Pub Date : 2024-09-24DOI: 10.1016/j.bbrc.2024.150733
Background
Obesity is a significant global public health issue linked to numerous chronic diseases, including diabetes, cardiovascular conditions, and various cancers. The vacuolar H + ATPase, a multi-subunit enzyme complex involved in maintaining pH balance, has been implicated in various health conditions, including obesity-related diseases.
Method
This study conducts a comprehensive analysis of V-ATPase subunits' roles in adipogenesis within the context of obesity, using knockdown and RNAseq technologies.
Result
This study conducts a comprehensive analysis of V-ATPase subunits' roles in adipogenesis, highlighting specific subunits, v0d2 and v1a, which show significant expression alterations. Our findings reveal that v1a plays a crucial role in adipocyte differentiation through pathways related to steroid and cholesterol metabolism.
Conclusion
This study provides a comprehensive analysis of the roles played by V-ATPase subunits in adipogenesis and finds the critical role of V-ATPase subunits, particularly v1a, in the differentiation of adipocytes and their potential impact on obesity.
{"title":"The different functions of V-ATPase subunits in adipocyte differentiation and their expression in obese mice","authors":"","doi":"10.1016/j.bbrc.2024.150733","DOIUrl":"10.1016/j.bbrc.2024.150733","url":null,"abstract":"<div><h3>Background</h3><div>Obesity is a significant global public health issue linked to numerous chronic diseases, including diabetes, cardiovascular conditions, and various cancers. The vacuolar H + ATPase, a multi-subunit enzyme complex involved in maintaining pH balance, has been implicated in various health conditions, including obesity-related diseases.</div></div><div><h3>Method</h3><div>This study conducts a comprehensive analysis of V-ATPase subunits' roles in adipogenesis within the context of obesity, using knockdown and RNAseq technologies.</div></div><div><h3>Result</h3><div>This study conducts a comprehensive analysis of V-ATPase subunits' roles in adipogenesis, highlighting specific subunits, v0d2 and v1a, which show significant expression alterations. Our findings reveal that v1a plays a crucial role in adipocyte differentiation through pathways related to steroid and cholesterol metabolism.</div></div><div><h3>Conclusion</h3><div>This study provides a comprehensive analysis of the roles played by V-ATPase subunits in adipogenesis and finds the critical role of V-ATPase subunits, particularly v1a, in the differentiation of adipocytes and their potential impact on obesity.</div></div>","PeriodicalId":8779,"journal":{"name":"Biochemical and biophysical research communications","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-24DOI: 10.1016/j.bbrc.2024.150724
3,3′-Diindolylmethane is recognized for its anti-cancer activities in various pathways, though its mechanism remains to be fully elucidated. Previous studies have shown that 3,3′-Diindolylmethane disturbed the localization of Cut11, a nuclear pore complex subunit in Schizosaccharomyces pombe. This study further reveals that in Schizosaccharomyces pombe, 3,3′-Diindolylmethane also disrupts other components of nuclear envelope, causing GFP-NLS leakage, making it evident that 3,3′-Diindolylmethane disrupts the nuclear envelope. 3,3′-Diindolylmethane also disturbs the localization of GFP-ADEL and Ost4, which are endoplasmic reticulum lumen proteins and membrane proteins respectively, suggesting the function of 3,3′-Diindolylmethane on endoplasmic reticulum disturbance. The nuclear envelope repairment, normal nuclear envelope physical properties, and lipid metabolism homeostasis are crucial for cell survival in the presence of 3,3′-Diindolylmethane. These findings provide new insights into the understanding and development of 3,3′-Diindolylmethane as an anti-cancer agent.
{"title":"3,3′-Diindolylmethane disrupts the endoplasmic reticulum and nuclear envelope in Schizosaccharomyces pombe","authors":"","doi":"10.1016/j.bbrc.2024.150724","DOIUrl":"10.1016/j.bbrc.2024.150724","url":null,"abstract":"<div><div>3,3′-Diindolylmethane is recognized for its anti-cancer activities in various pathways, though its mechanism remains to be fully elucidated. Previous studies have shown that 3,3′-Diindolylmethane disturbed the localization of Cut11, a nuclear pore complex subunit in <em>Schizosaccharomyces pombe</em>. This study further reveals that in <em>Schizosaccharomyces pombe,</em> 3,3′-Diindolylmethane also disrupts other components of nuclear envelope, causing GFP-NLS leakage, making it evident that 3,3′-Diindolylmethane <u>disrupts the</u> nuclear envelope. 3,3′-Diindolylmethane also disturbs the localization of GFP-ADEL and Ost4, which are endoplasmic reticulum lumen proteins and membrane proteins respectively, suggesting the function of 3,3′-Diindolylmethane on endoplasmic reticulum disturbance. The nuclear envelope repairment, normal nuclear envelope physical properties, and lipid metabolism homeostasis are crucial for cell survival in the presence of 3,3′-Diindolylmethane. These findings provide new insights into the understanding and development of 3,3′-Diindolylmethane as an anti-cancer agent.</div></div>","PeriodicalId":8779,"journal":{"name":"Biochemical and biophysical research communications","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-21DOI: 10.1016/j.bbrc.2024.150728
Agmatine, a natural polyamine also known as 4-aminobutyl-guanidine, is biosynthesized from arginine by decarboxylation. Aspergillus oryzae contains high amounts of agmatine, suggesting highly active arginine decarboxylase (ADC) in this organism. However, genome analysis revealed no ADC homolog in A. oryzae. A. oryzae strain RIB40 has six homologs of phosphatidylserine decarboxylase (PSD), an enzyme that synthesizes phosphatidyl ethanolamine from phosphatidylserine. We previously discovered that one of these homologs, AO090102000327, encodes arginine decarboxylase, which we named ADC1. In the present study, we determined the crystal structures of ligand-free, arginine-treated, and agmatine-treated ADC1 each at 1.9–2.15 Å resolution. Each structure contained four ADC1 molecules (chains A–D) in the asymmetric unit of the cell. Each ADC1 molecule is a heterodimer consisting of the N-terminal region (Asn60–Gly441) and C-terminal region (Ser442–Thr482). In the ligand-free ADC1, the N-terminus of Ser442 was modified to form a pyruvoyl group. In the arginine-treated ADC1, arginine was converted to agmatine, with the pyruvoyl group covalently bound to agmatine by forming a Schiff base. The same structure was observed in agmatine-treated ADC1. These results indicate that ADC1 is a pyruvoyl-dependent decarboxylase and unveils the reaction mechanism of ADC from A. oryzae.
麦角碱是一种天然多胺，又称 4-氨基丁基胍，由精氨酸通过脱羧作用生物合成。黑曲霉（Aspergillus oryzae）含有大量的γ-氨基丁酸，这表明该生物体内的精氨酸脱羧酶（ADC）非常活跃。然而，基因组分析表明，在黑曲霉中没有 ADC 同源物。A. oryzae 菌株 RIB40 有六个磷脂酰丝氨酸脱羧酶（PSD）同源物，PSD 是一种从磷脂酰丝氨酸合成磷脂酰乙醇胺的酶。我们之前发现其中一个同源物 AO090102000327 编码精氨酸脱羧酶，并将其命名为 ADC1。在本研究中，我们以 1.9-2.15 Å 的分辨率测定了无配体、精氨酸处理和琼脂糖处理的 ADC1 晶体结构。每个结构都包含细胞不对称单元中的四个 ADC1 分子（链 A-D）。每个 ADC1 分子都是由 N 端（Asn60-Gly441）和 C 端（Ser442-Thr482）组成的异源二聚体。在不含配体的 ADC1 中，Ser442 的 N 端被修饰成一个丙酮酰基。在精氨酸处理过的 ADC1 中，精氨酸转化为琼脂糖，丙酮酰基通过形成希夫碱与琼脂糖共价结合。在琼脂糖处理的 ADC1 中也观察到了相同的结构。这些结果表明 ADC1 是一种依赖丙酮酰的脱羧酶，并揭示了奥氏酵母中 ADC 的反应机制。
{"title":"Unveiling the reaction mechanism of arginine decarboxylase in Aspergillus oryzae: Insights from crystal structure analysis","authors":"","doi":"10.1016/j.bbrc.2024.150728","DOIUrl":"10.1016/j.bbrc.2024.150728","url":null,"abstract":"<div><div>Agmatine, a natural polyamine also known as 4-aminobutyl-guanidine, is biosynthesized from arginine by decarboxylation. <em>Aspergillus oryzae</em> contains high amounts of agmatine, suggesting highly active arginine decarboxylase (ADC) in this organism. However, genome analysis revealed no ADC homolog in <em>A. oryzae</em>. <em>A. oryzae</em> strain RIB40 has six homologs of phosphatidylserine decarboxylase (PSD), an enzyme that synthesizes phosphatidyl ethanolamine from phosphatidylserine. We previously discovered that one of these homologs, AO090102000327, encodes arginine decarboxylase, which we named ADC1. In the present study, we determined the crystal structures of ligand-free, arginine-treated, and agmatine-treated ADC1 each at 1.9–2.15 Å resolution. Each structure contained four ADC1 molecules (chains A–D) in the asymmetric unit of the cell. Each ADC1 molecule is a heterodimer consisting of the N-terminal region (Asn60–Gly441) and C-terminal region (Ser442–Thr482). In the ligand-free ADC1, the N-terminus of Ser442 was modified to form a pyruvoyl group. In the arginine-treated ADC1, arginine was converted to agmatine, with the pyruvoyl group covalently bound to agmatine by forming a Schiff base. The same structure was observed in agmatine-treated ADC1. These results indicate that ADC1 is a pyruvoyl-dependent decarboxylase and unveils the reaction mechanism of ADC from <em>A. oryzae</em>.</div></div>","PeriodicalId":8779,"journal":{"name":"Biochemical and biophysical research communications","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-21DOI: 10.1016/j.bbrc.2024.150723
The human Orai1 (hOrai1) channel plays a crucial role in extracellular Ca2+ influx and has emerged as an attractive drug target for various diseases. However, the activated structure of the hOrai1 channel assembly within a lipid bilayer remains unknown. In this study, we expressed and purified the hOrai1 channel covalently linked to two SOAR tandems (HOSS). Patch-clamp experiments in whole-cell configuration showed that HOSS is constitutively active. Biochemical characterization confirmed that the purified HOSS channels were successfully incorporated into MSP1E3D1 nanodiscs. Negative staining revealed that the HOSS channels resemble a mushroom, with the body representing the hOrai1 channel and the leg representing the SOAR domain. Surprisingly, 2D analysis of cryo-EM data demonstrated a pentameric assembly of HOSS in a lipid bilayer. Our findings suggest that the hOrai1 channel may assemble into different oligomeric states in response to varying membrane environments.
{"title":"Activated human Orai1 channel in lipid biolayer may exist as a pentamer","authors":"","doi":"10.1016/j.bbrc.2024.150723","DOIUrl":"10.1016/j.bbrc.2024.150723","url":null,"abstract":"<div><div>The human Orai1 (hOrai1) channel plays a crucial role in extracellular Ca<sup>2+</sup> influx and has emerged as an attractive drug target for various diseases. However, the activated structure of the hOrai1 channel assembly within a lipid bilayer remains unknown. In this study, we expressed and purified the hOrai1 channel covalently linked to two SOAR tandems (HOSS). Patch-clamp experiments in whole-cell configuration showed that HOSS is constitutively active. Biochemical characterization confirmed that the purified HOSS channels were successfully incorporated into MSP1E3D1 nanodiscs. Negative staining revealed that the HOSS channels resemble a mushroom, with the body representing the hOrai1 channel and the leg representing the SOAR domain. Surprisingly, 2D analysis of cryo-EM data demonstrated a pentameric assembly of HOSS in a lipid bilayer. Our findings suggest that the hOrai1 channel may assemble into different oligomeric states in response to varying membrane environments.</div></div>","PeriodicalId":8779,"journal":{"name":"Biochemical and biophysical research communications","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142307032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-21DOI: 10.1016/j.bbrc.2024.150729
Myotonic dystrophy type 1 (DM1) is caused by the expansion of a non-coding CTG repeat in DMPK. CUG-repeat-containing transcripts sequester the splicing regulator MBNL1 into nuclear RNA foci, causing aberrant splicing of many genes. Although the mislocalization of MBNL1 represents a causal event in DM1 pathogenesis, the effect of CUG repeat RNA on the protein level of MBNL1 remains unclear. Using a DM1 model cell line, we found that CUG repeat RNA caused a significant decrease in the protein, but not mRNA levels, of MBNL1. As CUG repeats did not decrease MBNL1 translation, we investigated protein degradation pathways. Although autophagy-related reagents induced little change, proteasome inhibitors partially recovered MBNL1 protein expression levels under conditions of CUG repeat expression and induced a slight, but significant, reversal of splicing dysregulation. MBNL1 was detected in the polyubiquitinated protein fraction, but MBNL1 polyubiquitination was not detected. Moreover, inhibition of the ubiquitin-activating enzyme E1 did not increase MBNL1 levels, suggesting that MBNL1 is a substrate of polyubiquitin-independent proteasomal degradation. These results suggest that CUG-repeat-induced proteasomal degradation partially contributes to the functional decline of MBNL1.
{"title":"CUG repeat RNA-dependent proteasomal degradation of MBNL1 in a cellular model of myotonic dystrophy type 1","authors":"","doi":"10.1016/j.bbrc.2024.150729","DOIUrl":"10.1016/j.bbrc.2024.150729","url":null,"abstract":"<div><div>Myotonic dystrophy type 1 (DM1) is caused by the expansion of a non-coding CTG repeat in <em>DMPK</em>. CUG-repeat-containing transcripts sequester the splicing regulator MBNL1 into nuclear RNA foci, causing aberrant splicing of many genes. Although the mislocalization of MBNL1 represents a causal event in DM1 pathogenesis, the effect of CUG repeat RNA on the protein level of MBNL1 remains unclear. Using a DM1 model cell line, we found that CUG repeat RNA caused a significant decrease in the protein, but not mRNA levels, of MBNL1. As CUG repeats did not decrease MBNL1 translation, we investigated protein degradation pathways. Although autophagy-related reagents induced little change, proteasome inhibitors partially recovered MBNL1 protein expression levels under conditions of CUG repeat expression and induced a slight, but significant, reversal of splicing dysregulation. MBNL1 was detected in the polyubiquitinated protein fraction, but MBNL1 polyubiquitination was not detected. Moreover, inhibition of the ubiquitin-activating enzyme E1 did not increase MBNL1 levels, suggesting that MBNL1 is a substrate of polyubiquitin-independent proteasomal degradation. These results suggest that CUG-repeat-induced proteasomal degradation partially contributes to the functional decline of MBNL1.</div></div>","PeriodicalId":8779,"journal":{"name":"Biochemical and biophysical research communications","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0006291X24012658/pdfft?md5=85fc757b2b410ffa2fd7c6d7a5cc6d20&pid=1-s2.0-S0006291X24012658-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-21DOI: 10.1016/j.bbrc.2024.150734
Pseudo-Response Regulator (PRR) proteins constitute a fundamental set of circadian clock components in plants. PRRs have an amino acid sequence stretch with similarity to the receiver (REC) domain of response regulators (RRs) in the Multi-Step Phosphorelay (MSP). However, it has never been elucidated whether PRRs interact with Histidine-containing Phosphotransfer (HPt) proteins, which transfer a phosphate to RRs. Here, we studied whether PRRs interact with HPts in the moss Physcomitrium patens by the Yeast Two-Hybrid system and Bimolecular Fluorescence Complementation. P. patens PRR1/2/3 interacted with HPt1/2 in the nucleus, but not with HPt3, suggesting that P. patens PRRs function as authentic RRs. We discuss these results in relation to the evolution and diversity of the plant circadian clocks.
{"title":"Nuclear interactions between the Pseudo-Response Regulator clock proteins and the Multi-Step Phosphorelay mediator Histidine-containing phosphotransfers in the moss Physcomitrium patens","authors":"","doi":"10.1016/j.bbrc.2024.150734","DOIUrl":"10.1016/j.bbrc.2024.150734","url":null,"abstract":"<div><div>Pseudo-Response Regulator (PRR) proteins constitute a fundamental set of circadian clock components in plants. PRRs have an amino acid sequence stretch with similarity to the receiver (REC) domain of response regulators (RRs) in the Multi-Step Phosphorelay (MSP). However, it has never been elucidated whether PRRs interact with Histidine-containing Phosphotransfer (HPt) proteins, which transfer a phosphate to RRs. Here, we studied whether PRRs interact with HPts in the moss <em>Physcomitrium patens</em> by the Yeast Two-Hybrid system and Bimolecular Fluorescence Complementation. <em>P. patens</em> PRR1/2/3 interacted with HPt1/2 in the nucleus, but not with HPt3, suggesting that <em>P. patens</em> PRRs function as authentic RRs. We discuss these results in relation to the evolution and diversity of the plant circadian clocks.</div></div>","PeriodicalId":8779,"journal":{"name":"Biochemical and biophysical research communications","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-21DOI: 10.1016/j.bbrc.2024.150736
Long-term changes of synaptic transmission can be induced by Hebbian-type homosynaptic mechanisms which require activation of both pre- and postsynapse and mediate associative learning, as well as by heterosynaptic mechanisms which do not require activation of the presynapse and are non-associative. The rules for induction of homosynaptic plasticity depend on the distance of the synapse from the soma. Does induction of heterosynaptic plasticity also depend on synaptic location? Here, we investigated heterosynaptic changes in pharmacologically isolated glutamatergic inputs arriving at either the proximal or the distal segments of the apical dendrite of layer 2/3 pyramidal neurons in rat visual cortex. We show that bursts of action potentials evoked without presynaptic stimulation induced potentiation of proximal inputs while having little effect on distal inputs. Such gradient of plasticity could be related to the attenuation of backpropagating action potentials along the dendrites. Thus, the location of the synapse on the dendritic tree is a determinant not only for homosynaptic but also for heterosynaptic plasticity.
{"title":"Non-associative potentiation of proximal excitatory inputs to layer 2/3 pyramidal cells in rat visual cortex","authors":"","doi":"10.1016/j.bbrc.2024.150736","DOIUrl":"10.1016/j.bbrc.2024.150736","url":null,"abstract":"<div><div>Long-term changes of synaptic transmission can be induced by Hebbian-type homosynaptic mechanisms which require activation of both pre- and postsynapse and mediate associative learning, as well as by heterosynaptic mechanisms which do not require activation of the presynapse and are non-associative. The rules for induction of homosynaptic plasticity depend on the distance of the synapse from the soma. Does induction of heterosynaptic plasticity also depend on synaptic location? Here, we investigated heterosynaptic changes in pharmacologically isolated glutamatergic inputs arriving at either the proximal or the distal segments of the apical dendrite of layer 2/3 pyramidal neurons in rat visual cortex. We show that bursts of action potentials evoked without presynaptic stimulation induced potentiation of proximal inputs while having little effect on distal inputs. Such gradient of plasticity could be related to the attenuation of backpropagating action potentials along the dendrites. Thus, the location of the synapse on the dendritic tree is a determinant not only for homosynaptic but also for heterosynaptic plasticity.</div></div>","PeriodicalId":8779,"journal":{"name":"Biochemical and biophysical research communications","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-20DOI: 10.1016/j.bbrc.2024.150727
Liver fibrosis, a common feature of most chronic liver diseases, poses significant health risks and results from various etiologies. While microRNAs (miRNAs) have demonstrated promising anti-fibrotic potential through the direct regulation of target genes, their therapeutic mechanisms remain incompletely understood. In this study, we identified miR-199a, initially discovered in anti-liver fibrotic exosomes, as a key modulator that alleviates thioacetamide-induced liver fibrosis in a mouse model. Consistent with its in vivo effects, treatment with an miR-199a mimic effectively inhibited the activation and function of human hepatic stellate cells (HSCs)-central drivers of liver fibrosis-as well as HSC proliferation and viability in vitro. Notably, miR-199a-3p exerted these anti-fibrotic effects by directly downregulating its biologically relevant target, cyclin-dependent kinase 17 (CDK17). Depletion of CDK17 alone in activated HSCs was sufficient to suppress their activation, function, proliferation, and viability, mirroring the effects of miR-199a mimic treatment. Conversely, overexpression of CDK17 reversed all cellular effects induced by miR-199a mimic treatment. Our findings highlight the miR-199a-3p-CDK17 regulatory axis and suggest that targeting CDK17 in activated HSCs could be a promising therapeutic strategy for liver fibrosis.
{"title":"MicroRNA miR-199a-3p alleviates liver fibrosis by targeting CDK17 in activated hepatic stellate cells","authors":"","doi":"10.1016/j.bbrc.2024.150727","DOIUrl":"10.1016/j.bbrc.2024.150727","url":null,"abstract":"<div><div>Liver fibrosis, a common feature of most chronic liver diseases, poses significant health risks and results from various etiologies. While microRNAs (miRNAs) have demonstrated promising anti-fibrotic potential through the direct regulation of target genes, their therapeutic mechanisms remain incompletely understood. In this study, we identified miR-199a, initially discovered in anti-liver fibrotic exosomes, as a key modulator that alleviates thioacetamide-induced liver fibrosis in a mouse model. Consistent with its <em>in vivo</em> effects, treatment with an miR-199a mimic effectively inhibited the activation and function of human hepatic stellate cells (HSCs)-central drivers of liver fibrosis-as well as HSC proliferation and viability <em>in vitro</em>. Notably, miR-199a-3p exerted these anti-fibrotic effects by directly downregulating its biologically relevant target, <em>cyclin-dependent kinase 17</em> (<em>CDK17</em>). Depletion of CDK17 alone in activated HSCs was sufficient to suppress their activation, function, proliferation, and viability, mirroring the effects of miR-199a mimic treatment. Conversely, overexpression of <em>CDK17</em> reversed all cellular effects induced by miR-199a mimic treatment. Our findings highlight the miR-199a-3p-<em>CDK17</em> regulatory axis and suggest that targeting CDK17 in activated HSCs could be a promising therapeutic strategy for liver fibrosis.</div></div>","PeriodicalId":8779,"journal":{"name":"Biochemical and biophysical research communications","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-20DOI: 10.1016/j.bbrc.2024.150725
Junctophilin-2 (JPH2) is traditionally recognized as a cardiomyocyte-enriched structural protein that anchors the junction between the plasma membrane and the endo/sarcoplasmic reticulum, facilitating excitation-induced cardiac contraction. In this study, we uncover a novel function of JPH2 as a double-stranded RNA (dsRNA)-binding protein, which forms complexes with dsRNA both in vitro and in cells. Stimulation by cytosolic dsRNA enhances the interaction of JPH2 with the dsRNA sensor MDA5. Notably, JPH2 inhibits MDA5's binding to its dsRNA ligand, likely by sequestering the dsRNA. Silencing JPH2 in cardiomyocytes increased the interaction between MDA5 and its dsRNA ligands, activated the MAVS/TBK1 signaling, and triggered spontaneous interferon-beta (IFNb1) production in the absence of foreign pathogen. Mouse hearts deficient in JPH2 exhibited upregulation of innate immune signaling cascade. Collectively, these findings identify JPH2 as a regulator of dsRNA sensing and highlight its role in suppressing the automatic activation of innate immune responses in cardiomyocytes, suggesting the cytosolic surface of the endo/sarcoplasmic reticulum as a hub for dsRNA sequestration.
{"title":"Junctophilin-2 is a double-stranded RNA-binding protein that regulates cardiomyocyte-autonomous innate immune response","authors":"","doi":"10.1016/j.bbrc.2024.150725","DOIUrl":"10.1016/j.bbrc.2024.150725","url":null,"abstract":"<div><div>Junctophilin-2 (JPH2) is traditionally recognized as a cardiomyocyte-enriched structural protein that anchors the junction between the plasma membrane and the endo/sarcoplasmic reticulum, facilitating excitation-induced cardiac contraction. In this study, we uncover a novel function of JPH2 as a double-stranded RNA (dsRNA)-binding protein, which forms complexes with dsRNA both in vitro and in cells. Stimulation by cytosolic dsRNA enhances the interaction of JPH2 with the dsRNA sensor MDA5. Notably, JPH2 inhibits MDA5's binding to its dsRNA ligand, likely by sequestering the dsRNA. Silencing JPH2 in cardiomyocytes increased the interaction between MDA5 and its dsRNA ligands, activated the MAVS/TBK1 signaling, and triggered spontaneous interferon-beta (IFNb1) production in the absence of foreign pathogen. Mouse hearts deficient in JPH2 exhibited upregulation of innate immune signaling cascade. Collectively, these findings identify JPH2 as a regulator of dsRNA sensing and highlight its role in suppressing the automatic activation of innate immune responses in cardiomyocytes, suggesting the cytosolic surface of the endo/sarcoplasmic reticulum as a hub for dsRNA sequestration.</div></div>","PeriodicalId":8779,"journal":{"name":"Biochemical and biophysical research communications","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-19DOI: 10.1016/j.bbrc.2024.150718
Sanfilippo disease is a lysosomal storage disorder from the group of mucopolysaccharidoses (MPS), characterized by storage of glycosaminoglycans (GAGs); thus, it is also called MPS type III. The syndrome is divided into 4 subtypes (MPS III A, B, C and D). Despite the storage of the same GAG, heparan sulfate (HS), the course of these subtypes can vary considerably. Here, we comprehensively evaluated the levels of protein aggregates (APP, β-amyloid, p-tau, α-synuclein, TDP43) in fibroblasts derived from patients with all MPS III subtypes, and tested whether lowering GAG levels results in a decrease in the levels of the investigated proteins and the number of aggregates they form. Elevated levels of APP, β-amyloid, tau, and TDP43 proteins were evident in all MPS III subtypes, and elevated levels of p-tau and α-synuclein were demonstrated in all subtypes except MPS IIIC. These findings were confirmed in the neural tissue of MPS IIIB mice. Fluorescence microscopy studies also indicated a high number of protein aggregates formed by β-amyloid and tau in all cell lines tested, and a high number of aggregates of p-tau, TDP43, and α-synuclein in all lines except MPS IIIC. Reduction of GAG levels by genistein led to the decrease of levels of all tested proteins and their aggregates except α-synuclein, indicating a relationship between GAG levels and those of some protein aggregates. This work describes for the first time the problem of deposited protein aggregates in all subtypes of Sanfilippo disease and suggests that GAGs are partly responsible for the formation of protein aggregates.
桑菲利波病是一种溶酶体贮积症，属于粘多糖（MPS）类，以贮存糖胺聚糖（GAGs）为特征，因此也被称为 MPS III 型。该综合征分为 4 个亚型（MPS III A、B、C 和 D 型）。尽管储存的是同一种 GAG--硫酸肝素（HS），但这些亚型的病程却有很大差异。在这里，我们全面评估了来自所有 MPS III 亚型患者的成纤维细胞中蛋白质聚集体（APP、β-淀粉样蛋白、p-tau、α-突触核蛋白、TDP43）的水平，并测试了降低 GAG 水平是否会导致所研究蛋白质水平的降低及其聚集体数量的减少。在所有 MPS III 亚型中，APP、β-淀粉样蛋白、tau 和 TDP43 蛋白的水平均明显升高，而在除 MPS IIIC 以外的所有亚型中，p-tau 和 α-突触核蛋白的水平均升高。这些发现在 MPS IIIB 小鼠的神经组织中得到了证实。荧光显微镜研究还表明，在所有测试的细胞系中，β-淀粉样蛋白和 tau 形成了大量的蛋白质聚集体，而在除 MPS IIIC 以外的所有细胞系中，p-tau、TDP43 和 α-突触核蛋白的聚集体数量也很多。用染料木素降低 GAG 含量会导致除 α-synuclein 以外的所有受测蛋白质及其聚集体的含量下降，这表明 GAG 含量与某些蛋白质聚集体的含量之间存在关系。这项研究首次描述了桑菲利波病所有亚型中沉积的蛋白质聚集问题，并表明 GAGs 是蛋白质聚集形成的部分原因。
{"title":"Comprehensive evaluation of pathogenic protein accumulation in fibroblasts from all subtypes of Sanfilippo disease patients","authors":"","doi":"10.1016/j.bbrc.2024.150718","DOIUrl":"10.1016/j.bbrc.2024.150718","url":null,"abstract":"<div><p>Sanfilippo disease is a lysosomal storage disorder from the group of mucopolysaccharidoses (MPS), characterized by storage of glycosaminoglycans (GAGs); thus, it is also called MPS type III. The syndrome is divided into 4 subtypes (MPS III A, B, C and D). Despite the storage of the same GAG, heparan sulfate (HS), the course of these subtypes can vary considerably. Here, we comprehensively evaluated the levels of protein aggregates (APP, β-amyloid, p-tau, α-synuclein, TDP43) in fibroblasts derived from patients with all MPS III subtypes, and tested whether lowering GAG levels results in a decrease in the levels of the investigated proteins and the number of aggregates they form. Elevated levels of APP, β-amyloid, tau, and TDP43 proteins were evident in all MPS III subtypes, and elevated levels of p-tau and α-synuclein were demonstrated in all subtypes except MPS IIIC. These findings were confirmed in the neural tissue of MPS IIIB mice. Fluorescence microscopy studies also indicated a high number of protein aggregates formed by β-amyloid and tau in all cell lines tested, and a high number of aggregates of p-tau, TDP43, and α-synuclein in all lines except MPS IIIC. Reduction of GAG levels by genistein led to the decrease of levels of all tested proteins and their aggregates except α-synuclein, indicating a relationship between GAG levels and those of some protein aggregates. This work describes for the first time the problem of deposited protein aggregates in all subtypes of Sanfilippo disease and suggests that GAGs are partly responsible for the formation of protein aggregates.</p></div>","PeriodicalId":8779,"journal":{"name":"Biochemical and biophysical research communications","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0006291X24012543/pdfft?md5=018d26cd984cead61249bcb1d7a2ed5b&pid=1-s2.0-S0006291X24012543-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142274191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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