Cyto and Genoprotective Potential of Tannic Acid Against Cadmium and Nickel Co-exposure Induced Hepato-Renal Toxicity in BALB/c Mice.

Tannic acid (TA) is a metal chelating polyphenol that plays a crucial role in metal detoxification, but its modulatory role in co-exposure of these heavy metals' exposure needs to be explored. Cadmium (Cd) and nickel (Ni) are inorganic hazardous chemicals in the environment. Humans are prone to be exposed to the co-exposure of Cd and Ni, but the toxicological interactions of these metals are poorly defined. Present study was undertaken to study the preventive role of TA in Cd-Ni co-exposure-evoked hepato-renal toxicity in BALB/c mice. In the current investigation, increased oxidative stress in metal intoxicated groups was confirmed by elevated peroxidation of the lipids and significant lowering of endogenous antioxidant enzymes. Altered hepato-renal serum markers, DNA fragmentation, and histological alterations were also detected in the metal-treated groups. Present study revealed that Cd is a stronger toxicant than Ni and when co-exposure was administered, additive, sub-additive, and detrimental effects were observed. Prophylactic treatment with TA significantly reinstated the levels of lipid peroxidation (LPO), non-enzymatic, and enzymatic antioxidants. Moreover, it also restored the serum biomarker levels, DNA damage, and histoarchitecture of the given tissues. TA due to its metal chelating and anti-oxidative properties exhibited cyto- and genoprotective potential against Cd-Ni co-exposure-induced hepatic and renal injury.

Gestational Fisetin Exerts Neuroprotection by Regulating Mitochondria-Directed Canonical Wnt Signaling, BBB Integrity, and Apoptosis in Prenatal VPA-Induced Rodent Model of Autism.

Embryonic valproic acid (VPA) has been considered a potential risk factor for autism. Majority of studies indicated that targeting autism-associated alterations in VPA-induced autistic model could be promising in defining and designing therapeutics for autism. Numerous investigations in this field investigated the role of canonical Wnt signaling cascade in regulating the pathophysiology of autism. The impaired blood-brain barrier (BBB) permeability and mitochondrial dysfunction are some key implied features of the autistic brain. So, the current study was conducted to target canonical Wnt signaling pathway with a natural polyphenolic modulator cum antioxidant namely fisetin. A single dose of intraperitoneal VPA sodium salt (400 mg/kg) at gestational day 12.5 induced developmental delays, social behaviour impairments (tube dominance test), and anxiety-like behaviour (sucrose preference test) similar to autism. VPA induced mitochondrial damage and over-activated the canonical Wnt signaling which further increased the blood-brain barrier (BBB) disruption, apoptosis, and neuronal damage. Our findings revealed that oral administration of 10 mg/kg gestational fisetin (GD 13-till parturition) improved social and anxiety-like behaviour by modulating the ROS-regulated mitochondrial-canonical Wnt signaling. Moreover, fisetin controls BBB permeability, apoptosis, and neuronal damage in autism model proving its neuroprotective efficacy. Collectively, our findings revealed that fisetin-evoked modulation of the Wnt signaling cascade successfully relieved the associated symptoms of autism along with developmental delays in the model and indicates its potential as a bioceutical against autism.

Neuroprotective Efficacy of Fisetin Against VPA-Induced Autistic Neurobehavioral Alterations by Targeting Dysregulated Redox Homeostasis.

Autism is a neurodevelopmental condition, and it's associated pathophysiology, viz., oxidative stress and altered cellular homeostasis, has been extensively intertwined with behavioral impairments. Therefore, targeting oxidative stress and redox cellular homeostasis could be beneficial in relieving autistic-like symptoms. For this purpose, we examined a library of nutraceutical compounds that led us to a bioflavonoid fisetin. Autism-like neurobehavior was induced by subjecting the pregnant rodents to valproic acid at the time of neural tube closure (GD12.5). In this novel study, fisetin was evaluated for its neuroprotective potential at gestational (GD13 until delivery) and post-weaning developmental windows (PND 23-32) in VPA-induced rodent model of autism. Developmental VPA exposure increased intracellular ROS production, oxidative stress, altered AChE and ATPases in brain regions, and induced autistic-like behavioral impairments (social, repetitive, stereotyped, and sensorimotor). The present findings suggested that gestational and post-weaning fisetin treatment significantly improved the behavioral impairments by attenuating elevated oxidative stress, ROS, lipid peroxidation, and re-establishing redox homeostasis. Also, it effectively reinstated the reduced levels of endogenous antioxidants, glutathione, AChE, and ATPases by its antioxidant potential. Therefore, fisetin with its properties could be used as a potential therapeutic agent in overcoming the symptoms associated with autism.

Critical Evaluation of Valproic Acid-Induced Rodent Models of Autism: Current and Future Perspectives.

Valproic acid (VPA) induced rodent model of autism is a widely accepted and extensively used rodent model to investigate the pharmacotherapy against autism. But, to date, its validation, suitability, and applicability as a well defining autistic model are still questionable. Previous research efforts highlighted that this model shows various core defining features of autism and related pathways, hence it is very necessary to explore its authenticity as a well-suited model for autism. Therefore, in this review, we summarize the preclinical and neurobiological relevant validated features, involved etiological mechanism, biological markers, treatment responses, drawbacks, current approaches, and future perspectives of VPA-induced model of autism. This review would help in deciphering the validation of the VPA-induced autistic model and its suitability as an experimental model of autism. A thorough investigation of behavioral, molecular, and neurobiological processes in animal models of autism would help in investigating the exact causation and effective treatment for autism.

Neuroprotective efficacy of berberine following developmental exposure to chlorpyrifos in F1 generation of Wistar rats: Apoptosis-autophagy interplay.

Chlorpyrifos (CPF), an organophosphate insecticide commonly used in agriculture and household applications, is considered a developmental neurotoxicant. This study aimed to explain the neuroprotective role of Berberine (BBR) against CPF-induced autophagy dysfunction and apoptotic neurodegeneration in the developing hippocampus. F1 generation of Wistar rats was exposed to CPF (3 mg/kg b.wt.) and co-treated with BBR (10 mg/kg b.wt) in two different exposure regimens, gestational (GD9-12 and GD17-21) and lactational (PND1-20). Our results demonstrated that CPF intoxication instigated cognitive and neurobehavioral impairment, oxidant-antioxidant imbalance, and histomorphological alterations in CA1, CA3, and DG regions of the offsprings. Furthermore, mRNA expression of pro-apoptotic genes (caspase3 and Bax) was upregulated, and that of anti-apoptotic BCl2 was downregulated. In addition, exposure to CPF also activated the autophagy inhibitor (mTOR) transcription and subsequently downregulated the expression of autophagy markers beclin1 and LC3-II. In contrast, gestational and lactational co-treatment of BBR significantly upregulated the enzymatic anti-oxidant bar of the hippocampus and attenuated histological alterations. Moreover, BBR co-treatments reduced apoptotic neurodegeneration in the hippocampal region by regulating the expression of apoptotic genes and upregulated the levels of autophagy, confirmed by ultrastructural studies, decreased gene expression and immunostaining of mTOR and increased, and increased expression gene expression and immunostaining of LC3-II positive cells. Our results confirm that treatment with BBR induces autophagy, which plays a neuroprotective role in CPF-induced developmental neuronal apoptosis in the F1 generation of Wistar rats by regulating the balance between autophagy and apoptosis.

Berberine affords protection against oxidative stress and apoptotic damage in F1 generation of wistar rats following lactational exposure to chlorpyrifos.

Chlorpyrifos (0,0-diethyl 0-(3,5,6-trichloro-2-pyridinyl)-phosphorothioate; (CPF)) is a widely used lipophilic organophosphorus insecticide that primarily manifests into central and peripheral nervous system toxicity. However, it is poorly investigated as a developmental neurotoxicant and thus remains less explored for pharmacological interventions as well. Berberine (BBR) is a benzylisoquinoline alkaloid, primarily found in the plants of Berberidaceae family, and is used for the synthesis of several bioactive derivatives. The goal of this study was to evaluate the CPF-induced neuronal damage through lactational route and analyze the neuroprotective efficacy of berberine (BBR), a potent antioxidant compound in the F1 generation. The environmentally relevant dose of CPF (3 mg/kg b.wt.) was administered via gavage to pregnant dams from postnatal day 1 to day 20 (PND 1-20). BBR (10 mg/kg b.wt.) was administered concurrently with CPF for the same duration as a co-treatment. Levels of reactive oxygen species, lipid peroxidation, membrane bound ATPases (Na+K+ATPase, Ca2+ATPase, and Mg2+ATPase), DNA damage, histomorphological alterations, cellular apoptosis were increased, and activities of glutathione reductase, endogenous antioxidant enzymes (SOD, CAT, GST, and GR) were decreased in cerebellum and cerebrum regions of CPF exposed pups. CPF triggered neuronal apoptosis by upregulating Bax and caspase-3 and downregulating Bcl-2. Co-treatment of BBR significantly attenuated these effects of CPF signifying oxidative stress mediated chlorpyrifos induced neuronal apoptosis. Berberine treatment ameliorated the CPF-induced downregulation of Bcl-2, Bax translocation, and up-regulation of caspase-3 in F1 pups. Therefore, BBR owing to its multiple pharmacological properties can be further explored for its therapeutic potential as an alternative neuroprotective agent against lactational exposure of chlorpyrifos-induced developmental neurotoxicity.

Naringenin Upregulates AMPK-Mediated Autophagy to Rescue Neuronal Cells From ß-Amyloid (1-42) Evoked Neurotoxicity.

Deposition of an amyloid-ß peptide is one of the first events in the pathophysiology of Alzheimer's disease (AD) and is clinically characterized by Aß plaques, tau tangles, and behavioral impairments that lead to neuronal death. A substantial number of studies encourage targeting the skewness in the production and degradation of amyloid-ß could be among the promising therapies in the disease. Neuronal autophagy has emerged for an essential role in the degradation of such toxic aggregate-prone proteins in various neurodegenerative diseases. We profiled a small library of common dietary compounds and identified those that can enhance autophagy in neuronal cells. Here we noted naringenin in silico exhibits a robust affinity with AMP-activated protein kinase (AMPK) and upregulated AMPK-mediated autophagy signaling in neurons. Naringenin can induce autophagy promoting proteins such as ULK1, Beclin1, ATG5, and ATG7 in Neuro2a cells and primary mouse neurons as well. The knockdown of AMPK by siRNA-AMPK was complemented by naringenin that restored transcript levels of AMPK. Further, naringenin can reduce the levels of Aß at a nontoxic concentration from neuronal cells. Moreover, it maintained the mitochondrial membrane potential and resisted reactive oxygen species production, which led to the protection against Aß1-42 evoked neurotoxicity. This highlights the neuroprotective potential of naringenin that can be developed as an anti-amyloidogenic nutraceutical.

Epigallocatechin gallate attenuates arsenic induced genotoxicity via regulation of oxidative stress in balb/C mice.

Arsenic is well known genotoxicant which causes the excessive generation of reactive oxygen species (ROS) and inhibition of antioxidant enzyme systems leading to cell damage through the activation of oxidative sensitive signaling pathways. Epigallocatechin gallate (EGCG), the main and active polyphenolic catechin present in green tea, has shown potent antioxidant, free radical scavenging and genoprotective activity in vivo. The present study attempted to investigate antioxidant and geno-protective efficacy of EGCG by regulating arsenic induced oxidative stress in mice. Animals received prophylactic and therapeutic treatments at two different doses (25 and 50 mg/kg b.wt.) of EGCG orally for 15 days and administered arsenic intraperitoneally at dose of 1.5 mg/kg b.wt (1/10th of LD50) for 10 days. Arsenic intoxication revealed enhanced ROS production (114%) in lymphocytes; elevated levels of LPO (2-4 fold); reduced levels of hepato-renal antioxidants (approx. 45%) and augmented genomic fragmentation in hepato-renal tissues; increased chromosomal anomalies (78%) and micronucleation (21.93%) in bone marrow cells and comet tailing (25%) in lymphocytes of mice. Both pre and post treatments of EGCG decreased ROS production, restored lipid peroxidation (LPO) and reduced hepato-renal antioxidants levels, reduced the DNA fragmentation, number of chromosomal aberrations (CA), micronucleation (MN), and comet tailing but prophylactic treatment of 50 mg/kg b.wt was the most effective treatment in regulating arsenic induced oxidative stress. The effectiveness of this dose was furthermore validated by calculating the inhibitory index. Thus, results of present work empirically demonstrate free radical scavenging, anti-oxidative and genoprotective efficacy of EGCG against arsenic toxicity.

Soluble Aß1-42 suppresses TNF-α and activates NLRP3 inflammasome in THP-1 macrophages.

Deposition of amyloid-ß in Alzheimer's disease is accompanied by chronic inflammation, which involves raised levels of pro-inflammatory cytokines TNF-α, IL-6 and IL-1ß. However, the role of Aß1-42 in the inflammatory process, before it gets deposited into aggregates has not been investigated thoroughly. Through this study, we are illustrating the dual role of soluble Aß1-42 (sAß1-42) in activating the NLRP3 inflammasome and simultaneously inhibiting TNF-α secretion. Our data suggested that the treatment of chronically induced THP-1 macrophages and N9 microglial cells with sAß1-42 can suppress the major inflammatory cytokine TNF-α without affecting the level of IL-6. However, the activation of NLRP3 inflammasome was well evidenced by secretion of IL-1ß, increased expression of NLRP3 and caspase-1, implicating sAß1-42 in enhancing and suppressing one or other type of inflammation. Further investigation revealed that sAß1-42 was able to severely abrogate the expression of NF-κB, p50 and restricting the translocation of NF-κB, p65 to nucleus by inhibiting phosphorylation of IκB-α in THP-1 macrophages. These data indicate that the sAß1-42 may play a dual role during inflammatory process, wherein, it may be involved in protecting the cells from inflammatory damage due to TNF-α. This ability of sAß1-42 might be playing some role in protecting the brain cells during the process of aging and Alzheimer's disease, where, chronic inflammatory environment plays a vital role.

miR-322/-503 cluster is expressed in the earliest cardiac progenitor cells and drives cardiomyocyte specification.

Understanding the mechanisms of early cardiac fate determination may lead to better approaches in promoting heart regeneration. We used a mesoderm posterior 1 (Mesp1)-Cre/Rosa26-EYFP reporter system to identify microRNAs (miRNAs) enriched in early cardiac progenitor cells. Most of these miRNA genes bear MESP1-binding sites and active histone signatures. In a calcium transient-based screening assay, we identified miRNAs that may promote the cardiomyocyte program. An X-chromosome miRNA cluster, miR-322/-503, is the most enriched in the Mesp1 lineage and is the most potent in the screening assay. It is specifically expressed in the looping heart. Ectopic miR-322/-503 mimicking the endogenous temporal patterns specifically drives a cardiomyocyte program while inhibiting neural lineages, likely by targeting the RNA-binding protein CUG-binding protein Elav-like family member 1 (Celf1). Thus, early miRNAs in lineage-committed cells may play powerful roles in cell-fate determination by cross-suppressing other lineages. miRNAs identified in this study, especially miR-322/-503, are potent regulators of early cardiac fate.

Transcription factors ETS2 and MESP1 transdifferentiate human dermal fibroblasts into cardiac progenitors.

Unique insights for the reprograming of cell lineages have come from embryonic development in the ascidian Ciona, which is dependent upon the transcription factors Ci-ets1/2 and Ci-mesp to generate cardiac progenitors. We tested the idea that mammalian v-ets erythroblastosis virus E26 oncogene homolog 2 (ETS2) and mesoderm posterior (MESP) homolog may be used to convert human dermal fibroblasts into cardiac progenitors. Here we show that murine ETS2 has a critical role in directing cardiac progenitors during cardiopoiesis in embryonic stem cells. We then use lentivirus-mediated forced expression of human ETS2 to convert normal human dermal fibroblasts into replicative cells expressing the cardiac mesoderm marker KDR(+). However, although neither ETS2 nor the purported cardiac master regulator MESP1 can by themselves generate cardiac progenitors de novo from fibroblasts, forced coexpression of ETS2 and MESP1 or cell treatment with purified proteins reprograms fibroblasts into cardiac progenitors, as shown by the de novo appearance of core cardiac transcription factors, Ca(2+) transients, and sarcomeres. Our data indicate that ETS2 and MESP1 play important roles in a genetic network that governs cardiopoiesis.

Modulation of myocardial mitochondrial mechanisms during severe polymicrobial sepsis in the rat.

BACKGROUND: We tested the hypothesis that 5-Hydroxydecanoic acid (5HD), a putative mitoK(ATP) channel blocker, will reverse sepsis-induced cardiodynamic and adult rat ventricular myocyte (ARVM) contractile dysfunction, restore mitochondrial membrane permeability alterations and improve survival. METHODOLOGY/PRINCIPAL FINDINGS: Male Sprague-Dawley rats (350-400 g) were made septic using 400 mg/kg cecal inoculum, ip. Sham animals received 5% dextrose water, ip. The Voltage Dependent Anion Channels (VDAC1), Bax and cytochrome C levels were determined in isolated single ARVMs obtained from sham and septic rat heart. Mitochondria and cytosolic fractions were isolated from ARVMs treated with norepinephrine (NE, 10 µmoles) in the presence/absence of 5HD (100 µmoles). A continuous infusion of 5HD using an Alzet pump reversed sepsis-induced mortality when administered at the time of induction of sepsis (-40%) and at 6 hr post-sepsis (-20%). Electrocardiography revealed that 5HD reversed sepsis-induced decrease in the average ejection fraction, Simpsons+m Mode (53.5±2.5 in sepsis and 69.2±1.2 at 24 hr in sepsis+5HD vs. 79.9±1.5 basal group) and cardiac output (63.3±1.2 mL/min sepsis and 79.3±3.9 mL/min at 24 hr in sepsis+5HD vs. 85.8±1.5 mL/min basal group). The treatment of ARVMs with 5HD also reversed sepsis-induced depressed contractility in both the vehicle and NE-treated groups. Sepsis produced a significant downregulation of VDAC1, and upregulation of Bax levels, along with mitochondrial membrane potential collapse in ARVMs. Pretreatment of septic ARVMs with 5HD blocked a NE-induced decrease in the VDAC1 and release of cytochrome C. CONCLUSION: The data suggest that Bax activation is an upstream event that may precede the opening of the mitoK(ATP) channels in sepsis. We concluded that mitoK(ATP) channel inhibition via decreased mitochondrial membrane potential and reduced release of cytochrome C provided protection against sepsis-induced ARVM and myocardial contractile dysfunction.

Norepinephrine induces systolic failure and inhibits antiapoptotic genes in a polymicrobial septic rat model.

AIMS: We examined the effect of norepinephrine (NE) infusion on left ventricular function and apoptotic genes during progression of polymicrobial sepsis. METHODS: Male Sprague-Dawley rats (350-400 g) were made septic by intraperitoneal (i.p.) administration of 200mg/kg cecal inoculum. Sham animals received 5% dextrose water, i.p. Echocardiography was performed at baseline, 3 days and 7 days post-sepsis/sham. NE (0.6 µgkg(-1)h(-1)) was infused for 2h, before the end of day 3 of echocardiography. At the end of day 7, rats were euthanized and heart tissues harvested for isolation of total RNA. PCR was performed using RT(2) profiler™ PCR array PARN-012 (Rat apoptosis array; SuperArray, MD) using RT(2) Real-Time™ SYBR Green PCR master mix PA-012. KEY FINDINGS: NE-infusion resulted in a significant decrease in the left ventricular ejection fraction (EF) (62.56±2.07 from the baseline 71.11±3.23, p<0.05) and fractional shortening (FS) (39.90±2.64 from the sham group 54.41±2.19, p<0.05) at 7 days post-sepsis, respectively. Super Array data revealed that during sepsis, tumor necrosis factor (TNF-α) (2.85±0.07 fold, p<0.0001), anti-apoptotic molecules, Prok2 (16.07±0.48 fold, p<0.0001) and interleukin-10 (IL-10) (23.5±0.57 fold, p<0.0001) were up regulated at day 1. At 7-days post-sepsis, CD40l g (2.49±0.54 fold, p<0.08) and Birc1b (17.8±0.58 fold, p<0.0001) were up regulated compared to the sham, 1 and 3-days post-sepsis groups. SIGNIFICANCE: The data suggest that upregulation of a series of pro-apoptotic molecules could be responsible for systolic and diastolic dysfunction during 3 and 7 days post sepsis.

Caspase-3 knock-down reverses contractile dysfunction induced by sepsis in adult rat ventricular myocytes.

BACKGROUND AND PURPOSE: The present study tested the hypothesis that selective caspase-3 (C-3) knock-out would regulate the contractile actions of noradrenaline (NA) in the dysfunction of adult rat ventricular myocytes (ARVMs) induced by sepsis. Here, we have studied the contractile response of ARVMs, transfected with C-3 small interfering RNA (C-3 siRNA), to NA. EXPERIMENTAL APPROACH: Single ARVMs were isolated from the hearts of male Sprague-Dawley rats 3 days after induction of sepsis, and from sham-treated rats. The sham and septic ARVMs were treated with NA (10 microM) alone or after transfection with C-3 siRNA or non-silencing RNA (2 microM). Mechanical properties were measured digitally, and immunoblotting and immunocytochemical analyses were carried out. KEY RESULTS: The NA-induced increase in peak shortening (PS) was less in septic ARVMs and transfection with C-3 siRNA produced a significant increase in this PS. Immunocytochemical and immunoblot analyses revealed that NA exacerbated sepsis-induced up-regulation of C-3. Transfection of septic ARVMs with C-3 siRNA exhibited a decreased expression of C-3 fluorescence after NA. In septic ARVMs, we also observed a down-regulation of contractile proteins (alpha-actin, myosin light chain-1 and tropomyosin) along with DNA damage. Transfection of septic ARVMs with C-3 siRNA produced an increase in the expression of contractile proteins, and a decrease in DNA damage. CONCLUSIONS AND IMPLICATIONS: These data suggest that C-3 knock-down improved the loss of contractile response to NA in septic ARVMs, suggesting that C-3 regulated contractile dysfunction induced by sepsis in ARVMs.

Contractile response of norepinephrine is modulated by caspase-3 in adult rat ventricular myocytes isolated from septic rat heart.

Sepsis accounts for 50% of intensive care unit deaths due to cardiac dysfunction. The cellular mechanisms following norepinephrine (NE) during sepsis are undefined. Using a septic adult rat ventricular myocyte (ARVM) paradigm, we examined the molecular mechanism responsible for the blunted contractile response of NE. We tested the hypothesis that NE-induced increases in active caspase-3 contribute to sepsis-induced ARVM contractile dysfunction. Single ARVMs were isolated from hearts harvested from sham and septic male rats. The contractile properties and expression of caspase-3 cascade proteins were determined in ARVMs treated with NE with and without QVD-OPH, prazosin and atenolol to characterize the effect of NE on their mechanical properties. Septic ARVMs exhibited a significant decrease in peak shortening (PS) compared to sham ARVMs. The effect of NE on the PS of the sham ARVMs was more pronounced compared to the septic ARVMs, suggesting a blunted contractile response of NE. NE in the presence of QVD-OPH ameliorated the sepsis-induced decrease in PS at 18h but not at 1h, while the effect of NE on sepsis-induced contractile response remained unaffected at 18h by prazosin and atenolol. An up-regulated expression of caspase-3 in NE-treated septic ARVMs was reversed by QVD-OPH, as seen by the increased number of septic ARVMs exhibiting caspase-3 fluorescence. Transfection of ARVMs using caspase-3 siRNA blocked sepsis-induced up-regulation of caspase-3 and increased PS following NE treatment. These data suggest that caspase-3 inhibition ameliorated sepsis-induced decreased ARVM contractility and blocked the blunted contractile response of NE.

Age-dependent differential expression of apoptosis markers in the gingival tissue.

OBJECTIVE: The current study was performed to test the hypothesis that periodontal disease produces age-dependent activation of apoptotic markers in the gingival tissues. METHODS: To address the hypothesis a prospective experimental study was designed and twenty-two patients were enrolled. Out of the twenty-two patients, gingival tissue biopsies samples were obtained from active sites of ten and twelve periodontal-healthy (HS) and periodontal disease (PD, probing depths >5mm patients, respectively. The groups were further divided into 25-50 and <5 years age subgroups. RESULTS: A significant decrease in the expression of TRADD (Tumour Necrosis Factor Receptor-Associated Death Domain) was observed in 25-50 years of PD group compared to the HS group. Bax (BCL(2)-associated X protein) expression in the PD groups was significantly decreased in PD 25-50 years age group but increased in the >50 years age group compared to respective HS age groups. PD patients of both 25-50 years and >50 years age exhibited a significant increase in the expression of Cytochrome C and Caspase-3 compared to the respective HS groups. The PD patients exhibited a stronger correlation with age in the expression of TRADD and Bax compared to the HS groups. Further analyses revealed that the expression of Caspase-3 correlated with an increase in the age of the healthy patients. CONCLUSIONS: The data suggested that modulation of apoptotic cascade may contribute to the damage of gingival tissues particularly in PD patients >50 years age.

Acute lung injury:apoptosis and signaling mechanisms.

Acute lung injury (ALI) has been documented clinically following several pathological states such as trauma, septic shock and pneumonia. The histopathological characteristics, paired with the production of a number of cellular pro-inflammatory mediators, play a crucial role in the progression of ALI. During ALI, polymorphonuclear neutrophil (PMN)-mediated apoptosis is delayed by macrophages, possibly via effects on the Fas/FasL mediated pathway, leading to the accumulation of these cells at the site of injury and inflammation. The transcriptional regulation of NFkappaB, CREB, and AP-1 also regulates the pathogenesis of ALI. During sepsis and septic shock, we found evidence of infiltrating leukocytes in the alveolar spaces along with an increased number of TUNEL-positive cells in the lung sections. We also observed an increased expression of TRADD and Bax/Bcl(2) ratio at 7 days post-sepsis. In contrast, the NFkappaB/IkappaB ratio increased at 1 day post-sepsis. Together, these data provide evidence illustrating the induction of apoptosis in lung tissues subsequent to the onset of polymicrobial sepsis. The results support the concept that the upregulation of apoptosis following lung inflammation plays a crucial role in the development of acute lung injury and related disorders such as ARDS.

Upregulation of myocardial syntaxin1A is associated with an early stage of polymicrobial sepsis.

This study was designed to test whether increased sympathetic stimulation during polymicrobial sepsis modulates the profile of the syntaxin1A and norepinephrine transporter (NET) in the heart. Sepsis of mild and severe intensity was induced in male Sprague-Dawley rats (275-350 g) using the cecal inoculum (CI) and cecal ligation and puncture (CLP) methods, respectively. The heart samples were isolated from sham, 1, 3, and 7 day post-sepsis in the CI model and at 2 and 20 h post-sepsis in the CLP model. In the CI model, the plasma concentration of norepinephrine (NE) significantly increased at 1, 3, and 7 days post-CI compared to the sham group. The myocardial syntaxin1A mRNA and protein expression also significantly increased at 1 day post-CI compared to the sham group. However, the sepsis-induced increase in syntaxin1A returned to the baseline values at 3 and 7 days post-CI. The expressions of myocardial NET mRNA and protein were not altered at 1 day post-CI but significantly decreased at 3 days post-CI compared to the sham and 1 day post-CI groups. The immunohistochemical analyses revealed an increased localization of NET and syntaxin1A in the heart tissue sections of the 1 day post-CI group. In the CLP model of severe sepsis, the myocardial syntaxin1A mRNA protein expressions significantly increased at 2 h post-CLP, but remained unchanged at 20 h post-CLP compared to the sham group. In contrast, the myocardial expressions of NET mRNA and protein significantly decreased at both 2 and 20 h post-CLP compared to the sham group. It appears that during severe sepsis (CLP model), both the upregulation of syntaxin1A and the downregulation of NET contribute to increased concentrations of NE during the early and late stages of sepsis.

Distinct cardiodynamic and molecular characteristics during early and late stages of sepsis-induced myocardial dysfunction.

We hypothesized that progressive decline in myocardial performance would correlate with upregulation of markers for apoptotic mechanisms following increased duration of polymicrobial sepsis in the rat. Male Sprague-Dawley rats (350-400 g) were randomized into sham, 1-, 3- and 7-day sepsis groups. Each septic rat received 200 mg/kg cecal inoculum intraperitoneally (i.p). The post-mortem analysis showed a severely inflamed peritoneum with the presence of pus in all septic animals that was directly proportional to the duration of sepsis. We observed 10, 33 and 42% mortality in the 1-, 3- and 7-day sepsis groups, respectively. Septic animals at 3 and 7 days exhibited an increased wet lung/total body weight and heart weight/total body weight. A significant increase in total cardiac troponin I (cTnI) and C Reactive Protein (CRP) and endothelin-1 (ET-1) was also observed with an increased duration of sepsis. Myocardial ET-1 concentration in the 7-day post-sepsis group was significantly elevated compared to the sham and 1-day post-sepsis groups. Sepsis also produced a significant decrease in the mean arterial pressure in the 7-day post-sepsis group and tachycardia in the 1-, 3-, and 7-day post-sepsis groups compared to the sham group. A significant prolongation of the left ventricular isovolumic relaxation rate constant, tau, and left ventricular end-diastolic pressure in the 1-, 3- and 7-day post-sepsis groups compared to the sham group was observed. In addition, a significant decrease in the rates of left ventricular relaxation (-dP/dt) and contraction (+dP/dt) in the 3- and 7-day post-sepsis groups compared to the sham and 1-day post-sepsis group was observed. Sepsis produced a significant upregulation in the expression of myocardial TRADD, cytosolic active caspase-3, the Bax/Bcl(2) ratio, and the mitochondrial release of cytochrome C in the 3- and 7-day post-sepsis groups. We observed a progressive increase in the number of TUNEL positive nuclei, cytosolic caspase-3 activation and co-localization of PARP in the nuclei at 1, 3 and 7 days post-sepsis. These data suggest that the progression of sepsis from 1 day to 3-7 days produce distinct cardiodynamic characteristics with a more profound effect during later stages. The sepsis-induced decline in myocardial performance correlates with the induction of myocardial apoptosis.

Apoptotic cardiomyocyte hypertrophy during sepsis and septic shock results from prolonged exposure to endothelin precursor.

Septic shock is a complex cardiovascular dysfunction which leads to regional circulatory alterations and multi-organ dysfunction in humans and animal models. To elucidate the role of stress-activated signaling molecules in the regulation of myocardial dysfunction, we have developed and standardized isolated ventricular myocyte techniques. These techniques allow the assessment of cardiodynamics at cellular (ventricular myocyte) level. These studies are carried out in a well defined model of systemic inflammatory response syndrome following polymicrobial sepsis in the rat. Evidence is provided that sepsis-induced myocardial dysfunction produces indications (signs) of early stages of heart failure. This evidence correlates with upregulation of stress-activated protein kinase cascade. These findings suggest that prolonged exposure to endothelin precursor causes decompensatory hypertrophy in adult rat ventricular myocytes (ARVMs) during sepsis. The decompensatory hypertrophy could, in turn, results in increased cytosolic caspases-3 activity in ARVMs.