scholarly journals Updates on the Mechanism and Management of Pterygium: A Brief Review

2021 ◽  
Vol 3 (4) ◽  
pp. 6-11
Author(s):  
Fazella Kirara Sakti

Pterygium is an ocular surface disease characterized by invasive fibrovascular growth due to pathological proliferation and inflammation on the conjunctival and corneal tissue. Its occurrence has been associated with chronic ultraviolet exposure, thus becoming one of the most common eye problems in tropical regions worldwide. Although pterygium rarely causes severe visual disturbances or blindness, it often becomes a distressing problem because of the high recurrence rate and unsatisfactory cosmetic outcomes, despite receiving removal management. In recent decades, studies regarding molecular mechanisms and management of pterygium have been advanced. This review provides a brief update on the mechanism and management to achieve more optimal and satisfactory pterygium therapeutic approaches.

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 405
Author(s):  
Anna Matysiak ◽  
Michal Kabza ◽  
Justyna A. Karolak ◽  
Marcelina M. Jaworska ◽  
Malgorzata Rydzanicz ◽  
...  

The ocular microbiome composition has only been partially characterized. Here, we used RNA-sequencing (RNA-Seq) data to assess microbial diversity in human corneal tissue. Additionally, conjunctival swab samples were examined to characterize ocular surface microbiota. Short RNA-Seq reads, obtained from a previous transcriptome study of 50 corneal tissues, were mapped to the human reference genome GRCh38 to remove sequences of human origin. The unmapped reads were then used for taxonomic classification by comparing them with known bacterial, archaeal, and viral sequences from public databases. The components of microbial communities were identified and characterized using both conventional microbiology and polymerase chain reaction (PCR) techniques in 36 conjunctival swabs. The majority of ocular samples examined by conventional and molecular techniques showed very similar microbial taxonomic profiles, with most of the microorganisms being classified into Proteobacteria, Firmicutes, and Actinobacteria phyla. Only 50% of conjunctival samples exhibited bacterial growth. The PCR detection provided a broader overview of positive results for conjunctival materials. The RNA-Seq assessment revealed significant variability of the corneal microbial communities, including fastidious bacteria and viruses. The use of the combined techniques allowed for a comprehensive characterization of the eye microbiome’s elements, especially in aspects of microbiota diversity.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Yuefei Jin ◽  
Wangquan Ji ◽  
Haiyan Yang ◽  
Shuaiyin Chen ◽  
Weiguo Zhang ◽  
...  

AbstractOn 12 March 2020, the outbreak of coronavirus disease 2019 (COVID-19) was declared a pandemic by the World Health Organization. As of 4 August 2020, more than 18 million confirmed infections had been reported globally. Most patients have mild symptoms, but some patients develop respiratory failure which is the leading cause of death among COVID-19 patients. Endothelial cells with high levels of angiotensin-converting enzyme 2 expression are major participants and regulators of inflammatory reactions and coagulation. Accumulating evidence suggests that endothelial activation and dysfunction participate in COVID-19 pathogenesis by altering the integrity of vessel barrier, promoting pro-coagulative state, inducing endothelial inflammation, and even mediating leukocyte infiltration. This review describes the proposed cellular and molecular mechanisms of endothelial activation and dysfunction during COVID-19 emphasizing the principal mediators and therapeutic implications.


Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 332
Author(s):  
Valentina Brillo ◽  
Leonardo Chieregato ◽  
Luigi Leanza ◽  
Silvia Muccioli ◽  
Roberto Costa

Mitochondria are key intracellular organelles involved not only in the metabolic state of the cell, but also in several cellular functions, such as proliferation, Calcium signaling, and lipid trafficking. Indeed, these organelles are characterized by continuous events of fission and fusion which contribute to the dynamic plasticity of their network, also strongly influenced by mitochondrial contacts with other subcellular organelles. Nevertheless, mitochondria release a major amount of reactive oxygen species (ROS) inside eukaryotic cells, which are reported to mediate a plethora of both physiological and pathological cellular functions, such as growth and proliferation, regulation of autophagy, apoptosis, and metastasis. Therefore, targeting mitochondrial ROS could be a promising strategy to overcome and hinder the development of diseases such as cancer, where malignant cells, possessing a higher amount of ROS with respect to healthy ones, could be specifically targeted by therapeutic treatments. In this review, we collected the ultimate findings on the blended interplay among mitochondrial shaping, mitochondrial ROS, and several signaling pathways, in order to contribute to the dissection of intracellular molecular mechanisms involved in the pathophysiology of eukaryotic cells, possibly improving future therapeutic approaches.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 863
Author(s):  
Simona Cavalu ◽  
George Roiu ◽  
Ovidiu Pop ◽  
Denisa A. Petricas Heredea ◽  
Traian Octavian Costea ◽  
...  

The efficiency of amniotic membrane (AM) transplantation in different types of ocular surface disorders is due to its outstanding properties such as antifibrotic, antibacterial, anti-inflammatory and antiangiogenic, working as a versatile scaffold to promote corneal tissue epithelialization. A proper preparation, preservation and clinical application are crucial for the best outcomes in the treatment of different severe ocular disorders, taking into account its fragility. In this context, by combining high-sensitivity tools such as atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopy with histological and immunohistochemical examination, we aimed to investigate the ultrastructural modifications of the amniotic membrane (AM) upon UV exposure and/or antibiotic treatment, with relevance for clinical applications in ocular surface surgery. From the morphological point of view, we noticed a loss of cuboidal cells in the basal membrane, accompanied by the splitting of collagen fibers upon UV and/or gentamicin treatment, while structural alteration of proteins was evidenced by the FTIR quantitative analysis of the secondary structure. A decrease in α-helix and β-sheet content, accompanied by increased content in less ordered structures (turns, random and side chains), was noticed after all the treatments. At the nano-scale, AFM details showed modifications of collagen fibrils in terms of their thickness and network compaction upon gentamicin and/or UV treatment. The enzymatic digestion assay demonstrated that UV exposure significantly reduces the degradation rate of the AM, while gentamicin treatment promotes an accelerated enzymatic digestion upon UV exposure. In order to highlight the clinical impact of the research, a clinical case is presented showing the relevance of amniotic membrane transplantation in pterygium surgery.


Author(s):  
George Hajishengallis ◽  
Tomoki Maekawa ◽  
Toshiharu Abe ◽  
Evlambia Hajishengallis ◽  
John D. Lambris

Author(s):  
Edward Hookway ◽  
Nicholas Athanasou ◽  
Udo Oppermann

Epigenetics is a term that refers to a collection of diverse mechanisms that are important in both the control of gene expression and the transmission of this information during cell division. Epigenetic processes are deranged in many cancers, leading to a combination of inappropriate silencing of tumour suppressor genes and overexpression of oncogenes. In this chapter, the molecular mechanisms that underpin the major epigenetic processes of DNA methylation, histone modification, and non-coding RNAs will be described in both their normal physiological roles and in the context of cancer. The challenge of understanding the complexity of the interactions between different epigenetic mechanisms and the limitations of our current knowledge will be highlighted. Therapeutic approaches towards targeting deranged epigenetic processes will also be described, such as the use of small molecule inhibitors of histone deacetylases.


Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 979 ◽  
Author(s):  
Valeria De Pasquale ◽  
Anna Moles ◽  
Luigi Michele Pavone

Cathepsins (CTSs) are ubiquitously expressed proteases normally found in the endolysosomal compartment where they mediate protein degradation and turnover. However, CTSs are also found in the cytoplasm, nucleus, and extracellular matrix where they actively participate in cell signaling, protein processing, and trafficking through the plasma and nuclear membranes and between intracellular organelles. Dysregulation in CTS expression and/or activity disrupts cellular homeostasis, thus contributing to many human diseases, including inflammatory and cardiovascular diseases, neurodegenerative disorders, diabetes, obesity, cancer, kidney dysfunction, and others. This review aimed to highlight the involvement of CTSs in inherited lysosomal storage disorders, with a primary focus to the emerging evidence on the role of CTSs in the pathophysiology of Mucopolysaccharidoses (MPSs). These latter diseases are characterized by severe neurological, skeletal and cardiovascular phenotypes, and no effective cure exists to date. The advance in the knowledge of the molecular mechanisms underlying the activity of CTSs in MPSs may open a new challenge for the development of novel therapeutic approaches for the cure of such intractable diseases.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1202
Author(s):  
Mikael Christer Puustinen ◽  
Lea Sistonen

Malignant transformation is accompanied by alterations in the key cellular pathways that regulate development, metabolism, proliferation and motility as well as stress resilience. The members of the transcription factor family, called heat shock factors (HSFs), have been shown to play important roles in all of these biological processes, and in the past decade it has become evident that their activities are rewired during tumorigenesis. This review focuses on the expression patterns and functions of HSF1, HSF2, and HSF4 in specific cancer types, highlighting the mechanisms by which the regulatory functions of these transcription factors are modulated. Recently developed therapeutic approaches that target HSFs are also discussed.


2009 ◽  
Vol 29 (21) ◽  
pp. 5941-5951 ◽  
Author(s):  
Yuanrong Gao ◽  
Guan Yang ◽  
Tujun Weng ◽  
Juan Du ◽  
Xuejiu Wang ◽  
...  

ABSTRACT Keratocystic odontogenic tumors (KCOTs) are cystic epithelial neoplasias with a high recurrence rate. However, the molecular mechanisms underlying the initiation and progression of KCOTs are still largely unknown. Here, we show that specific ablation of Smad4 in odontoblasts unexpectedly resulted in spontaneous KCOTs in mice. The mutant mice exhibited malformed teeth characterized by fractured incisors and truncated molar roots. These abnormalities were mainly caused by disrupted odontoblast differentiation that led to irregular dentin formation. The cystic tumors arising from the reactivation of epithelial rests of Malassez (ERM), in which Smad4 remained intact, proliferated and formed stratified and differentiated squamous epithelia that exhibited a dramatic upregulation of Hedgehog signaling. Odontoblasts, which are responsive to transforming growth factor beta (TGF-β)/bone morphogenetic protein (BMP) signals, may produce signal molecules to inhibit the activation of ERM. Indeed, we observed a downregulation of BMP signals from Smad4 mutant odontoblasts to the adjacent Hertwig's epithelial root sheath (HERS). Intriguingly, KCOTs frequently emerged from Smad4-deficient ERM in keratinocyte-specific Smad4 knockout mice, suggesting a novel mechanism in which reciprocal TGF-β/BMP signaling between odontoblasts and HERS was required for tooth root development and suppression of KCOT formation. These findings provide insight into the genetic basis underlying KCOTs and have important implications for new directions in KCOT treatment.


2020 ◽  
Vol 21 (12) ◽  
pp. 4277 ◽  
Author(s):  
Weronika Rzepnikowska ◽  
Joanna Kaminska ◽  
Dagmara Kabzińska ◽  
Katarzyna Binięda ◽  
Andrzej Kochański

Charcot–Marie–Tooth (CMT) disease encompasses a group of rare disorders that are characterized by similar clinical manifestations and a high genetic heterogeneity. Such excessive diversity presents many problems. Firstly, it makes a proper genetic diagnosis much more difficult and, even when using the most advanced tools, does not guarantee that the cause of the disease will be revealed. Secondly, the molecular mechanisms underlying the observed symptoms are extremely diverse and are probably different for most of the disease subtypes. Finally, there is no possibility of finding one efficient cure for all, or even the majority of CMT diseases. Every subtype of CMT needs an individual approach backed up by its own research field. Thus, it is little surprise that our knowledge of CMT disease as a whole is selective and therapeutic approaches are limited. There is an urgent need to develop new CMT models to fill the gaps. In this review, we discuss the advantages and disadvantages of yeast as a model system in which to study CMT diseases. We show how this single-cell organism may be used to discriminate between pathogenic variants, to uncover the mechanism of pathogenesis, and to discover new therapies for CMT disease.


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