scholarly journals Molecular mechanisms of LC3-associated phagocytosis in the macrophage response to Paracoccidioides spp

Author(s):  
Getúlio Pereira de Oliveira ◽  
Herdson Renney de Sousa ◽  
Kaio César de Melo Gorgonha ◽  
Tatiana Karla dos Santos Borges ◽  
Kellyanne Teixeira Rangel ◽  
...  

AbstractParacoccidiomycosis is a systemic fungal infection that is endemic in Latin America. The etiologic agents are thermodimorphic fungi from the Paracoccidiodes genus, which are facultative intracellular parasites of macrophages. LC3-associated phagocytosis (LAP), a noncanonical form of autophagy, is important in the immune response to similar pathogens, so we sought to determine the role LAP plays in the macrophage response to Paracoccidioides spp. By immunofluorescence, we found that LC3 was recruited to phagosomes containing Paracoccidioides spp. in both RAW264.7 and J774.16 cell lines and in bone marrow-derived macrophages. Interference with autophagy using RNAi against ATG5 reduced the antifungal activity of J774.16 cells, showing that LC3 recrutiment is important for proper control of the fungus by macrophages. Finally, we used pharmacological Syk kinase and NAPH oxidase inhibitors, which inhibit signalling pathways necessary for macrophage LAP against Aspergillus fumigatus and Candida albicans, to dissect part of the signaling pathways that trigger LAP agains Paracoccidioides spp. Interestingly, these inhibitors did not decrease LAP against P. brasiliensis, possibly due to differences in the fungal cell surface compositions. These observations suggest a potential role for autophagy as target for host-directed paracoccidioidomycosis therapies.

2016 ◽  
Vol 22 (37) ◽  
pp. 5730-5737 ◽  
Author(s):  
Amir Tajbakhsh ◽  
Mohammad Khorrami ◽  
Seyed Hassanian ◽  
Malihe Aghasizade ◽  
Alireza Pasdar ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Mehran Pashirzad ◽  
Thozhukat Sathyapalan ◽  
Amirhossein Sahebkar

Wnt5a is one of the potent signaling molecules that initiates responses involved in cancer through activation of both canonical and noncanonical signaling cascades. Wnt5a both directly and indirectly triggers cancer-associated signaling pathways based on the cancer type. In colorectal cancer (CRC), altering Wnt5a expression can influence several cellular processes of tumor cells, including proliferation, differentiation, migration, invasion, and metastasis. This review summarizes the molecular mechanisms and clinical importance of Wnt5a in the pathogenesis of CRC for better understanding the pathogenesis and its potential role as a prognostic marker and as an appropriate therapeutic target in the treatment of this disease in the future.


2021 ◽  
Vol 8 ◽  
Author(s):  
Mohammed M. Almutairi ◽  
Farzane Sivandzade ◽  
Thamer H. Albekairi ◽  
Faleh Alqahtani ◽  
Luca Cucullo

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The clinical manifestations of COVID-19 include dry cough, difficult breathing, fever, fatigue, and may lead to pneumonia and respiratory failure. There are significant gaps in the current understanding of whether SARS-CoV-2 attacks the CNS directly or through activation of the peripheral immune system and immune cell infiltration. Although the modality of neurological impairments associated with COVID-19 has not been thoroughly investigated, the latest studies have observed that SARS-CoV-2 induces neuroinflammation and may have severe long-term consequences. Here we review the literature on possible cellular and molecular mechanisms of SARS-CoV-2 induced-neuroinflammation. Activation of the innate immune system is associated with increased cytokine levels, chemokines, and free radicals in the SARS-CoV-2-induced pathogenic response at the blood-brain barrier (BBB). BBB disruption allows immune/inflammatory cell infiltration into the CNS activating immune resident cells (such as microglia and astrocytes). This review highlights the molecular and cellular mechanisms involved in COVID-19-induced neuroinflammation, which may lead to neuronal death. A better understanding of these mechanisms will help gain substantial knowledge about the potential role of SARS-CoV-2 in neurological changes and plan possible therapeutic intervention strategies.


2016 ◽  
Vol 2016 (1) ◽  
Author(s):  
Mohamed Hassan ◽  
Yasmine Aguib ◽  
Magdi Yacoub

The benefits of exercise have been recognized since ancient times. Physically active men and women have an approximately 30% lower risk of death compared with inactive people. Several trials have recently shown the favorable impact of exercise on survival and quality of life. In the PARIS study, four months of endurance exercise training in elderly patients with heart failure and preserved ejection fraction caused a significant improvement in peak exercise capacity. Moreover in the Copenhagen City Heart Study, jogging up to 2.5 h per week at a slow or average pace and a frequency of 3 times per week was associated with a significant increase in survival (6.2 years in men and 5.6 years in women). These findings imply that exercise improves peripheral vascular, microvascular, and/or skeletal muscle functions and causes an increase in oxygen transport and utilization by the active skeletal muscle.1 However, the exact molecular mechanisms of the cardiovascular benefits of exercise remained largely unknown until very recently. Two recent reports serve to shed some light on the potential role for irisin and miRNA-222 in this subject. 


2021 ◽  
Author(s):  
Zahra Heydarifard ◽  
Sevrin Zadheidar ◽  
Jila Yavarian ◽  
Somayeh Shatizadeh Malekshahi ◽  
Shirin Kalantari ◽  
...  

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Yung-Hsin Yeh ◽  
Reza Wakili ◽  
Xiao Yan Qi ◽  
Denis Chartier ◽  
Stefan Kääb ◽  
...  

Introduction: Heart failure (HF) frequently causes atrial fibrillation (AF) and focal sources of unknown mechanism have been implicated. Here, we studied the potential role and molecular mechanisms of Ca 2+ handling abnormalities. Methods: Ca 2+ handling (microfluorescence, Indo-1 AM) and related protein expression (Western blot) were assessed in left atria of 20 dogs with ventricular tachypacing (240 bpm × 2 wks)-induced HF and 20 controls (CTLs). Whole-cell perforated-patch was used to record action potentials (APs), delayed afterdepolarizations (DADs) and triggered activity. Results : HF increased [Ca 2+ ] i transient amplitude from 239±24 to 444±43* nM (*P<0.05), and [Ca 2+ ] i release by 10 mM local caffeine puffs (an index of SR Ca 2+ content) from 849±71 (CTL) to 1574±169* nM (HF). Spontaneous Ca 2+ release events increased from 1.8±0.5 (CTL) to 10.7±2.1* events/run (HF). HF significantly increased APD (by ~40% at 1 Hz). DADs and triggered activity were more common in HF (15.2±2.6 triggered APs/run, vs CTL 0.4±0.2*), and were abolished by ryanodine (10 μM), but not by the I f -blocker Cs + (2 mM). HF caused profound changes in protein expression of key Ca 2+ handling and regulatory proteins (Table ). Calsequestrin, the major SR Ca 2+ -binding protein, was reduced by 32%*. Fractional RYR2 PKA (Ser2809) phosphorylation decreased by 63%*, whereas CaMKII (Ser2815) RYR2 phosphorylation increased by 221%*. The catalytic and regulatory (RII) PKA subunits were downregulated by 15%* and 73%*, whereas expression and autophosphorylation (Thr287) of CaMKIIδ were increased by 45%* and 81%* respectively. NCX1, SERCA and total, PKA and CaMKII phosphorylated SERCA-regulatory phospholamban were unchanged by HF. Conclusions: HF causes profound changes in regulation and expression of atrial Ca 2+ handling proteins, producing increased SR Ca 2+ load and release, along with DADs and triggered activity that may account for focal mechanisms that initiate and/or sustain HF-related AF.


2018 ◽  
Vol 07 (02) ◽  
pp. 032-039
Author(s):  
Shruti Bagla ◽  
Alan Dombkowski

AbstractA rapidly growing body of evidence supports the premise that neuroinflammation plays an important role in initiating and sustaining seizures in a range of pediatric epilepsies. Clinical and experimental evidence indicates that neuroinflammation is both an outcome and a contributor to seizures. In this manner, seizures that arise from an initial insult (e.g., infection, trauma, and genetic mutation) contribute to an inflammatory response that subsequently promotes recurrent seizures. This cyclic relationship between seizures and neuroinflammation has been described as a “vicious cycle.” Studies of human tissue resected for surgical treatment of refractory epilepsy have reported activated inflammatory and immune signaling pathways, while animal models have been used to demonstrate that key inflammatory mediators lead to increased seizure susceptibility. Further characterization of the molecular mechanisms involved in this cycle may ultimately enable the development of new therapeutic approaches for the treatment of epilepsy. In this brief review, we focus on key inflammatory mediators that have become prominent in recent literature of epilepsy, including newly characterized microRNAs and their potential role in neuroinflammatory signaling.


2019 ◽  
Vol 77 (8) ◽  
pp. 1531-1550 ◽  
Author(s):  
Katarzyna Walczak ◽  
Artur Wnorowski ◽  
Waldemar A. Turski ◽  
Tomasz Plech

Abstract Kynurenic acid (KYNA) is an endogenous tryptophan metabolite exerting neuroprotective and anticonvulsant properties in the brain. However, its importance on the periphery is still not fully elucidated. KYNA is produced endogenously in various types of peripheral cells, tissues and by gastrointestinal microbiota. Furthermore, it was found in several products of daily human diet and its absorption in the digestive tract was evidenced. More recent studies were focused on the potential role of KYNA in carcinogenesis and cancer therapy; however, the results were ambiguous and the biological activity of KYNA in these processes has not been unequivocally established. This review aims to summarize the current views on the relationship between KYNA and cancer. The differences in KYNA concentration between physiological conditions and cancer, as well as KYNA production by both normal and cancer cells, will be discussed. The review also describes the effect of KYNA on cancer cell proliferation and the known potential molecular mechanisms of this activity.


Stem Cells ◽  
2018 ◽  
Vol 36 (10) ◽  
pp. 1630-1642 ◽  
Author(s):  
Anatolii Mamchur ◽  
Eva Leman ◽  
Safaa Salah ◽  
Aaron Avivi ◽  
Imad Shams ◽  
...  

2014 ◽  
Vol 955-959 ◽  
pp. 326-334 ◽  
Author(s):  
Peng Wan ◽  
Cheng Xi Wei ◽  
Jian Long Wu ◽  
Qing Hua Jin

Edible salt (ES) is also thought to exacerbate the symptoms of Alzheimer, however, the in vivo function of ES remains poorly understand. In this work, we investigated the phenomenon using the model of Alzheimer induced by D-gal. The behavious examination results exhibited that D-gal plus ES can weaken spatial memory function in the Morris water maze; the activities of T-SOD, GSH-Px and the CAT level in both hippocampus and cortex showed that D-gal plus ES decreased the expression of T-SOD and GSH-Px, but the expression of CAT increased, the protein expression determined in both of the hippocampus and cortex demonstrated that COX-2, iNOS, NFκ-B-p65-N proteins were significantly increased. It is possible that ES acts through several mechanisms, mediating a potential role in memory damage in mice. These results suggest that further study is necessary to evaluate the effect of salt on damage of memory and to determine the molecular mechanisms.


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