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1.
Bioessays ; : e2400126, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39268818

RESUMEN

Neuronal information processing depends on converting membrane depolarizations into compartmentalized biochemical signals that can modify neuronal activity and structure. However, our understanding of how neurons translate electrical signals into specific biochemical responses remains limited, especially in the soma where gene expression and ion channel function are crucial for neuronal activity. Here, I emphasize the importance of physically compartmentalizing action potential-triggered biochemical reactions within the soma. Emerging evidence suggests that somatic endoplasmic reticulum-plasma membrane (ER-PM) junctions are specialized organelles that coordinate electrical and biochemical signaling. The juxtaposition of ion channels and signaling proteins at a prominent subset of these sites enables compartmentalized calcium and cAMP-dependent protein kinase (PKA) signaling. I explore the hypothesis that these PKA-containing ER-PM junctions serve as critical sites for translating membrane depolarizations into PKA signals and identify key gaps in knowledge of the assembly, regulation, and neurobiological functions of this somatic signaling system.

2.
ACS Infect Dis ; 2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39119676

RESUMEN

Ras signaling and glycosylphosphatidylinositol (GPI) biosynthesis are mutually inhibitory in S. cerevisiae (Sc). The inhibition is mediated via an interaction of yeast Ras2 with the Eri1 subunit of its GPI-N-acetylglucosaminyl transferase (GPI-GnT), the enzyme catalyzing the very first GPI biosynthetic step. In contrast, Ras signaling and GPI biosynthesis in C. albicans (Ca) are mutually activated and together control the virulence traits of the human fungal pathogen. What might be the role of Eri1 in this pathogen? The present manuscript addresses this question while simultaneously characterizing the cellular role of CaEri1. It is either nonessential or required at very low levels for cell viability in C. albicans. Severe depletion of CaEri1 results in reduced GPI biosynthesis and cell wall defects. It also produces hyperfilamentation phenotypes in Spider medium as well as in bicarbonate medium containing 5% CO2, suggesting that both the Ras-dependent and Ras-independent cAMP-PKA pathways for hyphal morphogenesis are activated in these cells. Pull-down and acceptor-photobleaching FRET experiments suggest that CaEri1 does not directly interact with CaRas1 but does so through CaGpi2, another GPI-GnT subunit. We showed previously that CaGpi2 is downstream of CaEri1 in cross talk with CaRas1 and for Ras-dependent hyphal morphogenesis. Here we show that CaEri1 is downstream of all GPI-GnT subunits in inhibiting Ras-independent filamentation. CaERI1 also participates in intersubunit transcriptional cross talk within the GPI-GnT, a feature unique to C. albicans. Virulence studies using G. mellonella larvae show that a heterozygous strain of CaERI1 is better cleared by the host and is attenuated in virulence.

3.
Artículo en Inglés | MEDLINE | ID: mdl-38969290

RESUMEN

Previous studies have revealed the stimulatory and inhibitory actions of gonadotropin-releasing hormone (GnRH) and gonadotropin-inhibitory hormone (GnIH) on the control of reproduction in European sea bass (Dicentrarchus labrax) and other vertebrates, respectively. However, information on the possible interactions between GnRH and GnIH on cell signaling is sparse in vertebrates. In the current study, we investigated if activation of sea bass GnIH receptor (GnIHR) can interfere with GnRH receptor II-1a (GnRHR-II-1a) involving the PKA pathway. Our results showed that GnIH and GnRH functioned via their cognate receptors, respectively. However, it appears that neither GnIH1 nor GnIH2 can block GnRH/GnRHR-II-1a-induced PKA signaling in sea bass. This is the first study to examine the potential interactions of GnIH with GnRH receptor signaling in teleosts. Further research seems necessary to shed light on unknown interactions in other signaling pathways and other GnIH/GnRH receptors involved in the physiological functions of these two relevant neuropeptides, not only in sea bass but also in other species.


Asunto(s)
Lubina , Hormona Liberadora de Gonadotropina , Receptores LHRH , Transducción de Señal , Animales , Lubina/metabolismo , Hormona Liberadora de Gonadotropina/metabolismo , Receptores LHRH/metabolismo , Hormonas Hipotalámicas/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Proteínas de Peces/metabolismo , Proteínas de Peces/genética
4.
Cell Signal ; 122: 111311, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39059755

RESUMEN

Cyclic adenosine monophosphate (cAMP) is an intracellular second messenger that is derived from the conversion of adenosine triphosphate catalysed by adenylyl cyclase (AC). Protein kinase A (PKA), the main effector of cAMP, is a dimeric protein kinase consisting of two catalytic subunits and two regulatory subunits. When cAMP binds to the regulatory subunits of PKA, it leads to the dissociation and activation of PKA, which allows the catalytic subunit of PKA to phosphorylate target proteins, thereby regulating various physiological functions and metabolic processes in cellular function. Recent researches also implicate the involvement of cAMP-PKA signaling in the pathologenesis of anxiety disorder. However, there are still debates on the prevention and treatment of anxiety disorders from this signaling pathway. To review the function of cAMP-PKA signaling in anxiety disorder, we searched the publications with the keywords including "cAMP", "PKA" and "Anxiety" from Pubmed, Embase, Web of Science and CNKI databases. The results showed that the number of publications on cAMP-PKA pathway in anxiety disorder tended to increase. Bioinformatics results displayed a close association between the cAMP-PKA pathway and the occurrence of anxiety. Mechanistically, cAMP-PKA signaling could influence brain-derived neurotrophic factor and neuropeptide Y and participate in the regulation of anxiety. cAMP-PKA signaling could also oppose the dysfunctions of gamma-aminobutyric acid (GABA), intestinal flora, hypothalamic-pituitary-adrenal axis, neuroinflammation, and signaling proteins (MAPK and AMPK) in anxiety. In addition, chemical agents with the ability to activate cAMP-PKA signaling demonstrated therapy potential against anxiety disorders. This review emphasizes the central roles of cAMP-PKA signaling in anxiety and the targets of the cAMP-PKA pathway would be potential candidates for treatment of anxiety. Nevertheless, more laboratory investigations to improve the therapeutic effect and reduce the adverse effect, and continuous clinical research will warrant the drug development.


Asunto(s)
Ansiedad , Proteínas Quinasas Dependientes de AMP Cíclico , AMP Cíclico , Transducción de Señal , Humanos , AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Animales , Ansiedad/metabolismo
5.
J Biol Chem ; 300(7): 107444, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38838772

RESUMEN

Candida albicans is an opportunistic fungal pathogen that can switch between yeast and hyphal morphologies depending on the environmental cues it receives. The switch to hyphal form is crucial for the establishment of invasive infections. The hyphal form is also characterized by the cell surface expression of hyphae-specific proteins, many of which are GPI-anchored and important determinants of its virulence. The coordination between hyphal morphogenesis and the expression of GPI-anchored proteins is made possible by an interesting cross-talk between GPI biosynthesis and the cAMP-PKA signaling cascade in the fungus; a parallel interaction is not found in its human host. On the other hand, in the nonpathogenic yeast, Saccharomyces cerevisiae, GPI biosynthesis is shut down when filamentation is activated and vice versa. This too is achieved by a cross-talk between GPI biosynthesis and cAMP-PKA signaling. How are diametrically opposite effects obtained from the cross-talk between two reasonably well-conserved pathways present ubiquitously across eukarya? This Review attempts to provide a model to explain these differences. In order to do so, it first provides an overview of the two pathways for the interested reader, highlighting the similarities and differences that are observed in C. albicans versus the well-studied S. cerevisiae model, before going on to explain how the different mechanisms of regulation are effected. While commonalities enable the development of generalized theories, it is hoped that a more nuanced approach, that takes into consideration species-specific differences, will enable organism-specific understanding of these processes and contribute to the development of targeted therapies.


Asunto(s)
Candida albicans , Proteínas Quinasas Dependientes de AMP Cíclico , AMP Cíclico , Hifa , Saccharomyces cerevisiae , Transducción de Señal , Candida albicans/metabolismo , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Hifa/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Glicosilfosfatidilinositoles/metabolismo , Glicosilfosfatidilinositoles/biosíntesis , Humanos , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética
6.
Proc Natl Acad Sci U S A ; 121(24): e2400732121, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38838021

RESUMEN

Cytoplasmic mislocalization and aggregation of TDP-43 protein are hallmarks of amyotrophic lateral sclerosis (ALS) and are observed in the vast majority of both familial and sporadic cases. How these two interconnected processes are regulated on a molecular level, however, remains enigmatic. Genome-wide screens for modifiers of the ALS-associated genes TDP-43 and FUS have identified the phospholipase D (Pld) pathway as a key regulator of ALS-related phenotypes in the fruit fly Drosophila melanogaster [M. W. Kankel et al., Genetics 215, 747-766 (2020)]. Here, we report the results of our search for downstream targets of the enzymatic product of Pld, phosphatidic acid. We identify two conserved negative regulators of the cAMP/PKA signaling pathway, the phosphodiesterase dunce and the inhibitory subunit PKA-R2, as modifiers of pathogenic phenotypes resulting from overexpression of the Drosophila TDP-43 ortholog TBPH. We show that knockdown of either of these genes results in a mitigation of both TBPH aggregation and mislocalization in larval motor neuron cell bodies, as well as an amelioration of adult-onset motor defects and shortened lifespan induced by TBPH. We determine that PKA kinase activity is downstream of both TBPH and Pld and that overexpression of the PKA target CrebA can rescue TBPH mislocalization. These findings suggest a model whereby increasing cAMP/PKA signaling can ameliorate the molecular and functional effects of pathological TDP-43.


Asunto(s)
Proteínas Quinasas Dependientes de AMP Cíclico , AMP Cíclico , Proteínas de Unión al ADN , Proteínas de Drosophila , Drosophila melanogaster , Transducción de Señal , Animales , AMP Cíclico/metabolismo , Drosophila melanogaster/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/genética , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/genética , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/genética , Humanos , Neuronas Motoras/metabolismo
7.
Elife ; 122024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38690987

RESUMEN

Elastic cartilage constitutes a major component of the external ear, which functions to guide sound to the middle and inner ears. Defects in auricle development cause congenital microtia, which affects hearing and appearance in patients. Mutations in several genes have been implicated in microtia development, yet, the pathogenesis of this disorder remains incompletely understood. Here, we show that Prrx1 genetically marks auricular chondrocytes in adult mice. Interestingly, BMP-Smad1/5/9 signaling in chondrocytes is increasingly activated from the proximal to distal segments of the ear, which is associated with a decrease in chondrocyte regenerative activity. Ablation of Bmpr1a in auricular chondrocytes led to chondrocyte atrophy and microtia development at the distal part. Transcriptome analysis revealed that Bmpr1a deficiency caused a switch from the chondrogenic program to the osteogenic program, accompanied by enhanced protein kinase A activation, likely through increased expression of Adcy5/8. Inhibition of PKA blocked chondrocyte-to-osteoblast transformation and microtia development. Moreover, analysis of single-cell RNA-seq of human microtia samples uncovered enriched gene expression in the PKA pathway and chondrocyte-to-osteoblast transformation process. These findings suggest that auricle cartilage is actively maintained by BMP signaling, which maintains chondrocyte identity by suppressing osteogenic differentiation.


Asunto(s)
Condrocitos , Microtia Congénita , Proteínas Quinasas Dependientes de AMP Cíclico , Transducción de Señal , Animales , Condrocitos/metabolismo , Microtia Congénita/genética , Microtia Congénita/metabolismo , Ratones , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/genética , Proteínas Morfogenéticas Óseas/metabolismo , Proteínas Morfogenéticas Óseas/genética , Humanos , Receptores de Proteínas Morfogenéticas Óseas de Tipo 1/metabolismo , Receptores de Proteínas Morfogenéticas Óseas de Tipo 1/genética , Condrogénesis/genética , Proteínas de Homeodominio/metabolismo , Proteínas de Homeodominio/genética
8.
BMC Cardiovasc Disord ; 24(1): 197, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38580957

RESUMEN

BACKGROUND: Heart failure (HF) is a heterogeneous syndrome that affects millions worldwide, resulting in substantial health and economic burdens. However, the molecular mechanism of HF pathogenesis remains unclear. METHODS: HF-related key genes were screened by a bioinformatics approach.The impacts of HAPLN1 knockdown on Angiotensin II (Ang II)-induced AC16 cells were assessed through a series of cell function experiments. Enzyme-linked immunosorbent assay (ELISA) was used to measure levels of oxidative stress and apoptosis-related factors. The HF rat model was induced by subcutaneous injection isoprenaline and histopathologic changes in the cardiac tissue were assessed by hematoxylin and eosin (HE) staining and echocardiographic index. Downstream pathways regulated by HAPLN1 was predicted through bioinformatics and then confirmed in vivo and in vitro by western blot. RESULTS: Six hub genes were screened, of which HAPLN1, FMOD, NPPB, NPPA, and COMP were overexpressed, whereas NPPC was downregulated in HF. Further research found that silencing HAPLN1 promoted cell viability and reduced apoptosis in Ang II-induced AC16 cells. HAPLN1 knockdown promoted left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS), while decreasing left ventricular end-systolic volume (LVESV) in the HF rat model. HAPLN1 knockdown promoted the levels of GSH and suppressed the levels of MDA, LDH, TNF-α, and IL-6. Mechanistically, silencing HAPLN1 activated the PKA pathway, which were confirmed both in vivo and in vitro. CONCLUSION: HAPLN1 knockdown inhibited the progression of HF by activating the PKA pathway, which may provide novel perspectives on the management of HF.


Asunto(s)
Proteínas de la Matriz Extracelular , Insuficiencia Cardíaca , Función Ventricular Izquierda , Animales , Ratas , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/metabolismo , Ratas Sprague-Dawley , Transducción de Señal , Volumen Sistólico , Proteoglicanos/genética , Proteoglicanos/metabolismo , Proteínas de la Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo
9.
Redox Biol ; 71: 103096, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38387137

RESUMEN

Oxidative stress in muscles is closely related to the occurrence of insulin resistance, muscle weakness and atrophy, age-related sarcopenia, and cancer. Aldehydes, a primary oxidation intermediate of polyunsaturated fatty acids, have been proven to be an important trigger for oxidative stress. However, the potential role of linoleic acid (LA) as a donor for volatile aldehydes to trigger oxidative stress has not been reported. Here, we reported that excessive dietary LA caused muscle redox imbalance and volatile aldehydes containing hexanal, 2-hexenal, and nonanal were the main metabolites leading to oxidative stress. Importantly, we identified 5-lipoxygenase (5-LOX) as a key enzyme mediating LA peroxidation in crustaceans for the first time. The inhibition of 5-LOX significantly suppressed the content of aldehydes produced by excessive LA. Mechanistically, the activation of the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway facilitated the translocation of 5-LOX from the nucleus to the cytoplasm, where 5-LOX oxidized LA, leading to oxidative stress through the generation of aldehydes. This study suggests that 5-LOX is a potential target to prevent the production of harmful aldehydes.


Asunto(s)
Araquidonato 5-Lipooxigenasa , Ácido Linoleico , Ácido Linoleico/farmacología , Araquidonato 5-Lipooxigenasa/metabolismo , Estrés Oxidativo , Oxidación-Reducción , Músculos/metabolismo , Aldehídos/metabolismo
10.
Virus Res ; 341: 199313, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38244614

RESUMEN

Human immunodeficiency virus-1 (HIV-1) infection can cause chronic activation, exhaustion, and anergy of the immune system. Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is an immune checkpoint molecule, which plays an important role in immune homeostasis and disease. CTLA-4 expression is elevated in HIV-1-infected patients and is associated with disease progression. However, the mechanism controlling expression of CTLA-4 in HIV-1 infection is poorly characterized. In this study, we used a SIV-infected Chinese rhesus macaque (ChRM) model to explore CTLA-4 expression in SIV infection. Results showed that SIV infection significantly increased CTLA-4 expression in all T cell subsets, especially central memory T cells. CTLA-4+CD4+ T cell frequency was significantly associated with disease progression markers. Activation of the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) signaling pathway regulated CTLA-4 expression in CD4+T cells, as confirmed by stimulation with dibutyryl cyclic adenosine monophosphate, forskolin, and 3-isobutyl-1-methylxanthine, and inhibition with H-89 ex vivo. Simultaneously, cAMP concentration in PBMCs and PKA activity in both PBMCs and CD4+ T cells were increased in acute SIV-infected ChRMs, accompanied by an increase in adenylate cyclase 6 expression and a decrease in cAMP-phosphodiesterase 3A (PDE3A), PDE4B, and PDE5A expression in PBMCs. In addition, selective inhibition of PDE4B and PDE5A activity enhanced CTLA-4 expression in CD4+ T cells. These results suggest that SIV infection alters cAMP metabolism and increases cAMP-PKA signaling pathway activation, which up-regulates the expression of CTLA-4 in acute SIVmac239-infected ChRMs. Thus, regulation of the cAMP-PKA signaling pathway may be a potential strategy for the restoration of T cell function and therapy for AIDS.


Asunto(s)
Infecciones por VIH , Síndrome de Inmunodeficiencia Adquirida del Simio , Virus de la Inmunodeficiencia de los Simios , Animales , Humanos , Linfocitos T CD4-Positivos , Macaca mulatta , Virus de la Inmunodeficiencia de los Simios/fisiología , Antígeno CTLA-4/genética , Regulación hacia Arriba , Progresión de la Enfermedad , Transducción de Señal , Adenosina Monofosfato
11.
Neurosci Lett ; 822: 137626, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38191090

RESUMEN

Previous studies have shown that the hyperpolarized cyclic nucleotide gated (HCN) ion channels in the spinal dorsal horn (SDH) might be involved in the development of diabetic neuropathic pain (DNP). Additionally, other studies have shown that the decreased potassium-chloride cotransporter 2 (KCC2) expression in the SDH promotes pain hypersensitivity. Both HCN channels and KCC2 were highly expressed in spinal substantia gelatinosa neurons. However, whether the K+ efflux induced by the activation of HCN channels in DNP modulate KCC2 function and subsequently affect the role of γ-aminobutyric acid (GABA)/GABA-A receptors of neurons in the SDH remains to be clarified. The purpose of this work was to investigate the underlying mechanisms of KCC2 participating in HCN channels to promote DNP. Here, we found that the analgesic role of HCN channels blocker ZD7288 was associated with the up-regulated KCC2 expression and could be prevented by DIOA, a KCC2 blocker. Furthermore, the level of GABA in DNP rats significantly increased, which was decreased by ZD72288. Moreover, DIOA pretreatment could partly block the inhibitory effect of ZD7288 on the cyclic adenosine monophosphate-protein kinase A (cAMP-PKA) signaling activation of DNP rats. Finally, inhibition of cAMP-PKA signaling alleviated allodynia and elevated KCC2 expression in DNP rats. Altogether, this study reveals that the role of cAMP-PKA signaling-regulated HCN channels in DNP associated with decreased KCC2 expression in the spinal cord and altered GABA nature.


Asunto(s)
Diabetes Mellitus , Neuralgia , Animales , Ratas , Canales Catiónicos Regulados por Nucleótidos Cíclicos/metabolismo , Diabetes Mellitus/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Cotransportadores de K Cl , Neuralgia/metabolismo , Asta Dorsal de la Médula Espinal/metabolismo
12.
Acupunct Med ; 42(1): 32-38, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37899603

RESUMEN

BACKGROUND: Neurogenic bladder (NB) is a form of neurological bladder dysfunction characterized by excessive contraction of the bladder detrusor. Protein kinase A (PKA) signaling is involved in the contraction of the detrusor muscle. AIMS: To investigate whether PKA signaling mediates the effect of electroacupuncture (EA) on the excessive contraction of the bladder detrusor in NB. METHODS: Sixty rats were randomly divided into control, sham, NB, NB + EA, and NB + EA + H89 (a PKA receptor antagonist) groups. The modified Hassan Shaker spinal cord transection method was used to generate a NB model. After EA intervention for one week, urodynamic tests were used to evaluate bladder function, hematoxylin and eosin staining was conducted to assess morphological changes, enzyme-linked immunosorbent assay (ELISA) was performed to measure the concentration of PKA, and Western blotting was conducted to measure the protein levels of phosphorylated myosin light chain kinase (p-MLCK)/p-MLC. RESULTS: The results showed that NB resulted in morphological disruption, impairment of urodynamics, and decreases in the concentration of PKA and the protein levels of p-MLCK/p-MLC. EA reversed the changes induced by NB dysfunction. However, the improvement in urodynamics and the increases in the concentration of PKA and the protein levels of p-MLCK/p-MLC were inhibited by H89. CONCLUSION: Our findings indicate that the PKA signaling pathway mediates the beneficial effect of EA on excessive contraction of the bladder detrusor in a rat model of NB.


Asunto(s)
Electroacupuntura , Traumatismos de la Médula Espinal , Vejiga Urinaria Neurogénica , Ratas , Animales , Vejiga Urinaria , Vejiga Urinaria Neurogénica/etiología , Vejiga Urinaria Neurogénica/terapia , Transducción de Señal , Proteínas Quinasas Dependientes de AMP Cíclico
13.
Front Cell Infect Microbiol ; 13: 1257897, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37780854

RESUMEN

The surge of multidrug-resistant fungal pathogens, especially Candida auris, poses significant threats to global public health. Candida auris exhibits resistance to multiple antifungal drugs, leading to major outbreaks and a high mortality rate. With an urgent call for innovative therapeutic strategies, this study focused on the regulation and pathobiological significance of secreted aspartyl proteinases (SAPs) in C. auris, as these enzymes play pivotal roles in the virulence of some fungal species. We delved into the Ras/cAMP/PKA signaling pathway's influence on SAP activity in C. auris. Our findings underscored that the Ras/cAMP/PKA pathway significantly modulates SAP activity, with PKA catalytic subunits, Tpk1 and Tpk2, playing a key role. We identified a divergence in the SAPs of C. auris compared to Candida albicans, emphasizing the variation between Candida species. Among seven identified secreted aspartyl proteases in C. auris (Sapa1 to Sapa7), Sapa3 emerged as the primary SAP in the pathogen. Deletion of Sapa3 led to a significant decline in SAP activity. Furthermore, we have established the involvement of Sapa3 in the biofilm formation of C. auris. Notably, Sapa3 was primarily regulated by Tpk1 and Tpk2. Deletion of SAPA3 significantly reduced C. auris virulence, underscoring its pivotal role in C. auris pathogenicity. The outcomes of this study provide valuable insights into potential therapeutic targets, laying the groundwork for future interventions against C. auris infection.


Asunto(s)
Proteasas de Ácido Aspártico , Candida auris , Virulencia , Proteasas de Ácido Aspártico/genética , Proteasas de Ácido Aspártico/metabolismo , Candida/genética , Candida albicans , Antifúngicos/farmacología , Ácido Aspártico Endopeptidasas/genética , Ácido Aspártico Endopeptidasas/metabolismo
14.
Int J Mol Sci ; 24(20)2023 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-37894823

RESUMEN

The current view of the mitochondrial respiratory chain complexes I, III and IV foresees the occurrence of their assembly in supercomplexes, providing additional functional properties when compared with randomly colliding isolated complexes. According to the plasticity model, the two structural states of the respiratory chain may interconvert, influenced by the intracellular prevailing conditions. In previous studies, we suggested the mitochondrial membrane potential as a factor for controlling their dynamic balance. Here, we investigated if and how the cAMP/PKA-mediated signalling influences the aggregation state of the respiratory complexes. An analysis of the inhibitory titration profiles of the endogenous oxygen consumption rates in intact HepG2 cells with specific inhibitors of the respiratory complexes was performed to quantify, in the framework of the metabolic flux theory, the corresponding control coefficients. The attained results, pharmacologically inhibiting either PKA or sAC, indicated that the reversible phosphorylation of the respiratory chain complexes/supercomplexes influenced their assembly state in response to the membrane potential. This conclusion was supported by the scrutiny of the available structure of the CI/CIII2/CIV respirasome, enabling us to map several PKA-targeted serine residues exposed to the matrix side of the complexes I, III and IV at the contact interfaces of the three complexes.


Asunto(s)
Mitocondrias , Membranas Mitocondriales , Transporte de Electrón , Mitocondrias/metabolismo , Membranas Mitocondriales/metabolismo , Complejo I de Transporte de Electrón/metabolismo , Fosforilación
15.
Transgenic Res ; 32(6): 575-582, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37851308

RESUMEN

M-LP/Mpv17L (Mpv17-like protein) is an atypical cyclic nucleotide phosphodiesterase (PDE) without the molecular structure characteristic of the PDE family. Deficiency of M-LP/Mpv17L in mice has been found to result in development of ß-cell hyperplasia and improved glucose tolerance. Here, we report another phenotype observed in M-LP/Mpv17L-knockout (KO) mice: afferent cardiac hypertrophy. Although the hearts of M-LP/Mpv17L-KO mice did not differ in size from those of wild-type mice, there was marked narrowing of the left ventricular lumen and thickening of the ventricular wall. The diameter and cross-sectional area of cardiomyocytes in 8-month-old M-LP/Mpv17L-KO mice were increased 1.16-fold and 1.35-fold, respectively, relative to control mice, but showed no obvious abnormalities of cell structure, fibrosis or impaired cardiac function. In 80-day-old KO mice, the expression of hypertrophic marker genes, brain natriuretic peptide (BNF), actin alpha cardiac muscle 1 (ACTC1) and actin alpha 1 skeletal muscle (ACTA1), as well as the Wnt/ß-catenin pathway target genes, lymphoid enhancer-binding factor-1 (LEF1), axis inhibition protein 2 (AXIN2) and transcription factor 7 (TCF7), was significantly up-regulated relative to control mice, whereas fibrosis-related genes such as fibronectin 1 (FN1) and connective tissue growth factor (CTGF) were down-regulated. Western blot analysis revealed increased phosphorylation of molecules downstream of the cAMP/PKA signaling pathway, such as ß-catenin, ryanodine receptor 2 (RyR2), phospholamban (PLN) and troponin I (cTnI), as well as members of the MEK1-ERK1/2 signaling pathway, which is strongly involved in afferent cardiac hypertrophy. Taken together, these findings indicate that M-LP/Mpv17L is one of the PDEs actively functioning in the heart and that deficiency of M-LP/Mpv17L in mice promotes physiological cardiac hypertrophy.


Asunto(s)
3',5'-AMP Cíclico Fosfodiesterasas , Cardiomegalia , Animales , Ratones , Actinas/metabolismo , beta Catenina/metabolismo , Cardiomegalia/genética , Cardiomegalia/metabolismo , Fibrosis , Ratones Noqueados , Miocardio/metabolismo , Miocardio/patología , Miocitos Cardíacos/metabolismo , 3',5'-AMP Cíclico Fosfodiesterasas/genética , 3',5'-AMP Cíclico Fosfodiesterasas/metabolismo
16.
Antioxidants (Basel) ; 12(9)2023 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-37760005

RESUMEN

Candida auris, a multidrug-resistant fungal pathogen, significantly threatens global public health. Recent studies have identified melanin production, a key virulence factor in many pathogenic fungi that protects against external threats like reactive oxygen species, in C. auris. However, the melanin regulation mechanism remains elusive. This study explores the role of the Ras/cAMP/PKA signaling pathway in C. auris melanization. It reveals that the catalytic subunits Tpk1 and Tpk2 of protein kinase A (PKA) are essential, whereas Ras1, Gpr1, Gpa2, and Cyr1 are not. Under melanin-promoting conditions, the tpk1Δ tpk2Δ strain formed melanin granules in the supernatant akin to the wild-type strain but failed to adhere them properly to the cell wall. This discrepancy is likely due to a decreased expression of chitin-synthesis-related genes. Our findings also show that Tpk1 primarily drives melanization, with Tpk2 having a lesser impact. To corroborate this, we found that C. auris must deploy Tpk1-dependent melanin deposition as a defensive mechanism against antioxidant exposure. Moreover, we confirmed that deletion mutants of multicopper oxidase and ferroxidase genes, previously assumed to influence C. auris melanization, do not directly contribute to the process. Overall, this study sheds light on the role of PKA in C. auris melanization and enhances our understanding of the pathogenicity mechanisms of this emerging fungal pathogen.

17.
Theriogenology ; 210: 214-220, 2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37527623

RESUMEN

Granulosa cells (GCs) synthesize estrogens needed for follicular growth. However, the effects of hypoxia on steroidogenesis in buffalo GCs remain unclear. In this study, the impacts of hypoxic conditions (5% oxygen) on estrogen synthesis in buffalo GCs were examined. The results showed that hypoxia improved both the expression levels of estrogen synthesis-related genes (CYP11A1, CYP19A1, and 3ß-HSD) and the secretion levels of estradiol in buffalo GCs. Hypoxic conditions promoted the sensitivity of buffalo GCs to FSH. Furthermore, inhibition of cAMP/PKA signaling pathway (H89, a cAMP/PKA signaling pathway inhibitor) reduced both the expression levels of estrogen synthesis-related genes (CYP11A1, CYP19A1, and 3ß-HSD) and the secretion levels of estradiol in hypoxia-cultured buffalo GCs. Besides, inhibition of cAMP/PKA signaling pathway lowered the responsiveness of buffalo GCs to FSH under hypoxic conditions. The present study indicated that hypoxia enhanced the steroidogenic competence of buffalo GCs principal by affecting cAMP/PKA signaling pathway and subsequent sensitivity of GCs to FSH.


Asunto(s)
Bison , Búfalos , Femenino , Animales , Búfalos/metabolismo , Enzima de Desdoblamiento de la Cadena Lateral del Colesterol/metabolismo , Células de la Granulosa/fisiología , Estradiol/farmacología , Bison/metabolismo , Hormona Folículo Estimulante/farmacología , Hormona Folículo Estimulante/metabolismo , Estrógenos/farmacología , Hipoxia/metabolismo , Hipoxia/veterinaria , Células Cultivadas
18.
aBIOTECH ; 4(2): 108-123, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37581021

RESUMEN

Lipid droplets are important storages in fungal conidia and can be used by plant pathogenic fungi for infection. However, the regulatory mechanism of lipid droplets formation and the utilization during fungal development and infection are largely unknown. Here, in Magnaporthe oryzae, we identified a lipid droplet-associated protein Nem1 that played a key role in lipid droplets biogenesis and utilization. Nem1 was highly expressed in conidia, but lowly expressed in appressoria, and its encoded protein was localized to lipid droplets. Deletion of NEM1 resulted in reduced numbers of lipid droplets and decreased content of diacylglycerol (DAG) or triacylglycerol (TAG). NEM1 was required for asexual development especially conidia production. The Δnem1 mutant was nearly loss of virulence to host plants due to defects in appressorial penetration and invasive growth. Remarkably, Nem1 was regulated by the TOR signaling pathway and involved in the autophagy process. The Ser303 residue of Nem1 could be phosphorylated by the cAMP-PKA signaling pathway and was important for biological function of Nem1. Together, our study revealed a regulatory mechanism of lipid biogenesis and metabolism during the conidium and appressorium formation of the rice blast fungus. Supplementary Information: The online version contains supplementary material available at 10.1007/s42994-023-00098-5.

19.
Nutrients ; 15(13)2023 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-37447257

RESUMEN

Previous research has shown that both heat-treated green tea extract (HTGT) and enzymatically modified isoquercitrin (EMIQ) have anti-obesity effects. Given the absence of in vivo evidence demonstrating their synergistic effects, our study aimed to elucidate the combined obesity prevention potential of HTGT and EMIQ in mice. Mice were treated with these compounds for 8 weeks, while being fed a high-fat diet, to investigate their preventive anti-obesity effects. We demonstrated that the co-treatment of HTGT and EMIQ results in a synergistic anti-obesity effect, as determined by a Kruskal-Wallis test. Furthermore, the combined treatment of HTGT and EMIQ was more effective than orlistat in reducing body weight gain and adipocyte hypertrophy induced by high-fat diet. The co-treatment also significantly reduced total body fat mass and abdominal fat volume. Additionally, the group receiving the co-treatment exhibited increased energy expenditure and higher glucose intolerance. We observed a dose-dependent upregulation of genes associated with mitochondrial oxidative metabolism and PKA signaling, which is linked to lipolysis, in response to the co-treatment. The co-treatment group displayed elevated cAMP levels and AMPK activation in adipose tissue and increased excretion of fecal lipids. The results indicate that the co-treatment of HTGT and EMIQ holds the potential to be a promising combination therapy for combating obesity. To further validate the anti-obesity effect of the combined treatment of HTGT and EMIQ in human subjects, additional clinical studies are warranted.


Asunto(s)
Calor , Obesidad , Ratones , Humanos , Animales , Obesidad/metabolismo , Antioxidantes/uso terapéutico , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , , Dieta Alta en Grasa/efectos adversos , Ratones Endogámicos C57BL
20.
Mol Syst Biol ; 19(8): e11493, 2023 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-37485750

RESUMEN

The complexity of many cellular and organismal traits results from the integration of genetic and environmental factors via molecular networks. Network structure and effect propagation are best understood at the level of functional modules, but so far, no concept has been established to include the global network state. Here, we show when and how genetic perturbations lead to molecular changes that are confined to small parts of a network versus when they lead to modulation of network states. Integrating multi-omics profiling of genetically heterogeneous budding and fission yeast strains with an array of cellular traits identified a central state transition of the yeast molecular network that is related to PKA and TOR (PT) signaling. Genetic variants affecting this PT state globally shifted the molecular network along a single-dimensional axis, thereby modulating processes including energy and amino acid metabolism, transcription, translation, cell cycle control, and cellular stress response. We propose that genetic effects can propagate through large parts of molecular networks because of the functional requirement to centrally coordinate the activity of fundamental cellular processes.


Asunto(s)
Herencia Multifactorial , Proteínas de Saccharomyces cerevisiae , Transducción de Señal/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Fenotipo
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