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Upregulation of penile brain-derived neurotrophic factor (BDNF) and activation of the JAK/STAT signalling pathway in the major pelvic ganglion of the rat after cavernous nerve transection.

OBJECTIVES: Increasing attention is being focused on identifying novel approaches to recover cavernous nerve (CN) function after injury or secondary to disease states such as diabetes mellitus. We examined penile brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) expression, and activation of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) molecular pathway in the major pelvic ganglion (MPG) after CN injury in the rat. METHODS: Five groups of eight male Sprague-Dawley rats (4 mo, 250-300 g) were used in this study. The penis and MPG with attached CN segment were harvested at 0 h (controls), 12, and 24 h, as well as at 5 and 12 d after CN axotomy, for protein, messenger RNA (mRNA), and immunohistochemical analysis. RESULTS: mRNA and protein expression of BDNF was upregulated in the penis after injury (p<0.05). Levels of NT-3 were unchanged. The JAK/STAT pathway was activated in the MPG after transection, as evidenced by increased STAT1 (peak: 24 h) and STAT3 (peak: 5 d) phosphorylation (p<0.01 vs. controls). CONCLUSIONS: This study demonstrates increased expression of penile BDNF and upregulation of phosphorylated STAT1 and STAT3 in the MPG in response to CN transection. Activation of the JAK/STAT pathway after injury represents a promising new molecular target for modulating CN survival and regeneration.

Analysis of Variance↗

Folate and its preventive potential in colorectal carcinogenesis. How strong is the biological and epidemiological evidence?

Based on a 15-year old hypothesis, it is believed that an adequate ingestion of folate vitamins decreases, whereas a nutritional depletion of folate increases the risk of colorectal cancer. The present article reviews the efforts to provide biochemical and epidemiological evidence for folate as a chemopreventive agent against colorectal carcinogenesis. BIOLOGICAL EVIDENCE: Tetrahydrofolates govern the intracellular one-carbon metabolism and account for proper DNA biosynthesis and macromolecular modification. Numerous experimental studies traced different molecular pathways and tried to link folate depletion with DNA instability and/or mutagenesis. However, none of the proposed underlying molecular mechanisms appear clearly defined. EPIDEMIOLOGICAL EVIDENCE: Numerous case-control and prospective studies have been conducted on folate and colorectal cancer, which all together miss a clinical bottom line. The recommendation of folate intake to prevent colorectal cancer is therefore not evidence-based.

Case-Control Studies↗

Understanding the importance of smart drugs in renal cell carcinoma.

OBJECTIVE: To understand the mode of action of the currently most investigated new drugs in renal cell carcinoma (RCC) and ultimately to analyze what should be the role of the urologist in this new therapeutic era. METHODS: A comprehensive review of the peer-reviewed literature was performed on the topic of molecular pathways involved in RCC angiogenesis, vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor (VEGFR) and targeted molecular therapy for RCC. RESULTS: Von Hippel-Lindau (VHL) disease has provided a model for understanding that the early inactivation of the VHL gene was responsible for accumulation of hypoxia-inducible factor and therefore activation of hypoxia-inducible genes such as VEGF, platelet-derived growth factor, erythropoietin, carbonic anhydrase IX and tumor growth factor alpha. The fact that such VHL inactivation also was found in up to 70% of sporadic RCC has been the rationale for developing new drugs targeting VEGF, VEGFR, platelet-derived growth factor receptor and tyrosine kinase receptors that are required for intracellular transduction. CONCLUSION: Initial results from phase 2 trials in metastatic disease are very promising. There is a strong rationale for initiating adjuvant trials with those kind of agents in patients with high-risk localised tumors. Urologists who have a good understanding of prognostic parameters in localised RCC particularly should be involved in such new approaches.

Angiogenesis Inhibitors↗

Molecular and cellular biology of basal cell carcinoma.

The finding of mutations in the PTCH gene in both Gorlin's syndrome and sporadic basal cell carcinomas has significantly advanced our understanding of the molecular defects that lead to the formation of these tumours. Knowledge of the specific molecular and functional changes that have taken place in these tumours will help us devise more defined therapies, as well as give us a better understanding of normal molecular pathways involved in skin development and function. The following is a summary of our current understanding of the molecular and cellular biology of basal cell carcinoma.

Apoptosis↗

A Ca(2)+ signaling pathway regulates a K(+) channel for low-K response in Arabidopsis.

Nutrient sensing is critical for plant adaptation to the environment. Because of extensive farming and erosion, low content of mineral nutrients such as potassium (K(+)) in soils becomes a limiting factor for plant growth. In response to low-K conditions, plants enhance their capability of K(+) uptake through an unknown signaling mechanism. Here we report the identification of a Ca(2+)-dependent pathway for low-K response in Arabidopsis. We are not aware of any other example of a molecular pathway for a nutrient response in plants. Earlier genetic analyses revealed three genes encoding two Ca(2+) sensors (CBL1 and CBL9) and their target protein kinase (CIPK23) to be critical for plant growth on low-K media and for stomatal regulation, indicating that these calcium signaling components participate in the low-K response and turgor regulation. In this study, we show that the protein kinase CIPK23 interacted with, and phosphorylated, a voltage-gated inward K(+) channel (AKT1) required for K(+) acquisition in Arabidopsis. In the Xenopus oocyte system, our studies showed that interacting calcium sensors (CBL1 and CBL9) together with target kinase CIPK23, but not either component alone, activated the AKT1 channel in a Ca(2+)-dependent manner, connecting the Ca(2+) signal to enhanced K(+) uptake through activation of a K(+) channel. Disruption of both CBL1 and CBL9 or CIPK23 gene in Arabidopsis reduced the AKT1 activity in the mutant roots, confirming that the Ca(2+)-CBL-CIPK pathway functions to orchestrate transporting activities in planta according to external K(+) availability.

Animals↗

Activation of signaling lymphocytic activation molecule triggers a signaling cascade that enhances Th1 responses in human intracellular infection.

T cell production of IFN-gamma contributes to host defense against infection by intracellular pathogens, including mycobacteria. Lepromatous leprosy, the disseminated form of infection caused by Mycobacterium leprae, is characterized by loss of cellular response against the pathogen and diminished Th1 cytokine production. Relieving bacterial burden in Ag-unresponsive patients might be achieved through alternative receptors that stimulate IFN-gamma production. We have previously shown that ligation of signaling lymphocytic activation molecule (SLAM) enhances IFN-gamma in mycobacterial infection; therefore, we investigated molecular pathways leading from SLAM activation to IFN-gamma production in human leprosy. The expression of the SLAM-associated protein (an inhibitory factor for IFN-gamma induction) on M. leprae-stimulated cells from leprosy patients was inversely correlated to IFN-gamma production. However, SLAM ligation or exposure of cells from lepromatous patients to a proinflammatory microenvironment down-regulated SLAM-associated protein expression. Moreover, SLAM activation induced a sequence of signaling proteins, including activation of the NF-kappaB complex, phosphorylation of Stat1, and induction of T-bet expression, resulting in the promotion of IFN-gamma production, a pathway that remains quiescent in response to Ag in lepromatous patients. Therefore, our findings reveal a cascade of molecular events during signaling through SLAM in leprosy that cooperate to induce IFN-gamma production and strongly suggest that SLAM might be a focal point for therapeutic modulation of T cell cytokine responses in diseases characterized by dysfunctional Th2 responses.

Adjuvants, Immunologic↗

Hormone-regulated apoptosis results from reentry of differentiated prostate cells onto a defective cell cycle.

Castration initiates extensive apoptosis of the secretory epithelial cells lining the ducts of the rat ventral prostate, resulting in the striking regression of this male sexual accessory tissue. We had previously described the paradox of finding similar cascades of gene activity (c-fos greater than c-myc greater than hsp-70) induced during the early period of ventral prostate regression and during the regrowth of the ventral prostate gland initiated by testosterone replenishment. This common pattern of protooncogene expression during periods of predominant cellular apoptosis or proliferation caused us to examine further the possibility that the two cellular events occur through identical early molecular pathways. In the present study we demonstrate that apoptotic prostate epithelial cells incorporate bromodeoxyuridine into nuclear high-molecular-weight DNA prior to nuclear DNA fragmentation. The DNA synthetic activity occurs in coordination with a massive induction of proliferative cell nuclear antigen, a proliferation marker, in the nuclei of androgen-deprived prostatic epithelial cells. Moreover, this activity is also associated with the increased expression of mRNA encoding p53, a suppressor gene well known as a cell cycle-blocking agent. Our data indicate that quiescent (G0) prostate epithelial cells undergo apoptosis due to two sequential events initiated by testosterone depletion. The first event is the active reentry of these cells into the cell cycle. The second event is the apoptotic destruction resulting from the inability of the differentiated cells to successfully complete this cycle.

Animals↗

The biology of epilepsy genes.

Mutations in over 70 genes now define biological pathways leading to epilepsy, an episodic dysrhythmia of the cerebral cortex marked by abnormal network synchronization. Some of the inherited errors destabilize neuronal signaling by inflicting primary disorders of membrane excitability and synaptic transmission, whereas others do so indirectly by perturbing critical control points that balance the developmental assembly of inhibitory and excitatory circuits. The genetic diversity is now sufficient to discern short- and long-range functional convergence of epileptogenic molecular pathways, reducing the broad spectrum of primary molecular defects to a few common processes regulating cortical synchronization. Synaptic inhibition appears to be the most frequent target; however, each gene mutation retains unique phenotypic features. This review selects exemplary members of several gene families to illustrate principal categories of the disease and trace the biological pathways to epileptogenesis in the developing brain.

Animals↗

Integrated network pharmacology, molecular docking, and experimental validation to reveal the potential mechanism of Ginsenoside Rg1 on chronic obstructive pulmonary disease.

Ginsenoside Rg1 (GS Rg1), a natural flavonoid exhibiting anti-inflammatory and antioxidant properties, holds significant potential for treatment chronic obstructive pulmonary disease (COPD). Nevertheless, the precise mechanisms underlying its therapeutic effects remain to be fully elucidated. This study aimed to explore the role and potential mechanism of GS Rg1 in the treatment of COPD using network pharmacology, molecular docking, and experimental validation.Targets related to GS Rg1 and COPD were screened from public databases, and the potential common targets were then imported into the STRING database to construct a protein-protein interaction (PPI) network. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis were performed to identify key signaling pathways.&#xa0;Molecular docking was employed to predict the binding interactions between GS Rg1 and core targets. A BEAS-2B cell model induced by lipopolysaccharide(LPS) and cigarette smoke extract(CSE) was used to explore the protective mechanisms of GS Rg1. Western blot analysis was conducted to validate the critical targets and pathways involved in the anti-COPD effects of GS Rg1. Network pharmacology analysis revealed 105 common targets between GS Rg1 and COPD.&#xa0;The EGFR/PI3K/AKT and EGFR/STAT3 signaling pathways were selected for further validation. GS Rg1 was demonstrated to effectively inhibit inflammation and mucus hypersecretion in vitro models of COPD. Western blot results showed that GS Rg1 treatment significantly downregulated the expression of proteins involved in the EGFR/PI3K/AKT and EGFR/STAT3 signaling pathway, consistent with the network pharmacology findings. CSE/LPS exposure induces inflammation and oxidative stress in COPD by disrupting the EGFR/PI3K/AKT and EGFR/STAT3 signaling pathways, and GS Rg1 significantly alleviates these effects, which may be partially through regulating the EGFR/PI3K/AKT and EGFR/STAT3 signaling pathway.

Ginsenosides↗

The mitochondrial apoptotic pathway is activated by serum and glucose deprivation in cardiac myocytes.

Many cell types undergo apoptosis under conditions of ischemia. Little is known, however, about the molecular pathways that mediate this response. A cellular and biochemical approach to elucidate such signaling pathways was undertaken in primary cultures of cardiac myocytes, a cell type that is especially sensitive to ischemia-induced apoptosis. Deprivation of serum and glucose, components of ischemia in vivo, resulted in myocyte apoptosis, as determined by nuclear fragmentation, internucleosomal cleavage of DNA, and processing of caspase substrates. These manifestations of apoptosis were blocked by zVAD-fmk, a peptide caspase inhibitor, indicating that caspase activity is necessary for the progression of apoptosis in this model. In contrast to control cells, apoptotic myocytes exhibited cytoplasmic accumulation of cytochrome c, indicating release from the mitochondria. Furthermore, both caspase-9 and caspase-3 were processed to their active forms in serum-/glucose-deprived myocytes. Caspase processing, but not cytochrome c release, was inhibited by zVAD-fmk, placing the latter event upstream of caspase activation. This evidence demonstrates that components of ischemia activate the mitochondrial death pathway in cardiac myocytes.

Amino Acid Chloromethyl Ketones↗

The lentiginoses: cutaneous markers of systemic disease and a window to new aspects of tumourigenesis.

Familial lentiginosis syndromes cover a wide phenotypic spectrum ranging from a benign inherited predisposition to develop cutaneous lentigines unassociated with systemic disease, to associations with several syndromes carrying increased risk of formation of hamartomas, hyperplasias, and other neoplasms. The molecular pathways involved in the aetiology of these syndromes have recently been more clearly defined and several major cellular signalling pathways are probably involved: the protein kinase A (PKA) pathway in Carney complex (CNC), the Ras/Erk MAP kinase pathway in LEOPARD/Noonan syndromes, and the mammalian target of rapamycin pathway (mTOR) in Peutz-Jeghers syndrome and the diseases caused by PTEN mutations. Here we discuss the clinical presentation of these disorders and discuss the molecular mechanisms involved. The presence of lentigines in these diseases caused by diverse molecular defects is probably more than an associated clinical feature and likely reflects cross talk and convergence of signalling pathways of central importance to embryogenesis, neural crest differentiation, and end-organ growth and function of a broad range of tissues including those of the endocrine, reproductive, gastrointestinal, cardiac, and integument systems.

Cyclic AMP-Dependent Protein Kinases↗

Molecular mechanism of HaiZao-YuHu decoction in breast cancer treatment via network pharmacology and molecular docking: Computational pharmacology.

BACKGROUND: The molecular biological mechanisms of HaiZao-YuHu decoction were investigated using network pharmacology and molecular docking. METHODS: TCMSP database was used to collect the active ingredients and action targets of HaiZao-YuHu decoction, through the OMIM, PharmGkb, GeneCards, TDD, and DurgBank database query targets for breast cancer. Then, using the intersecting targets, the protein-protein interaction network of HaiZao-YuHu decoction was constructed using the STRING website. Network topology analysis was performed using Cytoscape 3.9.0 to identify the core targets. Gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed with the R package. The Autodock software was used for molecular docking. RESULTS: Thirty-four active ingredients, 219 intersection targets and 4 key targets were obtained. gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis get 2152 biological processes and 186 pathways. Molecular docking showed that the 4 core targets could combine well with the 5 main active components. CONCLUSION: HaiZao-YuHu decoction can play a role in the treatment of breast cancer through multi-targets, multi-components, and multi-pathways.

Molecular Docking Simulation↗

Novel biological agents for the treatment of hormone-refractory prostate cancer (HRPC).

Hormone-refractory prostate cancer (HRPC) is an inevitable evolution of prostate carcinogenesis, through which the normal dependence on hormones for growth and survival is bypassed. Although advances in terms of symptoms palliation and quality of life improvement have been addressed with current treatment options, innovative approaches are needed to improve survival rates. A thorough understanding of HRPC-associated molecular pathways and mechanisms of resistance are a prerequisite for novel potential therapeutic interventions. Preclinical and early clinical studies are ongoing to evaluate new therapies that target specific molecular entities. Agents under development include growth factor receptor inhibitors, small molecules targeting signal transduction pathways, apoptosis and cell-cycle regulators, angiogenesis and metastasis inhibitors, differentiation agents, telomerase inactivators, and epigenetic therapeutics. Incorporation of these agents into existing treatment regimens will guide us in the development of a multidisciplinary treatment strategy of HRPC. This article critically reviews published data on new biological agents that are being tested in HRPC clinical trials, highlights ongoing research and considers the future perspectives of this new class of agents.

Angiogenesis Inhibitors↗

Rhabdomyosarcomagenesis-Novel pathway found.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Recent work presented in this issue of Cancer Cell by Fleischmann et al. on gene knockout mice revealed a remarkable molecular pathway for rhabdomyosarcomagenesis, in which Trp53/Fos double mutant mice developed RMS of the facial and orbital regions with high penetrance. This finding may provide novel molecular mechanisms for Rhabdomyosarcomagenesis and therapeutic implications for RMS patients.

Animals↗

17beta-estradiol inhibits cyclic strain-induced endothelin-1 gene expression within vascular endothelial cells.

It has been well documented previously that 17beta-estradiol (E2) exerts a protective effect on cardiovascular tissue. The possible role of E2 in the regulation of endothelin (ET)-1 production has been previously reported, although the complex mechanisms by which E2 inhibits ET-1 expression are not completely understood. The aims of this study were to examine whether E2 was able to alter strain-induced ET-1 gene expression and also to identify the putative underlying signaling pathways that exist within endothelial cells. For cultured endothelial cells, E2 (1-100 nM), but not 17alpha-estradiol, inhibited the level of strain-induced ET-1 gene expression and also peptide secretion. This inhibitory effect elicited by E2 was able to be prevented by the coincubation of endothelial cells with the estrogen receptor antagonist ICI-182,780 (1 microM). E2 also inhibited strain-enhanced NADPH oxidase activity and intracellular reactive oxygen species (ROS) generation as measured by the redox-sensitive fluorescent dye 2',7'-dichlorofluorescin diacetate and the level of extracellular signal-regulated kinase (ERK) phosphorylation. Furthermore, the presence of E2 and antioxidants such as N-acetylcysteine and diphenylene iodonium were able to elicit a decrease in the level of strain-induced ET-1 secretion, ET-1 promoter activity, ET-1 mRNA, ERK phosphorylation, and activator protein-1 binding activity. In summary, we demonstrated, for the first time, that E2 inhibits strain-induced ET-1 gene expression, partially by interfering with the ERK pathway via the attenuation of strain-induced ROS generation. Thus this study delivers important new insight regarding the molecular pathways that may contribute to the proposed beneficial effects of estrogen on the cardiovascular system.

Acetylcysteine↗

Global gene annotation analysis and transcriptional profiling identify key biological modules in hypoxic pulmonary hypertension.

Chronic hypoxic pulmonary hypertension is an important clinical disorder causing significant morbidity. Despite recent discoveries, many molecular mechanisms involved in its pathogenesis remain unexplored. We have undertaken a systematic and unbiased approach to gain global insights into this complex process. By combining transcriptional profiling with rigorous statistical methods and cluster analysis, we identified the dominant temporal patterns of gene expression during progression and regression of hypoxic pulmonary hypertension. We next integrated these results with global gene annotation analysis to identify key biological themes involved in the development and resolution of hypoxic pulmonary hypertension and vascular remodeling. This novel approach assigned biological roles to thousands of candidate genes based on their temporal expression profiles and membership in specific biological modules. Our procedure confirmed several molecular pathways and gene products known to be important in hypoxic pulmonary hypertension. Furthermore, we discovered several novel candidates and molecular mechanisms, including IQ motif containing GTPase-activating protein-1 (IQGAP1), decorin, insulin-like growth factor binding protein-3 (IGFBP3), and lactotransferrin, that may play crucial roles in hypoxic pulmonary hypertension and vascular remodeling. Our methodology of integrating transcriptional profiling, cluster analysis, and global gene annotation provides new insights into the pathophysiology of pulmonary hypertension and is applicable to other models of human disease.

Animals↗

Developing gene expression signatures of pathway deregulation in tumors.

Recent advances in our understanding of cancer biology have led to the development of therapies targeting specific signaling pathways. Molecular targeting promises to improve our ability to predict who will respond by assessing the state of these targeted pathways in patients. However, a single pathway can be deregulated by multiple mechanisms, and for some pathways it may be difficult to assess activation state by analyzing a single oncogene or tumor suppressor. Therefore, developing gene expression signatures of pathway activation status using model systems or human tumor samples may enable a more reliable measurement of pathway activity. This review discusses recent advances in the identification of gene expression-based signatures of pathway deregulation and how this information may lead to improved therapeutic response prediction.

Animals↗

Ergothioneine Alleviated the Apoptosis of HK Cells by Regulating Ferroptosis.

INTRODUCTION/OBJECTIVE: Ergothioneine (EGT) is a naturally occurring antioxidant with protective effects on various human cell types. The impact of this substance on HK-2 cells, a human renal proximal tubular epithelial cell line, and the associated molecular mechanisms remain incompletely elucidated. METHODS: The present study aims to elucidate the effects of EGT on apoptosis induced by RAS-selective Lethal Molecule 3 (RSL3) and Erastin in HK-2 cells, as well as the potential mechanisms involved. The renal cortical proximal tubular epithelial HK-2 cells were cultured and exposed to RSL3 and Erastin, with or without EGT treatment. Cell viability and apoptosis were assessed using the Cell Counting Kit-8 (CCK-8) assay, while the detection of ferrous ion content and mitochondrial membrane potential changes was accomplished through the utilisation of flow cytometry and the JC-1 staining method, respectively. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, proteomic analysis, and western blotting were employed to explore the molecular pathways involved. RESULTS: The data demonstrated that RSL3 and Erastin exhibited a substantial inhibitory effect on HK-2 cell proliferation, concomitant with the accumulation of intracellular ferrous ions and a shift in mitochondrial membrane potential. The EGT treatment effectively mitigated RSL3- and Erastin-induced apoptosis in HK-2 cells. GO and KEGG enrichment analysis demonstrated that EGT suppressed pathways and functions associated with oxidative stress during ferroptosis. Proteomics analysis further demonstrated that EGT modulated various biological processes, molecular functions, and cellular components in HK-2 cells. The protective mechanism of EGT against RSL3- and Erastin-induced HK-2 cells was potentially mediated through regulation of ferroptosis. The results of the western blot analysis demonstrated that EGT modulated the expression levels of Glutathione Peroxidase 4 (GPX4) and Solute Carrier Family 7 member 11 (SLC7A11) in HK-2 cells. CONCLUSION: These data demonstrated that EGT exerts an alleviating effect on the apoptosis of HK-2 cells induced by RSL3 and Erastin by modulating ferroptosis. These findings suggest that EGT has the potential to serve as a therapeutic candidate for the treatment of kidney diseases in the future.

Ergothioneine↗