The role of lysosomal cysteine proteases in endocytosis-mediated retinal degeneration

2012 ◽  
Author(s):  
Ronald D. Kinser
Keyword(s):  
Retinal Degeneration ◽  
Cysteine Proteases ◽  
Lysosomal Cysteine Proteases

scholarly journals Loss of Non-Apoptotic Role of Caspase-3 in the PINK1 Mouse Model of Parkinson’s Disease

2019 ◽  
Vol 20 (14) ◽  
pp. 3407 ◽  
Author(s):  
Paola Imbriani ◽  
Annalisa Tassone ◽  
Maria Meringolo ◽  
Giulia Ponterio ◽  
Graziella Madeo ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Synaptic Plasticity ◽  
Mouse Model ◽  
Caspase 3 ◽  
Cysteine Proteases ◽  
Synaptic Function ◽  
Adult Brain ◽  
Striatal Slices

Caspases are a family of conserved cysteine proteases that play key roles in multiple cellular processes, including programmed cell death and inflammation. Recent evidence shows that caspases are also involved in crucial non-apoptotic functions, such as dendrite development, axon pruning, and synaptic plasticity mechanisms underlying learning and memory processes. The activated form of caspase-3, which is known to trigger widespread damage and degeneration, can also modulate synaptic function in the adult brain. Thus, in the present study, we tested the hypothesis that caspase-3 modulates synaptic plasticity at corticostriatal synapses in the phosphatase and tensin homolog (PTEN) induced kinase 1 (PINK1) mouse model of Parkinson’s disease (PD). Loss of PINK1 has been previously associated with an impairment of corticostriatal long-term depression (LTD), rescued by amphetamine-induced dopamine release. Here, we show that caspase-3 activity, measured after LTD induction, is significantly decreased in the PINK1 knockout model compared with wild-type mice. Accordingly, pretreatment of striatal slices with the caspase-3 activator α-(Trichloromethyl)-4-pyridineethanol (PETCM) rescues a physiological LTD in PINK1 knockout mice. Furthermore, the inhibition of caspase-3 prevents the amphetamine-induced rescue of LTD in the same model. Our data support a hormesis-based double role of caspase-3; when massively activated, it induces apoptosis, while at lower level of activation, it modulates physiological phenomena, like the expression of corticostriatal LTD. Exploring the non-apoptotic activation of caspase-3 may contribute to clarify the mechanisms involved in synaptic failure in PD, as well as in view of new potential pharmacological targets.

scholarly journals Role of Papain-Like Cysteine Proteases in Plant Development

2018 ◽  
Vol 9 ◽  
Author(s):  
Huijuan Liu ◽  
Menghui Hu ◽  
Qi Wang ◽  
Lin Cheng ◽  
Zaibao Zhang
Keyword(s):  
Plant Development ◽  
Cysteine Proteases

scholarly journals Redefining the role of Ca2+-permeable channels in photoreceptor degeneration using diltiazem

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Soumyaparna Das ◽  
Valerie Popp ◽  
Michael Power ◽  
Kathrin Groeneveld ◽  
Jie Yan ◽  
...  
Keyword(s):  
Cell Death ◽  
Retinal Degeneration ◽  
Photoreceptor Cell ◽  
Strong Increase ◽  
Channel Blockers ◽  
Photoreceptor Degeneration ◽  
Therapy Development ◽  
Hypertensive Drug ◽  
Future Therapy

AbstractHereditary degeneration of photoreceptors has been linked to over-activation of Ca2+-permeable channels, excessive Ca2+-influx, and downstream activation of Ca2+-dependent calpain-type proteases. Unfortunately, after more than 20 years of pertinent research, unequivocal evidence proving significant and reproducible photoreceptor protection with Ca2+-channel blockers is still lacking. Here, we show that both D- and L-cis enantiomers of the anti-hypertensive drug diltiazem were very effective at blocking photoreceptor Ca2+-influx, most probably by blocking the pore of Ca2+-permeable channels. Yet, unexpectedly, this block neither reduced the activity of calpain-type proteases, nor did it result in photoreceptor protection. Remarkably, application of the L-cis enantiomer of diltiazem even led to a strong increase in photoreceptor cell death. These findings shed doubt on the previously proposed links between Ca2+ and retinal degeneration and are highly relevant for future therapy development as they may serve to refocus research efforts towards alternative, Ca2+-independent degenerative mechanisms.

scholarly journals In vitro effects of L-arginine on lysosomal cysteine proteases activity in isolated experiment and in the state of oxidative stress

2015 ◽  
Vol 96 (5) ◽  
pp. 876-882
Author(s):  
M A Fomina ◽  
A M Kudlaeva
Keyword(s):  
Oxidative Stress ◽  
Sucrose Solution ◽  
Membrane Damage ◽  
Cysteine Proteases ◽  
Lysosomal Membranes ◽  
In Vitro Incubation ◽  
Cathepsin H ◽  
Lysosomal Cysteine Proteases ◽  
Stimulation Of

Aim. Assessment of direct influence of arginine on lysosomal cysteine proteases activity in vitro, in isolation as well as the stimulation of oxidative stress. Methods. The study was conducted on the 72 female conventional mature Wistar rats 280-320 g divided into 6 series of 12 rats each. Lysosome slurries were isolated from the liver of intact animals with a subsequent in vitro incubation in a sucrose solution, in the presence of L-arginine, as well as in the presence of L-arginine accompanied by the stimulation of oxidative stress. Samples of control groups were exposed in vitro with the addition of isolate and oxidant, respectively. Each batch was reproduced three times, incubation was performed at 37 °C in a water bath for 1, 2 and 4 hours. The activity of cathepsins B, L and H was studied using spectrofluorimetric method in two fractions - intra- and extralysosomal. Acid phosphatase activity was used as the main marker of membrane labialization. Results. One hour Incubation with 5 mM arginine in vitro led to inhibition of the cathepsin H activity and lysosomal membrane damage, however, further increase in incubation time led to its stabilization. In vitro exposure to 5 mM H2O2 caused an increase in activity of cathepsines B and L and the drop in the cathepsin H activity without obvious changes in the distribution of enzymes between extra and intralysosomal fractions. In a state of oxidative stress 2-hour in vitro incubation with 5 mM arginine reduced the permeability of lysosomal membranes for cathepsines B, H and L; while 4-hour incubation led to the destabilization of lysosomal membranes. Conclusion. The direct effect of arginine at a concentration of 5 mM within the 1,2 and 4-hour time intervals leads to a distinct change as a lysosomal cysteine protease activity and stability of lysosomal membranes.

The Role of RAD6B and PEDF in Retinal Degeneration

Neuroscience ◽  
2021 ◽  
Author(s):  
Qiang Ye ◽  
Jiaqi Wang ◽  
Xiangwen Liu ◽  
Zihua Liu ◽  
LuoSong BaZong ◽  
...  
Keyword(s):  
Retinal Degeneration

scholarly journals Inhibition of microRNA-155 Protects Retinal Function Through Attenuation of Inflammation in Retinal Degeneration

2020 ◽  
Author(s):  
Riemke Aggio-Bruce ◽  
Joshua A. Chu-Tan ◽  
Yvette Wooff ◽  
Adrian V. Cioanca ◽  
Ulrike Schumann ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Retinal Degeneration ◽  
Ganglion Cells ◽  
Retinal Function ◽  
Retinal Ganglion ◽  
Retinal Tissue ◽  
Inflammatory Conditions ◽  
Retinal Degenerative Diseases ◽  
Negative Controls

Abstract Although extensively investigated in inflammatory conditions, the role of pro-inflammatory microRNAs (miRNAs), miR-155 and miR-146a, has not been well-studied in retinal degenerative diseases. We therefore aimed to explore the role and regulation of these miRNA in the degenerating retina, with a focus on miR-155. C57BL/6J mice were subjected to photo-oxidative damage for up to 5 days to induce focal retinal degeneration. MiR-155 expression was quantified by qRT-PCR in whole retina, serum, and small-medium extracellular vesicles (s-mEVs), and a PrimeFlow™ assay was used to identify localisation of miR-155 in retinal cells. Constitutive miR-155 knockout (KO) mice and miR-155 and miR-146a inhibitors were utilised to determine the role of these miRNA in the degenerating retina. Electroretinography was employed as a measure of retinal function, while histological quantification of TUNEL+ and IBA1+ positive cells was used to quantify photoreceptor cell death and infiltrating immune cells, respectively. Upregulation of miR-155 was detected in retinal tissue, serum and s-mEVs in response to photo-oxidative damage, localising to the nucleus of a subset of retinal ganglion cells and glial cells and in the cytoplasm of photoreceptors. Inhibition of miR-155 showed increased function from negative controls and a less pathological pattern of IBA1+ cell localisation and morphology at 5 days photo-oxidative damage. While neither dim-reared nor damaged miR-155 KO animals showed retinal histological difference from controls, following photo-oxidative damage, miR-155 KO mice showed increased a-wave relative to controls. We therefore consider miR-155 to be associated with the inflammatory response of the retina in response to photoreceptor-specific degeneration.

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