolated mitochondria were functional, the organelles were administered at the dose of 0.5 mg/kg of mitochondrial protein on days 1, 3 and 5. Treatment with OXA caused both mechanical and cold allodynia in mice that were significant 7 days after the initial injection of OXA and persisted for up to 17 days. Mitotherapy significantly prevented the development of both sensory alterations, and attenuated body weight loss induced by OXA. Mitotherapy also prevented spinal cord ERK1/2 activation, microgliosis and the increase in TLR4 mRNA levels. Mitotherapy prevented OIPN by inhibiting neuroinflammation and the consequent cellular overactivity in the spinal cord, presenting a potential therapeutic strategy for pain management in oncologic patients undergoing OXA treatment.

SARS-CoV-2 Spike protein induces TLR4-mediated long-term cognitive dysfunction recapitulating post-COVID-19 syndrome in mice.

Cognitive dysfunction is often reported in patients with post-coronavirus disease 2019 (COVID-19) syndrome, but its underlying mechanisms are not completely understood. Evidence suggests that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Spike protein or its fragments are released from cells during infection, reaching different tissues, including the CNS, irrespective of the presence of the viral RNA. Here, we demonstrate that brain infusion of Spike protein in mice has a late impact on cognitive function, recapitulating post-COVID-19 syndrome. We also show that neuroinflammation and hippocampal microgliosis mediate Spike-induced memory dysfunction via complement-dependent engulfment of synapses. Genetic or pharmacological blockage of Toll-like receptor 4 (TLR4) signaling protects animals against synapse elimination and memory dysfunction induced by Spike brain infusion. Accordingly, in a cohort of 86 patients who recovered from mild COVID-19, the genotype GG TLR4-2604G>A (rs10759931) is associated with poor cognitive outcome. These results identify TLR4 as a key target to investigate the long-term cognitive dysfunction after COVID-19 infection in humans and rodents.

Taxane-induced neurotoxicity: Pathophysiology and therapeutic perspectives.

Taxane-derived drugs are antineoplastic agents used for the treatment of highly common malignancies. Paclitaxel and docetaxel are the most commonly used taxanes; however, other drugs and formulations have been used, such as cabazitaxel and nab-paclitaxel. Taxane treatment is associated with neurotoxicity, a well-known and relevant side effect, very prevalent amongst patients undergoing chemotherapy. Painful peripheral neuropathy is the most dose-limiting side effect of taxanes, affecting up to 97% of paclitaxel-treated patients. Central neurotoxicity is an emerging side effect of taxanes and it is characterized by cognitive impairment and encephalopathy. Besides impairing compliance to chemotherapy treatment, taxane-induced neurotoxicity (TIN) can adversely affect the patient's life quality on a long-term basis. Despite the clinical relevance, not many reviews have comprehensively addressed taxane-induced neurotoxicity when they are used therapeutically. This article provides an up-to-date review on the pathophysiology of TIN and the novel potential therapies to prevent or treat this side effect.

Late Cognitive Consequences of Gestational Diabetes to the Offspring, in a New Mouse Model.

Gestational diabetes mellitus (GD) is a form of insulin resistance triggered during gestation, which affects approximately 10% of pregnant women. Although previously considered a transient condition with few long-term consequences, growing evidence suggest that GD may be linked to permanent metabolic and neurologic changes in the offspring. Currently available GD models fail to recapitulate the full spectrum of this disease, thus providing limited information about the true burden of this condition. Here, we describe a new mouse model of GD, based on the administration of an insulin receptor antagonist (S961, 30 nmol/kg s.c. daily) during pregnancy. Pregnant mice developed increased fasting glycemia and glucose intolerance in the absence of maternal obesity, with a return to normoglycemia shortly after parturition. Moreover, we showed that the adult offspring of GD dams presented pronounced metabolic and cognitive dysfunction when exposed to short-term high-fat diet (HFD). Our data demonstrate that S961 administration to pregnant mice comprises a valuable approach to study the complex pathophysiology of GD, as well as strategies focused on prevention and treatment of both the mother and the offspring. Our findings suggest that the offspring of GD mothers are more susceptible to metabolic and cognitive impairments when exposed to high-fat diet later in life, thus indicating that approaches to prevent and treat these late effects should be pursued.

The selective TRPV4 channel antagonist HC-067047 attenuates mechanical allodynia in diabetic mice.

Painful diabetic neuropathy (PDN) is a serious symptom that compromises quality of life and remains without effective pharmacological treatment. The transient receptor vanilloid 4 (TRPV4) is a cation-permeable channel implicated in sensory transduction and pain signalling. Therefore, drugs that act on TRPV4 may have therapeutic applications to treat PDN. In the present work, we assessed the effect of the selective TRPV4 channel antagonist HC-067047 on painful neuropathy associated with streptozotocin (STZ)-induced diabetes in mice. STZ-treated animals presented both mechanical and cold allodynia at 6 weeks after diabetes induction. Notably, HC-067047 (1 mg/kg, s.c.) given daily between 2 and 6 weeks after diabetes induction significantly prevented the development of mechanical allodynia. Additionally, both single and repeated treatments with HC-067047 (10 mg/kg, s.c.) significantly reverted established mechanical allodynia induced by STZ. However, HC-067047 was not capable of affecting either thermal cold allodynia or hyperglycemia. Similarly, HC-067047 treatments showed no effect on body weight, temperature, locomotor activity or motor coordination of control mice. Immunohistochemistry assay showed that TRPV4 expression was not different in sciatic nerve, dorsal root ganglia (DRG) or hind paw plantar skin from diabetic and non-diabetic mice, suggesting that HC-067047 acts on constitutive receptors to inhibit mechanical allodynia. Taken together, the data generated in the present study show the potential relevance of using TRPV4 antagonists to treat painful neuropathy associated with diabetes.

Spinal blockage of CXCL1 and its receptor CXCR2 inhibits paclitaxel-induced peripheral neuropathy in mice.

Painful peripheral neuropathy is the most dose-limiting side effect of paclitaxel (PTX), a widely used anti-cancer drug to treat solid tumours. The understanding of the mechanisms involved in this side effect is crucial to the development of new therapeutic approaches. CXCL1 chemokine and its receptor CXCR2 have been pointed as promising targets to treat chronic pain. Herein, we sought to evaluate the possible involvement of CXCL1 and CXCR2 in the pathogenesis of PTX-induced neuropathic pain in mice. PTX treatment led to increased levels of CXCL1 in both dorsal root ganglion and spinal cord samples. Systemic treatment with the anti-CXCL1 antibody (10 µg/kg, i.v.) or the selective CXCR2 antagonist (SB225002, 3 mg/kg, i.p.) had minor effect on PTX-induced mechanical hypersensitivity. On the other hand, the intrathecal (i.t.) treatment with anti-CXCL1 (1 ng/site) or SB225002 (10 µg/site) consistently inhibited the nociceptive responses of PTX-treated mice. Similar results were obtained by inhibiting the PI3Kγ enzyme a downstream pathway of CXCL1/CXCR2 signalling with either the selective AS605240 (5 µg/site, i.t.) or the non-selective wortmannin PI3K inhibitor (0.4 µg/site, i.t.). Overall, the data indicates that the up-regulation of CXCL1 is important for the development and maintenance of PTX-induced neuropathic pain in mice. Therefore, the spinal blockage of CXCL1/CXCR2 signalling might be a new innovative therapeutic approach to treat this clinical side effect of PTX.

Consequences of gestational diabetes to the brain and behavior of the offspring.

Gestational diabetes mellitus (GD) is a form of insulin resistance triggered during the second/third trimesters of pregnancy in previously normoglycemic women. It is currently estimated that 10% of all pregnancies in the United States show this condition. For many years, the transient nature of GD has led researchers and physicians to assume that long-term consequences were absent. However, GD diagnosis leads to a six-fold increase in the risk of developing type 2 diabetes (T2D) in women and incidence of obesity and T2D is also higher among their infants. Recent and concerning evidences point to detrimental effects of GD on the behavior and cognition of the offspring, which often persist until adolescence or adulthood. Considering that the perinatal period is critical for determination of adult behavior, it is expected that the intra-uterine exposure to hyperglycemia, hyperinsulinemia and pro-inflammatory mediators, hallmark features of GD, might affect brain development. Here, we review early clinical and experimental evidence linking GD to consequences on the behavior of the offspring, focusing on memory and mood disorders. We also discuss initial evidence suggesting that downregulation of insulin signaling cascades are seen in the brains of GD offspring and could contribute to the consequences on their behavior.

Brain-Defective Insulin Signaling Is Associated to Late Cognitive Impairment in Post-Septic Mice.

Sepsis survivors frequently develop late cognitive impairment. Because little is known on the mechanisms of post-septic memory deficits, there are no current effective approaches to prevent or treat such symptoms. Here, we subjected mice to severe sepsis induced by cecal ligation and puncture (CLP) and evaluated the sepsis-surviving animals in the open field, novel object recognition (NOR), and step-down inhibitory avoidance (IA) task at different times after surgery. Post-septic mice (30 days post-surgery) failed in the NOR and IA tests but exhibited normal performance when re-evaluated 45 days after surgery. Cognitive impairment in post-septic mice was accompanied by reduced hippocampal levels of proteins involved in synaptic plasticity, including synaptophysin, cAMP response element-binding protein (CREB), CREB phosphorylated at serine residue 133 (CREBpSer133), and GluA1 phosphorylated at serine residue 845 (GluA1pSer845). Expression of tumor necrosis factor α (TNF-α) was increased and brain insulin signaling was disrupted, as indicated by increased hippocampal IRS-1 phosphorylation at serine 636 (IRS-1pSer636) and decreased phosphorylation of IRS-1 at tyrosine 465 (IRS-1pTyr465), in the hippocampus 30 days after CLP. Phosphorylation of Akt at serine 473 (AktpSer473) and of GSK3 at serine 9 (GSK3ßpSer9) were also decreased in hippocampi of post-septic animals, further indicating that brain insulin signaling is disrupted by sepsis. We then treated post-septic mice with liraglutide, a GLP-1 receptor agonist with insulinotropic activity, or TDZD-8, a GSK3ß inhibitor, which rescued NOR memory. In conclusion, these results establish that hippocampal inflammation and disrupted insulin signaling are induced by sepsis and are linked to late memory impairment in sepsis survivors.

Antiallodynic effect of ß-caryophyllene on paclitaxel-induced peripheral neuropathy in mice.

Painful peripheral neuropathy is a common side effect of paclitaxel (PTX). The use of analgesics is an important component for management of PTX-induced peripheral neuropathy (PINP). However, currently employed analgesics have several side effects and are poorly effective. ß-caryophyllene (BCP), a dietary selective CB2 agonist, has shown analgesic effect in neuropathic pain models, but its role in chemotherapy-induced neuropathic pain has not yet been investigated. Herein, we used the mouse model of PINP to show the therapeutic effects of BCP in this neuropathy. Male Swiss mice receiving PTX (2 mg kg-1, ip, four alternate days) were treated with BCP (25 mg kg-1, po, twice a day) either during or after PTX administration. Some groups were also pretreated with AM630 (CB2 antagonist, 3 mg kg-1, ip) or AM251 (CB1 antagonist, 1 mg kg-1, ip). Spinal cord samples were collected in different time points to perform immunohistochemical analysis. BCP attenuated the established mechanical allodynia induced by PTX (p < 0.0001) in a CB2-dependent manner. Of note, when given concomitantly with PTX, BCP was able to attenuate the development of PINP (p < 0.0001). Spinal cord immunohistochemistry revealed that preventive treatment with BCP reduced p38 MAPK and NF-κB activation, as well as the increased Iba-1 and IL-1ß immunoreactivity promoted by PTX. Our findings show that BCP effectively attenuated PINP, possibly through CB2-activation in the CNS and posterior inhibition of p38 MAPK/NF-κB activation and cytokine release. Taken together, our results suggest that BCP could be used to attenuate the establishment and/or treat PINP.

Comparison of Efficacy of Preventive and Therapeutic Vaccines Targeting the N Terminus of ß-Amyloid in an Animal Model of Alzheimer's Disease.

Previously, we reported that Alzheimer's disease (AD) epitope vaccines (EVs) composed of N-terminal ß-amyloid (Aß42) B cell epitope fused with universal foreign T helper (Th) epitope(s) were immunogenic, potent, and safe in different amyloid precursor protein (APP) transgenic mice with early AD-like pathology. However, developing an effective therapeutic vaccine is much more challenging, especially when a self-antigen such as Aß42 is a target. Here, we directly compare the efficacy of anti-Aß42 antibodies in Tg2576 mice with low or high levels of AD-like pathology at the start of immunizations: 6-6.5 months for preventive vaccinations and 16-19 months for therapeutic vaccinations. EV in a preventive setting induced high levels of anti-Aß antibodies, significantly reducing pathologic forms of Aß in the brains of Tg2576 mice. When used therapeutically for immunesenescent Tg2576 mice, EV induced low levels of antibodies not sufficient for clearing of AD-like pathology. Separately, we demonstrated that EV was also not effective in 11-11.5-month-old Tg2576 mice with moderate AD-like pathology. However, we augmented the titers of anti-Aß antibodies in transgenic (Tg) mice of the same age possessing the pre-existing memory Th cells and detected a significant decrease in diffuse and core plaques in cortical regions compared to control animals along with improved novel object recognition performance.

Blockade of hippocampal bradykinin B1 receptors improves spatial learning and memory deficits in middle-aged rats.

Previous studies have demonstrated that targeting bradykinin receptors is a promising strategy to counteract the cognitive impairment related with aging and Alzheimer's disease (AD). The hippocampus is critical for cognition, and abnormalities in this brain region are linked to the decline in mental ability. Nevertheless, the impact of bradykinin signaling on hippocampal function is unknown. Therefore, we sought to determine the role of hippocampal bradykinin receptors B1R and B2R on the cognitive decline of middle-aged rats. Twelve-month-old rats exhibited impaired ability to acquire and retrieve spatial information in the Morris water maze task. A single intra-hippocampal injection of the selective B1R antagonist des-Arg9-[Leu8]-bradykinin (DALBK, 3 nmol), but not the selective B2R antagonist D-Arg-[Hyp3,Thi5,D-Tic7,Oic8]-BK (Hoe 140, 3 nmol), reversed the spatial learning and memory deficits on these animals. However, both drugs did not affect the cognitive function in 3-month-old rats, suggesting absence of nootropic properties. Molecular biology analysis revealed an up-regulation of B1R expression in the hippocampal CA1 sub-region and in the pre-frontal cortex of 12-month-old rats, whereas no changes in the B2R expression were observed in middle-aged rats. These findings provide new evidence that inappropriate hippocampal B1R expression and activation exert a critical role on the spatial learning and memory deficits in middle-aged rats. Therefore, selective B1R antagonists, especially orally active non-peptide antagonists, may represent drugs of potential interest to counteract the age-related cognitive decline.

Experimental hypertension increases spontaneous intracerebral hemorrhages in a mouse model of cerebral amyloidosis.

Hypertension and cerebral amyloid angiopathy (CAA) are major risk factors for intracerebral hemorrhage (ICH); however the mechanisms of interplay between the two are not fully understood. We investigated the effect of hypertension in a transgenic mouse model with Alzheimer's-like pathology (Tg2576) treating them with angiotensin II and L-N(G)-nitroarginine methyl ester. A similar increase in systolic blood pressure was observed in both Tg2576 and control mice; however Tg2576 mice developed signs of stroke with a markedly shorter latency. Cerebral deposition of amyloid beta promotes the hypertension-induced ICH, thus supporting the notion that hypertension is a risk factor for ICH among patients with CAA.

Toxicological Evaluation of Anti-Scrapie Trimethoxychalcones and Oxadiazoles.

An altered form of the cellular prion protein, the PrPScor PrPRes, is implicated in the occurrence of the still untreatable transmissible spongiform encephalopathies. We have previously synthesized and characterized aromatic compounds that inhibit protease-resistant prion protein (PrPRes) accumulation in scrapie-infected cells. These compounds belong to different chemical classes, including acylhydrazones, chalcones and oxadiazoles. Some of the active compounds were non-toxic to neuroblastoma cells in culture and seem to possess drugable properties, since they are in agreement with the Lipinski´s rule of 5 and present desirable pharmacokinetic profiles as predicted in silico. Before the evaluation of the in vivo efficacy of the aromatic compounds in scrapie-infected mice, safety assessment in healthy mice is needed. Here we used Swiss mice to evaluate the acute toxicity profile of the six most promising anti-prionic compounds, the 2,4,5-trimethoxychalcones (J1, J8, J20 and J35) and the 1,3,4-oxadiazoles (Y13 and Y17). One single oral administration (300 mg/kg) of J1, J8, J20, J35, Y13 and Y17 or repeated intraperitoneal administration (10 mg/kg, 3 times a week, for 4 weeks) of J1, J8 and J35, did not elicit toxicity in mice. We strongly believe that the investigated trimethoxychalcones and oxadiazoles are interesting compounds to be further analyzed in vivo against prion diseases.

The bradykinin B1 receptor regulates Aß deposition and neuroinflammation in Tg-SwDI mice.

The deposition of amyloid-ß peptides (Aß) in the cerebral vasculature, a condition known as cerebral amyloid angiopathy, is increasingly recognized as an important component leading to intracerebral hemorrhage, neuroinflammation, and cognitive impairment in Alzheimer disease (AD) and related disorders. Recent studies demonstrated a role for the bradykinin B1 receptor (B1R) in cognitive deficits induced by Aß in mice; however, its involvement in AD and cerebral amyloid angiopathy is poorly understood. Herein, we investigated the effect of B1R inhibition on AD-like neuroinflammation and amyloidosis using the transgenic mouse model (Tg-SwDI). B1R expression was found to be up-regulated in brains of Tg-SwDI mice, specifically in the vasculature, neurons, and astrocytes. Notably, administration of the B1R antagonist, R715, to 8-month-old Tg-SwDI mice for 8 weeks resulted in higher Aß40 levels and increased thioflavin S-positive fibrillar Aß deposition. Moreover, blockage of B1R inhibited neuroinflammation, as evidenced by the decreased accumulation of activated microglia and reactive astrocytes, diminished NF-κB activation, and reduced cytokine and chemokine levels. Together, our results indicate that B1R activation plays an important role in limiting the accumulation of Aß in AD-like brain, likely through the regulation of activated glial cell accumulation and release of pro-inflammatory mediators. Therefore, the modulation of the receptor may represent a novel therapeutic approach for AD.

Aspirin-triggered lipoxin A4 stimulates alternative activation of microglia and reduces Alzheimer disease-like pathology in mice.

Microglia play an essential role in innate immunity, homeostasis, and neurotropic support in the central nervous system. In Alzheimer disease (AD), these cells may affect disease progression by modulating the buildup of ß-amyloid (Aß) or releasing proinflammatory cytokines and neurotoxic substances. Discovering agents capable of increasing Aß uptake by phagocytic cells is of potential therapeutic interest for AD. Lipoxin A4 (LXA4) is an endogenous lipid mediator with potent anti-inflammatory properties directly involved in inflammatory resolution, an active process essential for appropriate host responses, tissue protection, and the return to homeostasis. Herein, we demonstrate that aspirin-triggered LXA4 (15 µg/kg) s.c., twice a day, reduced NF-κB activation and levels of proinflammatory cytokines and chemokines, as well as increased levels of anti-inflammatory IL-10 and transforming growth factor-ß. Such changes in the cerebral milieu resulted in recruitment of microglia in an alternative phenotype, as characterized by the up-regulation of YM1 and arginase-1 and the down-regulation of inducible nitric oxide synthase expression. Microglia in an alternative phenotype-positive cells demonstrated improved phagocytic function, promoting clearance of Aß deposits and ultimately leading to reduction in synaptotoxicity and improvement in cognition. Our data indicate that activating LXA4 signaling may represent a novel therapeutic approach for AD.

The role of PKC/ERK1/2 signaling in the anti-inflammatory effect of tetracyclic triterpene euphol on TPA-induced skin inflammation in mice.

Inflammation underlies the development and progression of a number of skin disorders including psoriasis, atopic dermatitis and cancer. Therefore, novel antiinflammatory agents are of great clinical interest for prevention and treatment of these conditions. Herein, we demonstrated the underlying molecular mechanisms of the antiinflammatory activity of euphol, a tetracyclic triterpene isolated from the sap of Euphorbia tirucalli, in skin inflammation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in mice. Topical application of euphol (100 µg/ear) significantly inhibited TPA-induced ear edema and leukocyte influx through the reduction of keratinocyte-derived chemokine (CXCL1/KC) and macrophage inflammatory protein (MIP)-2 levels. At the intracellular level, euphol reduced TPA-induced extracellular signal-regulated protein kinase (ERK) activation and cyclooxygenase-2 (COX-2) upregulation. These effects were associated with euphol's ability to prevent TPA-induced protein kinase C (PKC) activation, namely PKCα and PKCδ isozymes. Our data indicate that topical application of euphol markedly inhibits the inflammatory response induced by TPA. Thus, euphol represents a promising agent for the management of skin diseases with an inflammatory component.

Therapeutic modulation of cerebral microhemorrhage in a mouse model of cerebral amyloid angiopathy.

BACKGROUND AND PURPOSE: The aging brain demonstrates frequent MRI and pathological evidence of cerebral microbleeds, which are often associated with cerebral amyloid angiopathy. To develop new therapeutic strategies for this disorder, we studied cerebral microhemorrhage in a well-characterized mouse model of cerebral amyloid angiopathy. METHODS: Tg2576 mice were studied at ages ranging from 2 to 21 months. Spontaneous and induced microscopic bleeding was analyzed with and without a passive anti-amyloid immunization regimen and dietary supplementation of ischemic stroke prevention medication dipyridamole. RESULTS: Areas of microhemorrhage were easily demonstrated and were significantly more prominent in the oldest mice and in animals treated with anti-amyloid immunotherapy. Dipyridamole supplementation in the diet generated plasma levels >790 ng/mL within the range seen clinically. Dipyridamole treatment did not worsen frequency and size of cerebral microscopic bleeding. CONCLUSIONS: The Tg2576 mouse is a useful model to study progression and modification of spontaneous and immunotherapy-induced cerebral microhemorrhage. Absence of microhemorrhage worsening with dipyridamole treatment suggests a potential therapeutic role of this agent when ischemic and microhemorrhagic lesions coexist.

Activation of cannabinoid receptors by the pentacyclic triterpene α,ß-amyrin inhibits inflammatory and neuropathic persistent pain in mice.

In this study, we report that α,ß-amyrin, a plant-derived pentacyclic triterpene, reduced persistent inflammatory and neuropathic hyperalgesia in mice by a direct activation of the CB(1) and CB(2) cannabinoid receptors (CB(1)R and CB(2)R). The oral treatment with α,ß-amyrin (30 mg/kg) significantly reduced mechanical and thermal hyperalgesia and inflammation induced by complete Freund's adjuvant (CFA) and by partial sciatic nerve ligation (PSNL). The pretreatment with either CB(1)R or CB(2)R antagonists and the knockdown gene of the receptors significantly reverted the antinociceptive effect of α,ß-amyrin. Of note, binding studies showed that α,ß-amyrin directly bound with very high affinity to CB(1)R (K(i)=0.133 nM) and with a lower affinity to CB(2)R (K(i)=1989 nM). Interestingly, α,ß-amyrin, ACEA (CB(1)R agonist), or JWH-133 (CB(2)R agonist), at doses that caused antinociception, failed to provoke any behavioral disturbance, as measured in the tetrad assay. In addition, α,ß-amyrin largely decreased interleukin-1ß (IL-1ß), tumor necrosis factor α (TNF-α), keratinocyte-derived chemokine (KC) and interleukin 6 (IL-6) levels, and myeloperoxidase activity. Likewise, α,ß-amyrin prevented the activation of the transcriptional factors: nuclear factor κB (NF-κB) and cyclic adenosine monophosphate response element binding (CREB) and the expression of cyclooxygenase 2 in mice footpads and spinal cords. The present results demonstrated that α,ß-amyrin exhibits long-lasting antinociceptive and anti-inflammatory properties in 2 models of persistent nociception via activation of cannabinoid receptors and by inhibiting the production of cytokines and expression of NF-κB, CREB and cyclooxygenase 2.

Aging and cerebrovascular dysfunction: contribution of hypertension, cerebral amyloid angiopathy, and immunotherapy.

Age-related cerebrovascular dysfunction contributes to ischemic stroke, intracerebral hemorrhages (ICHs), microbleeds, cerebral amyloid angiopathy (CAA), and cognitive decline. Importantly, there is increasing recognition that this dysfunction plays a critical secondary role in many neurodegenerative diseases, including Alzheimer's disease (AD). Atherosclerosis, hypertension, and CAA are the most common causes of blood-brain barrier (BBB) lesions. The accumulation of amyloid beta (Aß) in the cerebrovascular system is a significant risk factor for ICH and has been linked to endothelial transport failure and blockage of perivascular drainage. Moreover, recent anti-Aß immunotherapy clinical trials demonstrated efficient clearance of parenchymal amyloid deposits but have been plagued by CAA-associated adverse events. Although management of hypertension and atherosclerosis can reduce the incidence of ICH, there are currently no approved therapies for attenuating CAA. Thus, there is a critical need for new strategies that improve BBB function and limit the development of ß-amyloidosis in the cerebral vasculature.

The role of TNF-alpha signaling pathway on COX-2 upregulation and cognitive decline induced by beta-amyloid peptide.

Alzheimer's disease (AD), a chronic degenerative and inflammatory brain disorder characterized by neuronal dysfunction and loss, is linked to accumulation of beta-amyloid (Abeta) peptide. Tumor necrosis factor-alpha (TNF-alpha) and cyclooxygenase-2 (COX-2) are proteins that have key roles in immune cell activation, inflammation and cognitive function in the brain. Here, we evaluated the link between TNF-alpha and COX-2 on the acute responses elicited by Abeta. Behavioral and molecular analyses were performed in mice after an intracerebroventricular (i.c.v.) injection of Abeta(1-40). Genetic and/or pharmacological approaches were used to inhibit TNF-alpha and COX-2. I.c.v. Abeta(1-40) injection in mice activates TNF-alpha signaling pathway resulting in COX-2 upregulation, synaptic loss and cognitive decline. Pharmacological studies revealed that COX-2 is involved in the cognitive impairment mediated by TNF-alpha. However, COX-2 inhibition failed in reducing the synaptophysin loss induced by Abeta(1-40). The COX-2 upregulation induced by Abeta(1-40) was attributed to activation of different protein kinases and transcriptional factors that are greatly regulated by TNF-alpha. Together, these results indicate that Abeta(1-40) induces the activation of several TNF-alpha-dependent intracellular signaling pathways that play a key role in the control of COX-2 upregulation and activation, synaptic loss and cognitive decline in mice. Therefore, selective TNF-alpha inhibitors may be potentially interesting tools for AD drug development.