Dihydroergotamine ameliorates liver fibrosis by targeting transforming growth factor β type II receptor

BACKGROUND

The transforming growth factor β (TGFβ) signaling pathway plays a crucial role in the development of liver fibrosis by activating TGFβ type II receptor (TGFβR2), followed by the recruitment of TGFβR1 finally triggering downstream signaling pathway.

AIM

To find drugs targeting TGFβR2 that inhibit TGFβR1/TGFβR2 complex formation, theoretically inhibit TGFβ signaling pathway, and thereby ameliorate liver fibrosis.

METHODS

Food and Drug Administration-approved drugs were screened for binding affinity with TGFβR2 by virtual molecular docking. We identified 6 candidates and further explored their potential by Cell Counting Kit-8 (CCK-8) cell cytotoxic experiment to validate toxicity and titrated the best cellular working concentrations. Next, we further demonstrated the detailed molecular working mechanisms using mutagenesis analysis. Finally, we used a mouse model to investigate its potential anti-liver fibrosis effect.

RESULTS

We identified 6 drug candidates. Among these 6 drugs, dihydroergotamine (DHE) shows great ability in reducing fibrotic gene expressions such as collagen, p-SMAD3, and α-SMA in TGFβ induced cellular model of liver fibrosis in LX-2 cells. Furthermore, we demonstrated that DHE binds to TGFβR2. Moreover, mutation of Leu27, Phe30, Thr51, Ser52, Ile53, and Glu55 of TGFβR2 disrupted the binding of TGFβR2 with DHE. In addition, DHE significantly improved liver fibrosis, as evidenced by Masson’s trichrome staining of liver sections. This is further supported by the width and the velocity of the portal vein, and serum markers of liver function. In line with those observations, DHE also decreased macrophages infiltration and extracellular matrix deposition in the liver.

CONCLUSION

DHE alleviates liver fibrosis by binding to TGFβR2 thereby suppressing TGFβ signaling pathway. We show here that as far as drug repurposing, DHE has great potential to treat liver fibrosis.

Differences of core genes in liver fibrosis and hepatocellular carcinoma: Evidence from integrated bioinformatics and immunohistochemical analysis

BACKGROUND

Liver fibrosis and hepatocellular carcinoma (HCC) are common adverse consequences of chronic liver injury. The interaction of various risk factors may cause them to happen. Identification of specific biomarkers is of great significance for understanding the occurrence, development mechanisms, and determining the novel tools for diagnosis and treatment of both liver fibrosis and HCC.

AIM

To identify liver fibrosis-related core genes, we analyzed the differential expression pattern of core genes in liver fibrosis and HCC.

METHODS

Gene expression profiles of three datasets, GSE14323, GSE36411, and GSE89377, obtained from the Gene Expression Omnibus (GEO) database, were analyzed, and differentially expressed genes (DEGs) between patients with liver cirrhosis and healthy controls were identified by screening via R software packages and online tool for Venn diagrams. The WebGestalt online tool was used to identify DEGs enriched in biological processes, molecular functions, cellular components, and Kyoto Encyclopedia of Genes and Genomes pathways. The protein–protein interactions of DEGs were visualized using Cytoscape with STRING. Next, the expression pattern of core genes was analyzed using Western blot and immunohistochemistry in a carbon tetrachloride (CCl₄)-induced liver cirrhosis mouse model and in patient liver samples. Finally, Kaplan-Meier curves were constructed using the Kaplan-Meier plotter online server.

RESULTS

Forty-five DEGs (43 upregulated and 2 downregulated genes) associated with liver cirrhosis were identified from three GEO datasets. Ten hub genes were identified, which were upregulated in liver cirrhosis. Western blot and immunohistochemical analyses of the three core genes, decorin (DCN), dermatopontin (DPT), and SRY-box transcription factor 9 (SOX9), revealed that they were highly expressed in the CCl₄-induced liver cirrhosis mouse model. The expression levels of DCN and SOX 9 were positively correlated with the degree of fibrosis, and SOX 9 level in HCC patients was significantly higher than that in fibrosis patients. However, high expression of DPT was observed only in patients with liver fibrosis, and its expression in HCC was low. The gene expression profiling interactive analysis server (GEPIA) showed that SOX9 was significantly upregulated whereas DCN and DPT were significantly downregulated in patients with HCC. In addition, the Kaplan-Meier curves showed that HCC patients with higher SOX9 expression had significantly lower 5-year survival rate, while patients with higher expression of DCN or DPT had significantly higher 5-year survival rates.

CONCLUSION

The expression levels of DCN, DPT, and SOX9 were positively correlated with the degree of liver fibrosis but showed different correlations with the 5-year survival rates of HCC patients.

Population genomics reveals that natural variation in PRDM16 contributes to cold tolerance in domestic cattle

Environmental temperature serves as a major driver of adaptive changes in wild organisms. To discover the mechanisms underpinning cold tolerance in domestic animals, we sequenced the genomes of 28 cattle from warm and cold areas across China. By characterizing the population structure and demographic history, we identified two genetic clusters, i.e., northern and southern groups, as well as a common historic population peak at 30 kilo years ago. Genomic scan of cold-tolerant breeds determined potential candidate genes in the thermogenesis-related pathways that were under selection. Specifically, functional analysis identified a substitution of PRDM16 (p.P779L) in northern cattle, which maintains brown adipocyte formation by boosting thermogenesis-related gene expression, indicating a vital role of this gene in cold tolerance. These findings provide a basis for genetic variation in domestic cattle shaped by environmental temperature and highlight the role of reverse mutation in livestock species.

Effect of Al substitution on the magnetization reversal and complex magnetic properties of NiCr2O4 ceramics

A series of polycrystalline NiCr_2-xAl_xO₄ (0.1 ≤ x ≤ 0.25) spinel ceramics have been synthesized using a sol-gel method. DC magnetization measurements are carried out at different temperatures and magnetic fields. A novel magnetization reversal has been observed in the field cooling process for the x = 0.2 sample, which can be ascribed to the competition between two magnetic sublattices due to their different temperature dependences. The magnetic interaction evolution, related to the complex magnetic properties, is revealed by exchange constants that have been estimated according to ferrimagnetic Curie-Weiss fitting and mean field theory. The fitting result confirmed the evolution of antiferromagnetic and ferromagnetic components with Al substitution, which is supported by the observations from the isothermal magnetization measurements. The positive and negative values of the magnetic moment can be utilized for storage applications based on the results of magnetic switching effect measurements.

Negative magnetization, complex magnetic ordering and applications of Cr-doped Co2TiO4

Polycrystalline Co2Ti1-xCrxO4 (0 ≤ x ≤ 0.2) inverse spinel ceramics have been synthesized via a sol-gel technique. The dc magnetization measurement in the field-cooled mode shows that negative magnetization could be observed until x reaches 0.2. The exchange constants are calculated using the ferrimagnetic Curie-Weiss fitting and the mean-field theory. This reveals that the strength of the inter sublattice magnetic interaction presents a non-monotonic trend with the increase in Cr content and reaches the minimum at x = 0.1, giving rise to the highest compensation temperature in the x = 0.1 sample. The applicability of the x = 0.1 sample is investigated in light of two prominent magnetic effects: (i) the stable magnetic switching effect indicates the potential applications in magnetic switching and data storage and (ii) the coexistence of normal and inverse magnetocaloric effects suggests a potential application in a constant temperature bath at 54 K.

A mitochondrial phylogeny and biogeographical scenario for Asiatic water shrews of the genus Chimarrogale: implications for taxonomy and low-latitude migration routes

The six species and three subspecies in the genus Chimarrogale (Soricomorpha: Soricidae) are commonly referred to as Asiatic water shrews. The Chimarrogale are the most widely distributed group of Nectogaline shrews, extending throughout the Oriental region and Japan. Because of the limited numbers of specimens available for study, the phylogenetic relationships and biogeographical history of this genus have not been comprehensively discussed. We used mitochondrial cytochrome b gene sequences to estimate phylogenetic relationships and divergence times among four Chimarrogale species, including all three subspecies of Chimarrogale himalayica. We also conducted a species delimitation analysis and tested two alternative migration scenarios in Asia through species distribution modeling and a reconstruction of the ancestral distribution. Here, we present the first proposed hypothesis regarding the Asiatic water shrew phylogeny and reveal ten putative species within the four recognized species. Distinct phylogenetic statuses of Chimarrogale phaeura, Chimarrogale platycephala, and Chimarrogale styani were confirmed. Chimarrogale himalayica was strongly supported as paraphyletic. We suggest that three subspecies of Chimarrogale himalayica should be reconsidered as distinct species. However, these suggestions must be considered with caution because only a single locus of a mtDNA gene was used. Four additional putative species, possibly distributed in central southwestern China and Taiwan, are currently undescribed; therefore, comprehensive morphological analyses are warranted to test their taxonomic statuses. The estimated molecular divergence times indicated that rapid speciation occurred during the early Pliocene, and current distribution patterns may have been affected by global cooling during the Pliocene/Pleistocene boundary. Reconstruction of the ancestral distribution and species distribution modeling for Asiatic water shrews revealed a low-latitude migration route over which ancestral Chimarrogale migrated from Europe via Central Asia to their current distribution. Our results demonstrated that Asiatic water shrews could have evolved throughout the low-latitude migration route from Europe to East and Southeast Asia.

Phylogeography of the mole-shrew (Anourosorex yamashinai) in Taiwan: implications of interglacial refugia in a high-elevation small mammal

To test the Pleistocene interglacial refugia hypothesis with a high-elevation mammal, we studied the phylogeography of the mole-shrew (Anourosorex yamashinai) using partial mitochondrial cytochrome b gene sequences (737 bases). This shrew is endemic to Taiwan. It is mainly distributed in the highlands from 1000 to 2500 m in elevation. We examined 103 specimens from 24 localities in three mountain ranges of Taiwan and found 36 haplotypes. These haplotypes separated into two major phylogroups (Northern and Southern) plus a minor phylogroup (Houhuan) of only one haplotype. This demonstrated strong association with geography. The formation of these three phylogroups may be the result of interglacial refugia during the middle Pleistocene. Distinct sublineages were not found within each major phylogroup, suggesting that the populations (phylogroups) explosively expanded from the interglacial refugia of ancestral founder haplotypes. The present distribution pattern of haplotypes suggests that Mount Houhuan is an effective refugium in central Taiwan. It was not possible to specify the refugia for the Northern and Southern phylogroups.

Aggregation between Xanthan and Nonyphenyloxypropyl β-Hydroxyltrimethylammonium Bromide in Aqueous Solution: MesoDyn Simulation and Binding Isotherm Measurement

The aggregation behavior of nonyphenyloxypropyl beta-hydroxyltrimethylammonium bromide (C9phNBr) and xanthan (XC) in aqueous solution was investigated by MesoDyn density functional simulation and binding isotherm measurement. The process of aggregate formation and the aggregate morphology are reported. The formation of aggregates includes three stages and the morphology of XC-C9phNBr aggregates is rodlike or ellipsoidal. The effects of temperature and XC concentration on the aggregation are analyzed. Results indicate that the formation of aggregates is an exothermic process, and their formation becomes more difficult and the formation rate decreases with increasing temperature. The formation of aggregates is also related to XC concentration, and it becomes much more difficult when the concentration of XC is higher than 20 vol %. The simulation results agree with binding isotherms of C9phNBr to XC obtained via the potentiometric titration method, which shows a typical cooperative binding between C9phNBr and XC.

Extrapyramidal motor symptoms versus striatal infarction volume after focal ischemia in mongolian gerbils

Few behavioral tests are available to evaluate extrapyramidal dysfunctions after focal cerebral ischemia in rodents, although extrapyramidal motor dysfunctions are often observed clinically in patients with cerebral infarction. We evaluated the methamphetamine (MP)-induced rotation test for the detection and quantification of extrapyramidal motor dysfunction induced by striatal infarction in gerbils after focal cerebral ischemia. Mongolian gerbils (n=79) underwent the left common carotid artery occlusion (CCAO) for 10, 15, or 20 min. Spontaneous and MP-induced rotation tests were repeated postischemia, and the results compared with the extent of ischemic tissue injury. The density of dopaminergic neurons immunostained with a tyrosine hydroxylase antibody in the substantia nigra pars compacta (SNpc) also was measured. Histological examination revealed selective neuronal death of the hippocampal cornu ammonis 1 (CA1) sector in 10-min CCAO animals, infarction confined to the striatum and hippocampal neuronal death in 15-min CCAO animals, and widespread hemispheric infarction in 20-min CCAO animals. Dopaminergic neurons in the SNpc were preserved in 10- and 15-min CCAO animals but were significantly reduced in 20-min CCAO animals. In MP-induced rotation tests, 15-min CCAO animals showed biased rotation ipsilateral to the lesioned side. Biased rotation persisted 4 weeks postischemia, and the number of rotations significantly correlated with the regional infarction volume of the striatum. Twenty-minute CCAO animals showed biased rotation contralateral to the lesioned side; rotation number was not correlated with the infarction volume. Our results show that biased rotation behavior is a sensitive parameter of the extent of striatal injury after focal cerebral ischemia provided the lesion is not extended to the ipsilateral cortex. MP-induced rotation in rodents probably coordinates with the extrapyramidal motor dysfunction after striatal infarction in patients with vascular Parkinsonism.

High-level expression of Amsacta moorei entomopoxvirus spheroidin depends on sequences within the gene

Spheroidin (SPH) is the most highly expressed gene of the entomopoxvirus isolated from Amsacta moorei (AmEPV). The level of expression of poxvirus genes is believed to be governed in large part by the promoter. Poxvirus promoters generally consist of approximately 40 bp which frequently terminate at the 3' end with a translation initiating TAAATG sequence. We have examined the requirements for high levels of SPH gene expression by constructing AmEPV recombinants containing either the SPH promoter or the late vertebrate poxvirus promoter derived from the cowpox virus A-type inclusion (ATI) gene. In addition, we have examined SPH promoter derivatives which extend beyond the 3' TAAATG to include 2 or 20 bp of the 5' coding sequence of the SPH gene. Examination of insect cells infected with these AmEPV ATI-lacZ or SPH-lacZ recombinants suggests that ATI-lacZ expression begins 12 h before and is essentially complete prior to any SPH-lacZ expression, allowing functional distinction between the ATI and SPH promoters and implying that different factors regulate the two promoters within the insect environment. SPH promoter-regulated expression is significantly enhanced within infected insect cells by including the additional 20 bp of the N-terminal SPH coding sequences as part of the promoter. However, when any of the SPH promoter constructs, including those containing the downstream sequences, were inserted into vaccinia virus, only very low levels of beta-galactosidase expression were observed. These results imply that downstream coding sequences within the SPH gene enhance SPH gene expression only within the insect environment.

[Distribution, content and action site of leucine-enkephalin in pulmonary artery wall of rat and rabbit]

Using immunohistochemical method to investigate the distribution of peptidergic fibers in the pulmonary artery wall of SD rat, L-enkephalin immunoreactive (L-ENK ir) fibers were easily demonstrated. The contents of L-ENK in pulmonary artery of rat and rabbit measured by radioimmunoassay were respectively 439.18 +/- 30.52 and 29.9 +/- 1.4 (pg/mg of wct tissue). Contraction of superfused strips of pulmonary artery of rabbit could be evoked by parameter I electric field stimulation. The response was blocked by alpha-receptor antagonist phentolamine. Alpha 2-receptor antagonist Yohimbine enhanced the response in small doses (0.06-0.12 mumol/L), while inhibited in large (3.2 mumol/L). The contraction could also be enhanced when the artery strips were preincubated with naloxone. After the alpha-receptors were blocked with phentolamine, stronger contraction could still be evoked by parameter II electric field stimulation and the response was not affected by naloxone. L-ENK had no effect on the contraction evoked by exogenous NE. The present experiments demonstrate that enkephalin presented in the pulmonary artery wall are released by electric field stimulation. Enkephalin may reduce the release of NE from sympathetic nerve endings via opioid receptors and inhibit the contraction response.

[Effects of diazepam on the rat open field behavior and high K+ induced release of monoamine neurotransmitters from brain slices]

Acute i. p injection of diazepam (3 mg/kg) significantly decreased the open field behaviors (locomotion and rearing) of rats. However, when diazepam (3 mg/kg) was given ip daily for 15 consecutive days, no depressive effect on the open field behaviors was observed. After the open field observation, rats were immediately decapitated and brain slices of cortex, hippocampus, amygdala and brain stem were stimulated by high K+ (65 mmol/L) to cause the release of noradrenaline (NA), dopamine (DA) and serotonin (5-HT). Diazepam (9 mumol/Ls) significantly depressed the release of monoamine neurotransmitters caused by high K+, which were antagonized by Ro 15-1788 (5 mumol/L) in vitro. Acute administration of diazepam (ip 3 mg/kg) also significantly depressed the release of monoamine neurotransmitters caused by high K+ from all regions observed. However, hippocampus showed tolerance to the depressive effects of diazepam on the releases of NA and DA, and amygdala only on the release of DA, caused by high K+, when given ip chronically (3 mg/kg, 15 d). Our results suggest that the depressive effect of benzodiazepines on the release caused by anxiogenic factors of catecholamine in the hippocampus, front cortex and amygdala regions may be one of the mechanisms of sedative and anxiolytic actions of benzodiazepines.

The molecular weight and thiol residues of acetyl-coenzyme A synthetase from ox heart mitochondria

1. A constant molecular weight of 57000 was obtained by gel filtration of highly purified acetyl-CoA synthetase over a 1000-fold range of enzyme concentrations. The amino acid analysis is reported. 2. With native enzyme at 20 degrees C the relatively rapid reaction of four thiol residues with p-hydroxymercuribenzoate caused an immediate inhibition reversible by either CoA or mercaptoethanol. Other substrates did not protect against this rapid inhibition. 3. The much slower reaction of the remaining four thiol residues was independent of the concentration of the mercurial, first-order with respect to enzyme, and had a large energy of activation (+136kJ/mol), suggesting that a conformation change in the protein was rate-limiting. This slow phase of the reaction was accompanied by an irreversible inactivation of the enzyme. 4. The effects of substrates on this irreversible inactivation at pH7.0 in 5 mm-MgCl(2) indicated strong binding of ATP and pyrophosphate by the enzyme (concentrations for half-maximal effects, K((1/2)), were <30mum and <10mum respectively) and weaker binding of acetyl-CoA (K((1/2)) about 1 mm), AMP (K((1/2)) about 2mm) and acetate. In the presence of acetate, MgCl(2) and p-hydroxymercuribenzoate, titration of the enzyme with ATP revealed at least two ATP binding sites/mol. 5. The experiments suggest that reaction of the thiol residues with mercurial causes loss of enzymic activity by altering the structure of the enzyme, rather than that the thiol residues play a direct role in the catalysis.