Alisol B 23-Acetate Ameliorates Lipopolysaccharide-Induced Intestinal Barrier Dysfunction by Inhibiting TLR4-NOX1/ROS Signaling Pathway in Caco-2 Cells.

Alisol B 23-Acetate (AB23A) is a naturally occurring triterpenoid, which can be indicated in the rhizome of medicinal and dietary plants from Alisma species. Previous studies have demonstrated that AB23A could inhibit intestinal permeability by regulating tight junction (TJ)-related proteins. Even so, the AB23A protective mechanism against intestinal barrier dysfunction remains poorly understood. This investigation seeks to evaluate the AB23A protective effects on intestinal barrier dysfunction and determine the mechanisms for restoring intestinal barrier dysfunction in LPS-stimulated Caco-2 monolayers. According to our findings, AB23A attenuated the inflammation by reducing pro-inflammatory cytokines production like IL-6, TNF-α, IL-1ß, and prevented the paracellular permeability by inhibiting the disruption of TJ in LPS-induced Caco-2 monolayers after treated with LPS. AB23A also inhibited LPS-induced TLR4, NOX1 overexpression and subsequent ROS generation in Caco-2 monolayers. Transfected with NOX1-specific shRNA diminished the up-regulating AB23A effect on ZO-1 and occludin expression. Moreover, transfected with shRNA of TLR4 not only enhanced ZO-1 and occludin expression but attenuated NOX1 expression and ROS generation. Therefore, AB23A ameliorates LPS-induced intestinal barrier dysfunction by inhibiting TLR4-NOX1/ROS signaling pathway in Caco-2 monolayers, suggesting that AB23A may have positive impact on maintaining the intestinal barrier's integrity.

Effects of Cervical Rotatory Manipulation on Hemodynamics and Plaque Stability of Atherosclerotic Internal Carotid Artery in Rabbits.

OBJECTIVE: The purpose of this study was to investigate the effects of cervical rotatory manipulation (CRM) on hemodynamics and plaque stability of atherosclerotic internal carotid artery (ICA) in rabbits. METHODS: Forty rabbits were randomly divided into 4 groups: (1) internal carotid atherosclerosis (ICAS) rabbits treated with CRM (ICAS-CRM group); (2) ICAS rabbits treated without CRM (ICAS group), (3) Normal-CRM group (normal rabbits treated with CRM), and (4) blank control group. In the ICAS-CRM group and ICAS group, the ICAS model was induced by ICA balloon injury combined with a high-fat diet for 12 weeks. CRM was applied to rabbits in the ICAS-CRM and the Normal-CRM groups. During the study, an ultrasonography examination was performed for detecting plaque and hemodynamics on the ICAs. At the end of the study, all atherosclerotic ICAs were removed for histological and immunohistochemical detection. RESULTS: The hemodynamics (especially end-diastolic velocity, resistance index, and pulsatility index) through the ICAs were adversely affected by atherosclerosis while not adversely affected by CRM. Compared with the ICAS group, the micro-vessel density and average integrated optical densities of macrophages in the ICAS-CRM group were significantly increased. Compared to the ICAS group, in the ICAS-CRM group, the atherosclerosis was more serious, and the tunica intima was more unstable. CONCLUSIONS: Although CRM did not affect the hemodynamic index of ICA, it was observed to decrease the stability of severe ICAS plaques in rabbits, which may increase the plaque vulnerability.

Quantitative study on the biomechanical mechanism of sacroiliac joint subluxation: A finite element study.

The biomechanical mechanism of sacroiliac joint pain caused by sacroiliac joint subluxation is still unclear. And the purpose of this study is to elucidate the mechanism. In the present study, a finite element model of female lumbar spine-pelvis-femur was established. To simulate the sacroiliac joint subluxation quantitatively, the left ilium was shifted ±1, ±2, and ±3 mm along each axis, respectively. The stress and strain of articular surfaces and ligaments between the sacroiliac joint subluxation model and the normal model were compared. When the left ilium shifted along the positive direction of the X/Y/Z axis, the stress on most articular surfaces of the sacroiliac joint increased, of which the stress on the iliac surface of the right sacroiliac joint increased most obviously. The stress and strain of the ligaments increased most obviously when the left ilium shifted along the Y-axis, of which the left sacrospinous ligament increased the most, followed by the right sacrospinous ligament and right long posterior sacroiliac ligament. While the left long posterior sacroiliac ligament decreased the most, followed by the left short posterior sacroiliac ligament. The present study suggests that when the sacroiliac joint subluxation happens, even a slight shift, different biomechanical changes of different ligaments around the sacroiliac joint will happen. This may lead to an abnormal proprioceptive sensation of the ligaments, resulting in stress imbalance of the sacroiliac joint, and finally resulting in sacroiliac joint pain.

The dietary flavonoid isoliquiritigenin induced apoptosis and suppressed metastasis in melanoma cells: An in vitro and in vivo study.

AIMS: This study aimed to explore the role of Isoliquiritigenin (ISL) in the proliferation and invasion of melanoma cells and investigate the mechanism of action of this compound. MAIN METHODS: The functional roles of ISL in melanoma cells were determined by CCK8 assay, colony formation assay, flow cytometry and wound healing assay. The antitumor activity of ISL was assessed in vivo in a mouse xenograft model using A2058 cells. Quantitative real-time PCR analysis (RT-qPCR) and western blot assays were used to evaluate the gene and protein expression in cell lines or tumor tissue samples. Bioinformatic analysis, luciferase reporter assay, and gene set enrichment analysis (GSEA) were performed to confirm the mechanism of ISL effect on cell growth and metastasis of melanoma. KEY FINDINGS: ISL suppressed proliferation and migration of melanoma cells via downregulation of miR-27a expression. The inhibitory effect of ISL on growth and metastasis of melanoma cells was reversed by ectopic expression of miR-27a. Bioinformatic analysis showed that miR-27a targets POU class 2 homeobox 3 (POU2F3); this result was verified by the luciferase reporter assay and by a decrease in the expression of POU2F3 by miR-27a intervention. GSEA demonstrated that POU2F3 is associated with the c-MYC/p53 signaling pathway and metastasis. POU2F3 knockdown reversed the inhibitory effect of ISL on the growth and metastasis of melanoma. Additionally, POU2F3 was found to be downregulated in melanoma tissue samples and was negatively correlated with miR-27a. SIGNIFICANCE: ISL inhibits proliferation and metastasis of melanoma via the miR-27a/POU2F3/c-MYC/p53 axis; these results may provide a new thought for the treatment of melanoma.

Myricetin antagonizes semen-derived enhancer of viral infection (SEVI) formation and influences its infection-enhancing activity.

BACKGROUND: Semen is a critical vector for human immunodeficiency virus (HIV) sexual transmission and harbors seminal amyloid fibrils that can markedly enhance HIV infection. Semen-derived enhancer of viral infection (SEVI) is one of the best-characterized seminal amyloid fibrils. Due to their highly cationic properties, SEVI fibrils can capture HIV virions, increase viral attachment to target cells, and augment viral fusion. Some studies have reported that myricetin antagonizes amyloid ß-protein (Aß) formation; myricetin also displays strong anti-HIV activity in vitro. RESULTS: Here, we report that myricetin inhibits the formation of SEVI fibrils by binding to the amyloidogenic region of the SEVI precursor peptide (PAP248-286) and disrupting PAP248-286 oligomerization. In addition, myricetin was found to remodel preformed SEVI fibrils and to influence the activity of SEVI in promoting HIV-1 infection. Moreover, myricetin showed synergistic effects against HIV-1 infection in combination with other antiretroviral drugs in semen. CONCLUSIONS: Incorporation of myricetin into a combination bifunctional microbicide with both anti-SEVI and anti-HIV activities is a highly promising approach to preventing sexual transmission of HIV.

3-Hydroxyphthalic Anhydride- Modified Rabbit Anti-PAP IgG as a Potential Bifunctional HIV-1 Entry Inhibitor.

Several studies have reported that amyloid fibrils in human semen formed from a naturally occurring peptide fragment of prostatic acidic phosphatase (PAP248-286), known as semen-derived enhancer of viral infection (SEVI), could dramatically enhance human immunodeficiency virus type 1 (HIV-1) infection. Accordingly, SEVI might serve as a novel target for new antiviral drugs or microbicide candidates for the prevention of sexually transmitted HIV. Theoretically, a special anti-PAP or anti-SEVI antibody could reduce the enhancement of viral infection by blocking the binding of HIV and SEVI fibrils. Here, 3-hydroxyphthalic anhydride modified anti-PAP248-286 antibody, named HP-API, exhibited broad-spectrum and highly effective anti-HIV-1 activities on different subtypes and tropism. By using time-of-addition, cell-cell fusion and a single-cycle HIV-1 infection assays, we demonstrated that HP-API is an HIV-1 entry/fusion inhibitor. Mechanism studies suggest that HP-API inhibited HIV-1 entry/fusion by targeting both HIV-1 gp120 envelop and CD4 receptor on the host cell specifically. It is noteworthy that HP-API abrogated the formation of SEVI fibrils and partially interfered with SEVI-mediated enhancement of HIV-1 infection. Based on these findings, HP-API could be considered a bifunctional HIV-1 entry/fusion inhibitor with high potential.

A Degraded Fragment of HIV-1 Gp120 in Rat Hepatocytes Forms Fibrils and Enhances HIV-1 Infection.

Identification of the host or viral factors that enhance HIV infection is critical for preventing sexual transmission of HIV. Amyloid fibrils derived from human semen, including semen-derived enhancer of virus infection and semenogelins, enhance HIV-1 infection dramatically in vitro. In this study, we reported that a short-degraded peptide fragment 1 (DPF1) derived from native HIV-1 envelope protein gp120-loaded rat hepatocytes, formed fibrils by self-assembly and thus enhanced HIV-1 infection by promoting the binding of HIV-1 to target cells. Furthermore, DPF1-formed fibrils might be used as a crossing seed to accelerate the formation of semen-derived enhancer of virus infection and semenogelin fibrils. It will be helpful to clarify the viral factors that affect HIV-1 infection. DPF1 as an analog of gp120 containing the critical residues for CD4 binding might be useful for designing of HIV vaccines and developing HIV entry inhibitors.

Heat Shock Protein 90 Facilitates Latent HIV Reactivation through Maintaining the Function of Positive Transcriptional Elongation Factor b (p-TEFb) under Proteasome Inhibition.

The persistence of HIV in resting memory CD4+ T cells at a latent state is considered as the major barrier on the path to achieve a cure for HIV. Proteasome inhibitors (PIs) were previously reported as latency reversing agents (LRAs) but the mechanism underlying this function is yet unclear. Here we demonstrate that PIs reactivate latent HIV ex vivo without global T cell activation, and may facilitate host innate immune responses. Mechanistically, latent HIV reactivation induced by PIs is mediated by heat shock factor 1 (HSF1) via the recruitment of the heat shock protein (HSP) 90-positive transcriptional elongation factor b (p-TEFb) complex. Specifically, HSP90 downstream HSF1 gives positive feedback to the reactivation process through binding to cyclin-dependent kinase 9 (CDK9) and preventing it from undergoing degradation by the proteasome. Overall, these findings suggest proteasome inhibitors as potential latency reversing agents. In addition, HSF1/HSP90 involved in HIV transcription elongation, may serve as therapeutic targets in HIV eradication.

A facile and dynamic assay for the detection of peptide aggregation.

We report on a facile method to detect the aggregation and co-aggregation of peptides by tryptophan fluorescence spectroscopy. Peptide aggregates (PAs) play a pivotal role in neurodegenerative diseases, such as Alzheimer's and Parkinson's. The detection of the formation of aggregates, especially in the early stage, will facilitate the diagnosis and treatment of the associated disease. In this study, by choosing a tryptophan-containing peptide of EP2, we investigated its fluorescence spectroscopic characteristics in the process of PAs. The results showed that the intensity of emission spectra was significantly enhanced with the formation of PAs within 48 h. In addition, by employing EP2 as a fluorescence probe, we found that EP2 was able to effectively monitor the aggregation of other peptides/proteins that are otherwise difficult to detect with conventional approach. Thus, these preliminary data provide a promising diagnostic tool to detect the formation of PAs.

A Peptide Derived from the HIV-1 gp120 Coreceptor-Binding Region Promotes Formation of PAP248-286 Amyloid Fibrils to Enhance HIV-1 Infection.

BACKGROUND: Semen is a major vehicle for HIV transmission. Prostatic acid phosphatase (PAP) fragments, such as PAP248-286, in human semen can form amyloid fibrils to enhance HIV infection. Other endogenous or exogenous factors present during sexual intercourse have also been reported to promote the formation of seminal amyloid fibrils. METHODOLOGY AND PRINCIPAL FINDINGS: Here, we demonstrated that a synthetic 15-residue peptide derived from the HIV-1 gp120 coreceptor-binding region, designated enhancing peptide 2 (EP2), can rapidly self-assemble into nanofibers. These EP2-derivated nanofibers promptly accelerated the formation of semen amyloid fibrils by PAP248-286, as shown by Thioflavin T (ThT) and Congo red assays. The amyloid fibrils presented similar morphology, assessed via transmission electron microscopy (TEM), in the presence or absence of EP2. Circular dichroism (CD) spectroscopy revealed that EP2 accelerates PAP248-286 amyloid fibril formation by promoting the structural transition of PAP248-286 from a random coil into a cross-ß-sheet. Newly formed semen amyloid fibrils effectively enhanced HIV-1 infection in TZM-bl cells and U87 cells by promoting the binding of HIV-1 virions to target cells. CONCLUSIONS AND SIGNIFICANCE: Nanofibers composed of EP2 promote the formation of PAP248-286 amyloid fibrils and enhance HIV-1 infection.