tissue destruction
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2022 ◽  
Vol 12 ◽  
Author(s):  
Xuan Ying Poh ◽  
Fei Kean Loh ◽  
Jon S. Friedland ◽  
Catherine W. M. Ong

Tuberculosis (TB) remains one of the leading infectious killers in the world, infecting approximately a quarter of the world’s population with the causative organism Mycobacterium tuberculosis (M. tb). Central nervous system tuberculosis (CNS-TB) is the most severe form of TB, with high mortality and residual neurological sequelae even with effective TB treatment. In CNS-TB, recruited neutrophils infiltrate into the brain to carry out its antimicrobial functions of degranulation, phagocytosis and NETosis. However, neutrophils also mediate inflammation, tissue destruction and immunopathology in the CNS. Neutrophils release key mediators including matrix metalloproteinase (MMPs) which degrade brain extracellular matrix (ECM), tumor necrosis factor (TNF)-α which may drive inflammation, reactive oxygen species (ROS) that drive cellular necrosis and neutrophil extracellular traps (NETs), interacting with platelets to form thrombi that may lead to ischemic stroke. Host-directed therapies (HDTs) targeting these key mediators are potentially exciting, but currently remain of unproven effectiveness. This article reviews the key role of neutrophils and neutrophil-derived mediators in driving CNS-TB immunopathology.


2022 ◽  
Author(s):  
Brenda Kischkel ◽  
Leila M Lopes-Bezerra ◽  
Carlos P Taborda ◽  
Leo A.B Joosten ◽  
Jessica C dos Santos ◽  
...  

Sporotrichosis is a deep mycosis caused by dimorphic species of the genus Sporothrix, with differences in pathogenicity between S. schenckii and S. brasiliensis species. Recently, it was discovered that the cell wall peptidorhamnomannan (PRM) of Sporothrix spp . is a pathogen associated molecular pattern (PAMP). Interestingly, S. brasiliensis PRM has additional unknown rhamnose residues. We hypothesize that the structural differences of Sporothrix spp PRMs impact the host's immune response and may explain the severity of sporotrichosis caused by S. brasiliensis. Here we demonstrate that S. brasiliensis yeasts and its PRM (S.b PRM) induced a strong inflammatory response in human PBMCs, with high production of TNF-α, IL-6 and IL-1β and induction of T-helper cytokines IFN-γ, IL-17 and IL-22. In contrast, S. schenckii yeasts and its PRM induced higher concentrations of interleukin-1 receptor antagonist (IL-1Ra), which resulted in low production of T-helper cytokines such as IL-17 and IL-22. CR3 and dectin-1 were required for cytokine induction by both PRMs, while TLR2 and TLR4 were required for the response of S.s PRM and S.b PRM, respectively. IL-1β and IL-1α production induced by S. brasiliensis yeasts and S.b PRM were dependent on inflammasome and caspase-1 activation. S. schenckii and S.s PRM were able to induce IL-1β independent of ROS. In conclusion, these findings improve our understanding of the pathogenesis of Sporothrix spp. by reporting differences of immunological responses induced by S. schenckii and S. brasiliensis. The study also opens the gateway for novel treatment strategies targeting local inflammation and tissue destruction induced by S. brasiliensis infection through IL-1 inhibition.


2022 ◽  
Vol 12 ◽  
Author(s):  
Rui Gui ◽  
Quanjiao Chen

Viral infection usually leads to cell death. Moderate cell death is a protective innate immune response. By contrast, excessive, uncontrolled cell death causes tissue destruction, cytokine storm, or even host death. Thus, the struggle between the host and virus determines whether the host survives. Influenza A virus (IAV) infection in humans can lead to unbridled hyper-inflammatory reactions and cause serious illnesses and even death. A full understanding of the molecular mechanisms and regulatory networks through which IAVs induce cell death could facilitate the development of more effective antiviral treatments. In this review, we discuss current progress in research on cell death induced by IAV infection and evaluate the role of cell death in IAV replication and disease prognosis.


PeerJ ◽  
2022 ◽  
Vol 9 ◽  
pp. e12251
Author(s):  
Ayesha Fahim ◽  
Wan Harun Himratul-Aznita ◽  
Puteri Shafinaz Abdul-Rahman ◽  
Mohammad K. Alam

Background Polymicrobial biofilms are notorious for causing intraoral tissue destruction. Streptococcus sanguinis and Streptococcus mitis, commensals of oral cavities, have been found co-existing with C. albicans in resistant oral infections. There is an urgent need to find alternative treatment options. This study aims to assess the efficacy of garlic (G) and bakuchiol (Bk) combination against candida virulent genes and their subsequently secreted proteins. Methods In vitro single species biofilms of C. albicans, and mixed species biofilms formed in combination with streptococci were exposed to bakuchiol and garlic extract (Bk+G). Gene expression of agglutinin-like sequence (ALS1), (ALS3), adhesin-like wall proteins (HWP1) and aspartyl proteinases (SAP5) were determined using qPCR and their subsequent proteins were assessed through Western blotting. Results Virulent genes were significantly downregulated in single species biofilms when they were treated with Bk+G combination. However, Bk+G did not have significant effect on ALS1 and HWP1 gene in polymicrobial biofilms. ALS3 and SAP5 were significantly downregulated in Bk+G treated polymicrobial biofilm. Similar results were portrayed in Western blotting. Conclusion Bk+G combination exhibited antimicrobial effects against single and mixed species biofilms. The findings might provide insights for treating resistant candida infections. This combination could potentially serve as an herbal alternative to traditional antifungals following further research.


2022 ◽  
pp. 137-252

Microbial keratitis is an infectious process that occurs due to the proliferation of microorganisms (bacteria, fungi, viruses, and parasites) and associated inflammation and tissue destruction. Smears and cultures are indicated for the isolation of microorganisms and for making the correct diagnosis and immediate initiation of antimicrobial therapy, especially in cases where corneal infiltrate is chronic, large, deep, or atypical. Microbial keratitis is considered a vision-threatening ocular emergency. Therefore, this chapter, which consists of almost all cases studied before and after treatment, highlights the importance of early recognition, isolation of specific microorganisms, and sensitivity-based therapy. Also, the evaluation of these cases helps to show the appearance of the eye after the therapeutic treatment and demonstrates the emergency of immediate surgery to save the eyeball in cases where medical treatment is ineffective. The authors have summarized the treatment options they have used for bacterial, fungal, acanthamoeba, and herpetic keratitis cases.


2021 ◽  
Vol 14 (4) ◽  
pp. 2307-2318
Author(s):  
Rajathilagam T Rajathilagam T ◽  
Thuthi Mohan Thuthi Mohan ◽  
Aruna B Patil ◽  
Mohanavalli S Mohanavalli S ◽  
Seethalakshmi S Seethalakshmi S

Periodontitis is a common multifactorial inflammatory disease with gradual loss of supportive tissues around the teeth which eventually leads to decrease in the quality of life. Blocking Interleukin-6 (IL-6), a multifunctional cytokine with pro-inflammatory properties has demonstrated therapeutic efficacy in inflammatory diseases like Rheumatoid arthritis, SLE and multiple sclerosis. Host immune response, the underlying cause for this progressive disease is targeted by Host modulatory therapy (HMT), an emerging treatment modality. Omega-3 polyunsaturated fatty acids (ώ 3 PUFAs), one of the relatively safe HMTs, reduces tissue destruction, stabilizes or even regenerates the periodontium through its anti-inflammatory & immunoregulatory properties. ώ 3 PUFAs are essential for the synthesis of eicosanoids which are involved in anti-inflammatory, antiplatelet aggregatory, vasodilation, vasoconstriction, immune response, cell growth and proliferation. The key factor examined and extrapolated in this study is the anti-inflammatory property of ώ 3 PUFA. The aim of the study was to evaluate the immunological and clinical response to ώ 3 PUFA supplementation therapy in chronic periodontitis by measuring the inflammatory cytokine, IL-6 levels in serum. In this open label exploratory study, 40 patients with a Female: Male ratio of 4:1were enrolled and assessed clinically by measuring Oral Hygiene Index-Simplified (OHI-S), Probing Pocket Depth (PPD), Clinical Attachment Level (CAL) and their serum for IL-6 levels. Subsequently 300 mg (concentration of EPA 180/DHA120) of ώ 3 PUFA was prescribed twice daily for 3 months and periodically reviewed to assess their IL-6 levels and periodontal status. IL-6 levels which were at a maximum mean of 10.2 pg/ml prior to treatment, showed a gradual and notable reduction to 2.3 pg/ml at the end of the study following ώ 3 PUFA supplementation therapy. The coefficient of variation R2 and ANOVA showed statistically significant periodic variation in biomarker IL-6 and in all clinical measurements at all time intervals. ώ 3 PUFA adjunctive therapy significantly reduces the inflammatory cytokine (IL-6) levels and causes noteworthy improvement of the most relevant clinical parameters (OHI-S, PPD, CAL). Hence ώ 3 PUFA can be recommended as a dietary supplementation and a safe host modulatory treatment in chronic periodontitis.


2021 ◽  
Vol 23 (1) ◽  
pp. 372
Author(s):  
Mariane Beatriz Sordi ◽  
Ricardo de Souza Magini ◽  
Layla Panahipour ◽  
Reinhard Gruber

Pyroptosis is a caspase-dependent process relevant to the understanding of beneficial host responses and medical conditions for which inflammation is central to the pathophysiology of the disease. Pyroptosis has been recently suggested as one of the pathways of exacerbated inflammation of periodontal tissues. Hence, this focused review aims to discuss pyroptosis as a pathological mechanism in the cause of periodontitis. The included articles presented similarities regarding methods, type of cells applied, and cell stimulation, as the outcomes also point to the same direction considering the cellular events. The collected data indicate that virulence factors present in the diseased periodontal tissues initiate the inflammasome route of tissue destruction with caspase activation, cleavage of gasdermin D, and secretion of interleukins IL-1β and IL-18. Consequently, removing periopathogens’ virulence factors, triggering pyroptosis, is a potential strategy to combat periodontal disease and regain tissue homeostasis.


Life ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 26
Author(s):  
Ping-Hung Lin ◽  
Lu-Ting Kuo ◽  
Hui-Tzung Luh

Neurotrophins are a collection of structurally and functionally related proteins. They play important roles in many aspects of neural development, survival, and plasticity. Traumatic brain injury (TBI) leads to different levels of central nervous tissue destruction and cellular repair through various compensatory mechanisms promoted by the injured brain. Many studies have shown that neurotrophins are key modulators of neuroinflammation, apoptosis, blood–brain barrier permeability, memory capacity, and neurite regeneration. The expression of neurotrophins following TBI is affected by the severity of injury, genetic polymorphism, and different post-traumatic time points. Emerging research is focused on the potential therapeutic applications of neurotrophins in managing TBI. We conducted a comprehensive review by organizing the studies that demonstrate the role of neurotrophins in the management of TBI.


2021 ◽  
Vol 23 (1) ◽  
pp. 146
Author(s):  
Stephan Niland ◽  
Andrea Ximena Riscanevo ◽  
Johannes Andreas Eble

Cancer progression with uncontrolled tumor growth, local invasion, and metastasis depends largely on the proteolytic activity of numerous matrix metalloproteinases (MMPs), which affect tissue integrity, immune cell recruitment, and tissue turnover by degrading extracellular matrix (ECM) components and by releasing matrikines, cell surface-bound cytokines, growth factors, or their receptors. Among the MMPs, MMP-14 is the driving force behind extracellular matrix and tissue destruction during cancer invasion and metastasis. MMP-14 also influences both intercellular as well as cell–matrix communication by regulating the activity of many plasma membrane-anchored and extracellular proteins. Cancer cells and other cells of the tumor stroma, embedded in a common extracellular matrix, interact with their matrix by means of various adhesive structures, of which particularly invadopodia are capable to remodel the matrix through spatially and temporally finely tuned proteolysis. As a deeper understanding of the underlying functional mechanisms is beneficial for the development of new prognostic and predictive markers and for targeted therapies, this review examined the current knowledge of the interplay of the various MMPs in the cancer context on the protein, subcellular, and cellular level with a focus on MMP14.


2021 ◽  
Vol 12 ◽  
Author(s):  
A. Dal-Bianco ◽  
R. Schranzer ◽  
G. Grabner ◽  
M. Lanzinger ◽  
S. Kolbrink ◽  
...  

Introduction: Multiple sclerosis (MS) is a demyelinating and neurodegenerative disease of the central nervous system, characterized by inflammatory-driven demyelination. Symptoms in MS manifest as both physical and neuropsychological deficits. With time, inflammation is accompanied by neurodegeneration, indicated by brain volume loss on an MRI. Here, we combined clinical, imaging, and serum biomarkers in patients with iron rim lesions (IRLs), which lead to severe tissue destruction and thus contribute to the accumulation of clinical disability.Objectives: Subcortical atrophy and ventricular enlargement using an automatic segmentation pipeline for 7 Tesla (T) MRI, serum neurofilament light chain (sNfL) levels, and neuropsychological performance in patients with MS with IRLs and non-IRLs were assessed.Methods: In total 29 patients with MS [15 women, 24 relapsing-remitting multiple sclerosis (RRMS), and five secondary-progressive multiple sclerosis (SPMS)] aged 38 (22–69) years with an Expanded Disability Status Score of 2 (0–8) and a disease duration of 11 (5–40) years underwent neurological and neuropsychological examinations. Volumes of lesions, subcortical structures, and lateral ventricles on 7-T MRI (SWI, FLAIR, and MP2RAGE, 3D Segmentation Software) and sNfL concentrations using the Simoa SR-X Analyzer in IRL and non-IRL patients were assessed.Results: (1) Iron rim lesions patients had a higher FLAIR lesion count (p = 0.047). Patients with higher MP2Rage lesion volume exhibited more IRLs (p <0.014) and showed poorer performance in the information processing speed tested within 1 year using the Symbol Digit Modalities Test (SDMT) (p <0.047). (2) Within 3 years, patients showed atrophy of the thalamus (p = 0.021) and putamen (p = 0.043) and enlargement of the lateral ventricles (p = 0.012). At baseline and after 3 years, thalamic volumes were lower in IRLs than in non-IRL patients (p = 0.045). (3) At baseline, IRL patients had higher sNfL concentrations (p = 0.028). Higher sNfL concentrations were associated with poorer SDMT (p = 0.004), regardless of IRL presence. (4) IRL and non-IRL patients showed no significant difference in the neuropsychological performance within 1 year.Conclusions: Compared with non-IRL patients, IRL patients had higher FLAIR lesion counts, smaller thalamic volumes, and higher sNfL concentrations. Our pilot study combines IRL and sNfL, two biomarkers considered indicative for neurodegenerative processes. Our preliminary data underscore the reported destructive nature of IRLs.


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