APLF facilitates interstrand DNA crosslink repair and replication fork protection to confer cisplatin resistance.

Replication stress converts the stalled forks into reversed forks, which is an important protection mechanism to prevent fork degradation and collapse into poisonous DNA double-strand breaks (DSBs). Paradoxically, the mechanism also acts in cancer cells to contribute to chemoresistance against various DNA-damaging agents. PARP1 binds to and is activated by stalled forks to facilitate fork reversal. Aprataxin and polynucleotide kinase/phosphatase-like factor (APLF) binds to PARP1 through the poly(ADP-ribose) zinc finger (PBZ) domain and is known to be involved in non-homologous end joining (NHEJ). Here, we identify a novel function of APLF involved in interstrand DNA crosslink (ICL) repair and fork protection. We demonstrate that PARP1 activity facilitates the APLF recruitment to stalled forks, enabling the FANCD2 recruitment to stalled forks. The depletion of APLF sensitizes cells to cisplatin, impairs ICL repair, reduces the FANCD2 recruitment to stalled forks, and results in nascent DNA degradation by MRE11 nucleases. Additionally, cisplatin-resistant cancer cells show high levels of APLF and homologous recombination-related gene expression. The depletion of APLF sensitizes cells to cisplatin and results in fork instability. Our results reveal the novel function of APLF to facilitate ICL repair and fork protection, thereby contributing to cisplatin-resistant phenotypes of cancer cells.

Exploring the Impact of BKCa Channel Function in Cellular Membranes on Cardiac Electrical Activity.

This review paper delves into the current body of evidence, offering a thorough analysis of the impact of large-conductance Ca2+-activated K+ (BKCa or BK) channels on the electrical dynamics of the heart. Alterations in the activity of BKCa channels, responsible for the generation of the overall magnitude of Ca2+-activated K+ current at the whole-cell level, occur through allosteric mechanisms. The collaborative interplay between membrane depolarization and heightened intracellular Ca2+ ion concentrations collectively contribute to the activation of BKCa channels. Although fully developed mammalian cardiac cells do not exhibit functional expression of these ion channels, evidence suggests their presence in cardiac fibroblasts that surround and potentially establish close connections with neighboring cardiac cells. When cardiac cells form close associations with fibroblasts, the high single-ion conductance of these channels, approximately ranging from 150 to 250 pS, can result in the random depolarization of the adjacent cardiac cell membranes. While cardiac fibroblasts are typically electrically non-excitable, their prevalence within heart tissue increases, particularly in the context of aging myocardial infarction or atrial fibrillation. This augmented presence of BKCa channels' conductance holds the potential to amplify the excitability of cardiac cell membranes through effective electrical coupling between fibroblasts and cardiomyocytes. In this scenario, this heightened excitability may contribute to the onset of cardiac arrhythmias. Moreover, it is worth noting that the substances influencing the activity of these BKCa channels might influence cardiac electrical activity as well. Taken together, the BKCa channel activity residing in cardiac fibroblasts may contribute to cardiac electrical function occurring in vivo.

Upregulation of galectin-3 in influenza A virus infection promotes viral RNA synthesis through its association with viral PA protein.

BACKGROUND: Influenza is one of the most important viral infections globally. Viral RNA-dependent RNA polymerase (RdRp) consists of the PA, PB1, and PB2 subunits, and the amino acid residues of each subunit are highly conserved among influenza A virus (IAV) strains. Due to the high mutation rate and emergence of drug resistance, new antiviral strategies are needed. Host cell factors are involved in the transcription and replication of influenza virus. Here, we investigated the role of galectin-3, a member of the ß-galactoside-binding animal lectin family, in the life cycle of IAV infection in vitro and in mice. METHODS: We used galectin-3 knockout and wild-type mice and cells to study the intracellular role of galectin-3 in influenza pathogenesis. Body weight and survival time of IAV-infected mice were analyzed, and viral production in mouse macrophages and lung fibroblasts was examined. Overexpression and knockdown of galectin-3 in A549 human lung epithelial cells were exploited to assess viral entry, viral ribonucleoprotein (vRNP) import/export, transcription, replication, virion production, as well as interactions between galectin-3 and viral proteins by immunoblotting, immunofluorescence, co-immunoprecipitation, RT-qPCR, minireplicon, and plaque assays. We also employed recombinant galectin-3 proteins to identify specific step(s) of the viral life cycle that was affected by exogenously added galectin-3 in A549 cells. RESULTS: Galectin-3 levels were increased in the bronchoalveolar lavage fluid and lungs of IAV-infected mice. There was a positive correlation between galectin-3 levels and viral loads. Notably, galectin-3 knockout mice were resistant to IAV infection. Knockdown of galectin-3 significantly reduced the production of viral proteins and virions in A549 cells. While intracellular galectin-3 did not affect viral entry, it increased vRNP nuclear import, RdRp activity, and viral transcription and replication, which were associated with the interaction of galectin-3 with viral PA subunit. Galectin-3 enhanced the interaction between viral PA and PB1 proteins. Moreover, exogenously added recombinant galectin-3 proteins also enhanced viral adsorption and promoted IAV infection in A549 cells. CONCLUSION: We demonstrate that galectin-3 enhances viral infection through increases in vRNP nuclear import and RdRp activity, thereby facilitating viral transcription and replication. Our findings also identify galectin-3 as a potential therapeutic target for influenza.

Galectin-3 Mediates NETosis and Acts as an Autoantigen in Systemic Lupus Erythematosus-Associated Diffuse Alveolar Haemorrhage.

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with enhanced NETosis and impaired degradation of neutrophil extracellular traps (NETs). Galectin-3 is a ß-galactoside binding protein and is associated with neutrophil functions as well as involved in mediating autoimmune disorders. In this study, we plan to examine the associations of galectin-3 with the pathogenesis of SLE and NETosis. Galectin-3 expression levels were determined in peripheral blood mononuclear cells (PBMCs) of SLE patients for the association with lupus nephritis (LN) or correlation of SLE disease activity index 2000 (SLEDAI-2K). NETosis was observed in human normal and SLE and murine galectin-3 knockout (Gal-3 KO) neutrophils. Gal-3 KO and wild-type (WT) mice induced by pristane were used to evaluate disease signs, including diffuse alveolar haemorrhage (DAH), LN, proteinuria, anti-ribonucleoprotein (RNP) antibody, citrullinated histone 3 (CitH3) levels, and NETosis. Galectin-3 levels are higher in PBMCs of SLE patients compared with normal donors and positively correlated with LN or SLEDAI-2K. Gal-3 KO mice have higher percent survival and lower DAH, LN proteinuria, and anti-RNP antibody levels than WT mice induced by pristane. NETosis and citH3 levels are reduced in Gal-3 KO neutrophils. Furthermore, galectin-3 resides in NETs while human neutrophils undergo NETosis. Galectin-3-associated immune complex deposition can be observed in NETs from spontaneously NETotic cells of SLE patients. In this study, we provide clinical relevance of galectin-3 to the lupus phenotypes and the underlying mechanisms of galectin-3-mediated NETosis for developing novel therapeutic strategies targeting galectin-3 for SLE.

Evodiamine Exhibits Anti-Bladder Cancer Activity by Suppression of Glutathione Peroxidase 4 and Induction of Ferroptosis.

Evodiamine (EVO) exhibits anti-cancer activity through the inhibition of cell proliferation; however, little is known about its underlying mechanism. To determine whether ferroptosis is involved in the therapeutic effects of EVO, we investigated critical factors, such as lipid peroxidation levels and glutathione peroxidase 4 (GPX4) expression, under EVO treatment. Our results showed that EVO inhibited the cell proliferation of poorly differentiated, high-grade bladder cancer TCCSUP cells in a dose- and time-dependent manner. Lipid peroxides were detected by fluorescence microscopy after cancer cell exposure to EVO. GPX4, which catalyzes the conversion of lipid peroxides to prevent cells from undergoing ferroptosis, was decreased dose-dependently by EVO treatment. Given the features of iron dependency and lipid-peroxidation-driven death in ferroptosis, the iron chelator deferoxamine (DFO) was used to suppress EVO-induced ferroptosis. The lipid peroxide level significantly decreased when cells were treated with DFO prior to EVO treatment. DFO also attenuated EVO-induced cell death. Co-treatment with a pan-caspase inhibitor or necroptosis inhibitor with EVO did not alleviate cancer cell death. These results indicate that EVO induces ferroptosis rather than apoptosis or necroptosis. Furthermore, EVO suppressed the migratory ability, decreased the expression of mesenchymal markers, and increased epithelial marker expression, determined by a transwell migration assay and Western blotting. The TCCSUP bladder tumor xenograft tumor model confirmed the effects of EVO on the inhibition of tumor growth and EMT. In conclusion, EVO is a novel inducer for activating the ferroptosis of bladder cancer cells and may be a potential therapeutic agent for bladder cancer.

Interruption of the long non-coding RNA HOTAIR signaling axis ameliorates chemotherapy-induced cachexia in bladder cancer.

BACKGROUND: Cisplatin-based chemotherapy is the first line of treatment for bladder cancer. However, cisplatin induces muscle wasting associated with NF-κB and cancer cachexia. HOTAIR, an oncogenic long non-coding RNA (lncRNA), promotes cancer progression in different cancers. Crosstalk between HOTAIR and NF-κB is documented. Prothymosin α (ProT) plays important roles in cancer progression and inflammation. However, the potential link between HOTAIR, ProT, and cisplatin-induced cancer cachexia remains unexplored. Here, we investigated the contribution of HOTAIR in cisplatin-induced cancer cachexia and dissected the potential signaling cascade involving the epidermal growth factor receptor (EGFR), ProT, NF-κB, and HOTAIR. MATERIALS AND METHODS: Expression of ProT and HOTAIR transcripts and their correlations in tumor tissues of bladder cancer patients and bladder cancer cell lines were determined by RT-qPCR. Next, levels of phospho-EGFR, EGFR, phospho-NF-κB, and NF-κB were examined by immunoblot analysis in human bladder cancer cells treated with cisplatin. Expression of HOTAIR in cisplatin-treated cells was also assessed by RT-qPCR. Pharmacological inhibitors and overexpression and knockdown approaches were exploited to decipher the signaling pathway. The murine C2C12 myoblasts were used as an in vitro muscle atrophy model. The syngeneic murine MBT-2 bladder tumor was used to investigate the role of mouse Hotair in cisplatin-induced cancer cachexia. RESULTS: Expression of ProT and HOTAIR was higher in bladder tumors than in normal adjacent tissues. There were positive correlations between ProT and HOTAIR expression in clinical bladder tumors and bladder cancer cell lines. Cisplatin treatment increased EGFR and NF-κB activation and upregulated ProT and HOTAIR expression in bladder cancer cells. ProT overexpression increased, whereas ProT knockdown decreased, HOTAIR expression. Notably, cisplatin-induced HOTAIR upregulation was abrogated by EGFR inhibitors or ProT knockdown. ProT-induced HOTAIR overexpression was diminished by NF-κB inhibitors. HOTAIR overexpression enhanced, whereas its knockdown reduced, cell proliferation, cachexia-associated pro-inflammatory cytokine expression, and muscle atrophy. Cachexia-associated symptoms were ameliorated in mice bearing Hotair-knockdown bladder tumors undergoing cisplatin treatment. CONCLUSIONS: We demonstrate for the first time a critical role for HOTAIR and identify the involvement of the EGFR-ProT-NF-κB-HOTAIR signaling axis in cisplatin-induced cachexia in bladder cancer and likely other cancers. Our findings also provide therapeutic targets for this disease.

MicroRNA-133 suppresses cell viability and migration of rheumatoid arthritis fibroblast-like synoviocytes by down-regulation of MET, EGFR, and FSCN1 expression.

Aberrant proliferation and migration of fibroblast-like synoviocytes (FLS) are major characteristics of rheumatoid arthritis (RA). MicroRNA-133 (miR-133) is a tumor-suppressive miRNA that targets various genes responsive for cell proliferation and migration. The aim of this study was to examine the effect of miR-133 on RA FLS. A high throughput miRNA microarray was performed in synovium from mice with collagen-induced arthritis (CIA). Expression levels of miR-133 and the putative targets were determined in synovium and FLS from patients with RA and mice with CIA. Overexpression of miR-133 in RA FLS was performed by lentiviral vector-mediated transfer of precursor miRNA (pre-miR). The expression of miR-133a/b was decreased in the joint tissue and FLS of CIA mice, as determined by miRNA array and qRT-PCR. Down-regulation of miR-133a/b expression could also be observed in synovium and FLS from patients with RA. Overexpression of miR-133 reduced cell viability and migration of RA FLS, with decreased levels of FSCN1, EGFR, and MET. Our findings demonstrated the inhibitory effects of miR-133 on FLS viability and migration, and might contribute to the pharmacologic development of miR-133 therapeutics in patients with RA.

Effective Perturbations by Small-Molecule Modulators on Voltage-Dependent Hysteresis of Transmembrane Ionic Currents.

The non-linear voltage-dependent hysteresis (Hys(V)) of voltage-gated ionic currents can be robustly activated by the isosceles-triangular ramp voltage (Vramp) through digital-to-analog conversion. Perturbations on this Hys(V) behavior play a role in regulating membrane excitability in different excitable cells. A variety of small molecules may influence the strength of Hys(V) in different types of ionic currents elicited by long-lasting triangular Vramp. Pirfenidone, an anti-fibrotic drug, decreased the magnitude of Ih's Hys(V) activated by triangular Vramp, while dexmedetomidine, an agonist of α2-adrenoceptors, effectively suppressed Ih as well as diminished the Hys(V) strength of Ih. Oxaliplatin, a platinum-based anti-neoplastic drug, was noted to enhance the Ih's Hys(V) strength, which is thought to be linked to the occurrence of neuropathic pain, while honokiol, a hydroxylated biphenyl compound, decreased Ih's Hys(V). Cell exposure to lutein, a xanthophyll carotenoid, resulted in a reduction of Ih's Hys(V) magnitude. Moreover, with cell exposure to UCL-2077, SM-102, isoplumbagin, or plumbagin, the Hys(V) strength of erg-mediated K+ current activated by triangular Vramp was effectively diminished, whereas the presence of either remdesivir or QO-58 respectively decreased or increased Hys(V) magnitude of M-type K+ current. Zingerone, a methoxyphenol, was found to attenuate Hys(V) (with low- and high-threshold loops) of L-type Ca2+ current induced by long-lasting triangular Vramp. The Hys(V) properties of persistent Na+ current (INa(P)) evoked by triangular Vramp were characterized by a figure-of-eight (i.e., ∞) configuration with two distinct loops (i.e., low- and high-threshold loops). The presence of either tefluthrin, a pyrethroid insecticide, or t-butyl hydroperoxide, an oxidant, enhanced the Hys(V) strength of INa(P). However, further addition of dapagliflozin can reverse their augmenting effects in the Hys(V) magnitude of the current. Furthermore, the addition of esaxerenone, mirogabalin, or dapagliflozin was effective in inhibiting the strength of INa(P). Taken together, the observed perturbations by these small-molecule modulators on Hys(V) strength in different types of ionic currents evoked during triangular Vramp are expected to influence the functional activities (e.g., electrical behaviors) of different excitable cells in vitro or in vivo.

Evidence for Dual Activation of IK(M) and IK(Ca) Caused by QO-58 (5-(2,6-Dichloro-5-fluoropyridin-3-yl)-3-phenyl-2-(trifluoromethyl)-1H-pyrazolol[1,5-a]pyrimidin-7-one).

QO-58 (5-(2,6-dichloro-5-fluoropyridin-3-yl)-3-phenyl-2-(trifluoromethyl)-1H-pyrazolol[1,5-a]pyrimidin-7-one) has been regarded to be an activator of KV7 channels with analgesic properties. However, whether and how the presence of this compound can result in any modifications of other types of membrane ion channels in native cells are not thoroughly investigated. In this study, we investigated its perturbations on M-type K+ current (IK(M)), Ca2+-activated K+ current (IK(Ca)), large-conductance Ca2+-activated K+ (BKCa) channels, and erg-mediated K+ current (IK(erg)) identified from pituitary tumor (GH3) cells. Addition of QO-58 can increase the amplitude of IK(M) and IK(Ca) in a concentration-dependent fashion, with effective EC50 of 3.1 and 4.2 µM, respectively. This compound could shift the activation curve of IK(M) toward a leftward direction with being void of changes in the gating charge. The strength in voltage-dependent hysteresis (Vhys) of IK(M) evoked by upright triangular ramp pulse (Vramp) was enhanced by adding QO-58. The probabilities of M-type K+ (KM) channels that will be open increased upon the exposure to QO-58, although no modification in single-channel conductance was seen. Furthermore, GH3-cell exposure to QO-58 effectively increased the amplitude of IK(Ca) as well as enhanced the activity of BKCa channels. Under inside-out configuration, QO-58, applied at the cytosolic leaflet of the channel, activated BKCa-channel activity, and its increase could be attenuated by further addition of verruculogen, but not by linopirdine (10 µM). The application of QO-58 could lead to a leftward shift in the activation curve of BKCa channels with neither change in the gating charge nor in single-channel conductance. Moreover, cell exposure of QO-58 (10 µM) resulted in a minor suppression of IK(erg) amplitude in response to membrane hyperpolarization. The docking results also revealed that there are possible interactions of the QO-58 molecule with the KCNQ or KCa1.1 channel. Overall, dual activation of IK(M) and IK(Ca) caused by the presence of QO-58 eventually may have high impacts on the functional activity (e.g., anti-nociceptive effect) residing in electrically excitable cells. Care must be exercised when interpreting data generated with QO-58 as it is not entirely KCNQ/KV7 selective.

The Evidence for Effective Inhibition of INa Produced by Mirogabalin ((1R,5S,6S)-6-(aminomethyl)-3-ethyl-bicyclo [3.2.0] hept-3-ene-6-acetic acid), a Known Blocker of CaV Channels.

Mirogabalin (MGB, Tarlige®), an inhibitor of the α2δ-1 subunit of voltage-gated Ca2+ (CaV) channels, is used as a way to alleviate peripheral neuropathic pain and diabetic neuropathy. However, to what extent MGB modifies the magnitude, gating, and/or hysteresis of various types of plasmalemmal ionic currents remains largely unexplored. In pituitary tumor (GH3) cells, we found that MGB was effective at suppressing the peak (transient, INa(T)) and sustained (late, INa(L)) components of the voltage-gated Na+ current (INa) in a concentration-dependent manner, with an effective IC50 of 19.5 and 7.3 µM, respectively, while the KD value calculated on the basis of minimum reaction scheme was 8.2 µM. The recovery of INa(T) inactivation slowed in the presence of MGB, although the overall current-voltage relation of INa(T) was unaltered; however, there was a leftward shift in the inactivation curve of the current. The magnitude of the window (INa(W)) or resurgent INa (INa(R)) evoked by the respective ascending or descending ramp pulse (Vramp) was reduced during cell exposure to MGB. MGB-induced attenuation in INa(W) or INa(R) was reversed by the further addition of tefluthrin, a pyrethroid insecticide known to stimulate INa. MGB also effectively lessened the strength of voltage-dependent hysteresis of persistent INa in response to the isosceles triangular Vramp. The cumulative inhibition of INa(T), evoked by pulse train stimulation, was enhanced in its presence. Taken together, in addition to the inhibition of CaV channels, the NaV channel attenuation produced by MGB might have an impact in its analgesic effects occurring in vivo.

Crassolide Induces G2/M Cell Cycle Arrest, Apoptosis, and Autophagy in Human Lung Cancer Cells via ROS-Mediated ER Stress Pathways.

Crassolide, a cembranoid diterpene extracted from the soft coral Lobophytum crissum, has been proven to possess antioxidant and immunomodulatory properties. In the present study, we assessed the anticancer effects of crassolide on human H460 non-small-cell lung cancer (NSCLC) cells. We found that crassolide exerted cytotoxic effects on H460 cancer cells in vitro, inducing G2/M phase arrest and apoptosis. In addition, in H460 cells exposed to crassolide, the expression of the autophagy-related proteins LC3-II and beclin was increased, while the expression of p62 was decreased. Moreover, inhibiting autophagy with chloroquine (CQ) suppressed the crassolide-induced G2/M arrest and apoptosis of H460 cells. Moreover, we also found that crassolide induced endoplasmic reticulum (ER) stress in lung cancer cells by increasing the expression of ER stress marker proteins and that the crassolide-induced G2/M arrest, apoptosis, and autophagy were markedly attenuated by the ER stress inhibitor 4-phenylbutyric acid (4-PBA). Furthermore, we found that crassolide promoted reactive oxygen species (ROS) production by H460 cells and that the ROS inhibitor N-acetylcysteine (NAC) decreased the crassolide-induced ER stress, G2/M arrest, apoptosis, and autophagy. In conclusion, our findings show that crassolide inhibits NSCLC cell malignant biological behaviors for the first time, suggesting that this effect may be mechanistically achieved by inducing G2/M arrest, apoptosis, and autophagy through ROS accumulation, which activates the ER stress pathway. As a result of our findings, we now have a better understanding of the molecular mechanism underlying the anticancer effect of crassolide, and we believe crassolide might be a candidate for targeted cancer therapy.

Characterization of Inhibitory Capability on Hyperpolarization-Activated Cation Current Caused by Lutein (ß,ε-Carotene-3,3'-Diol), a Dietary Xanthophyll Carotenoid.

Lutein (ß,ε-carotene-3,3'-diol), a xanthophyll carotenoid, is found in high concentrations in the macula of the human retina. It has been recognized to exert potential effectiveness in antioxidative and anti-inflammatory properties. However, whether and how its modifications on varying types of plasmalemmal ionic currents occur in electrically excitable cells remain incompletely answered. The current hypothesis is that lutein produces any direct adjustments on ionic currents (e.g., hyperpolarization-activated cation current, Ih [or funny current, If]). In the present study, GH3-cell exposure to lutein resulted in a time-, state- and concentration-dependent reduction in Ih amplitude with an IC50 value of 4.1 µM. There was a hyperpolarizing shift along the voltage axis in the steady-state activation curve of Ih in the presence of this compound, despite being void of changes in the gating charge of the curve. Under continued exposure to lutein (3 µM), further addition of oxaliplatin (10 µM) or ivabradine (3 µM) could be effective at either reversing or further decreasing lutein-induced suppression of hyperpolarization-evoked Ih, respectively. The voltage-dependent anti-clockwise hysteresis of Ih responding to long-lasting inverted isosceles-triangular ramp concentration-dependently became diminished by adding this compound. However, the addition of 10 µM lutein caused a mild but significant suppression in the amplitude of erg-mediated or A-type K+ currents. Under current-clamp potential recordings, the sag potential evoked by long-lasting hyperpolarizing current stimulus was reduced under cell exposure to lutein. Altogether, findings from the current observations enabled us to reflect that during cell exposure to lutein used at pharmacologically achievable concentrations, lutein-perturbed inhibition of Ih would be an ionic mechanism underlying its changes in membrane excitability.

Characterization in Potent Modulation on Voltage-Gated Na+ Current Exerted by Deltamethrin, a Pyrethroid Insecticide.

Deltamethrin (DLT) is a type-II pyrethroid ester insecticide used in agricultural and domestic applications as well as in public health. However, transmembrane ionic channels perturbed by this compound remain largely unclear, although the agent is thought to alter the gating characteristics of voltage-gated Na+ (NaV) channel current. In this study, we reappraised whether and how it and other related compounds can make any further modifications on voltage-gated Na+ current (INa) in pituitary tumor (GH3) cells. Cell exposure to DLT produced a differential and dose-dependent stimulation of peak (transient, INa(T)) or sustained (late, INa(L)) INa; consequently, the EC50 value required for DLT-stimulated INa(T) or INa(L) was determined to be 11.2 or 2.5 µM, respectively. However, neither the fast nor slow component in the inactivation time constant of INa(T) activated by short depolarizing pulse was changed with the DLT presence; conversely, tefluthrin (Tef), a type-I pyrethroid insecticide, can accentuate INa with a slowing in inactivation time course of the current. The INa(L) augmented by DLT was attenuated by further application of either dapagliflozin (Dapa) or amiloride, but not by chlorotoxin. During pulse train (PT) stimulation, with the Tef or DLT presence, the cumulative inhibition of INa(T) became slowed; moreover, following PT stimuli, a large tail current with a slowly recovering process was observed. Alternatively, during rapid depolarizing pulse, the amplitude of INa(L) and tail INa (INa(Tail)) for each depolarizing pulse became progressively increased by adding DLT, not by Tef. The recovery time constant following PT stimulation with continued presence of Tef or DLT was shortened by further addition of Dapa. The voltage-dependent hysteresis (Hys(V)) of persistent INa was differentially augmented by Tef or DLT. Taken together, the magnitude, gating, frequency dependence, as well as Hys(V) behavior of INa exerted by the presence of DLT or Tef might exert a synergistic impact on varying functional activities of excitable cells in culture or in vivo.

Interleukin-23 Mediates Osteoclastogenesis in Collagen-Induced Arthritis by Modulating MicroRNA-223.

Interleukin-23 (IL-23) plays a pivotal role in rheumatoid arthritis (RA). IL-23 and microRNA-223 (miR-223) are both up-regulated and mediate osteoclastogenesis in mice with collagen-induced arthritis (CIA). The aim of this study was to examine the association between IL-23 and miR-223 in contributing to osteoclastogenesis and arthritis. Levels of IL-23p19 in joints of mice with CIA were determined. Lentiviral vectors expressing short hairpin RNA (shRNA) targeting IL-23p19 and lisofylline (LSF) were injected intraperitoneally into arthritic mice. Bone marrow-derived macrophages (BMMs) were treated with signal transducers and activators of transcription 4 (STAT4) specific shRNA and miR-223 sponge carried by lentiviral vectors in response to IL-23 stimulation. Treatment responses were determined by evaluating arthritis scores and histopathology in vivo, and detecting osteoclast differentiation and miR-223 levels in vitro. The binding of STAT4 to the promoter region of primary miR-223 (pri-miR-223) was determined in the Raw264.7 cell line. IL-23p19 expression was increased in the synovium of mice with CIA. Silencing IL-23p19 and inhibiting STAT4 activity ameliorates arthritis by reducing miR-223 expression. BMMs from mice in which STAT4 and miR-223 were silenced showed decreased osteoclast differentiation in response to IL-23 stimulation. IL-23 treatment increased the expression of miR-223 and enhanced the binding of STAT4 to the promoter of pri-miR-223. This study is the first to demonstrate that IL-23 promotes osteoclastogenesis by transcriptional regulation of miR-223 in murine macrophages and mice with CIA. Furthermore, our data indicate that LSF, a selective inhibitor of STAT4, should be an ideal therapeutic agent for treating RA through down-regulating miR-223-associated osteoclastogenesis.

Prothymosin α Gene Transfer Modulates Myocardial Remodeling after Ischemia-Reperfusion Injury.

Background: Prothymosin α (ProT), a polypeptide, attenuates inflammation and inhibits transforming growth factor (TGF)-ß signaling in pulmonary tissues. We investigated the potential role of ProT in myocardial ischemia-reperfusion (MyoIR) injury using ProT cDNA transfer. Methods: Serum ProT levels were investigated in cardiogenic shock patients with MyoIR (n = 9). In addition, the myocardium of Sprague-Dawley rats (n = 52) was subjected to 25 min of ischemia followed by an injection of adenoviral vectors (2 × 109 plaque-forming units) carrying ProT or the luciferase gene, 10 min before reperfusion. Echocardiography, serum ProT, and biochemical analyses of organ functions were performed before euthanasia, 14 days after treatment. Immunohistochemistry and immunoblotting of the myocardial tissue were also performed. Results: Serum ProT levels were transiently elevated in the rats and patients early after MyoIR, which was reduced to baseline levels in control rats and patients. ProT gene transfer persistently mobilized ProT serum levels, reduced dilatation, attenuated fibrotic changes, and preserved the left ventricular ejection fraction after MyoIR. Tissue thrombospondin-1 level was abundant, and matrix metalloproteinase-2, collagen I, and collagen IV levels were decreased in the treatment group. While TGF-ß protein level remained stable, ProT transduction mobilized Smad7, which counteracted TGF-ß. ProT reduced tissue microRNA-223 expression, inhibited the associated interleukin-1ß, and preserved RAS p21 protein activator 1 protein abundance. Conclusions: An increase in transient serum ProT levels could be a protective response in the acute stage of MyoIR. ProT gene transfer further preserved ventricular morphology and function through anti-inflammatory and anti-fibrotic effects in the subacute stage after injury.

Baseline plasma KL-6 level predicts adverse outcomes in patients with idiopathic pulmonary fibrosis receiving nintedanib: a retrospective real-world cohort study.

BACKGROUND: Nintedanib is effective for treating idiopathic pulmonary fibrosis (IPF), but some patients may exhibit a suboptimal response and develop on-treatment acute exacerbation (AE-IPF), hepatic injury, or mortality. It remains unclear which patients are at risk for these adverse outcomes. METHODS: We analysed the demographic and clinical data, baseline plasma levels of Krebs von den Lungen-6 (KL-6) and surfactant protein A (SPA), and longitudinal clinical courses of a real-world cohort of IPF patients who received nintedanib ≥ 14 days between March 2017 and December 2020. Cox proportional-hazards regression, subdistribution hazards regression, and sensitivity analyses were performed to investigate the association between baseline predictors and AE-IPF, mortality, and nintedanib-related hepatic injury. The relationship between baseline predictors and pulmonary function decline was determined. RESULTS: Fifty-seven patients were included, of whom 24 (42%) developed hepatic injury, 20 (35%) had AE-IPF, and 16 (28%) died on-treatment. A baseline plasma KL-6 level ≥ 2.5 ng/mL, and diffusion capacity for carbon monoxide (DLCO) < 55% predicted, were associated with increased risk of hepatic injury (adjusted hazard ratio [aHR] was 3.46; 95% CI 1.13-10.60; p = 0.029 for KL-6, and 6.05; 95% CI 1.89-19.32; p = 0.002 for DLCO). Both factors also predicted severe and recurrent hepatic injury. Patients with baseline KL-6 ≥ 2.5 ng/mL also had a higher risk of AE-IPF (aHR 4.52; 95% CI 1.63-12.55; p = 0.004). For on-treatment mortality, baseline KL-6 ≥ 3.5 ng/mL and SPA ≥ 600 pg/mL were significant predictors (aHR 5.39; 95% CI 1.16-24.97; p = 0.031 for KL-6, and aHR 12.28; 95% CI 2.06-73.05; p = 0.006 for SPA). Results from subdistribution hazard regression and sensitivity analyses supported these findings. Patients with elevated baseline plasma KL-6 levels also exhibited a trend towards faster pulmonary function decline. CONCLUSIONS: For patients with IPF who are receiving nintedanib, we have identified baseline predictors, in particular plasma KL-6 levels, for the risk of adverse outcomes. Patients with these predictors may require close monitoring for unfavourable responses during treatment. Our findings also support the prognostic role of molecular markers like KL-6 and may contribute to future formulation of more individualized therapeutic strategies for IPF.

Targeting Intra-Pulmonary P53-Dependent Long Non-Coding RNA Expression as a Therapeutic Intervention for Systemic Lupus Erythematosus-Associated Diffuse Alveolar Hemorrhage.

Diffuse alveolar hemorrhage (DAH) in systemic lupus erythematosus (SLE) is associated with significant mortality, requiring a thorough understanding of its complex mechanisms to develop novel therapeutics for disease control. Activated p53-dependent apoptosis with dysregulated long non-coding RNA (lncRNA) expression is involved in the SLE pathogenesis and correlated with clinical activity. We examined the expression of apoptosis-related p53-dependent lncRNA, including H19, HOTAIR and lincRNA-p21 in SLE-associated DAH patients. Increased lincRNA-p21 levels were detected in circulating mononuclear cells, mainly in CD4+ and CD14+ cells. Higher expression of p53, lincRNA-p21 and cell apoptosis was identified in lung tissues. Lentivirus-based short hairpin RNA (shRNA)-transduced stable transfectants were created for examining the targeting efficacy in lncRNA. Under pristane stimulation, alveolar epithelial cells had increased p53, lincRNA-p21 and downstream Bax levels with elevated apoptotic ratios. After pristane injection, C57/BL6 mice developed DAH with increased pulmonary expression of p53, lincRNA-p21 and cell apoptosis. Intra-pulmonary delivery of shRNA targeting lincRNA-p21 reduced hemorrhage frequencies and improved anemia status through decreasing Bax expression and cell apoptosis. Our findings demonstrate increased p53-dependent lncRNA expression with accelerated cell apoptosis in the lungs of SLE-associated DAH patients, and show the therapeutic potential of targeting intra-pulmonary lncRNA expression in a pristane-induced model of DAH.

Inhibition of CD44 induces apoptosis, inflammation, and matrix metalloproteinase expression in tendinopathy.

Apoptosis has emerged as a primary cause of tendinopathy. CD44 signaling pathways exert anti-apoptotic and -inflammatory effects on tumor cells, chondrocytes, and fibroblast-like synoviocytes. The aim of this study was to examine the association among CD44, apoptosis, and inflammation in tendinopathy. Expression of CD44 and apoptotic cell numbers in tendon tissue from patients with long head of biceps (LHB) tendinopathy were determined according to the histological grades of tendinopathy. Primary tenocytes from Achilles tendon of Sprague-Dawley rats 1 week after collagenase injection were cultured with an antagonizing antibody against CD44. Treatment responses were determined by evaluating cell viability and expression of tendon-related proliferation markers, inflammatory mediators, and apoptosis. The expression of CD44 and apoptosis were positively correlated with the severity of tendinopathy in the human LHB tendinopathy. Furthermore, CD44 expression and apoptotic cells were co-stained in tendinopathic tendon. Blocking the CD44 signaling pathways in rat primary tenocytes by OX-50 induced cell apoptosis and the elevated levels of cleaved caspase-3. Furthermore, they had decreased cell viability and expression of collagen type I, type III, tenomodulin, and phosphorylated AKT. In contrast, there were elevated levels of inflammatory mediators, including interleukin (IL)-1ß, IL-6, tumor necrosis factor-α, cyclooxygenase-2, and phosphorylated NF-κB, as well as matrix metalloproteinase (MMP) family members including MMP-1, -3, -9, and -13 in tenocytes upon OX-50 treatment. This study is the first to demonstrate the association of CD44 and apoptosis in tendinopathy. Our data imply that CD44 may play a role in tendinopathy via regulating apoptosis, inflammation, and extracellular matrix homeostasis.

Prothymosin α activates type I collagen to develop a fibrotic placenta in gestational diabetes.

High-risk pregnancies, such as pregnancies with gestational diabetes mellitus (GDM), are becoming more common and as such, have become important public health issues worldwide. GDM increases the risks of macrosomia, premature infants, and preeclampsia. Although placental dysfunction, including fibrosis is associated with the development of GDM, factors that link these observations remain unknown. Prothymosin α (ProTα) is expressed in the placenta and is involved in cell proliferation and immunomodulation. It also plays an important role in insulin resistance and fibrosis. However, the role of ProTα in GDM is still unclear. In the present study, we found that fibrosis-related protein expressions, such as type I collagen (Col-1) were significantly increased in the placentae of ProTα transgenic mice. With elevated fibrosis-related protein expressions, placental weights significantly increased in GDM group. In addition, placental and circulating ProTα levels were significantly higher in patients with GDM (n=39), compared with the healthy group (n=102), and were positively correlated with Col-1 expression. Mice with streptozotocin (STZ)-induced GDM had increased ProTα, fasting blood glucose, Col-1, and placental weight, whereas plasma insulin levels were decreased. ProTα overexpression enhanced nuclear factor κB (NFκB) activation to increase fibrosis-related protein expressions in 3A-Sub-E trophoblasts, while treatment with an NFκB inhibitor reversed the effect of ProTα on fibrosis-related protein expressions. We further investigated whether ProTα is regulated by hyperglycemia-induced reactive oxygen species (ROS). In conclusion, ProTα increases the amount of placental connective tissue and thus contributes to the pathogenesis of placental fibrosis in GDM. Therefore, ProTα may be a novel therapeutic target for GDM.

Prothymosin α promotes STAT3 acetylation to induce cystogenesis in Pkd1-deficient mice.

Polycystic kidney disease (PKD) is characterized by the expansion of fluid-filled cysts in the kidney, which impair the function of kidney and eventually leads to end-stage renal failure. It has been previously demonstrated that transgenic overexpression of prothymosin α (ProT) induces the development of PKD; however, the underlying mechanisms remain unclear. In this study, we used a mouse PKD model that sustains kidney-specific low-expression of Pkd1 to illustrate that aberrant up-regulation of ProT occurs in cyst-lining epithelial cells, and we further developed an in vitro cystogenesis model to demonstrate that the suppression of ProT is sufficient to reduce cyst formation. Next, we found that the expression of ProT was accompanied with prominent augmentation of protein acetylation in PKD, which results in the activation of downstream signal transducer and activator of transcription (STAT) 3. The pathologic role of STAT3 in PKD has been previously reported. We determined that this molecular mechanism of protein acetylation is involved with the interaction between ProT and STAT3; consequently, it causes the deprivation of histone deacetylase 3 from the indicated protein. Conclusively, these results elucidate the significant role of ProT, including protein acetylation and STAT3 activation in PKD, which represent potential for ameliorating the disease progression of PKD.-Chen, Y.-C., Su, Y.-C., Shieh, G.-S., Su, B.-H., Su, W.-C., Huang, P.-H., Jiang, S.-T., Shiau, A.-L., Wu, C.-L. Prothymosin α promotes STAT3 acetylation to induce cystogenesis in Pkd1-deficient mice.