Inhibition of nuclear factor-κB p65 phosphorylation by 3,4-dihydroxybenzalacetone and caffeic acid phenethyl ester

Importin α inhibitors act against the differentiated stages of apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii

BACKGROUND

Nuclear import, dependent on the transporter importin α (IMPα), is a drug target for apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii. Indeed, a panel of small molecule inhibit interactions between IMPα and nuclear localization signals (NLSs) in vitro and the growth of rapidly dividing stages (P. falciparum blood stages and T. gondii tachyzoites) in culture.

OBJECTIVES

As new drugs targeting multiple life cycle stages of both parasites are required, the panel of IMPα inhibitors was tested for their ability to inhibit nuclear transport in the rapidly dividing stages and the maturation of differentiated stages (P. falciparum gametocytes and T. gondii bradyzoites).

METHODS

Using biophysical assays, Bay 11-7082, a Bay 11-7085 structural analogue, was tested for inhibition of IMPα:NLS interactions. The effect of the panel of inhibitors on the nuclear localization of reporter proteins was analysed in both parasites using transfections and microscopy. Also, using microscopy, the effect of inhibitors on differentiated stages of both parasites was tested.

RESULTS

Bay 11-7085 can inhibit nuclear transport in tachyzoites, while GW5074 and Caffeic Acid Phenethyl Ester (CAPE) can inhibit nuclear transport in the blood stages. Interestingly, CAPE can strongly inhibit gametocyte maturation, and Bay 11-7082 and Bay 11-7085 weakly inhibit bradyzoite differentiation.

CONCLUSIONS

As differentiation of gametocytes and bradyzoites is dependent on the activation of gene expression triggered by the nuclear translocation of transcription factors, our work provides a 'proof of concept' that targeting nuclear import is a viable strategy for the development of therapeutics against multiple stages of apicomplexan parasites, some of which are recalcitrant to existing drugs.

BRD4/nuclear PD-L1/RelB circuit is involved in the stemness of breast cancer cells

BACKGROUND

Breast cancer (BC) is the most common cancer diagnosed in women worldwide. BC stem cells (BCSCs) have been known to be involved in the carcinogenesis of the breast and contribute to therapeutic resistance. The programmed death-ligand 1 (PD-L1) expression of BC correlated with a poor prognosis. Immunotherapies that target PD-L1 have great potential and have been successful when applied to cancer treatment. However, whether PD-L1 regulates BCSC formation is unknown.

METHODS

BCSCs were enriched by serum-free suspension culture. The properties of BCSCs were examined by mammosphere formation assay, CD44+/Cd24-, aldehyde dehydrogenase (ALDH) assay, CSC marker analysis, and mammosphere growth assay. To elucidate the functions of bromodomain-containing protein 4 (BRD4), nuclear PD-L1, and RelB proteins in the stemness of BCSCs, mammosphere formation was examined using BRD4 inhibitor and degrader, PD-L1 degrader, and RelB inhibitor. The antitumor function of 3',4',7,8-tetrahydroxyflavone (THF), a specific BRD4 inhibitor, was studied through in vivo tumor model and mouse studies, and the protein levels of c-Myc, PD-L1, and RelB were examined in tumor model under THF treatment.

RESULTS

BRD4 was upregulated in breast CSCs and regulates the stemness of BCs. The downregulation of BRD4 using BRD4 PROTAC, ARV-825, and BRD4 inhibitor, (+)-JQ1, inhibits mammosphere formation and reduces the levels of breast CSC markers (CD44+/CD24- and ALDH1), stem cell marker genes, and mammosphere growth. BRD4 inhibitor (JQ1) and degrader (ARV825) downregulate membrane and nuclear fractions of PD-L1 through the inhibition of PD-L1 transcript levels. The knockdown of PD-L1 inhibits mammosphere formation. Verteporfin, a PD-L1 degrader, inhibits the transcripts and protein levels of PD-L1 and downregulates the transcript and protein levels of RelB. Calcitriol, a RelB inhibitor, and the knockdown of RelB using si-RelB regulate mammosphere formation through interleukin-6 (IL-6) expression. THF is a natural product and a potent selective BRD4 inhibitor, inhibits mammosphere formation, and reduces the levels of CD44+/CD24- and mammosphere growth by downregulating c-Myc, PD-L1, and RelB. 3',4',7,8-THF shows tumoricidal activity and increased levels of CD3+CD4+ and CD3+CD8+ T-cells in the tumor and tumor-draining lymph nodes (TDLNs) in the murine tumor model using 4T1 and MC38 cells.

CONCLUSIONS

The results show the first evidence of the essential role of the BRD4/nuclear PD-L1/RelB axis in breast CSC formation. The nuclear PD-L1 regulates RelB, and the RelB/p65 complex induces IL6 and breast CSC formation. Targeting nuclear PD-L1 represents a potential and novel tool for immunotherapies of intractable BC. Video Abstract.

Molecular characterization and functional analysis of TRIM37 from black tiger shrimp (Penaeus monodon)

The family of TRIM proteins with E3 ubiquitin ligase activity served important roles in the regulation of innate immune processes, in particular antiviral and proinflammatory cytokine responses. In this study, a novel TRIM37 homolog was identified from Penaeus monodon (named PmTRIM37). The PmTRIM37 protein contained three conserved domains (one RING finger domain, a B-box, and one Coiled-coil region) at its N-terminal and one Meprin and MATH domain at its C-terminal. The MATH domain was the characteristic of TRIM37 family. PmTRIM37 has relatively high expression in immune-related tissues such as hepatopancreas, gills, lymphoid organs and hemocytes. The expression levels of PmTRIM37 in hepatopancreas and lymphoid organs were significantly up-regulated after white spot syndrome virus (WSSV) infection. Knock down of PmTRIM37 promoted WSSV replication and VP28 expression, suggesting that PmTRIM37 played a negative role in WSSV infection. Further studies revealed that PmTRIM37 positively regulated the NF-κB pathway and Antimicrobial peptides (AMP) expression during WSSV infection. These findings indicated that PmTRIM37 might restrict WSSV replication by positively regulating NF-κB pathway during WSSV infection in P. monodon.

Phytochemicals in the treatment of inflammation-associated diseases: the journey from preclinical trials to clinical practice

Advances in biomedical research have demonstrated that inflammation and its related diseases are the greatest threat to public health. Inflammatory action is the pathological response of the body towards the external stimuli such as infections, environmental factors, and autoimmune conditions to reduce tissue damage and improve patient comfort. However, when detrimental signal-transduction pathways are activated and inflammatory mediators are released over an extended period of time, the inflammatory process continues and a mild but persistent pro-inflammatory state may develop. Numerous degenerative disorders and chronic health issues including arthritis, diabetes, obesity, cancer, and cardiovascular diseases, among others, are associated with the emergence of a low-grade inflammatory state. Though, anti-inflammatory steroidal, as well as non-steroidal drugs, are extensively used against different inflammatory conditions, they show undesirable side effects upon long-term exposure, at times, leading to life-threatening consequences. Thus, drugs targeting chronic inflammation need to be developed to achieve better therapeutic management without or with a fewer side effects. Plants have been well known for their medicinal use for thousands of years due to their pharmacologically active phytochemicals belonging to diverse chemical classes with a number of these demonstrating potent anti-inflammatory activity. Some typical examples include colchicine (alkaloid), escin (triterpenoid saponin), capsaicin (methoxy phenol), bicyclol (lignan), borneol (monoterpene), and quercetin (flavonoid). These phytochemicals often act via regulating molecular mechanisms that synergize the anti-inflammatory pathways such as increased production of anti-inflammatory cytokines or interfere with the inflammatory pathways such as to reduce the production of pro-inflammatory cytokines and other modulators to improve the underlying pathological condition. This review describes the anti-inflammatory properties of a number of biologically active compounds derived from medicinal plants, and their mechanisms of pharmacological intervention to alleviate inflammation-associated diseases. The emphasis is given to information on anti-inflammatory phytochemicals that have been evaluated at the preclinical and clinical levels. Recent trends and gaps in the development of phytochemical-based anti-inflammatory drugs have also been included.

Polyphenols as Potential Protectors against Radiation-Induced Adverse Effects in Patients with Thoracic Cancer

Radiotherapy is one of the standard treatment approaches used against thoracic cancers, occasionally combined with chemotherapy, immunotherapy and molecular targeted therapy. However, these cancers are often not highly sensitive to standard of care treatments, making the use of high dose radiotherapy necessary, which is linked with high rates of radiation-induced adverse effects in healthy tissues of the thorax. These tissues remain therefore dose-limiting factors in radiation oncology despite recent technological advances in treatment planning and delivery of irradiation. Polyphenols are metabolites found in plants that have been suggested to improve the therapeutic window by sensitizing the tumor to radiotherapy, while simultaneously protecting normal cells from therapy-induced damage by preventing DNA damage, as well as having anti-oxidant, anti-inflammatory or immunomodulatory properties. This review focuses on the radioprotective effect of polyphenols and the molecular mechanisms underlying these effects in the normal tissue, especially in the lung, heart and esophagus.

3,4-Dihydroxybenzalacetone Inhibits the Propagation of Hydrogen Peroxide-Induced Oxidative Effect via Secretory Components from SH-SY5Y Cells

The polyphenol derivative 3,4-dihydroxybenzalacetone (DBL) is the primary antioxidative component of the medicinal folk mushroom Chaga (Inonotus obliquus (persoon) Pilat). In this study, we investigated whether the antioxidative effect of DBL could propagate to recipient cells via secreted components, including extracellular vesicles (EVs), after pre-exposing SH-SY5Y human neuroblastoma cells to DBL. First, we prepared EV-enriched fractions via sucrose density gradient ultracentrifugation using conditioned medium from SH-SY5Y cells exposed to 100 µM hydrogen peroxide (H₂O₂) for 24 h, with and without 1 h of 5 µM DBL pre-treatment. CD63 immuno-dot blot analysis demonstrated that fractions with density of 1.06-1.09 g/cm³ had CD63-like immuno-reactivities. Furthermore, the 2,2-diphenyl-1-picrylhydrazyl assay revealed that the radical scavenging activity of fraction 11 (density of 1.06 g/cm³), prepared after 24-h H₂O₂ treatment, was significantly increased compared to that in the control group (no H₂O₂ treatment). Notably, 1 h of 5 µM DBL pre-treatment or 5 min of heat treatment (100 °C) diminished this effect, although concentrating the fraction by 100 kDa ultrafiltration enhanced it. Overall, the effect was not specific to the recipient cell types. In addition, the uptake of fluorescent Paul Karl Horan-labeled EVs in concentrated fraction 11 was detected in all treatment groups, particularly in the H₂O₂-treated group. The results suggest that cell-to-cell communication via bioactive substances, such as EVs, in conditioned SH-SY5Y cell medium, propagates the H₂O₂-induced radical scavenging effect, whereas pre-conditioning with DBL inhibits it.

The Role of Inflammation in Cognitive Impairment of Obstructive Sleep Apnea Syndrome

Obstructive sleep apnea syndrome (OSAS) has become a major worldwide public health concern, given its global prevalence. It has clear links with multiple comorbidities and mortality. Cognitive impairment is one related comorbidity causing great pressure on individuals and society. The clinical manifestations of cognitive impairment in OSAS include decline in attention/vigilance, verbal–visual memory loss, visuospatial/structural ability impairment, and executive dysfunction. It has been proven that chronic intermittent hypoxia (CIH) may be a main cause of cognitive impairment in OSAS. Inflammation plays important roles in CIH-induced cognitive dysfunction. Furthermore, the nuclear factor kappa B and hypoxia-inducible factor 1 alpha pathways play significant roles in this inflammatory mechanism. Continuous positive airway pressure is an effective therapy for OSAS; however, its effect on cognitive impairment is suboptimal. Therefore, in this review, we address the role inflammation plays in the development of neuro-impairment in OSAS and the association between OSAS and cognitive impairment to provide an overview of its pathophysiology. We believe that furthering the understanding of the inflammatory mechanisms involved in OSAS-associated cognitive impairment could lead to the development of appropriate and effective therapy.

Thunbergia laurifolia leaf extract partially recovers lead-induced renotoxicity through modulating the cell signaling pathways

This research investigated the reno-protective effect of Thunbergia laurifolia Linn. (TL) in a lead-induced toxicity test through the modulation of cell signaling pathways. The study carried out to evaluate the effect of TL leaf extracts in Swiss Albino mice exposed to lead acetate (PbAc). Prior to in vivo study, a probable kidney-protective effect of the plant leaf extract was presumed through an activity-specific (PASS) molecular docking analysis. In animal model study, albino mice were divided in seven groups and co-treated with PbAc and TL (100, 200 mg/kgBW) or vitamin E (100 mg/kgBW) for 38 days, whereas the untreated control, TL control, and vehicle control groups received sodium acetate, PbAc, sodium acetate plus mineral oil, respectively. At the end of treatment, blood and kidney tissue were collected for investigating Pb concentration, estimating biochemical profile, evaluating oxidative stress and inflammatory parameters. The histopathological change of kidney along with apoptosis was assessed from kidney sections using H & E staining and TUNEL assay. Pb-exposed mice were found to be increased concentration of Pb in the blood and kidney sample, which further led to increased MDA levels in the plasma, blood, and tissue. Followed by kidney damage, increased expression of TNF-α, iNOS, and COX-2 in kidney tissues were noticed, which were related to elevated TNF-α in the systemic circulation of Pb-treated mice. Co-treatment with TL or vitamin E significantly reduced altered structure and apoptosis of kidney tissues. Downregulation of inflammatory markers especially TNF-α, iNOS, and COX-2 with simultaneous improvement of renal function through reduced plasma BUN and creatinine levels demonstrate that TL act as a potential dietary supplement to detoxify Pb in kidney showing an antioxidant and anti-inflammatory effect.

Activation of nuclear factor-kappa B by TNF promotes nucleus pulposus mineralization through inhibition of ANKH and ENPP1

Spontaneous mineralization of the nucleus pulposus (NP) has been observed in cases of intervertebral disc degeneration (IDD). Inflammatory cytokines have been implicated in mineralization of multiple tissues through their modulation of expression of factors that enable or inhibit mineralization, including TNAP, ANKH or ENPP1. This study examines the underlying factors leading to NP mineralization, focusing on the contribution of the inflammatory cytokine, TNF, to this pathologic event. We show that human and bovine primary NP cells express high levels of ANKH and ENPP1, and low or undetectable levels of TNAP. Bovine NPs transduced to express TNAP were capable of matrix mineralization, which was further enhanced by ANKH knockdown. TNF treatment or overexpression promoted a greater increase in mineralization of TNAP-expressing cells by downregulating the expression of ANKH and ENPP1 via NF-κB activation. The increased mineralization was accompanied by phenotypic changes that resemble chondrocyte hypertrophy, including increased RUNX2 and COL10A1 mRNA; mirroring the cellular alterations typical of samples from IDD patients. Disc organ explants injected with TNAP/TNF- or TNAP/shANKH-overexpressing cells showed increased mineral content inside the NP. Together, our results confirm interactions between TNF and downstream regulators of matrix mineralization in NP cells, providing evidence to suggest their participation in NP calcification during IDD.

LncRNA NEAT1 acts as a key regulator of cell apoptosis and inflammatory response by the miR-944/TRIM37 axis in acute lung injury

Acute lung injury (ALI), a common complication of sepsis, is characterized by the impairment and injury of pulmonary function. The nuclear factor kappa-B (NF-κB) pathway is activated in ALI. Tripartite motif-containing 37 (TRIM37) can activate the NF-κB pathway and is closely associated with inflammation. The purpose of our study is to reveal the role of TRIM37 in ALI. The present study revealed that TRIM37 presented high levels in lung tissues of ALI mice, and knockdown of TRIM37 alleviated lipopolysaccharide (LPS)-induced lung injury, inflammatory response, and cell apoptosis in vivo. In addition, knockdown of TRIM37 inhibited the inflammatory response, and cell apoptosis of LPS-treated WI-38 cells. Mechanistically, miR-944 was identified to bind with and negatively regulate TRIM37. Furthermore, NEAT1 was indicated to act as a competitive endogenous RNA to promote TRIM37 expression by sequestering miR-944. Detailly, NEAT1 bound with miR-944, negatively modulated miR-944 expression, and positively modulated TRIM37 expression. The rescue assays suggested that overexpression of TRIM37 rescued the influence of NEAT1 knockdown on cell apoptosis and inflammatory response. Overall, NEAT1 facilitated cell apoptosis and inflammatory response of WI-38 cells by the miR-944/TRIM37 axis in sepsis-induced ALI, implying that NEAT1 may provide a novel insight for the treatment of sepsis-induced ALI.

Antidepressant-like Effect of Merazin Hydrate Depends on NO/ERK by Suppressing Its Downstream NF-κB or Nonactivating CREB/BDNF in Mouse Hippocampus

Merazin hydrate (MH), an essential ingredient of Fructus aurantii, has been identified to have an antidepressant-like effect. However, the molecular mechanisms of MH modulate depressive behavior are largely uncharacterized. Here, in lipopolysaccharide-induced mice, we identified that a single administration of MH recovered depressive behaviors and down-regulated the expressions of neuronal nitric oxide synthase (nNOS) in the hippocampus after 1 day. Activation of nNOS by l-arginine led to depressive behaviors, and inhibition of nNOS contributed to antidepressive behaviors. Notably, MH only reversed the expression of nNOS's downstream NF-κB and not the CREB/BDNF pathway in the hippocampus, and MH's antidepressant-like effects were prevented by Asatone (an agonist of NF-κB) and not H89 (an antagonist of CREB). MH also normalized the expressions of GFAP and IB-1 in dentate gyrus in the hippocampus and inflammatory factors such as IL-1β, IL-10, and TNF-α in serum. Overall, our studies reveal the molecular mechanisms of MH's antidepressant-like effect.

SOCS3 protects against neonatal necrotizing enterocolitis via suppressing NLRP3 and AIM2 inflammasome activation and p65 nuclear translocation

BACKGROUND

Necrotizing enterocolitis (NEC) is an acquired disorder of mucosal damage characterized by the diffuse or local necrosis of the intestine. The suppressor of cytokine signaling 3 (SOCS3) has been demonstrated to possess anti-inflammatory action in gastritis, ulcerative colitis and other inflammatory diseases. The present study aims to explore the effects of SOCS3 on LPS-induced colonic cell model of NEC, and investigate the underlying mechanisms.

METHODS

Expression of SOCS3 in tissue samples of NEC and LPS-induced enterocytes were evaluated by real-time quantitative PCR (RT-qPCR). Western blotting and enzyme-linked immunosorbent assay (ELISA) were applied to examine the effect of SOCS3 on inflammatory molecules. Co-immunoprecipitation assay were devoted to explore the relation between SOCS3 and TLR4.

RESULTS

We proved that SOCS3 was expressed at a low level in tissue samples of NEC and LPS-induced enterocytes, and LPS inhibited SOCS3 expression via JAK2/STAT3 pathway. Overexpression of SOCS3 weaken the LPS-induced inflammatory response in FHC and CACO2 cells. Moreover, SOCS3 downregulates proinflammatory cytokines by targeting TLR4, thus mediating the p65 nuclear translocation, and the activation of NLR family pyrin domain containing 3/absent in melanoma-2 (NLRP3/AIM2) inflammasome, ultimately reveals its anti-inflammatory effects.

CONCLUSIONS

Taken together, our data revealed that LPS inhibited SOCS3 expression via JAK2/STAT3 pathway, and SOCS3 protects enterocytes against NEC through mediating p65 nuclear translocation and NLRP3/AIM2 inflammasome activation in a TLR4 dependent manner.