A New Approach of Short Wave Protection against Middle Cerebral Artery Occlusion/Reperfusion Injury via Attenuation of Golgi Apparatus Stress by Inhibition of Downregulation of Secretory Pathway Ca(2+)-ATPase Isoform 1 in Rats

The role of metal ions in the Golgi apparatus

The Golgi apparatus is a membrane-bound organelle that functions as a central role in the secretory pathway. Since the discovery of the Golgi apparatus, its structure and function have attracted ever-increasing attention from researchers. Recently, it has been demonstrated that metal ions are necessary for the Golgi apparatus to maintain its proper structure and functions. Given that metal ions play an important role in various biological processes, their abnormal homeostasis is related to many diseases. Therefore, in this paper, we reviewed the uptake and release mechanisms of the Golgi apparatus Ca²⁺ , Cu, and Zn²⁺ . Furthermore, we describe the diseases associated with Golgi apparatus Ca²⁺ , Cu, and Zn²⁺ imbalance.

OM-MSCs Alleviate the Golgi Apparatus Stress Response following Cerebral Ischemia/Reperfusion Injury via the PEDF-PI3K/Akt/mTOR Signaling Pathway

The mechanism of Golgi apparatus (GA) stress responses mediated by GOLPH3 has been widely studied in ischemic stroke, and the neuroprotection effect of olfactory mucosa mesenchymal stem cells (OM-MSCs) against cerebral ischemia/reperfusion injury (IRI) has been preliminarily presented. However, the exact role of OM-MSCs in the GA stress response following cerebral IRI remains to be elucidated. In the present study, we used an oxygen-glucose deprivation/reoxygenation (OGD/R) model and reversible middle cerebral artery occlusion (MCAO) model to simulate cerebral IRI in vitro and in vivo. Our results showed that the level of GOLPH3 protein, reactive oxygen species (ROS), and Ca²⁺ was upregulated, SPCA1 level was downregulated, and GA fragmentation was increased in ischemic stroke models, and OM-MSC treatment clearly ameliorated these GA stress responses in vitro and in vivo. Subsequently, the knockdown of PEDF in OM-MSCs using PEDF-specific siRNA further demonstrated that secretion of PEDF in OM-MSCs protected OGD/R-treated N2a cells and MCAO rats from GA stress response. Additionally, rescue experiment using specific pathway inhibitors suggested that OM-MSCs could promote the phosphorylation of the PI3K/Akt/mTOR pathway, thereby mitigating OGD/R-induced GA stress response and excessive autophagy. In conclusion, OM-MSCs minimized the GA stress response following cerebral IRI, at least partially, through the PEDF-PI3K/Akt/mTOR pathway.

A Negative Feedback Loop in Ultraviolet A-Induced Senescence in Human Dermal Fibroblasts Formed by SPCA1 and MAPK

Secretory pathway calcium ATPase 1 (SPCA1) is a calcium pump localized specifically to the Golgi. Its effects on UVA-induced senescence have never been examined. In our study, expression of SPCA1 was increased in UVA-irradiated human dermal fibroblasts (HDFs) by activating mitogen-activated protein kinase (MAPK) and its downstream transcription factor, c-jun. Dual-luciferase reporter and chromatin immunoprecipitation assays revealed that c-jun regulated SPCA1 by binding to its promoter. Furthermore, downregulating SPCA1 with siRNA transfection aggravated UVA-induced senescence due to an elevation of intracellular calcium concentrations and a subsequent increase in reactive oxygen species (ROS) and MAPK activity. In contrast, overexpression of SPCA1 reduced calcium overload, consequently lowering the ROS level and suppressing MAPK activation. This alleviated the cellular senescence caused by UVA irradiation. These results indicated that SPCA1 might exert a protective effect on UVA-induced senescence in HDFs via forming a negative feedback loop. Specifically, activation of MAPK/c-jun triggered by UVA transcriptionally upregulated SPCA1. In turn, the increased SPCA1 lowered the intracellular Ca²⁺ level, probably through pumping Ca²⁺ into the Golgi, leading to a reduction of ROS, eventually decreasing MAPK activity and diminishing UVA-induced senescence.

Olfactory Mucosa Mesenchymal Stem Cells Alleviate Cerebral Ischemia/Reperfusion Injury Via Golgi Apparatus Secretory Pathway Ca2+ -ATPase Isoform1

Olfactory mucosa mesenchymal stem cells (OM-MSCs) have exhibited their effectiveness in central nervous system diseases and provided an appealing candidate for the treatment of ischemic stroke. Previous evidence have shown that Golgi apparatus (GA) secretory pathway Ca²⁺-ATPase isoform1 (SPCA1) was a potential therapeutic target for ischemic stroke. In this study, we explored the neuroprotective mechanism of OM-MSCs and its effect on the expression and function of SPCA1 during cerebral ischemia/reperfusion. Based on in vitro and in vivo experiments, we discovered that OM-MSCs attenuated apoptosis and oxidative stress in ischemic stroke models, reduced the cerebral infarction volume, and improved the neurologic deficits of rats. OM-MSCs also upregulated SPCA1 expression and alleviated Ca²⁺ overload and decreased the edema and dissolution of the GA in neurons. Moreover, we discovered that SPCA1 depletion in oxygen and glucose deprivation/reoxygenation (OGD/R)-treated N2a cells mitigated the protective effects of OM-MSCs. Altogether, OM-MSCs exerted neuroprotective effects in ischemic stroke probably via modulating SPCA1 and reducing the edema and dissolution of the GA in neurons.

Plasma Exosomal miR-450b-5p as a Possible Biomarker and Therapeutic Target for Transient Ischaemic Attacks in Rats

Transient ischaemic attack (TIA) and cerebral infarction are difficult to identify within the thrombolytic time window. Blood markers are efficient, economical and noninvasive and can be beneficial in the diagnosis of many diseases. Plasma exosomal biomarkers are rarely reported in TIA. Exosomal microRNAs (miRNAs) were extracted from plasma and cerebrospinal fluid after middle cerebral artery occlusion (MCAo) in rats (0 min, 5 min, 10 min, 2 h). Deep sequencing was used to detect exosomal miRNAs in rat plasma and confirm significant differentially expressed miRNAs. Polymerase chain reaction (PCR) was used to detect the differentially expressed miRNAs in plasma and cerebrospinal fluid. Exosomal miRNAs with the same expression trends in plasma and cerebrospinal fluid were selected, and bioinformatics analysis was then carried out. Finally, the area under the curve (AUC) of the receiver operating characteristic (ROC) curve was determined to assess the diagnostic accuracy of miRNAs for TIA in rats. First, high-throughput sequencing was used to detect the expression level of plasma exosome miRNA, and rno-miR-450b-5p with a decreasing expression level was screened. Second, the expression levels of exosomal miRNAs were verified in cerebrospinal fluid and plasma samples by PCR, and the results indicated that exosomal rno-miR-450b-5p was similarly expressed in cerebrospinal fluid and plasma. ROC analysis showed high AUC values for rno-miR-450b-5p (0.880) in the 10 min ischaemia rats compared with the control rats. Finally, bioinformatic analysis indicated that exosomal rno-miR-450b-5p may be involved in cerebral ischaemia. Plasma exosomal rno-miR-450b-5p has a high diagnostic value and may become a therapeutic target for rat TIA.

N,N-dimethyltryptamine Prevents Renal Ischemia-Reperfusion Injury in a Rat Model

BACKGROUND

Ischemia reperfusion (I/R) injury remains one of the most challenging fields of organ transplantation. It is highly associated with the use of expanded criteria donors that might conclude to delayed graft function or early or late graft failure.

OBJECTIVE

To investigate the metabolic, microcirculatory parameters, and histologic changes under the effect of N,N-dimethyltryptamine (DMT) in a renal I/R model in rats.

METHOD

In 26 anesthetized rats both kidneys were exposed. In the control group (n = 6) no other intervention happened. In 20 other animals, the right renal vessels were ligated, and after 60 minutes the right kidney was removed. The left renal vessels were clamped for 60 minutes then released, followed by 120 minutes of reperfusion. In the I/R group (n = 10), there was no additive treatment, while in I/R + DMT group (n = 10) DMT was administered 15 minutes before ischemia. Blood samples were taken, laser Doppler measurement was performed, and both kidneys were evaluated histologically.

RESULTS

Microcirculation (blood flux units [BFU]) diminished in all groups, but remarkably so in the I/R + DMT group. This group compensated better after the 30th minute of reperfusion. The control and I/R + DMT groups had similar BFUs after 120 minutes of reperfusion, but in the I/R group BFU was higher. Tubular necrosis developed in the I/R and I/R + DMT groups too; it was moderated under DMT effect, and severe without. Histologic injuries were less in I/R + DMT Group compared to non-treated animals.

CONCLUSION

Histologic changes characteristic to I/R injuries were reversible and microcirculation recovered at the end of 120 minutes reperfusion under the administration of DMT. DMT can be used for renoprotection in kidney transplantation.

The significant role of the Golgi apparatus in cardiovascular diseases

The Golgi apparatus (GA) is a ribbon-like system of stacks which consist of multiple closely apposed flattened cisternae and vesicles usually localized in the juxta-nuclear area. As for the biological functions, the GA plays a major role in protein biosynthesis, post-translational modification, and sorting protein from ER to plasma membrane and other destinations. Structural changes and functional disorder of the GA is associated with various diseases. Moreover, increasing evidence revealed that swelling, poor development, and other morphological alterations of the GA are linked to cardiovascular diseases such as heart failure (HF), arrhythmia, and dilated cardiomyopathy. Furthermore, dysfunction of the GA is also related to cardiovascular diseases since the GA is extremely responsible for transport, glycosylation, biosynthesis, and subcellular distribution of cardiovascular proteins. This review gives a brief overview of the intricate relationship between the GA and cardiovascular diseases. In addition, we provide a further prospective that the GA may provide diagnosis reference for cardiovascular diseases, and changes in the ultrastructure and morphology of the GA such as swelling, poor development, and fragmentation may serve as a reliable index for cardiovascular diseases.