Cold acclimation and pioglitazone combined increase thermogenic capacity of brown and white adipose tissues but this does not translate into higher energy expenditure in mice.

Cold acclimation and pharmacological peroxisome proliferator-activated receptor γ (PPARγ) activation have each earlier been shown to recruit brown adipose tissue (BAT) and beige adipocytes thermogenic machinery, enhancing uncoupling protein 1 (UCP1)-mediated thermogenic capacity. We here investigated whether cold acclimation and PPARγ agonism combined have additive effects in inducing brown and beige adipocytes UCP1 content and whether this translates into a higher thermogenic capacity and energy expenditure. C57BL/6J mice treated or not with pioglitazone (30 mg/kg/day) were maintained at 21°C or exposed to cold (7°C) for 15 days and evaluated for thermogenic capacity, energy expenditure and interscapular BAT (iBAT) and inguinal white adipose tissue (iWAT) mass, morphology, UCP1 content and gene expression, glucose uptake and oxygen consumption. Cold acclimation and PPARγ agonism combined synergistically increased iBAT and iWAT total UCP1 content and mRNA levels of the thermogenesis-related proteins PGC1a, CIDEA, FABP4, GYK, PPARa, LPL, GLUTs (GLUT1 in iBAT and GLUT4 in iWAT), and ATG when compared to cold and pioglitazone individually. This translated into a stronger increase in body temperature in response to the ß3-adrenergic agonist CL316,243 and iBAT and iWAT respiration induced by succinate and pyruvate in comparison to that seen in either cold-acclimated or pioglitazone-treated mice. However, basal energy expenditure, BAT glucose uptake and glucose tolerance were not increased above that seen in cold-acclimated untreated mice. In conclusion, cold acclimation and PPARγ agonism combined induced a robust increase in brown and beige adipocytes UCP1 content and thermogenic capacity, much higher than each treatment individually. However, our findings enforce the concept that increases in total UCP1 do not innately lead to higher energy expenditure.NEW & NOTEWORTHY Cold acclimation and PPARγ agonism combined markedly increase brown and white adipose tissue total UCP1 content and mRNA levels of thermogenesis-related proteins. Higher UCP1 protein levels did not result in higher energy expenditure. The high thermogenic capacity induced by PPARγ agonism in cold-exposed animals markedly increases animals' body temperature in response to the ß3-adrenergic agonist CL316,243.

Proteomic analysis reveals rattlesnake venom modulation of proteins associated with cardiac tissue damage in mouse hearts

Snake envenomation is a common but neglected disease that affects millions of people around the world annually. Among venomous snake species in Brazil, the tropical rattlesnake (Crotalus durissus terrificus) accounts for the highest number of fatal envenomations and is responsible for the second highest number of bites. Snake venoms are complex secretions which, upon injection, trigger diverse physiological effects that can cause significant injury or death. The components of C. d. terrificus venom exhibit neurotoxic, myotoxic, hemotoxic, nephrotoxic, and cardiotoxic properties which present clinically as alteration of central nervous system function, motor paralysis, seizures, eyelid ptosis, ophthalmoplesia, blurred vision, coagulation disorders, rhabdomyolysis, myoglobinuria, and cardiorespiratory arrest. In this study, we focused on proteomic characterization of the cardiotoxic effects of C. d. terrificus venom in mouse models. We injected venom at half the lethal dose (LD50) into the gastrocnemius muscle. Mouse hearts were removed at set time points after venom injection (1 h, 6 h, 12 h, or 24 h) and subjected to trypsin digestion prior to high-resolution mass spectrometry. We analyzed the proteomic profiles of >1300 proteins and observed that several proteins showed noteworthy changes in their quantitative profiles, likely reflecting the toxic activity of venom components. Among the affected proteins were several associated with cellular deregulation and tissue damage. Changes in heart protein abundance offer insights into how they may work synergistically upon envenomation. Significance Venom of the tropical rattlesnake (Crotalus durissus terririficus) is known to be neurotoxic, myotoxic, nephrotoxic and cardiotoxic. Although there are several studies describing the biochemical effects of this venom, no work has yet described its proteomic effects in the cardiac tissue of mice. In this work, we describe the changes in several mouse cardiac proteins upon venom treatment. Our data shed new light on the clinical outcome of the envenomation by C. d. terrificus, as well as candidate proteins that could be investigated in efforts to improve current treatment approaches or in the development of novel therapeutic interventions in order to reduce mortality and morbidity resulting from envenomation.

Training-Induced Deactivation of the AT1 Receptor Pathway Drives Autonomic Control and Heart Remodeling During the Transition From the Pre- to Hypertensive Phase in Spontaneously Hypertensive Rats.

BACKGROUND: The effects of hypertension and exercise training (T) on the sequential interplay between renin-angiotensin system (RAS), autonomic control and heart remodeling during the development of hypertension in spontaneously hypertensive rats (SHR), was evaluated.Methods and Results:Time course changes of these parameters were recorded in 4-week-old SHR submitted to a T or sedentary (S) protocol. Wistar Kyoto rats served as controls. Hemodynamic recordings were obtained in conscious rats at experimental weeks 0, 1, 2, 4, and 8. The left ventricle (LV) was collected to evaluate RAS gene and protein expression, cardiomyocytes' hypertrophy and collagen accumulation. Pre-hypertensive SHR exhibited augmented AT1R gene expression; at 5 weeks, they presented with elevated pressure, increased LV angiotensinogen and ACE mRNA expression, followed by sympathoexcitation (from the 8thweek onwards). Marked AT1R protein content, myocytes's hypertrophy, collagen deposition and increased pressure variability were observed in 12-week-old sedentary SHR. In addition to attenuating all these effects, T activated Mas receptor expression augmented parasympathetic modulation of the heart, and delayed the onset and reduced the magnitude, but did not block the development of genetic hypertension. CONCLUSIONS: The close temporal relationship between changes in the LV ACE-Ang II-AT1R axis, autonomic control and cardiac remodeling at both the establishment of hypertension and during exercise training reveals the essential role played by the AT1R pathway in driving cardiac remodeling and autonomic modulation during the transition from the pre- to hypertensive phase.

The impact of rattlesnake venom on mice cerebellum proteomics points to synaptic inhibition and tissue damage.

Snake envenomation is responsible for more than 130,000 deaths worldwide. In Brazil, the Crotalus rattlesnake is responsible for the second largest number of accidental snake bites in the country. Although there are many descriptions of the clinical and biochemical effects of Crotalus envenoming, there are few works describing the molecular events in the central nervous system of an organism due to envenomation. In this study, we analyzed the proteomic effect of Crotalus durissus terrificus snake venom on mice cerebellums. To monitor the envenomation over time, changes in the protein abundance were evaluated at 1 h, 6 h, 12 h and 24 h after venom injection by mass spectrometry. The analysis of the variation of over 4600 identified proteins over time showed a reduction in components of inhibitory synapse signaling, oxidative stress, and maintenance of neuronal cells, which paralleled increasing tissue damage and apoptosis factors. These analyses revealed the potential protein targets of the C. d. terrificus venom on the murine cerebellum, showing new aspects of the snake envenomation effect. These data may contribute to new therapeutic approaches (i.e., approaches directed at protein targets affected by the envenomation) on the treatment of envenomation by the neurotoxic C. d. terrificus snake venom. SIGNIFICANCE: Snakebites are a neglected global health problem that affects mostly rural and tropical areas of developing countries. It is estimated that over 5.4 million people are bitten by snakes each year, from which 2.7 million people are bitten by venomous snakes, resulting in disabilities such as amputations and in some cases leading to death. The C. d. terrificus snake is the most lethal snake in Brazil. Studying the molecular changes upon envenomation in a specific tissue may lead to a better understanding of the envenomation process by C. d. terrificus snakebites.

The impact of rattlesnake venom on mice cerebellum proteomics points to synaptic inhibition and tissue damage

Snake envenomation is responsible for more than 130,000 deaths worldwide. In Brazil, the Crotalus rattlesnake is responsible for the second largest number of accidental snake bites in the country. Although there are many descriptions of the clinical and biochemical effects of Crotalus envenoming, there are few works describing the molecular events in the central nervous system of an organism due to envenomation. In this study, we analyzed the proteomic effect of Crotalus durissus terrificus snake venom on mice cerebellums. To monitor the envenomation over time, changes in the protein abundance were evaluated at 1 h, 6 h, 12 h and 24 h after venom injection by mass spectrometry. The analysis of the variation of over 4600 identified proteins over time showed a reduction in components of inhibitory synapse signaling, oxidative stress, and maintenance of neuronal cells, which paralleled increasing tissue damage and apoptosis factors. These analyses revealed the potential protein targets of the C. d. terrificus venom on the murine cerebellum, showing new aspects of the snake envenomation effect. These data may contribute to new therapeutic approaches (i.e., approaches directed at protein targets affected by the envenomation) on the treatment of envenomation by the neurotoxic C. d. terrificus snake venom. Significance Snakebites are a neglected global health problem that affects mostly rural and tropical areas of developing countries. It is estimated that over 5.4 million people are bitten by snakes each year, from which 2.7 million people are bitten by venomous snakes, resulting in disabilities such as amputations and in some cases leading to death. The C. d. terrificus snake is the most lethal snake in Brazil. Studying the molecular changes upon envenomation in a specific tissue may lead to a better understanding of the envenomation process by C. d. terrificus snakebites.

The impact of rattlesnake venom on mice cerebellum proteomics points to synaptic inhibition and tissue damage

Snake envenomation is responsible for more than 130,000 deaths worldwide. In Brazil, the Crotalus rattlesnake is responsible for the second largest number of accidental snake bites in the country. Although there are many descriptions of the clinical and biochemical effects of Crotalus envenoming, there are few works describing the molecular events in the central nervous system of an organism due to envenomation. In this study, we analyzed the proteomic effect of Crotalus durissus terrificus snake venom on mice cerebellums. To monitor the envenomation over time, changes in the protein abundance were evaluated at 1 h, 6 h, 12 h and 24 h after venom injection by mass spectrometry. The analysis of the variation of over 4600 identified proteins over time showed a reduction in components of inhibitory synapse signaling, oxidative stress, and maintenance of neuronal cells, which paralleled increasing tissue damage and apoptosis factors. These analyses revealed the potential protein targets of the C. d. terrificus venom on the murine cerebellum, showing new aspects of the snake envenomation effect. These data may contribute to new therapeutic approaches (i.e., approaches directed at protein targets affected by the envenomation) on the treatment of envenomation by the neurotoxic C. d. terrificus snake venom. Significance Snakebites are a neglected global health problem that affects mostly rural and tropical areas of developing countries. It is estimated that over 5.4 million people are bitten by snakes each year, from which 2.7 million people are bitten by venomous snakes, resulting in disabilities such as amputations and in some cases leading to death. The C. d. terrificus snake is the most lethal snake in Brazil. Studying the molecular changes upon envenomation in a specific tissue may lead to a better understanding of the envenomation process by C. d. terrificus snakebites.

PAR-2 expression in the gingival crevicular fluid reflects chronic periodontitis severity.

Recent studies investigating protease-activated receptor type 2 (PAR-2) suggest an association between the receptor and periodontal inflammation. It is known that gingipain, a bacterial protease secreted by the important periodontopathogen Porphyromonas gingivalis can activate PAR-2. Previous studies by our group found that PAR-2 is overexpressed in the gingival crevicular fluid (GCF) of patients with moderate chronic periodontitis (MP). The present study aimed at evaluating whether PAR-2 expression is associated with chronic periodontitis severity. GCF samples and clinical parameters, including plaque and bleeding on probing indices, probing pocket depth and clinical attachment level, were collected from the control group (n = 19) at baseline, and from MP patients (n = 19) and severe chronic periodontitis (SP) (n = 19) patients before and 6 weeks after periodontal non-surgical treatment. PAR-2 and gingipain messenger RNA (mRNA) in the GCF of 4 periodontal sites per patient were evaluated by Reverse Transcription Polymerase Chain Reaction (RT-qPCR). PAR-2 and gingipain expressions were greater in periodontitis patients than in control group patients. In addition, the SP group presented increased PAR-2 and gingipain mRNA levels, compared with the MP group. Furthermore, periodontal treatment significantly reduced (p <0.05) PAR-2 expression in patients with periodontitis. In conclusion, PAR-2 is associated with chronic periodontitis severity and with gingipain levels in the periodontal pocket, thus suggesting that PAR-2 expression in the GCF reflects the severity of destruction during periodontal infection.

PAR-2 expression in the gingival crevicular fluid reflects chronic periodontitis severity

Abstract Recent studies investigating protease-activated receptor type 2 (PAR-2) suggest an association between the receptor and periodontal inflammation. It is known that gingipain, a bacterial protease secreted by the important periodontopathogen Porphyromonas gingivalis can activate PAR-2. Previous studies by our group found that PAR-2 is overexpressed in the gingival crevicular fluid (GCF) of patients with moderate chronic periodontitis (MP). The present study aimed at evaluating whether PAR-2 expression is associated with chronic periodontitis severity. GCF samples and clinical parameters, including plaque and bleeding on probing indices, probing pocket depth and clinical attachment level, were collected from the control group (n = 19) at baseline, and from MP patients (n = 19) and severe chronic periodontitis (SP) (n = 19) patients before and 6 weeks after periodontal non-surgical treatment. PAR-2 and gingipain messenger RNA (mRNA) in the GCF of 4 periodontal sites per patient were evaluated by Reverse Transcription Polymerase Chain Reaction (RT-qPCR). PAR-2 and gingipain expressions were greater in periodontitis patients than in control group patients. In addition, the SP group presented increased PAR-2 and gingipain mRNA levels, compared with the MP group. Furthermore, periodontal treatment significantly reduced (p <0.05) PAR-2 expression in patients with periodontitis. In conclusion, PAR-2 is associated with chronic periodontitis severity and with gingipain levels in the periodontal pocket, thus suggesting that PAR-2 expression in the GCF reflects the severity of destruction during periodontal infection.