Isobavachalcone, a natural sirtuin 2 inhibitor, exhibits anti-triple-negative breast cancer efficacy in vitro and in vivo

Triple-negative breast cancer (TNBC) is the most aggressive and lethal clinical subtype and lacks effective targeted therapies at present. Isobavachalcone (IBC), the main active component of Psoralea corylifolia L., has potential anticancer effects. Herein, we identified IBC as a natural sirtuin 2 (SIRT2) inhibitor and characterized the potential mechanisms underlying the inhibition of TNBC. Molecular dynamics analysis, enzyme activity assay, and cellular thermal shift assay were performed to evaluate the combination of IBC and SIRT2. The therapeutic effects, mechanism, and safety of IBC were analyzed in vitro and in vivo using cellular and xenograft models. IBC effectively inhibited SIRT2 enzyme activity with an IC50 value of 0.84 ± 0.22 μM by forming hydrogen bonds with VAL233 and ALA135 within its catalytic domain. In the cellular environment, IBC bound to and stabilized SIRT2, consequently inhibiting cellular proliferation and migration, and inducing apoptosis and cell cycle arrest by disrupting the SIRT2/α-tubulin interaction and inhibiting the downstream Snail/MMP and STAT3/c-Myc pathways. In the in vivo model, 30 mg/kg IBC markedly inhibited tumor growth by targeting the SIRT2/α-tubulin interaction. Furthermore, IBC exerted its effects by inducing apoptosis in tumor tissues and was well-tolerated. IBC alleviated TNBC by targeting SIRT2 and triggering the reactive oxygen species ROS/β-catenin/CDK2 axis. It is a promising natural lead compound for future development of SIRT2-targeting drugs.

Weight regain, but not weight loss exacerbates hepatic fibrosis during multiple weight cycling events in male mice

PURPOSE

Weight cycling is a phenomenon characterized by fluctuating body weight that is commonly observed in individuals employing intentional weight loss methods. Despite its prevalence, the impact of weight cycling on health remains equivocal. The current investigation aimed to examine the effects of weight cycling on liver health.

METHODS

The weight cycling model was established by switching the feeding method of mice between ad libitum (AL) and restricted intake (DR or 60% of AL) of the breeding diet to cause weight gain and weight loss, respectively. The weight cycling model comprised two and a half cycles, with one group terminating the experience during the weight-gain period (S-AL) and the other during the weight-loss period (S-DR). Liver tissue was collected to investigate morphology alterations, apoptosis, lipid metabolism, and mitochondrial homeostasis.

RESULTS

The results demonstrated that the termination point of weight cycling affected body weight and hepatic steatosis. All parameters examined in the S-DR mice exhibited a comparable trend to those observed in the DR mice. Notably, S-AL mice showed a significant increase in lipid metabolism-related proteins in the liver compared to AL-fed mice, along with reduced lipid droplets. Moreover, hepatic apoptosis and fibrosis were exacerbated in the S-AL mice compared to AL mice, whereas mitochondrial fusion, biogenesis, and mitophagy were decreased in the S-AL mice.

CONCLUSION

Weight cycling ending in weight gain exacerbated hepatic fibrosis, potentially by inducing apoptosis or disrupting mitochondrial homeostasis. Conversely, weight cycling ending in weight loss demonstrated beneficial effects on hepatic health.

Age and dietary restriction modulate mitochondrial quality in quadriceps femoris muscle of male mice

Dietary restriction (DR) is a potential intervention for ameliorating ageing-related damages. Mitochondrial quality control is the key mechanism for regulating cellular functions in skeletal muscle. This study aimed to explore the effect of age and DR on the homeostasis of mitochondrial quality control in skeletal muscle. To study the effect of age on mitochondrial homeostasis, young (3 months old) male C57BL/6J mice were fed ad libitum (AL) until 7 (Young), 14 (Middle), and 19 months (Aged) of age. For the DR intervention, 60% of AL intake was given to the mice at 3 months of age until they reached 19 months of age (16 months). The quadriceps femoris muscle was collected for further analysis. Significant changes in the skeletal muscle were noticed during the transition between middle age and the elderly stages. An accumulation of collagen was observed in the muscle after middle age. Compared with the Middle muscle, Aged muscle displayed a greater expression of VDAC, and lower expressions of mitochondrial dynamic proteins and OXPHOS proteins. The DR intervention attenuated collagen content and elongated the sarcomere length in the skeletal muscle during ageing. In addition, DR adjusted the abnormalities in mitochondrial morphology in the Aged muscle. DR downregulated VDAC expression, but upregulated OPA1 and DRP1 expressions. Taken together, greater pathological changes were noticed in the skeletal muscle during ageing, especially in the transition between middle age and the elderly, whereas early-onset DR attenuated the muscular ageing via normalising partial functions of mitochondria.

Long-term dietary restriction ameliorates ageing-related renal fibrosis in male mice by normalizing mitochondrial functions and autophagy

As the kidneys age, gradual changes in the structures and functions of mitochondria occur. Dietary restriction (DR) can play a protective role in ageing-associated renal decline, however the exact mechanisms involved are still unclear. This study aims to clarify the beneficial effects of long-term DR on renal ageing and to explore the potential mechanisms of mitochondrial homeostasis. Eight-week-old C57BL/6 male mice (n = 30) were randomly divided into three groups, Young-AL (AL, ad libitum), Aged-AL, and Aged-DR (60% intake of AL). Mice were sacrificed at age of 7 months (Young) or 22 months (Aged). Heavier body and kidney weights were associated with ageing, but DR reduced these increases in aged mice. Ageing caused extensive tubulointerstitial fibrosis and glomerulosclerosis in the kidney. Giant mitochondria with looser and irregular crista were observed in Aged-AL kidneys. DR retarded these morphological alterations in aged kidneys. In addition, DR reversed the increase of MDA caused by ageing. Renal ATP level was elevated by DR treatment. Mitochondrial-related proteins were analysed to elucidate this association. Ageing downregulated the renal levels of VDAC, FOXO1, SOD2, LC3I and II, and upregulated the renal levels of MFN2 and PINK1. In contrast, DR elevated the levels of VDAC, FOXO1, and LC3I and reduced the ratio of LC3II to LC3I in aged kidneys. To conclude, impaired mitochondria, increased oxidative stress, and severe fibrosis were noticed in the aged kidneys, and DR improved these changes by increasing functional mitochondria and promoting autophagic clearance.

Identification of a glutathione S-transferase gene of Physarum polycephalum as a biomarker for nanosized TiO2 exposure under dark conditions

In this study, a glutathione S-transferase gene (gst) from sensitive Physarum polycephalum was selected for its ability to detect nanosized TiO₂ (nTiO₂ ) exposure under dark conditions. The concentration of nTiO₂ (25, 40 and 60 nm) for subsequent assays was first determined (5-18 mg ml^-1 ) and total GST enzyme activity of P. polycephalum was confirmed to be increased 6-44 fold in groups treated with nTiO₂ . Second, an RNA-seq study was performed to identify candidate gst genes before isolation of an optimum gst gene of P. polycephalum (Ppgst), which encoded 223 amino acids. Third, the transcriptional level of the Ppgst gene was further confirmed to be positively correlated with nTiO₂ exposure within the concentration range of (5-15 mg ml^-1 ) by qPCR. In conclusion, these results indicated that the transcriptional level of Ppgst can reflect nTiO₂ exposure, suggesting that it may be employed as a new biomarker for nTiO₂ pollution under dark conditions.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study identifies a new gst gene for indicating nanosized TiO₂ under dark conditions and provides a new option for detection of nanosized TiO₂ pollution under dark conditions.

Efficacy of Bifidobacterium tetravaccine tablets and Jinghua Weikang capsules in eradication of Helicobacter pylori

AIM: To investigate the clinical efficacy of Bifidobacterium tetravaccine tablets and Jinghua Weikang capsules in the eradication of Helicobacter pylori (H. pylori).

METHODS: One hundred and twenty patients with H. pylori infection who were treated from January 2011 to December 2013 at our hospital were randomly and equally divided into three groups: A, B and C. Group A was treated with standard triple therapy, groups B and C were given Bifidobacterium tetravaccine tablets and Jinghua Weikang capsules on the basis of standard triple therapy, respectively. The clinical effects were compared between the three groups.

RESULTS: The rates of H. pylori eradication in groups B and C were higher than that in group A (82.5%, 80.0% vs 72.5%, P > 0.05), but the difference was not significant. There was also no significant difference between groups B and C (P > 0.05). The incidence of adverse reactions was significantly higher in group A than in groups B and C (37.5% vs 12.5%, 10.0%, P < 0.05), although there was no significant difference between groups B and C (P > 0.05).

CONCLUSION: Bifidobacterium tetravaccine tablets and Jinghua Weikang capsules show good clinical effects in H. pylori eradication therapy in terms of improved H. pylori eradication rate and fewer adverse reactions.

Observation of two new N* resonances in the decay ψ(3686)→ppπ0

Based on 106×10(6)ψ(3686) events collected with the BESIII detector at the BEPCII facility, a partial wave analysis of ψ(3686)→ppπ0 is performed. The branching fraction of this channel has been determined to be B(ψ(3686)→ppπ0)=(1.65±0.03±0.15)×10(-4). In this decay, 7 N* intermediate resonances are observed. Among these, two new resonances, N(2300) and N(2570) are significant, one 1/2+ resonance with a mass of 2300(-30-0)(+40+109)  MeV/c2 and width of 340(-30-58)(+30+110)  MeV/c2, and one 5/2- resonance with a mass of 2570(-10-10)(+19+34)  MeV/c2 and width of 250(-24-21)(+14+69)  MeV/c2. For the remaining 5 N* intermediate resonances [N(1440), N(1520), N(1535), N(1650) and N(1720)], the analysis yields mass and width values that are consistent with those from established resonances.

Evidence for the direct two-photon transition from ψ(3686) to J/ψ

The two-photon transition ψ(3686)→γγJ/ψ is studied in a sample of 1.06×10(8) ψ(3686) decays collected by the BESIII detector. The branching fraction is measured to be (3.1±0.6(stat)(-1.0)(+0.8)(syst))×10(-4) using J/ψ→e(+)e(-) and J/ψ→μ(+)μ(-) decays, and its upper limit is estimated to be 4.5×10(-4) at the 90% confidence level. This work represents the first measurement of a two-photon transition among charmonium states. The orientation of the ψ(3686) decay plane and the J/ψ polarization in this decay are also studied. In addition, the product branching fractions of sequential E1 transitions ψ(3686)→γχ(cJ) and χ(cJ)→γJ/ψ(J=0,1,2) are reported.

First observation of the M1 transition ψ(3686)→γη(c)(2S)

Using a sample of 106×10(6) ψ(3686) events collected with the BESIII detector at the BEPCII storage ring, we have made the first measurement of the M1 transition between the radially excited charmonium S-wave spin-triplet and the radially excited S-wave spin-singlet states: ψ(3686)→γη(c)(2S). Analyses of the processes ψ(3686)→γη(c)(2S) with η(c)(2S)→K(S)(0)K(±)π(∓) and K(+)K(-)π(0) give an η(c)(2S) signal with a statistical significance of greater than 10 standard deviations under a wide range of assumptions about the signal and background properties. The data are used to obtain measurements of the η(c)(2S) mass (M(η(c)(2S))=3637.6±2.9(stat)±1.6(syst) MeV/c(2)), width (Γ(η(c)(2S))=16.9±6.4(stat)±4.8(syst) MeV), and the product branching-fraction (B(ψ(3686)→γη(c)(2S))×B(η(c)(2S)→KKπ)=(1.30±0.20(stat)±0.30(syst))×10(-5)). Combining our result with a BABAR measurement of B(η(c)(2S)→KKπ), we find the branching fraction of the M1 transition to be B(ψ(3686)→γη(c)(2S))=(6.8±1.1(stat)±4.5(syst))×10(-4).

Measurements of the mass and width of the η(c) using the decay ψ(3686)→γη(c)

The mass and width of the lowest-lying S-wave spin singlet charmonium state, the η(c), are measured using a data sample of 1.06×10(8) ψ(3686) decays collected with the BESIII detector at the BEPCII storage ring. We use a model that incorporates full interference between the signal reaction, ψ(3686)→γη(c), and a nonresonant radiative background to describe the line shape of the η(c) successfully. We measure the η(c) mass to be 2984.3±0.6±0.6 MeV/c(2) and the total width to be 32.0±1.2±1.0 MeV, where the first errors are statistical and the second are systematic.

First observation of η(1405) decays into f(0)(980)π0

The decays J/ψ → γ π+ π- π0 and J/ψ → γ π0 π0 π0 are analyzed using a sample of 225×10(6) J/ψ events collected with the BESIII detector. The decay of η(1405) → f(0)(980)π0 with a large isospin violation is observed for the first time. The width of the f(0)(980) observed in the dipion mass spectra is anomalously narrower than the world average. Decay rates for three-pion decays of the η' are also measured precisely.

Spin-parity analysis of pp¯ mass threshold structure in J/ψ and ψ(3686) radiative decays

A partial wave analysis of the pp¯ mass-threshold enhancement in the reaction J/ψ→γpp¯ is used to determine its J(PC) quantum numbers to be 0(-+), its peak mass to be below threshold at M=1832(-5)(+19)(stat)(-17)(+18)(syst)±19(model) MeV/c(2), and its total width to be Γ<76 MeV/c(2) at the 90% C.L. The product of branching ratios is measured to be BR[J/ψ→γX(pp¯)]BR[X(pp¯)→pp¯]=[9.0(-1.1)(+0.4)(stat)(-5.0)(+1.5)(syst)±2.3(model)]×10(-5). A similar analysis performed on ψ(3686)→γpp¯ decays shows, for the first time, the presence of a corresponding enhancement with a production rate relative to that for J/ψ decays of R=[5.08(-0.45)(+0.71)(stat)(-3.58)(+0.67)(syst)±0.12(model)]%.

ηπ+ π- resonant structure around 1.8 GeV/c(2) and η(1405) in J/ψ → ωηπ+ π-

We present results of a study of the decay J/ψ → ωηπ+ π- using a sample of (225.2 ± 2.8) × 10(6) J/ψ events collected by the BESIII detector, and report the observation of a new process J/ψ → ωX(1870) with a statistical significance of 7.2σ, in which X(1870) decays to a(0)(±)(980)π±. Fitting to ηπ+ π- mass spectrum yields a mass M = 1877.3 ± 6.3(stat)(-7.4)(+3.4)(syst) MeV/c(2), a width Γ = 57 ± 12(stat)(-4)(+19)(syst) MeV/c(2), and a product branching fraction B(J/ψ → ωX) × B(X→a(0)(±)(980)π±) × B(a(0) (±)(980) → ηπ±) = [1.50 ± 0.26(stat)(-0.36)(+0.72) (syst)] × 10(-4). Signals for J/ψ → ωf(1)(1285) and J/ψ → ω η(1405) are also clearly observed and measured.

Observation of χ(c1) decays into vector meson pairs φφ, ωω, and ωφ

Using (106±4)×10⁻⁶ ψ(3686) events accumulated with the BESIII detector at the BEPCII e⁺e⁻ collider, we present the first measurement of decays of χ(c1) to vector meson pairs φφ, ωω, and ωφ. The branching fractions are measured to be (4.4±0.3±0.5)×10⁻⁴, (6.0±0.3±0.7)×10⁻⁴, and (2.2±0.6±0.2)×10⁻⁵, for χ(c1)→φφ, ωω, and ωφ, respectively, which indicates that the hadron helicity selection rule is significantly violated in χ(cJ) decays. In addition, the measurement of χ(cJ)→ωφ provides the first indication of the rate of doubly OZI-suppressed χ(cJ) decay. Finally, we present improved measurements for the branching fractions of χ(c0) and χ(c2) to vector meson pairs.

Confirmation of the X(1835) and observation of the resonances X(2120) and X(2370) in J/ψ→γπ+π-η'

With a sample of (225.2±2.8)×10(6) J/ψ events registered in the BESIII detector, J/ψ→γπ(+)π(-)η(') is studied using two η(') decay modes: η(')→π(+)π(-)η and η(')→γρ(0). The X(1835), which was previously observed by BESII, is confirmed with a statistical significance that is larger than 20σ. In addition, in the π(+)π(-)η(') invariant-mass spectrum, the X(2120) and the X(2370), are observed with statistical significances larger than 7.2σ and 6.4σ, respectively. For the X(1835), the angular distribution of the radiative photon is consistent with expectations for a pseudoscalar.

Evidence for ψ' decays into γπ0 and γη

The decays ψ'→γπ(0), γη and γη' are studied using data collected with the BESIII detector at the BEPCII e(+)e(-) collider. The processes ψ'→γπ(0) and ψ'→γη are observed for the first time with signal significances of 4.6σ and 4.3σ, respectively. The branching fractions are determined to be B(ψ'→γπ(0))=(1.58±0.40±0.13)×10(-6), B(ψ'→γη)=(1.38±0.48±0.09)×10(-6), and B(ψ'→γη')=(126±3±8)×10(-6), where the first errors are statistical and the second ones systematic.

Parasellar epidural hydatid cysts

We report two rare cases of parasellar epidural hydatid cysts. Among the 64 patients with intracranial hydatid cysts we have treated in the past 20 years, only these two cases were located epidurally. Because the location and the computed tomographic characteristics were so different from the other cysts, the preoperative diagnosis was difficult to make. We were unable to remove the cysts without rupturing them because they were tightly surrounded. Both patients underwent surgery twice because of a recurrence. The treatment of this kind of case requires further discussion.

Phase and group velocity matching for second harmonic generation of femtosecond pulses

We theoretically analyze a method for matching group velocities of fundamental and second harmonic femtosecond pulses during phase matched frequncy doubling by predispersing the fundamental pulse with a prism. The method permits improved conversion efficiency by allowing crystal lengths of several millimeters without sacrificing second harmonic pulse duration. Second harmonic pulse energy and duration are analyzed for beta-BaB(2)O(4), and limiting experimental factors are discussed. The results show that the method is most advantageous for incident pulses between 0.1- and 1.0-ps duration and microjoule and higher energies and that second harmonic pulse duration and conversion efficiency are not highly sensitive to optical misalignments of the order of 1 degrees .