scholarly journals Targeting Tumor Necrosis Factor Alpha for Alzheimer’s Disease

2017 ◽  
Vol 14 (4) ◽  
pp. 412-425 ◽  
Author(s):  
Boris Decourt ◽  
Debomoy K. Lahiri ◽  
Marwan N. Sabbagh

Alzheimer’s disease (AD) affects an estimated 44 million individuals worldwide, yet no therapeutic intervention is available to stop the progression of the dementia. Neuropathological hallmarks of AD are extracellular deposits of amyloid beta (Aβ) peptides assembled in plaques, intraneuronal accumulation of hyperphosphorylated tau protein forming tangles, and chronic inflammation. A pivotal molecule in inflammation is the pro-inflammatory cytokine TNF-α. Several lines of evidence using genetic and pharmacological manipulations indicate that TNF-α signaling exacerbates both Aβ and tau pathologies in vivo. Interestingly, preventive and intervention anti-inflammatory strategies demonstrated a reduction in brain pathology and an amelioration of cognitive function in rodent models of AD. Phase I and IIa clinical trials suggest that TNF-α inhibitors might slow down cognitive decline and improve daily activities in AD patients. In the present review, we summarize the evidence pointing towards a beneficial role of anti-TNF-α therapies to prevent or slow the progression of AD. We also present possible physical and pharmacological interventions to modulate TNF-α signaling in AD subjects along with their limitations.

1998 ◽  
Vol 66 (1) ◽  
pp. 65-69 ◽  
Author(s):  
J. K. Brieland ◽  
D. G. Remick ◽  
M. L. LeGendre ◽  
N. C. Engleberg ◽  
J. C. Fantone

ABSTRACT The in vivo role of endogenous interleukin 12 (IL-12) in modulating intrapulmonary growth of Legionella pneumophila was assessed by using a murine model of replicative L. pneumophila lung infection. Intratracheal inoculation of A/J mice with virulent bacteria (106 L. pneumophilacells per mouse) resulted in induction of IL-12, which preceded clearance of the bacteria from the lung. Inhibition of endogenous IL-12 activity, via administration of IL-12 neutralizing antiserum, resulted in enhanced intrapulmonary growth of the bacteria within 5 days postinfection (compared to untreated L. pneumophila-infected mice). Because IL-12 has previously been shown to modulate the expression of cytokines, including gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and IL-10, which regulate L. pneumophila growth, immunomodulatory effects of endogenous IL-12 on intrapulmonary levels of these cytokines during replicative L. pneumophila lung infection were subsequently assessed. Results of these experiments demonstrated that TNF-α activity was significantly lower, while protein levels of IFN-γ and IL-10 in the lung were similar, in L. pneumophila-infected mice administered IL-12 antiserum, compared to similarly infected untreated mice. Together, these results demonstrate that IL-12 is critical for resolution of replicativeL. pneumophila lung infection and suggest that regulation of intrapulmonary growth of L. pneumophila by endogenous IL-12 is mediated, at least in part, by TNF-α.


Author(s):  
Sridhar Muthusami ◽  
Ilangovan Ramachandran ◽  
Sneha Krishnamoorthy ◽  
Yuvaraj Sambandam ◽  
Satish Ramalingam ◽  
...  

: The development of colorectal cancer (CRC) is a multi-stage process. The inflammation of the colon as in inflammatory bowel disease (IBD) such as ulcerative colitis (UC) or Crohn’s disease (CD) is often regarded as the initial trigger for the development of CRC. Many cytokines such as tumor necrosis factor alpha (TNF-α) and several interleukins (ILs) are known to exert proinflammatory actions, and inflammation initiates or promotes tumorigenesis of various cancers, including CRC through differential regulation of microRNAs (miRNAs/miRs). miRNAs can be oncogenic miRNAs (oncomiRs) or anti-oncomiRs/tumor suppressor miRNAs, and they play key roles during colorectal carcinogenesis. However, the functions and molecular mechanisms of regulation of miRNAs involved in inflammation-associated CRC are still anecdotal and largely unknown. Consolidating the published results and offering perspective solutions to circumvent CRC, the current review is focused on the role of miRNAs and their regulation in the development of CRC. We have also discussed the model systems adapted by researchers to delineate the role of miRNAs in inflammation-associated CRC.


2001 ◽  
Vol 21 (15) ◽  
pp. 4856-4867 ◽  
Author(s):  
Okot Nyormoi ◽  
Zhi Wang ◽  
Dao Doan ◽  
Maribelis Ruiz ◽  
David McConkey ◽  
...  

ABSTRACT Several reports have linked activating protein 2α (AP-2α) to apoptosis, leading us to hypothesize that AP-2α is a substrate for caspases. We tested this hypothesis by examining the effects of tumor necrosis factor alpha (TNF-α) on the expression of AP-2 in breast cancer cells. Here, we provide evidence that TNF-α downregulates AP-2α and AP-2γ expression posttranscriptionally during TNF-α-induced apoptosis. Both a general caspase antagonist (zVADfmk) and a caspase 6-preferred antagonist (zVEIDfmk) inhibited TNF-α-induced apoptosis and AP-2α downregulation. In vivo tests showed that AP-2α was cleaved by caspases ahead of the DNA fragmentation phase of apoptosis. Recombinant caspase 6 cleaved AP-2α preferentially, although caspases 1 and 3 also cleaved it, albeit at 50-fold or higher concentrations. Activated caspase 6 was detected in TNF-α-treated cells, thus confirming its involvement in AP-2α cleavage. All three caspases cleaved AP-2α at asp19 of the sequence asp-arg-his-asp (DRHD19). Mutating D19 to A19abrogated AP-2α cleavage by all three caspases. TNF-α-induced cleavage of AP-2α in vivo led to AP-2α degradation and loss of DNA-binding activity, both of which were prevented by pretreatment with zVEIDfmk. AP-2α degradation but not cleavage was inhibited in vivo by PS-431 (a proteasome antagonist), suggesting that AP-2α is degraded subsequent to cleavage by caspase 6 or caspase 6-like enzymes. Cells transfected with green fluorescent protein-tagged mutant AP-2α are resistant to TNF-α-induced apoptosis, further demonstrating the link between caspase-mediated cleavage of AP-2α and apoptosis. This is the first report to demonstrate that degradation of AP-2α is a critical event in TNF-α-induced apoptosis. Since the DRHD sequence in vertebrate AP-2 is widely conserved, its cleavage by caspases may represent an important mechanism for regulating cell survival, proliferation, differentiation, and apoptosis.


2020 ◽  
Vol 11 (1) ◽  
pp. 391-401
Author(s):  
Jiang Cheng ◽  
Guowei Wang ◽  
Na Zhang ◽  
Fang Li ◽  
Lina Shi ◽  
...  

AbstractBackground:Alzheimer’s disease (AD) is an ultimately fatal, degenerative brain disease in the elderly people. In the current work, we assessed the defensive capability of isovitexin (IVX) through an intracerebroventricular injection of streptozotocin (STZ)-induced AD mouse model.Methods:Mice were separated into four cohorts: sham-operated control mice; STZ-intoxicated Alzheimer’s mice; IVX cohort, IVX + STZ; and Ant-107 cohort, antagomiR-107 + IVX/STZ as in the IVX cohort.Results:The outcomes indicated that IVX administration ameliorated spatial memory loss and blunted a cascade of neuro-noxious episodes – including increased amyloid-beta (Aβ) and degraded myelin basic protein burden, neuroinflammation (represented by elevated caspase-1, TNF-α and IL-6 levels) and autophagic dysfunction (represented by altered LC3-II, Atg7 and beclin-1 expressions) – via the inhibition of PI3K/Akt/mTOR signalling axis. We considered the question of whether the epigenetic role of microRNA-107 (miR-107) has any impact on these events, by using antagomiR-107.Conclusion:This probing underscored that miR-107 could be a pivotal regulatory button in the activation of molecular signals linked with the beneficial autophagic process and anti-inflammatory activities in relation to IVX treatment. Hence, this report exemplifies that IVX could guard against Aβ toxicity and serve as an effectual treatment for patients afflicted with AD.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 967
Author(s):  
Micaely Cristina dos Santos Tenório ◽  
Nayara Gomes Graciliano ◽  
Fabiana Andréa Moura ◽  
Alane Cabral Menezes de Oliveira ◽  
Marília Oliveira Fonseca Goulart

N-acetylcysteine (NAC) is a medicine widely used to treat paracetamol overdose and as a mucolytic compound. It has a well-established safety profile, and its toxicity is uncommon and dependent on the route of administration and high dosages. Its remarkable antioxidant and anti-inflammatory capacity is the biochemical basis used to treat several diseases related to oxidative stress and inflammation. The primary role of NAC as an antioxidant stems from its ability to increase the intracellular concentration of glutathione (GSH), which is the most crucial biothiol responsible for cellular redox imbalance. As an anti-inflammatory compound, NAC can reduce levels of tumor necrosis factor-alpha (TNF-α) and interleukins (IL-6 and IL-1β) by suppressing the activity of nuclear factor kappa B (NF-κB). Despite NAC’s relevant therapeutic potential, in several experimental studies, its effectiveness in clinical trials, addressing different pathological conditions, is still limited. Thus, the purpose of this chapter is to provide an overview of the medicinal effects and applications of NAC to human health based on current therapeutic evidence.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
T. Secher ◽  
F. Rodrigues Coelho ◽  
N. Noulin ◽  
A. Lino dos Santos Franco ◽  
V. Quesniaux ◽  
...  

Inhaled bacterial lipopolysaccharides (LPSs) induce an acute tumour necrosis factor-alpha (TNF-α-) dependent inflammatory response in the murine airways mediated by Toll-like receptor 4 (TLR4) via the myeloid differentiation MyD88 adaptor protein pathway. However, the contractile response of the bronchial smooth muscle and the role of endogenous TNFα in this process have been elusive. We determined the in vivo respiratory pattern of C57BL/6 mice after intranasal LPS administration with or without the presence of increasing doses of methacholine (MCh). We found that LPS administration altered the basal and MCh-evoked respiratory pattern that peaked at 90 min and decreased thereafter in the next 48 h, reaching basal levels 7 days later. We investigated in controlled ex vivo condition the isometric contraction of isolated tracheal rings in response to MCh cholinergic stimulation. We observed that preincubation of the tracheal rings with LPS for 90 min enhanced the subsequent MCh-induced contractile response (hyperreactivity), which was prevented by prior neutralization of TNFα with a specific antibody. Furthermore, hyperreactivity induced by LPS depended on an intact epithelium, whereas hyperreactivity induced by TNFα was well maintained in the absence of epithelium. Finally, the enhanced contractile response to MCh induced by LPS when compared with control mice was not observed in tracheal rings from TLR4- or TNF- or TNF-receptor-deficient mice. We conclude that bacterial endotoxin-mediated hyperreactivity of isolated tracheal rings to MCh depends upon TLR4 integrity that signals the activation of epithelium, which release endogenous TNFα.


2003 ◽  
Vol 71 (9) ◽  
pp. 4873-4882 ◽  
Author(s):  
Qian Li ◽  
Bobby J. Cherayil

ABSTRACT Toll-like receptors (TLRs) play an important role in the innate immune response, particularly in the initial interaction between the infecting microorganism and phagocytic cells, such as macrophages. We investigated the role of TLR4 during infection of primary murine peritoneal macrophages with Salmonella enterica serovar Typhimurium. We found that macrophages from the C3H/HeJ mouse strain, which carries a functionally inactive Tlr4 gene, exhibit marked impairment of tumor necrosis factor alpha (TNF-α) secretion in response to S. enterica serovar Typhimurium infection. However, activation of extracellular growth factor-regulated kinase and NF-κB signaling pathways was relatively unaffected, as was increased expression of TNF-α mRNA. Furthermore, macrophage tolerance, which is associated with increased expression of the NF-κB p50 and p52 subunits, was induced by S. enterica serovar Typhimurium even in the absence of functional TLR4. These results indicate that during infection of macrophages by S. enterica serovar Typhimurium, TLR4 signals are required at a posttranscriptional step to maximize secretion of TNF-α. Signals delivered by pattern recognition receptors other than TLR4 are sufficient for the increased expression of the TNF-α transcript and at least some genes associated with macrophage tolerance.


2010 ◽  
Vol 78 (9) ◽  
pp. 3689-3699 ◽  
Author(s):  
Erin K. Lentz ◽  
Rama P. Cherla ◽  
Valery Jaspers ◽  
Bradley R. Weeks ◽  
Vernon L. Tesh

ABSTRACTMice have been extensively employed as an animal model of renal damage caused by Shiga toxins. In this study, we examined the role of the proinflammatory cytokine tumor necrosis factor alpha (TNF-α) in the development of toxin-mediated renal disease in mice. Mice pretreated with TNF-α and challenged with Shiga toxin type 1 (Stx1) showed increased survival compared to that of mice treated with Stx1 alone. Conversely, mice treated with Stx1 before TNF-α administration succumbed more quickly than mice given Stx1 alone. Increased lethality in mice treated with Stx1 followed by TNF-α was associated with evidence of glomerular damage and the loss of renal function. No differences in renal histopathology were noted between animals treated with Stx1 alone and the TNF-α pretreatment group, although we noted a sparing of renal function when TNF-α was administered before toxin. Compared to that of treatment with Stx1 alone, treatment with TNF-α after toxin altered the renal cytokine profile so that the expression of proinflammatory cytokines TNF-α and interleukin-1β (IL-1β) increased, and the expression of the anti-inflammatory cytokine IL-10 decreased. Increased lethality in mice treated with Stx1 followed by TNF-α was associated with higher numbers of dUTP-biotin nick end labeling-positive renal tubule cells, suggesting that increased lethality involved enhanced apoptosis. These data suggest that the early administration of TNF-α is a candidate interventional strategy blocking disease progression, while TNF-α production after intoxication exacerbates disease.


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