Correlation between the dynamic changes of γδT cells, Th17 cells, CD4+CD25+ regulatory T cells in peripheral blood and pharmacological interventions against bleomycin-induced pulmonary fibrosis progression in mice.

The involvement of γδT cells, Th17 cells, and CD4+CD25+ regulatory T cells (Tregs) is crucial in the progression of pulmonary fibrosis (PF), particularly in maintaining immune tolerance and homeostasis. However, the dynamics of these cells in relation to PF progression, especially under pharmacological interventions, remains poorly understood. This study aims to unravel the interplay between the dynamic changes of these cells and the effect of pharmacological agents in a mouse model of PF induced by intratracheal instillation of bleomycin. We analyzed changes in lung histology, lung index, hydroxyproline levels, and the proportions of γδT cells, Th17 cells, and Tregs on the 3rd, 14th, and 28th days following treatment with Neferine, Isoliensinine, Pirfenidone, and Prednisolone. Our results demonstrate that these drugs can partially or dynamically reverse weight loss, decrease lung index and hydroxyproline levels, and ameliorate lung histopathological damage. Additionally, they significantly modulated the abnormal changes in γδT, Th17, and Treg cell proportions. Notably, on day 3, the proportion of γδT cells increased in the Neferine and Prednisolone groups but decreased in the Isoliensinine and Pirfenidone groups, while the proportion of Th17 cells decreased across all treated groups. On day 14, the Neferine group showed an increase in all three cell types, whereas the Pirfenidone group exhibited a decrease. In the Isoliensinine group, γδT and Th17 cells increased, and in the Prednisolone group, only Tregs increased. By day 28, an increase in Th17 cell proportion was observed in all treatment groups, with a decrease in γδT cells noted in the Neferine group. These shifts in cell proportions are consistent with the pathogenesis changes induced by these anti-PF drugs, suggesting a correlation between cellular dynamics and pharmacological interventions in PF progression. Our findings imply potential strategies for assessing the efficacy and timing of anti-PF treatments based on these cellular changes.

Benzylisoquinoline alkaloids inhibit lung fibroblast activation mainly via inhibiting TGF-ß1/Smads and ERK1/2 pathway proteins.

Backgrounds: Liensinine (Lien), Neferine (Nef), Isoliensinine (Iso) and Tetrandrine (Tet), benzylisoquinoline alkaloids (BIAs), have been shown inhibitory effects on pulmonary fibrosis (PF) through anti-inflammatory, anti-oxidative activities, inhibition of cytokines and NF-κB. Effects of other similar BIAs, Dauricine (Dau), Papaverine (Pap) and lotusine (Lot), on PF remain unclear. Here, we explored the effects of five bisbenzylisoquinoline (Lien, Nef, Iso, Tet and Dau) and two monobenzylisoquinoline (Pap, Lot) alkaloids on normal and PF fibroblasts. Methods: Primary normal and PF lung fibroblasts were cultured and treated with these alkaloids. Proliferation, activation, migration and apoptosis changes were detected by MTT, wound healing assay, flow cytometry. Protein level was analyzed by Western blot. Results: All BIAs inhibited proliferation of normal and PF lung fibroblasts induced by TGF-ß. α-SMA protein level in normal and PF lung fibroblasts decreased after Lien, Nef, Iso, Tet and Dau treatment. Pap and Lot had no influence on α-SMA expression. Dau showed the strongest inhibitory effects on proliferation and activation among alkaloids. The migration rates of normal and PF lung fibroblasts were inhibited by Lien, Nef, Iso, and Dau. Lien, Nef, Iso and Dau significantly promoted apoptosis, while Tet had no effect on apoptosis. Pap and Lot had no influence on activation, migration and apoptosis. Dau significantly inhibited Smad3/4 and p-ERK1/2 protein overexpression induced by TGF-ß1. Conclusions: Bisbenzylisoquinoline alkaloids had stronger effects on inhibiting lung fibroblasts than monobenzylisoquinoline alkaloids. Dau expressed the strongest inhibitory effects, which may be related to its inhibition of TGF-ß1/Smad3/4 and p-ERK1/2 pathway proteins.

Ethylene Acts as a Local and Systemic Signal to Mediate UV-B-Induced Nitrate Reallocation to Arabidopsis Leaves and Roots via Regulating the ERFs-NRT1.8 Signaling Module.

Nitrate is the preferred nitrogen source for plants and plays an important role in plant growth and development. Under various soil stresses, plants reallocate nitrate to roots to promote stress tolerance through the ethylene-ethylene response factors (ERFs)-nitrate transporter (NRT) signaling module. As a light signal, ultraviolet B (UV-B) also stimulates the production of ethylene. However, whether UV-B regulates nitrate reallocation in plants via ethylene remains unknown. Here, we found that UV-B-induced expression of ERF1B, ORA59, ERF104, and NRT1.8 in both Arabidopsis shoots and roots as well as nitrate reallocation from hypocotyls to leaves and roots were impaired in ethylene signaling mutants for Ethylene Insensitive2 (EIN2) and EIN3. UV-B-induced NRT1.8 expression and nitrate reallocation to leaves and roots were also inhibited in the triple mutants for ERF1B, ORA59, and ERF104. Deletion of NRT1.8 impaired UV-B-induced nitrate reallocation to both leaves and roots. Furthermore, UV-B promoted ethylene release in both shoots and roots by enhancing the gene expression and enzymatic activities of ethylene biosynthetic enzymes only in shoots. These results show that ethylene acts as a local and systemic signal to mediate UV-B-induced nitrate reallocation from Arabidopsis hypocotyls to both leaves and roots via regulating the gene expression of the ERFs-NRT1.8 signaling module.

A novel multiplex qPCR method for assessing the comparative lengths of telomeres.

BACKGROUND: The comparative length of telomeres is considered to be related to diseases such as cancer, aging, and cardiovascular diseases. qPCR is currently one of the main methods for detecting telomere length. However, due to the unique sequence of telomeres (highly repetitive six-base sequence), it is difficult to design primers and probes to expand and detect telomere and to put internal reference gene and telomere into the same tube for detection to reduce the possible inter-pore errors and improve amplification efficiency. Besides, the stability and accuracy of the test results are greatly affected by the difference between reference genes and telomere copy number. METHODS: In this study, the single-copy genes were replaced with high-copy genes (300 copies) as the internal control to reduce the copy number difference of the internal genes and telomere. In addition, a multiplex qPCR system was constructed to detect the telomeres and an internal reference gene product. We also detected the lengths of telomeres in the genomic DNA in immortalized cells (293T and Hela) from different generations of cells. RESULTS: We detected the comparative telomere lengths of 1500 random Chinese volunteers of different ages with the multiplex qPCR method; the result shows that the comparative length of telomeres is negatively related to age. In addition, we compared our qPCR detection method with a terminal restriction fragmentation (TRF) method. Both of them were highly consistent, indicating that the qPCR method was reliable. CONCLUSIONS: In conclusion, we developed a stable, convenient, and accurate comparative telomere length detection method.

CD4+CD25+ Tregs as dependent factor in the course of bleomycin-induced pulmonary fibrosis in mice.

The immune system is felt to play an essential role in pulmonary fibrosis (PF). CD4+CD25+ regulatory T cells (Tregs) are crucial in maintaining immune tolerance and immune homeostasis, but their role in the pathogenesis of PF is controversial and still unclear. We here explored the relationship between peripheral blood CD4+CD25+ Tregs and the course of bleomycin-induced PF in mice. Mouse PF models were established by intratracheal instillation of bleomycin. Lung histology, hydroxyproline, Th1/Th2 balanc, CD4+CD25+ Tregse were analyzed at the 3rd，7th，14th，21st and 28th days after instillation. CD4+CD25+ Tregs were also transferred into mice with or without PF by tail vein injection. The trend of CD4+CD25+ Tregs changes was increased firstly, decreased, increased again from 7th to 28th days after bleomycin instillation, which had great relevance with alveolitis and fibrosis scores. There also were high Th1 polarization index from 3rd to 14th days and high Th2 polarization index at 21st and 28th days after bleomycin treatment. CD4+CD25+ Tregs could promote the secretion of Th2 cytokines and inhibit the secretion of Th1 cytokines, allow the Th1/Th2 balance to Th2 direction in PF. Moreover, preventive adoptive transfer of CD4+CD25+ Tregs may ameliorate the process of PF, while acute adoptive transfer of CD4+CD25+ Tregs may aggravate the process of PF. These findings suggested that the dynamic changes of CD4+CD25+ Tregs as dependent factor might designate a different course of PF induced by bleomycin in mice, and might be a selected drug use indicator for therapy of PF.

Combination of L-Arginine and L-Norvaline protects against pulmonary fibrosis progression induced by bleomycin in mice.

Pulmonary fibrosis (PF) progression may be involved with arginine (Arg) metabolism and immune balance. The present study aimed to explore the effects of L-Arginine (L-Arg) and L-Norvaline (L-Nor) on bleomycin (BLM)-induced PF in mice, meanwhile, and observe dynamic changes of Arg metabolism, immune balance and crosstalk between them in PF progression. Followed intratracheal instillation of BLM or saline, Kunming mice were treated orally with saline, L-Arg, L-Nor and L-Arg + L-Nor three times a day. And the mice were sacrificed on Day 3, 14 and 28 after treatment. Changes of body weight, lung index, lung hydroxyproline and histopathology were analyzed to evaluate the PF degree. Peripheral blood Arg, Citrulline (Cit), Ornithine (Orn) and Proline (Pro), lung NO, NOS and arginase were analyzed to evaluate the Arg metabolism. Peripheral blood Tregs, Th17 and γδT cells were analyzed to evaluate the immune balance. Our data showed that combination of L-Arg and L-Nor dynamically reversed the weight loss, decreased lung index and hydroxyproline, and improved lung histopathological damages induced by BLM. The combination dynamically and significantly rectified Tregs, Th17, γδT and Tregs/Th17 abnormal changes. Meanwhile, these disorders of peripheral blood Arg, Cit, Orn, Pro, Orn/Cit and Pro/Orn, and lung NO, iNOS and TNOS were also improved accordingly. These results demonstrated that combination of L-Arg and L-Nor had inhibitory effects on BLM-induced PF progression, possibly due to their corrective action on immune imbalance, Arg metabolism disorder and crosstalk abnormality in the progression of PF.

A novel multiplex fluorescent competitive PCR for copy number variation detection.

The copy number variation (CNV) is an important genetic marker in cancer and other diseases. To detect CNVs of specific genetic loci, the multiplex ligation-dependent probe amplification (MLPA) is an appropriate approach, but the experimental optimization and probe synthesis are still great challenges. The multiplex competitive PCR is an alternative method for CNV detection. However, the construction of internal competitive template and establishment of a stable multiplex PCR system are the main limiting factors for this method. Here, we introduce a novel multiplex fluorescent competitive PCR (NMFC-PCR) for detecting CNVs. In this method, the blunt hairpin primers are used to rapidly establish a stable multiplex PCR system due to the reduction of non-specific amplification, and limited cycles' amplification is used to obtain the internal competitive template instead of artificial synthesis. With this method, we tested 21 clinical samples with potential LIM homeobox 1 (LHX1) or T-box 6 (TBX6) deletion. Every three segments located on the LHX1 and TBX6 were selected as the target regions, while two segments located on X-chromosome and five segments located on autosome were selected as the reference regions for detecting CNVs. The results showed that the gender information of 21 samples can be accurately inferred by the copy number ratio (CNR) of X-chromosomal reference region to autosomal reference region (X/A), and 2 samples had one copy of LHX1 and 9 samples had one copy of TBX6. To evaluate the accuracy of NMFC-PCR, 5 random samples with CNV were also detected by array-based comparative genomic hybridization (aCGH), and the results of aCGH were consistent with the NMFC-PCR results. To further assess the performance of NMFC-PCR, 60 normal samples were simultaneously tested. The results showed that the gender results were exactly the same as known information, and CNVs of LHX1 or TBX6 were not found. In conclusion, the method is a cheap, efficient, accurate, and convenient competitive PCR method for CNV detection.

MicroRNA­449a is a potential predictor of colitis­associated colorectal cancer progression.

An early diagnosis of colitis­associated colorectal cancer (CAC) is important for its clinical management. However, it is currently difficult to distinguish the different stages of CAC development. MicroRNA dysregulation is common in human colorectal disorders, however little is known regarding whether miRNA affects tumor progression by regulating inflammation. In the present study, we identified a novel miRNA (miR­449a), the expression of which was significantly reduced in CAC tissues than in paired adjacent non­cancerous tissues (ANTs). Notably, the level of miR­449a was in a markedly decreased pattern during the neoplastic transformation of ulcerative colitis (UC)­to­CAC, as demonstrated by both clinical investigations and the experimental mouse model induced by AOM/DSS treatment. In addition, we observed that decreased miR­449a expression was associated with advanced T or N status, later clinical stage and poor histological differentiation of CAC. Mechanistic studies revealed that miR­449a inhibited the growth and metastasis of human colon cancer cells by directly binding to the 3'­UTR of Notch­1 and thereby, suppressed the activation of the Notch signaling pathway. Therefore, these findings provide strong evidence for the translational potential of miR­449a in the discrimination of patients with UC that is likely to progress into CAC, from those unlikely to progress, as well as in the prognosis and diagnosis of CAC.

TRPC3 overexpression and intervention in airway smooth muscle of ovalbumin-induced hyperresponsiveness and remodeling.

Transient receptor potential canonical channel 3 (TRPC3) proteins function as non-voltage-gated Ca2+ -permeable channels and play divergent roles in many processes of pathophysiology. The purpose of this study was to determine the relationship between TRPC3 expression and airway hyperresponsiveness and remodeling in ovalbumin-induced asthmatic Kunming mice. Mice were sensitized and challenged by ovalbumin to establish asthmatic model. Hematoxylin-eosin staining, hydroxyproline assay, and isometric tracheal ring force measurement were used to evaluate airway remodeling and hyperresponsiveness in asthmatic mice. Western blot was performed to detect the expression of TRPC3 proteins. MTT assay was used to measure the proliferation of airway smooth muscle cells. TRPC3 protein expression increased in airway smooth muscle of asthmatic mice. GdCl3 , a nonspecific TRPC blocker, attenuated the contractile force of airway smooth muscle. Fetal bovine serum stimulated airway smooth muscle cells proliferation and augmented TRPC3 protein expression. Both TRPC3 blockade by GdCl3 or specific TRPC3 antibodies and gene silencing by siRNA inhibited the proliferation of airway smooth muscle cells. In contrast, the current drugs treatment for asthma such as Dexamethasone and Aminophylline had no effects on TRPC3 protein overexpression. Therefore, TRPC3 protein overexpression may be involved in airway smooth muscle hyperresponsiveness and remodeling in asthmatic mice, providing evidence for a new direction of asthma pathogenesis research and a new target for drug intervention.

Emerging Role of MicroRNAs and Long Noncoding RNAs in Healthy and Diseased Lung.

Pulmonary hypertension (PH) is a complex and multifactorial disease. An inability to fully unravel the molecular complexities has led to various clinical challenges in developing new therapies for this disease. Noncoding RNAs (ncRNAs) are RNA molecules with limited ability of coding proteins. The amount of ncRNAs is up to 98% of the whole genome's transcripts. Many ncRNAs with a regulatory function of genes have been identified to date and found to act at various steps along the protein biosynthetic process, which includes transcription, RNA maturation, translation, and protein degradation. These discoveries are fueling a new era in understanding the pathophysiology and therapeutic pathways of PH. In this chapter, we discuss the emerging role of noncoding RNAs in PH as well as other pulmonary diseases.

Role of canonical transient receptor potential channel-3 in acetylcholine-induced mouse airway smooth muscle cell proliferation.

AIMS: Canonical transient receptor potential channel-3 (TRPC3)-encoded Ca2+-permeable nonselective cation channel (NSCC) has been proven to be an important native constitutively active channel in airway smooth muscle cell (ASMC), which plays significant roles in physiological and pathological conditions by controlling Ca2+ homeostasis in ASMC. Acetylcholine (ACh) is generally accepted as a contractile parasympathetic neurotransmitter in the airway. Recently studies have revealed the pathological role of ACh in airway remodeling, however, the mechanisms remain unclear. Here, we investigated the role of TRPC3 in ACh-induced ASMC proliferation. MATERIALS AND METHODS: Primary mouse ASMCs were cultured with or without ACh treatment, then cell viability, TRPC3 expression, NSCC currents and [Ca2+]i changes were examined by MTT assay, cell counting, Western blotting, standard whole-cell patch clamp recording and calcium imaging, respectively. Small interfering RNA (siRNA) technology was used to confirm the contribution of TRPC3 to ACh-induced ASMC proliferation. KEY FINDINGS: TRPC3 blocker Gd3+, antibody or siRNA largely inhibited ACh-induced up-regulation of TRPC3 protein, enhancement of NSCC currents, resting [Ca2+]i and KCl-induced changes in [Ca2+]i, eventually inhibiting ACh-induced ASMC proliferation. SIGNIFICANCE: Our data suggested ACh could induce ASMC proliferation, and TRPC3 may be involved in ACh-induced ASMC proliferation that occurs with airway remodeling.

Deregulated expression of Cdc6 as BCR/ABL-dependent survival factor in chronic myeloid leukemia cells.

Chronic myeloid leukemia is characterized by the presence of the reciprocal translocation t(9;22) and the BCR/ABL oncogene. The BCR/ABL oncogene activates multiple signaling pathways and involves the dysregulation of oncogenes during the progression of chronic myeloid leukemia. The cell division cycle protein 6, an essential regulator of DNA replication, is elevated in some human cancer cells. However, the expression of cell division cycle protein 6 in chronic myeloid leukemia and the underlying regulatory mechanism remain to be elucidated. In this study, our data showed that cell division cycle protein 6 expression was significantly upregulated in primary chronic myeloid leukemia cells and the chronic myeloid leukemia cell line K562 cells, as compared to the normal bone marrow mononuclear cells. BCR/ABL kinase inhibitor STI571 or BCR/ABL small interfering RNA could significantly downregulate cell division cycle protein 6 messenger RNA expression in K562 cells. Moreover, phosphoinositide 3-kinase/AKT pathway inhibitor LY294002 and Janus kinase/signal transducer and activator of transcription pathway inhibitor AG490 could downregulate cell division cycle protein 6 expression in K562 cells, but not RAS/mitogen-activated protein kinase pathway inhibitor PD98059 had such effect. Cell division cycle protein 6 gene silencing by small interfering RNA effectively resulted in decrease of proliferation, increase of apoptosis, and arrest of cell cycle in K562 cells. These findings have demonstrated that cell division cycle protein 6 overexpression may contribute to the high proliferation and low apoptosis in chronic myeloid leukemia cells and can be regulated by BCR/ABL signal transduction through downstream phosphoinositide 3-kinase/Akt and Janus kinase/signal transducer and activator of transcription pathways, suggesting cell division cycle protein 6 as a potential therapeutic target in chronic myeloid leukemia.

MicroRNA-155 promotes the pathogenesis of experimental colitis by repressing SHIP-1 expression.

AIM: To explore the mechanism by which microRNA-155 (miR-155) regulates the pathogenesis of experimental colitis. METHODS: A luciferase assay was performed to confirm the binding of miR-155 to the SHIP-1 3'-UTR. MiR-155 mimics, negative controls and SHIP-1 expression/knockdown vectors were established and then utilized in gain- and loss-of-function studies performed in raw264.7 cells and primary bone marrow-derived macrophages (BMDMs). Thereafter, dextran sulfate sodium (DSS)-induced colitis mouse model with or without antagomiR-155 treatment was established, and the levels of miR-155 and SHIP-1, as well as the pro-inflammatory capabilities, were measured by western blot, quantitative polymerase chain reaction, and immunohistochemistry. RESULTS: MiR-155 directly bound to the 3'-UTR of SHIP-1 mRNA and induced a significant decrease in SHIP-1 expression in both raw264.7 cells and primary BMDMs. MiR-155 markedly promoted cell proliferation and pro-inflammatory secretions including IL-6, TNF-α, IL-1ß, and IFN-γ, whereas these effects could be reversed by the restoration of SHIP-1 expression. In vivo studies showed that antagomiR-155 administration could alleviate DSS-induced intestinal inflammation in Balb/c mice. Moreover, significantly increased SHIP-1 expression, as well as decreased Akt activation and inflammatory response, were observed in the antagomiR-155-treated mice. CONCLUSION: MiR-155 promotes experimental colitis by repressing SHIP-1 expression. Thus, the inhibition of miR-155 might be a promising strategy for therapy.

Inhibitory effects of neferine on Nav1.5 channels expressed in HEK293 cells.

Neferine, a bisbenzylisoquinoline alkaloid in Lotus Plumule, was proved to have a wide range of biological activities. In the present study, using whole-cell patch-clamp technique, we investigated the effects of neferine on Nav1.5 channels that are stably expressed in HEK 293 cells. We found that neferine potently and reversibly inhibited Nav1.5 currents in a concentration dependent manner with a half-maximal inhibition (IC50) being 26.15 µmol/L. The inhibitory effects of neferine on Nav1.5 currents were weaker than those of quinidine at the same concentration. The steady-state inactivation curve was significantly shifted towards hyperpolarizing direction in the presence of 30 µmol/L neferine, while the voltage-dependent activation was unaltered. Neferine prolonged the time to peak of activation, increased the inactivation time constants of Nav1.5 currents and markedly slowed the recovery from inactivation. The inhibitory effect of neferine could be potentiated in a frequency-dependent manner. These results suggested that neferine can block Nav1.5 channels under the open state and inactivating state and it is an open channel blocker of Nav1.5 channels.

TRPC3-mediated Ca(2+) entry contributes to mouse airway smooth muscle cell proliferation induced by lipopolysaccharide.

Airway remodeling is a histopathological hallmark of chronic respiratory diseases that includes airway smooth muscle cell (ASMC) proliferation. Canonical transient receptor potential channel-3 (TRPC3)-encoded nonselective cation channels (NSCCs) are important native constitutively active channels that play significant roles in physiological and pathological conditions in ASMCs. Lipopolysaccharides (LPSs), known as lipoglycans and endotoxin, have been proven to be inducers of airway remodeling, though the mechanisms remain unclear. We hypothesized that TRPC3 is important in LPS-induced airway remodeling by regulating ASMC proliferation. To test this hypothesis, mouse ASMCs were cultured with or without LPS for 48h. Cell viability, TRPC3 protein expression, NSCC currents and changes in intracellular calcium concentration ([Ca(2+)]i) were then analyzed using an MTT assay, western blotting, whole-cell patch clamp and calcium imaging, respectively. The results showed that LPS treatment significantly induced ASMC proliferation, up-regulation of TRPC3 protein expression and enhancement of NSCC currents, resting [Ca(2+)]i and ACh-elicited changes in [Ca(2+)]i. TRPC3 blocker Gd(3+), TRPC3 blocking antibody or TRPC3 gene silencing by siRNA significantly inhibited LPS-induced up-regulation of TRPC3 protein, enhancement of NSCC currents, resting [Ca(2+)]i and ACh-elicited changes in [Ca(2+)]i, eventually inhibiting LPS-induced ASMCproliferation. These results demonstrated that TRPC3-mediated Ca(2+) entry contributed to LPS-induced ASMC proliferation and identified TRPC3 as a possible key target in airway remodeling intervention.

A novel three-round multiplex PCR for SNP genotyping with next generation sequencing.

Owing to the high throughput and low cost, next generation sequencing has attracted much attention for SNP genotyping application for researchers. Here, we introduce a new method based on three-round multiplex PCR to precisely genotype SNPs with next generation sequencing. This method can as much as possible consume the equivalent amount of each pair of specific primers to largely eliminate the amplification discrepancy between different loci. After the PCR amplification, the products can be directly subjected to next generation sequencing platform. We simultaneously amplified 37 SNP loci of 757 samples and sequenced all amplicons on ion torrent PGM platform; 90.5 % of the target SNP loci were accurately genotyped (at least 15×) and 90.4 % amplicons had uniform coverage with a variation less than 50-fold. Ligase detection reaction (LDR) was performed to genotype the 19 SNP loci (as part of the 37 SNP loci) with 91 samples randomly selected from the 757 samples, and 99.5 % genotyping data were consistent with the next generation sequencing results. Our results demonstrate that three-round PCR coupled with next generation sequencing is an efficient and economical genotyping approach. Graphical Abstract The schematic diagram of three-round PCR.

Na (+) /Ca (2+) Exchanger 3 is Downregulated in the Hippocampus and Cerebrocortex of Rats with Hyperthermia-induced Convulsion.

BACKGROUND: Na + /Ca 2+ exchanger (NCX) plays a crucial role in pentylenetetrazol-induced convulsion. However, it is unclear whether NCX is critically involved in hyperthermia-induced convulsion. In this study, we examined the potential changes in NCX3 in the hippocampus and cerebrocortex of rats with hyperthermia-induced convulsion. METHODS: Twenty-one Sprague Dawley rats were randomly assigned to control group, convulsion-prone group and convulsion-resistant group (n = 7 in each group). Whole-cell patch-clamp method was used to record NCX currents. Both the Western blotting analysis and immunofluorescence labeling techniques were used to examine the expression of NCX3. RESULTS: NCX currents were decreased in rats after febrile convulsion. Compared to the control group, NCX3 expression was decreased by about 40% and 50% in the hippocampus and cerebrocortex of convulsion-prone rats, respectively. Furthermore, the extent of reduction in NCX3 expression seemed to correlate with the number of seizures. CONCLUSIONS: There is a significant reduction in NCX3 expression in rats with febrile convulsions. Our findings also indicate a potential link between NCX3 expression, febrile convulsion in early childhood, and adult onset of epilepsy.

Effects of neferine on Kv4.3 channels expressed in HEK293 cells and ex vivo electrophysiology of rabbit hearts.

AIM: Neferine is an isoquinoline alkaloid isolated from seed embryos of Nelumbo nucifera (Gaertn), which has a variety of biological activities. In this study we examined the effects of neferine on Kv4.3 channels, a major contributor to the transient outward current (I(to)) in rabbit heart, and on ex vivo electrophysiology of rabbit hearts. METHODS: Whole-cell Kv4.3 currents were recorded in HEK293 cells expressing human cardiac Kv4.3 channels using patch-clamp technique. Arterially perfused wedges of rabbit left ventricles (LV) were prepared, and transmembrane action potentials were simultaneously recorded from epicardial (Epi) and endocardial (Endo) sites with floating microelectrodes together with transmural electrocardiography (ECG). RESULTS: Neferine (0.1-100 µmol/L) dose-dependently and reversibly inhibited Kv4.3 currents (the IC50 value was 8.437 µmol/L, and the maximal inhibition at 100 µmol/L was 44.12%). Neferine (10 µmol/L) caused a positive shift of the steady-state activation curve of Kv4.3 currents, and a negative shift of the steady-state inactivation curve. Furthermore, neferine (10 µmol/L) accelerated the inactivation but not the activation of Kv4.3 currents, and markedly slowed the recovery of Kv4.3 currents from inactivation. Neferine-induced blocking of Kv4.3 currents was frequency-dependent. In arterially perfused wedges of rabbit LV, neferine (1, 3, and 10 µmol/L) dose-dependently prolonged the QT intervals and action potential durations (APD) at both Epi and Endo sites, and caused dramatic increase of APD10 at Epi sites. CONCLUSION: Neferine inhibits Kv4.3 channels likely by blocking the open state and inactivating state channels, which contributes to neferine-induced dramatic increase of APD10 at Epi sites of rabbit heart.

ceRNA in cancer: possible functions and clinical implications.

Competing endogenous RNAs (ceRNAs) are transcripts that can regulate each other at post-transcription level by competing for shared miRNAs. CeRNA networks link the function of protein-coding mRNAs with that of non-coding RNAs such as microRNA, long non-coding RNA, pseudogenic RNA and circular RNA. Given that any transcripts harbouring miRNA response element can theoretically function as ceRNAs, they may represent a widespread form of post-transcriptional regulation of gene expression in both physiology and pathology. CeRNA activity is influenced by multiple factors such as the abundance and subcellular localisation of ceRNA components, binding affinity of miRNAs to their sponges, RNA editing, RNA secondary structures and RNA-binding proteins. Aberrations in these factors may deregulate ceRNA networks and thus lead to human diseases including cancer. In this review, we introduce the mechanisms and molecular bases of ceRNA networks, discuss their roles in the pathogenesis of cancer as well as methods of predicting and validating ceRNA interplay. At last, we discuss the limitations of current ceRNA theory, propose possible directions and envision the possibilities of ceRNAs as diagnostic biomarkers or therapeutic targets.

Anti-fibrotic effects of neferine on carbon tetrachloride-induced hepatic fibrosis in mice.

The effects of neferine, a bisbenzylisoquinline alkaloid extracted from the seed embryo of the Chinese traditional medicine Nelumbo nucifera Gaertn, on carbon tetrachloride (CCl4)-induced hepatic fibrosis in mice were evaluated. Adult male Kunming mice were administered with CCl4 1 ml/kg via intraperitoneal injection twice a week for 8 weeks. At the beginning of the 9th week, mice were treated with normal saline, colchicine (0.1 mg/kg), and neferine (5, 10, 20 mg/kg) via intraperitoneal injection once a day for 2 weeks. The liver index and histological examination, plasma ALT/AST levels, hydroxyproline and TGF-ß1 content of liver tissue were examined. In the model group, the liver index, the hydroxyproline content of liver tissue and plasma ALT/AST levels were increased, and a high expression of TGF-ß1 was observed. The abnormal changes could be improved by neferine in a dose-dependent manner. Our data showed that neferine had an antifibrosis effect on CCl4-induced hepatic fibrosis in mice, possibly partly due to the decreased expression of TGF-ß1 in the liver.