A proactive/reactive mass screening approach with uncertain symptomatic cases.

We study the problem of mass screening of heterogeneous populations under limited testing budget. Mass screening is an essential tool that arises in various settings, e.g., the COVID-19 pandemic. The objective of mass screening is to classify the entire population as positive or negative for a disease as efficiently and accurately as possible. Under limited budget, testing facilities need to allocate a portion of the budget to target sub-populations (i.e., proactive screening) while reserving the remaining budget to screen for symptomatic cases (i.e., reactive screening). This paper addresses this decision problem by taking advantage of accessible population-level risk information to identify the optimal set of sub-populations for proactive/reactive screening. The framework also incorporates two widely used testing schemes: Individual and Dorfman group testing. By leveraging the special structure of the resulting bilinear optimization problem, we identify key structural properties, which in turn enable us to develop efficient solution schemes. Furthermore, we extend the model to accommodate customized testing schemes across different sub-populations and introduce a highly efficient heuristic solution algorithm for the generalized model. We conduct a comprehensive case study on COVID-19 in the US, utilizing geographically-based data. Numerical results demonstrate a significant improvement of up to 52% in total misclassifications compared to conventional screening strategies. In addition, our case study offers valuable managerial insights regarding the allocation of proactive/reactive measures and budget across diverse geographic regions.

BACH1 deficiency prevents neointima formation and maintains the differentiated phenotype of vascular smooth muscle cells by regulating chromatin accessibility.

The transcription factor BTB and CNC homology 1(BACH1) has been linked to coronary artery disease risk by human genome-wide association studies, but little is known about the role of BACH1 in vascular smooth muscle cell (VSMC) phenotype switching and neointima formation following vascular injury. Therefore, this study aims to explore the role of BACH1 in vascular remodeling and its underlying mechanisms. BACH1 was highly expressed in human atherosclerotic plaques and has high transcriptional factor activity in VSMCs of human atherosclerotic arteries. VSMC-specific loss of Bach1 in mice inhibited the transformation of VSMC from contractile to synthetic phenotype and VSMC proliferation and attenuated the neointimal hyperplasia induced by wire injury. Mechanistically, BACH1 suppressed chromatin accessibility at the promoters of VSMC marker genes via recruiting histone methyltransferase G9a and cofactor YAP and maintaining the H3K9me2 state, thereby repressing VSMC marker genes expression in human aortic smooth muscle cells (HASMCs). BACH1-induced repression of VSMC marker genes was abolished by the silencing of G9a or YAP. Thus, these findings demonstrate a crucial regulatory role of BACH1 in VSMC phenotypic transition and vascular homeostasis and shed light on potential future protective vascular disease intervention via manipulation of BACH1.

Progress in RAS-targeted therapeutic strategies: From small molecule inhibitors to proteolysis targeting chimeras.

As a widely considerable target in chemical biology and pharmacological research, rat sarcoma (RAS) gene mutations play a critical driving factor in several fatal cancers. Despite the great progress of RAS subtype-specific inhibitors, rapid acquired drug resistance could limit their further clinical applications. Proteolysis targeting chimera (PROTAC) has emerged as a powerful tool to handle "undruggable" targets and exhibited significant therapeutic benefit for the combat of drug resistance. Owing to unique molecular mechanism and binding kinetics, PROTAC is expected to become a feasible strategy to break the bottleneck of classical RAS inhibitors. This review aims to discuss the current advances of RAS inhibitors and especially focus on PROTAC strategy targeting RAS mutations and their downstream effectors for relevant cancer treatment.

Polarization state tomography technique based on coherent synthesis of polarization state and orthogonal polarization state separation method for comprehensive optical imaging.

Comprehensive optical imaging of the intensity, phase, and birefringent information of the biological sample is important because important physical or pathological changes always accompany the changes in multiple optical parameters. Current studies lack such a metric that can present the comprehensive optical property of the sample in one figure. In this paper, a polarization state synthesis tomography (PoST) method, which is based on the principle of polarization state coherent synthesis and demodulation, is proposed to achieve full-field tomographic imaging of the comprehensive information (i.e., intensity, phase, and birefringence) of the biological sample. In this method, the synthesis of the polarization state is achieved by the time-domain full-field low coherence interferometer, where the polarization states of the sample beam and the reference beam are set to be orthogonal for the synthesis of the polarization state. The synthesis of the polarization state enables two functions of the PoST system: (1) Depth information of the sample can be encoded by the synthesized polarization state because only when the optical path length difference between the two arms is within the coherence length, a new polarization state can be synthesized; (2) Since the scattering coefficient, refractive index and the birefringent property of the sample can modulate the intensity and phase of the sample beam, the synthesized polarization state is sensitive to all these three parameters and can provide the comprehensive optical information of the sample. In this work, the depth-resolved ability and the comprehensive optical imaging metric have been demonstrated by the standard samples and the onion cells, demonstrating the potential application value of this method for further investigation of the important physical or pathological process of the biological tissues.

Targeting metabolism to enhance immunotherapy within tumor microenvironment.

Cancer metabolic reprogramming has been considered an emerging hallmark in tumorigenesis and the antitumor immune response. Like cancer cells, immune cells within the tumor microenvironment or premetastatic niche also undergo extensive metabolic reprogramming, which profoundly impacts anti-tumor immune responses. Numerous evidence has illuminated that immunosuppressive TME and the metabolites released by tumor cells, including lactic acid, Prostaglandin E2 (PGE2), fatty acids (FAs), cholesterol, D-2-Hydroxyglutaric acid (2-HG), adenosine (ADO), and kynurenine (KYN) can contribute to CD8+ T cell dysfunction. Dynamic alterations of these metabolites between tumor cells and immune cells can similarly initiate metabolic competition in the TME, leading to nutrient deprivation and subsequent microenvironmental acidosis, which impedes immune response. This review summarizes the new landscape beyond the classical metabolic pathways in tumor cells, highlighting the pivotal role of metabolic disturbance in the immunosuppressive microenvironment, especially how nutrient deprivation in TME leads to metabolic reprogramming of CD8+ T cells. Likewise, it emphasizes the current therapeutic targets or strategies related to tumor metabolism and immune response, providing therapeutic benefits for tumor immunotherapy and drug development in the future. Cancer metabolic reprogramming has been considered an emerging hallmark in tumorigenesis and the antitumor immune response. Dynamic alterations of metabolites between tumor cells and immune cells initiate metabolic competition in the TME, leading to nutrient deprivation and subsequent microenvironmental acidosis, which impedes immune response.

FvKex2 is required for development, virulence, and mycotoxin production in Fusarium verticillioides.

Fusarium verticillioides is one of the most important fungal pathogens causing maize ear and stalk rots, thereby undermining global food security. Infected seeds are usually unhealthy for consumption due to contamination with fumonisin B1 (FB1) mycotoxin produced by the fungus as a virulence factor. Unveiling the molecular factors that determine fungal development and pathogenesis will help in the control and management of the diseases. Kex2 is a kexin-like Golgi-resident proprotein convertase that is involved in the activation of some important proproteins. Herein, we identified and functionally characterized FvKex2 in relation to F. verticillioides development and virulence by bioinformatics and functional genomics approaches. We found that FvKex2 is required for the fungal normal vegetative growth, because the growth of the ∆Fvkex2 mutant was significantly reduced on culture media compared to the wild-type and complemented strains. The mutant also produced very few conidia with morphologically abnormal shapes when compared with those from the wild type. However, the kexin-like protein was dispensable for the male role in sexual reproduction in F. verticillioides. In contrast, pathogenicity was nearly abolished on wounded maize stalks and sugarcane leaves in the absence of FvKEX2 gene, suggesting an essential role of Fvkex2 in the virulence of F. verticillioides. Furthermore, high-performance liquid chromatography analysis revealed that the ∆Fvkex2 mutant produced a significantly lower level of FB1 mycotoxin compared to the wild-type and complemented strains, consistent with the loss of virulence observed in the mutant. Taken together, our results indicate that FvKex2 is critical for vegetative growth, FB1 biosynthesis, and virulence, but dispensable for sexual reproduction in F. verticillioides. The study presents the kexin-like protein as a potential drug target for the management of the devastating maize ear and stalk rot diseases. Further studies should aim at uncovering the link between FvKex2 activity and FB1 biosynthesis genes. KEY POINTS: •The kexin-like protein FvKex2 contributes significantly to the vegetative growth of Fusarium verticillioides. •The conserved protein is required for fungal conidiation and conidial morphology, but dispensable for sexual reproduction. •Deletion of FvKEX2 greatly attenuates the virulence and mycotoxin production potential of F. verticillioides.

An optimization framework for large-scale screening under limited testing capacity with application to COVID-19.

We consider the problem of targeted mass screening of heterogeneous populations under limited testing capacity. Mass screening is an essential tool that arises in various settings, e.g., ensuring a safe supply of blood, reducing prevalence of sexually transmitted diseases, and mitigating the spread of infectious disease outbreaks. The goal of mass screening is to classify whole population groups as positive or negative for an infectious disease as efficiently and accurately as possible. Under limited testing capacity, it is not possible to screen the entire population and hence administrators must reserve testing and target those among the population that are most in need or most susceptible. This paper addresses this decision problem by taking advantage of accessible population-level risk information to identify the optimal set of sub-populations to target for screening. We conduct a comprehensive analysis that considers the two most commonly adopted schemes: Individual testing and Dorfman group testing. For both schemes, we formulate an optimization model that aims to minimize the number of misclassifications under a testing capacity constraint. By analyzing the formulations, we establish key structural properties which we use to construct efficient and accurate solution techniques. We conduct a case study on COVID-19 in the United States using geographic-based data. Our results reveal that the considered proactive targeted schemes outperform commonly adopted practices by substantially reducing misclassifications. Our case study provides important managerial insights with regards to optimal allocation of tests, testing designs, and protocols that dictate the optimality of schemes. Such insights can inform policy-makers with tailored and implementable data-driven recommendations.

Greenness on mortality of infant and under-5 child: A nationwide study in 147 Chinese cities.

BACKGROUND: Higher greenness was associated with a lower risk of adult mortality. However, the effects of greenness on the mortality of infant and child under-5 have not been fully examined. OBJECTIVES: The association of greenness on the infant mortality rate (IMR) and child under-5 mortality rate (U5MR) in 147 Chinese cities from 2009 to 2020 was evaluated. METHODS: Average and maximum annual population-weighted greenness, IMR (per 1000 live births), and U5MR (per 1000 live births) in 147 cities from 2009 to 2020 were collected, and a longitudinal panel study was conducted. Greenness exposure was evaluated using satellite-derived data at a spatial resolution of 250 m ×250 m in urban regions, and linear mixed-effect models were applied to assess the associations between greenness and IMR or U5MR in China. RESULTS: This national study showed that long-term exposure to greenness was associated with lower IMR and U5MR, respectively. Specifically, a 0.1 increase of Normalized Difference Vegetation Index (NDVI) in greenness was statistically significant with a decrease in IMR (-1.05 ‰, 95 % CI: -1.48, -0.63 ‰) and U5MR (-1.82 ‰, 95 % CI: -2.39, -1.25 ‰) in fully-adjusted model, respectively. In the stratified analyses, greenness effects on U5MR in the western (-2.33 ‰, 95 % CI: -3.43, -1.23 ‰) and central regions (-2.06 ‰, 95 % CI: -3.01, -1.10 ‰) were stronger than that in the eastern region (-0.86 ‰, 95 % CI: -1.66, -0.07 ‰). CONCLUSIONS: This nationwide study indicated that exposure to higher greenness was associated with lower mortality rates in infant and child under-5 in China.

Targeted Protein Degradation Technology and Nanomedicine: Powerful Allies against Cancer.

Targeted protein degradation (TPD) is an emerging therapeutic strategy with the potential of targeting undruggable pathogenic proteins. After the first proof-of-concept proteolysis-targeting chimeric (PROTAC) molecule was reported, the TPD field has entered a new era. In addition to PROTAC, numerous novel TPD strategies have emerged to expand the degradation landscape. However, their physicochemical properties and uncontrolled off-target side effects have limited their therapeutic efficacy, raising concerns regarding TPD delivery system. The combination of TPD and nanotechnology offers great promise in improving safety and therapeutic efficacy. This review provides an overview of novel TPD technologies, discusses their clinical applications, and highlights the trends and perspectives in TPD nanomedicine.

Room-Temperature Magnetic Phase Transition in an Electrically Tuned van der Waals Ferromagnet.

Finding tunable van der Waals (vdW) ferromagnets that operate at above room temperature is an important research focus in physics and materials science. Most vdW magnets are only intrinsically magnetic far below room temperature and magnetism with square-shaped hysteresis at room temperature has yet to be observed. Here, we report magnetism in a quasi-2D magnet Cr_{1.2}Te_{2} observed at room temperature (290 K). This magnetism was tuned via a protonic gate with an electron doping concentration up to 3.8×10^{21} cm^{-3}. We observed nonmonotonic evolutions in both coercivity and anomalous Hall resistivity. Under increased electron doping, the coercivities and anomalous Hall effects (AHEs) vanished, indicating a doping-induced magnetic phase transition. This occurred up to room temperature. DFT calculations showed the formation of an antiferromagnetic (AFM) phase caused by the intercalation of protons which induced significant electron doping in the Cr_{1.2}Te_{2}. The tunability of the magnetic properties and phase in room temperature magnetic vdW Cr_{1.2}Te_{2} is a significant step towards practical spintronic devices.

Neutrophils as potential therapeutic targets for breast cancer.

Breast cancer (BC) remains the foremost cause of cancer mortality globally, with neutrophils playing a critical role in its pathogenesis. As an essential tumor microenvironment (TME) component, neutrophils are emerging as pivotal factors in BC progression. Growing evidence has proved that neutrophils play a Janus- role in BC by polarizing into the anti-tumor (N1) or pro-tumor (N2) phenotype. Clinical trials are evaluating neutrophil-targeted therapies, including Reparixin (NCT02370238) and Tigatuzumab (NCT01307891); however, their clinical efficacy remains suboptimal. This review summarizes the evidence regarding the close relationship between neutrophils and BC, emphasizing the critical roles of neutrophils in regulating metabolic and immune pathways. Additionally, we summarize the existing therapeutic approaches that target neutrophils, highlighting the challenges, and affirming the rationale for continuing to explore neutrophils as a viable therapeutic target in BC management.

Clinical characteristics of severe influenza virus-associated pneumonia complicated with bacterial infection in children: a retrospective analysis.

BACKGROUND: We aimed to investigate the clinical characteristics of severe influenza virus-associated pneumonia complicated with bacterial infection in children. METHODS: We retrospectively analysed data concerning 64 paediatric patients with severe influenza virus-associated pneumonia who had been treated at our hospital. The patients were divided into observation (44 patients) and control (20 patients) groups, based on the presence or absence of concomitant bacterial infection, and clinical data were compared between the groups. RESULTS: The mean age in the observation group was 2.71 ± 1.44 years, 42 (95.45%) were aged ≤ 5 years, and 18 (40.9%) had underlying diseases. The mean age in the control group was 4.05 ± 2.21 years, 13 (65%) were aged ≤ 5 years, and 3 (15%) had underlying diseases. There was a statistically significant difference in patient age and the proportion of patients with underlying diseases (P < 0.05). The observation group had higher duration of fever values, a higher number of patients with duration of fever ≥ 7 days, a higher incidence of gasping, and a higher incidence of seizures/consciousness disturbance, and the differences were statistically significant (P < 0.05). Secondary bacterial infections in the observation group were mainly due to gram-negative bacteria, with Haemophilus influenzae and Moraxella catarrhalis being the most common pathogens. The observation group had a higher proportion of patients treated in the paediatric intensive care unit and a longer hospital stay, and the differences were statistically significant (P < 0.05). CONCLUSION: Severe influenza virus-associated pneumonia complicated with bacterial infection was more common in children aged ≤ 5 years. Younger patients with underlying diseases were more susceptible to bacterial infection (mainly due to gram-negative bacteria). The timely administration of neuraminidase inhibitors and antibiotics against susceptible bacteria is likely to help improve cure rates.

Structural properties of Phoenix oolong tea polysaccharide conjugates and the interfacial stability in nanoemulsions.

BACKGROUND: Tea polysaccharide conjugate (TPC) is a naturally occurring active substance that is extracted from tea. Owing to its benefits in enhancing human immunity and antioxidant effects, TPC is widely used in culinary products. The binding mode of polysaccharides and proteins in TPC, however, has not been well studied; it may be closely related to their functional properties, especially emulsification. RESULTS: The molecular weights and monosaccharide compositions of TPC were determined by ion chromatography and high-performance gel permeation chromatography. Although the functional groups of polysaccharides and proteins were confirmed by infrared spectroscopy, the presence of proteins could not be detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis and ultraviolet spectroscopy. It was hypothesized that the hydrophobic groups of the proteins in TPC were wrapped by polysaccharide chains, thus making the proteins undetectable. The rheology and interfacial protein adsorption results show that TPC forms a viscoelastic film at the oil-water interface to prevent the aggregation of oil droplets, thereby enhancing the stability of the emulsion. Based on these structural and emulsifying properties of TPC, the binding mode of polysaccharides and proteins along with their phase behavior at the oil-water interface of the emulsion was speculated. CONCLUSION: In TPC, the hydrophilic groups of the proteins are linked to polysaccharides by covalent interactions, where the hydrophobic groups are wrapped with the polysaccharide chains with the help of hydrophobic forces to form a hydrophobic core. The unique binding of polysaccharides and proteins in TPC enhances its amphiphilic properties, which can be effectively distributed at the oil-water interface and form stable emulsions. © 2023 Society of Chemical Industry.

Teaching Performance of Chemistry Teachers in Chinese Mainland during the COVID-19 Pandemic: A Content Analysis Study.

Chemistry education has been affected in various aspects, especially teaching models, teaching technology, curriculum design, and teaching assessment, in Chinese Mainland since COVID-19 struck. To explore the change in teaching performance and differences in those teaching performances between middle school teachers and university teachers, this study analyzes 46 chemical education journal articles in three academic levels, including Junior High School (JHS), Senior High School (SHS), and university through content analysis method. The result shows that all levels of chemistry teachers (CTs) prefer to adopt two teaching models (live teaching or a combination of live and recorded teaching) and use Tencent Meeting as a teaching platform, but, university chemistry professors can integrate some software (MOOC and WeiXin as well as QQ) into their class to improve the effectiveness of teaching. As for curriculum design and teaching assessment, university teachers can employ the news in the context of the COVID-19 pandemic to carry out teaching more deeply than middle school teachers because university students learn more professional chemistry knowledge, but, all of them tend to evaluate students promptly (like oral assessment) through classroom interaction. Thus, it suggests the government and the school develop educational applications/software and teaching resources and a diverse curriculum to enhance online teaching work both domestically and foreign. And, it is also suggested that teachers should actively participate in the training of educational technology and strengthen cooperation with teachers in other disciplines to build interdisciplinary classrooms.

[Stapled anoplin peptide combined with photothermal therapy enhances oncolytic immunotherapy of triple-negative breast cancer].

This study constructed a nano-drug delivery system, A3@GMH, by co-delivering the stapled anoplin peptide(Ano-3, A3) with the light-harvesting material graphene oxide(GO), and evaluated its oncolytic immunotherapy effect on triple-negative breast cancer(TNBC). A3@GMH was prepared using an emulsion template method and its physicochemical properties were characterized. The in vivo and in vitro photothermal conversion abilities of A3@GMH were investigated using an infrared thermal imager. The oncoly-tic activity of A3@GMH against TNBC 4T1 cells was evaluated through cell counting kit-8(CCK-8), lactate dehydrogenase(LDH) release, live/dead cell staining, and super-resolution microscopy. The targeting properties of A3@GMH on 4T1 cells were assessed using a high-content imaging system and flow cytometry. In vitro and in vivo studies were conducted to investigate the antitumor mechanism of A3@GMH in combination with photothermal therapy(PTT) through inducing immunogenic cell death(ICD) in 4T1 cells. The results showed that the prepared A3@GMH exhibited distinct mesoporous and coated structures with an average particle size of(308.9±7.5) nm and a surface potential of(-6.79±0.58) mV. The encapsulation efficiency and drug loading of A3 were 23.9%±0.6% and 20.5%±0.5%, respectively. A3@GMH demonstrated excellent photothermal conversion ability and biological safety. A3@GMH actively mediated oncolytic features such as 4T1 cell lysis and LDH release, as well as ICD effects, and showed enhanced in vitro antitumor activity when combined with PTT. In vivo, A3@GMH efficiently induced ICD effects with two rounds of PTT, activated the host's antitumor immune response, and effectively suppressed tumor growth in 4T1 tumor-bearing mice, achieving an 88.9% tumor inhibition rate with no apparent toxic side effects. This study suggests that the combination of stapled anoplin peptide and PTT significantly enhances the oncolytic immunotherapy for TNBC and provides a basis for the innovative application of anti-tumor peptides derived from TCM in TNBC treatment.

High-level production and extraction of C-phycocyanin from cyanobacteria Synechococcus sp. PCC7002 for antioxidation, antibacterial and lead adsorption.

Global warming and climate change because carbon dioxide (CO2) release to atmosphere is the forecasting challenges to human being. We are facing how to overcome the dilemma on the balance between economic and environment, thus taking more efforts on green processes to meet agreement of sustainable society are urgent and crucial. The absorption of CO2 by microalgae reduces the impact of CO2 on the environment. In this study, the CO2 removal efficiency was the highest in the culture of Cyanobacterium Synechococcus sp. PCC7002 (also called blue-green algae), at 2% CO2 to reach a value of 0.86 g-CO2/g-DCW. The main product of PCC7002 is C-phycocyanin (C-PC) which regarding to phycobilisome complex in all cyanobacterial species. A 160% increasing C-PC was achieved in the cultivation under 100 µmol/m2/s light intensity, 12:12 light-period with 2% CO2 at 30 °C. The mix-culture of nitric and ammonia ions had positive effect on the cell growth and C-PC accumulation, thus realized the highest yield of 0.439 g-CPC/g-DCW. Additionally, the partial purified C-PC displayed 89% antioxidant activity of 2,2-diphenyl-1-picryhydrazyl (DPPH) and 11% of superoxide free radical scavenging activity, respectively. The production of C-PC from PCC7002 reduced the CO2 emission and exhibited antibacterial activity against Escherichia coli and lead ion adsorption at room temperature, which has the great potential for eco-friendly application.

Time series study on the effects of daily average temperature on the mortality from respiratory diseases and circulatory diseases: a case study in Mianyang City.

BACKGROUND: Climate change caused by environmental pollution is the most important one of many environmental health hazards currently faced by human beings. In particular, the extreme temperature is an important risk factor for death from respiratory and circulatory diseases. This study aims to explore the meteorological-health effect and find out the vulnerable individuals of extreme temperature events in a less developed city in western China. METHOD: We collected the meteorological data and data of death caused by respiratory and circulatory diseases in Mianyang City from 2013 to 2019. The nonlinear distributed lag model and the generalized additive models were combined to study the influence of daily average temperature (DAT) on mortality from respiratory and circulatory diseases in different genders, ages. RESULTS: The exposure-response curves between DAT and mortality from respiratory and circulatory diseases presented a nonlinear characteristic of the "V" type. Cumulative Relative Risk of 30 days (CRR30) of deaths from respiratory diseases with 4.48 (2.98, 6.73) was higher than that from circulatory diseases with 2.77 (1.96, 3.92) at extremely low temperature, while there was no obvious difference at extremely high temperature. The health effects of low temperatures on the respiratory system of people of all ages and genders were persistent, while that of high temperatures were acute and short-term. The circulatory systems of people aged < 65 years were more susceptible to acute effects of cold temperatures, while the effects were delayed in females and people aged ≥65 years. CONCLUSION: Both low and high temperatures increased the risk of mortality from respiratory and circulatory diseases. Cold effects seemed to last longer than heat did.

SIRT3 mitigates intervertebral disc degeneration by delaying oxidative stress-induced senescence of nucleus pulposus cells.

Senescence of nucleus pulposus (NP) cells (NPC) is a major cause of intervertebral disc degeneration (IVDD), so delay NPC senescence may be beneficial for mitigating IVDD. We studied the effect and mechanism of silent information regulator 2 homolog 3 (SIRT3) on NPC senescence in vivo and in vitro. First, we observed SIRT3 expression in normal and degenerated NPC with immunohistochemical and immunofluorescence staining. Second, using SIRT3 lentivirus transfection, reactive oxygen species probe, senescence-associated ß-galactosidase staining, polymerase chain reaction, and western blot to observe the oxidative stress, senescence, and degeneration degree among groups. Subsequently, pretreatment with adenosine monophosphate-activated protein kinase (AMPK) agonists and inhibitors, observing oxidative stress, senescence, and degeneration degree among groups. Finally, the IVDD model was constructed and divided into Ctrl, Vehicle, LV-shSIRT3, and LV-SIRT3 groups. X-ray and magnetic resonance imaging scans were performed on rat's tails after 1 week; hematoxylin and eosin and safranin-O staining were used to evaluate the degree of IVDD; immunofluorescence staining was used to observe SIRT3 expression; immunohistochemical staining was used to observe oxidative stress, senescence, and degeneration degree of NP. We found that SIRT3 expression is reduced in degenerated NP tissues but increased in H2 O2 -induced NPC. Moreover, SIRT3 upregulation decreased oxidative stress, delayed senescence, and degeneration of NPC. In addition, activation of the AMPK/PGC-1α pathway can partially mitigate the NPC oxidative stress, senescence, and degeneration caused by SIRT3 knockdown. The study in vivo revealed that local SIRT3 overexpression can significantly reduce oxidative stress and ECM degradation of NPC, delay NPC senescence, thereby mitigating IVDD. In summary, SIRT3 mediated by the AMPK/PGC-1α pathway mitigates IVDD by delaying oxidative stress-induced NPC senescence.

CB2-mediated attenuation of nucleus pulposus degeneration via the amelioration of inflammation and oxidative stress in vivo and in vitro.

BACKGROUND: Nucleus pulposus cell (NPC) degeneration is widely accepted as one of the major causes of intervertebral disc (IVD) degeneration (IVDD). The pathogenesis of IVDD is complex and consists of inflammation, oxidative stress, and the loss of extracellular matrix (ECM). Cannabinoid type 2 receptor (CB2) has been shown to be involved in the pathological mechanism of a variety of diseases due to its anti-inflammatory effects and antioxidative stress capacity. METHOD: In Vitro, H2O2 was used to induce degeneration of nucleus pulposus cells, mRNA and protein expression level was determined by RT-PCR and Western Blot, and Immunocytochemical staining were used to detect expression of collagen II, aggrecan, MMP3/13, superoxide dismutase 2 (SOD2) and inducible nitric oxide synthase (iNOS). In vivo, the potential therapeutic effect of CB2 was detected in the rat acupuncture model. RESULT: In vitro, we found that the CB2 agonist (JWH133) treatment reduced the oxidative stress level in NPCs induced by hydrogen peroxide (H2O2) treatment. Furthermore, the expression of inflammatory cytokines was also decreased by JWH133 treatment. We found that collagen II and aggrecan expression was preserved, whereas matrix metalloproteinase levels were reduced. In vivo, we established a rat model by needle puncture. Imaging assessment revealed that the disc height index (DHI) and morphology of IVD were significantly improved, and the disc degeneration process was delayed by treatment of JWH133. Furthermore, immunohistochemical (IHC) staining revealed that JWH133 could inhibit the degradation of collagen II and decrease the expression of MMP3. CONCLUSIONS: The experiment indicates the oxidative stress and inflammatory response of rat NPCs induced by H2O2 could be inhibited by activating CB2. This study reveals that CB2 activation can effectively delay the development of IVDD, providing an effective therapeutic target for IVDD.

Pulse photothermal optical coherence tomography for multimodal hemodynamic imaging.

To realize multimodal hemodynamic imaging, pulse photothermal optical coherence tomography (P-PTOCT) is proposed in this Letter to solve the separation problem of photothermal phase and Doppler phase, which is difficult to solve in traditional PTOCT. This technique can obtain blood flow distribution, light absorption distribution, and concentration images simultaneously. Based on the difference between pulse photothermal phase and Doppler phase, we propose an even number differential demodulation algorithm that can separate the photothermal phase and Doppler phase from the same scanning data set. The separated photothermal phase can characterize the trend of drug concentration, which provides the possibility for quantitative measurement of plasma concentration. The combination of photothermal phase and Doppler phase is helpful for potential clinical research on hemodynamics of cerebral ischemia and provides a technical reference for the rapid acquisition of perfusion volume and plasma concentration at one time.