Outcomes of Three Different Minimal Invasive Approaches for Secundum Atrial Septal Defect Closure: A Single Institute Experience

OBJECTIVE

The aims of this retrospective study were to investigate and evaluate the safety and efficacy of three approaches for closure of secundum atrial septal defect (ASD).

METHODS

In this study, we reviewed clinical data for transcatheter occlusion (TCO, n=63), transthoracic occlusion (TTO, n=55), and right anterolateral minithoracotomy (RALT, n=60) techniques used for ASD closure. We compared the safety and efficacy of the three approaches.

RESULTS

ASD size in the TTO group was similar to that in the RALT group (P=0.645) and significantly larger than that in the TCO group (P<0.001). The RALT group had more non-central types of ASD than the TTO and TCO groups (P=0.019 and P<0.001). The operative time in the TTO group was shorter than that in the TCO and RALT groups (P<0.001 and P<0.001). The ventilation time and intensive care unit duration were shorter in the TTO group than in the RALT group (P<0.001 and P<0.001). Hospital duration in the TCO group was shorter than that in the TTO and RALT groups (P<0.001 and P<0.001). There were no residual shunt and mortality in any group in hospital or during follow-up. There was no significant difference in the incidence of total complications among the three groups (P=0.738).

CONCLUSION

TCO, TTO, and RALT can be performed with favorable cosmetic and clinical results for closing ASD. Appropriate patient selection is an important factor for successful closure. These techniques are promising alternatives to standard median sternotomy and merit additional study.

Hippocampal CysLT1R overexpression or activation accelerates memory deficits, synaptic dysfunction, and amyloidogenesis in young APP/PS1 transgenic mice

Background

Our previous studies demonstrated that cysteinyl leukotrienes receptor 1 (CysLT₁R) knockout, pharmacological blockade, or hippocampus knockdown produced beneficial effects against Alzheimer’s disease (AD); however, whether CysLT₁R upregulation has deleterious effects on AD remains elusive.

Methods

In this study, we investigated the changes in behaviors, hippocampal amyloidogenesis, and synapse plasticity after CysLT₁R overexpression by microinfusion of the lentiviral vector, containing its coding sequence of mouse (LV-CysLT₁R), into the bilateral dentate gyri (DG) of the hippocampus or CysLT₁R activation by repeated systemic administration of its agonist YM-17690 (0.1 mg/kg, once a day, i.p., for 28 d).

Results

The behavior data showed that overexpression of CysLT₁R in hippocampal DG or administration of YM-17690 deteriorated behavioral performance in Morris water maze (MWM), Y-maze tests, and novel object recognition (NOR) in young APP/PS1 mice. The further studies showed that these treatments significantly destroyed synaptic function, as evidenced by impaired hippocampal long-term potentiation (LTP), decreased spine density, low number of synapses, and decreased postsynaptic protein (PSD95), and promoted the generation of amyloid β (Aβ) through increased expression of BACE1 and PS1 in the hippocampus of young APP/PS1 mice.

Conclusions

Together, our results indicate that CysLT₁R upregulation accelerates memory impairment in young APP/PS1 mice, which is associated with promoting synaptic dysfunction and amyloidogenesis in the hippocampus.

Neuroprotective effects of novel compound Tozan on cognition, neurogenesis and apoptosis in diabetes

Background

Cognitive impairment is a serious complication of diabetes that manifests as an impairment of spatial memory and learning ability. Its pathogenesis is unclear, and effective therapeutic drugs are very limited. Our group designed and synthesized a novel compound named 3-p-tolyl-9H-xanthen-9-one (Tozan). In this study, we sought to investigate the effects and mechanism of Tozan on diabetic cognitive impairment.

Methods

Methylglyoxal (MG)-induced SH-SY5Y cells and streptozotocin (STZ)-induced type 1 diabetic mice were treated with Tozan. Methyl thiazolul tetrazolium (MTT) and lactate dehydrogenase (LDH) were used to test cytotoxicity. Morris water maze (MWM) and Y-maze tests were used to evaluate cognitive function. Immunofluorescence and western blot analyses were used to evaluate neurogenesis, apoptosis, and signal transduction pathway-related proteins. In addition, Lentivirus (LV)-estrogen receptor beta (ERβ)-ribonucleic acid interference (RNAi) was used to knockdown the ERβ gene in SH-SY5Y cells.

Results

We found that Tozan ameliorated MG-induced cytotoxicity in SH-SY5Y cells, improved cognitive dysfunction in STZ-induced type 1 diabetic mice, increased neurogenesis, and prevented apoptotic responses in vitro and in vivo. Importantly, Tozan (2, 4, and 8 mg/kg) mediated phosphatidylinositol-3-kinase and protein kinase B cAMP-response element binding protein (PI3K/Akt-CREB) signaling by activating membrane ERβ, and a high dose of Tozan (8 mg/kg) mediated CREB signaling by activating nuclear ERβ in the hippocampus. Notably, Tozan did not have an anti-apoptosis and regeneration protective role in ERβ gene knockdown cells.

Conclusions

Our study demonstrates Tozan’s contributions to and role in cognition, neurogenesis, and apoptosis in diabetes, and lays an experimental foundation for the development of new anti-diabetic cognitive impairment drugs.

Sequential drug delivery by injectable macroporous hydrogels for combined photodynamic-chemotherapy

With hollow mesoporous silica (hMSN) and injectable macroporous hydrogel (Gel) used as the internal and external drug-loading material respectively, a sequential drug delivery system DOX-CA4P@Gel was constructed, in which combretastatin A4 phosphate (CA4P) and doxorubicin (DOX) were both loaded. The anti-angiogenic drug, CA4P was initially released due to the degradation of Gel, followed by the anti-cell proliferative drug, DOX, released from hMSN in tumor microenvironment. Results showed that CA4P was mainly released at the early stage. At 48 h, CA4P release reached 71.08%, while DOX was only 24.39%. At 144 h, CA4P was 78.20%, while DOX release significantly increased to 61.60%, showing an obvious sequential release behavior. Photodynamic properties of porphyrin endow hydrogel (ϕΔ(Gel) = 0.91) with enhanced tumor therapy effect. In vitro and in vivo experiments showed that dual drugs treated groups have better tumor inhibition than solo drug under near infrared laser irradiation, indicating the effectivity of combined photodynamic-chemotherapy.

PEGylated Nanoscale Metal-Organic Frameworks for Targeted Cancer Imaging and Drug Delivery

Nanoscale metal-organic frameworks (nMOFs) are a unique type of hybrid materials, which are broadly applicable as cargo delivery systems. However, the relatively low material stability and insufficient cancer cell interacting capacity have limited nMOFs' applications in cancer theranostics. Herein, a zirconium-based nMOF UiO-66-N₃ was synthesized, and its surface was covalently functionalized with alkyne-containing polyethylene glycol (PEG) via the azide-alkyne click chemistry. After that, F3 peptide was attached for targeting of cancer cells (the material was denoted as UiO-66-PEG-F3). Doxorubicin (DOX) served as a therapeutic drug and a fluorescent label in this study, and it was transported into UiO-66-PEG conjugates with sufficient drug loading efficiency. pH-responsive release of DOX from UiO-66 conjugates was witnessed. The structural integrity of UiO-66-N₃ was maintained post the surface modification process. Flow cytometry and confocal fluorescence microscopy revealed that DOX/UiO-66-PEG-F3 had stronger accumulation in MDA-MB-231 cells (nucleolin⁺) compared with DOX/UiO-66-PEG. In order to track the pharmacokinetic behavior (organ distribution profile) in vivo, the positron-emitting zirconium-89 (⁸⁹Zr) was incorporated into UiO-66-N₃. Similar PEGylation and F3 peptide conjugation resulted in the formation of ⁸⁹Zr-UiO-66-PEG-F3. Serial positron emission tomography (PET) imaging demonstrated that the preferential accumulation of ⁸⁹Zr-UiO-66-PEG-F3 in MDA-MB-231 tumors, and their liver clearance was faster than PEGylated UiO-66 using noncovalent methods. Thus, the PEGylated nMOFs using covalent strategies may find broad application in future cancer theranostics.

Cytoplasmic and nuclear Sw-5b NLR act both independently and synergistically to confer full host defense against tospovirus infection

Plant intracellular nucleotide-binding leucine-rich repeat (NLR) receptors play critical roles in mediating host immunity to pathogen attack. We use tomato Sw-5b::tospovirus as a model system to study the specific role of the compartmentalized plant NLR in dictating host defenses against the virus at different infection steps. We demonstrated here that tomato NLR Sw-5b distributes to the cytoplasm and nucleus, respectively, to play different roles in inducing host resistances against tomato spotted wilt orthotospovirus (TSWV) infection. The cytoplasmic-enriched Sw-5b induces a strong cell death response to inhibit TSWV replication. This host response is, however, insufficient to block viral intercellular and long-distance movement. The nuclear-enriched Sw-5b triggers a host defense that weakly inhibits viral replication but strongly impedes virus intercellular and systemic movement. Furthermore, the cytoplasmic and nuclear Sw-5b act synergistically to dictate a full host defense of TSWV infection. We further demonstrated that the extended N-terminal Solanaceae domain (SD) of Sw-5b plays critical roles in cytoplasm/nucleus partitioning. Sw-5b NLR controls its cytoplasm localization. Strikingly, the SD but not coil-coil domain is crucial for Sw-5b receptor to import into the nucleus to trigger the immunity. The SD was found to interact with importins. Silencing both importin α and β expression disrupted Sw-5b nucleus import and host immunity against TSWV systemic infection. Collectively, our findings suggest that Sw-5b bifurcates disease resistances by cytoplasm/nucleus partitioning to block different infection steps of TSWV. The findings also identified a new regulatory role of extra domain of a plant NLR in mediating host innate immunity.

IFP35 family proteins promote neuroinflammation and multiple sclerosis

Excessive activation of T cells and microglia represents a hallmark of the pathogenesis of human multiple sclerosis (MS). However, the regulatory molecules overactivating these immune cells remain to be identified. Previously, we reported that extracellular IFP35 family proteins, including IFP35 and NMI, activated macrophages as proinflammatory molecules in the periphery. Here, we investigated their functions in the process of neuroinflammation both in the central nervous system (CNS) and the periphery. Our analysis of clinical transcriptomic data showed that expression of IFP35 family proteins was up-regulated in patients with MS. Additional in vitro studies demonstrated that IFP35 and NMI were released by multiple cells. IFP35 and NMI subsequently triggered nuclear factor kappa B-dependent activation of microglia via the TLR4 pathway. Importantly, we showed that both IFP35 and NMI activated dendritic cells and promoted naïve T cell differentiation into Th1 and Th17 cells. Nmi-/- , Ifp35-/- , or administration of neutralizing antibodies against IFP35 alleviated the immune cells' infiltration and demyelination in the CNS, thus reducing the severity of experimental autoimmune encephalomyelitis. Together, our findings reveal a hitherto unknown mechanism by which IFP35 family proteins facilitate overactivation of both T cells and microglia and propose avenues to study the pathogenesis of MS.

Rapid Quality Identification of Decoction Pieces of Crude and Processed Corydalis Rhizoma by Near-Infrared Spectroscopy Coupled with Chemometrics

In order to identify the quality of crude and processed Corydalis Rhizoma decoction pieces, the research established a simple, fast, reliable, and validated near-infrared qualitative and quantitative model combined with chemometrics. 51 batches of crude and 40 batches of processed Corydalis Rhizoma from the Zhejiang and Jiangsu provinces of China were collected and analyzed. Crude and processed Corydalis Rhizoma samples were crushed to obtain NIR spectra. The content of seven alkaloids in crude and processed Corydalis Rhizoma was determined by high-performance liquid chromatography (HPLC). Pretreatment methods were screened such as normalization methods, offset filtering methods, and smoothing. Combined with partial least squares-discriminant analysis (PLS-DA) and partial least squares (PLS), the qualitative and quantitative models of crude and processed Corydalis Rhizoma were established, and the correlation coefficient (R ²), root mean square error of calibration (RMSEC), and root mean square error of prediction (RMSEP) were used as evaluation indexes. Tetrahydropalmatine was used as an example for screening pretreatment methods; the results showed that MSC combined with the second derivative and no smoothing and the model with the wavelength range of 10000-5000 cm^-1 had the best predictive ability and applied to all seven alkaloid components. Among them, the correlation coefficients were all higher than 0.99, and RMSEC and RMSEP were all less than 1%. The qualitative and quantitative model of the seven alkaloids in Corydalis Rhizoma can effectively identify the crude and processed Corydalis Rhizoma and determine the content of the seven alkaloids. By studying the NIR qualitative and quantitative models of crude and processed Corydalis Rhizoma, we can achieve rapid discrimination and quantitative prediction of crude and processed Corydalis Rhizoma. These methods can greatly improve the efficiency of traditional Chinese medicine analysis and provide a strong scientific basis for the quality identification and control of traditional Chinese medicine.

Antiviral RISC mainly targets viral mRNA but not genomic RNA of tospovirus

Antiviral RNA silencing/interference (RNAi) of negative-strand (-) RNA plant viruses (NSVs) has been studied less than for single-stranded, positive-sense (+)RNA plant viruses. From the latter, genomic and subgenomic mRNA molecules are targeted by RNAi. However, genomic RNA strands from plant NSVs are generally wrapped tightly within viral nucleocapsid (N) protein to form ribonucleoproteins (RNPs), the core unit for viral replication, transcription and movement. In this study, the targeting of the NSV tospoviral genomic RNA and mRNA molecules by antiviral RNA-induced silencing complexes (RISC) was investigated, in vitro and in planta. RISC fractions isolated from tospovirus-infected N. benthamiana plants specifically cleaved naked, purified tospoviral genomic RNAs in vitro, but not genomic RNAs complexed with viral N protein. In planta RISC complexes, activated by a tobacco rattle virus (TRV) carrying tospovirus NSs or Gn gene fragments, mainly targeted the corresponding viral mRNAs and hardly genomic (viral and viral-complementary strands) RNA assembled into RNPs. In contrast, for the (+)ssRNA cucumber mosaic virus (CMV), RISC complexes, activated by TRV carrying CMV 2a or 2b gene fragments, targeted CMV genomic RNA. Altogether, the results indicated that antiviral RNAi primarily targets tospoviral mRNAs whilst their genomic RNA is well protected in RNPs against RISC-mediated cleavage. Considering the important role of RNPs in the replication cycle of all NSVs, the findings made in this study are likely applicable to all viruses belonging to this group.

Continuously Graded Quantum Dots: Synthesis, Applications in Quantum Dot Light-Emitting Diodes, and Perspectives

Colloidal quantum dot (QD) light-emitting diodes (QLEDs) hold the promise of next-generation displays and illumination owing to their excellent color saturation, high efficiency, and solution processability. For achieving high-performance light-emitting diodes (LEDs), engineering the fine compositions and structures of QDs is of paramount importance and attracts tremendous research interest. The recently developed continuously graded QDs (cg-QDs) with gradually altered nanocompositions and electronic band structures present the most advanced example in this area. In this Perspective, we summarize the current progress in LEDs based on cg-QDs, mainly concentrating on their synthesis and advantages in addressing the great challenges in QLEDs, like efficiency roll-off at high current densities, short operation lifetimes at high brightness, and low brightness near the voltage around the bandgap. In addition, we propose accessible approaches exploiting the cutting-edge mechanisms and techniques to further optimize and improve the performance of QLEDs.

Takeda G Protein-Coupled Receptor 5 Modulates Depression-like Behaviors via Hippocampal CA3 Pyramidal Neurons Afferent to Dorsolateral Septum

BACKGROUND

Takeda G protein-coupled receptor 5 (TGR5) is recognized as a promising target for type 2 diabetes and metabolic syndrome; its expression has been demonstrated in the brain and is thought to be neuroprotective. Here, we hypothesize that dysfunction of central TGR5 may contribute to the pathogenesis of depression.

METHODS

In well-established chronic social defeat stress (CSDS) and chronic restraint stress (CRS) models of depression, we investigated the functional roles of TGR5 in CA3 pyramidal neurons (PyNs) and underlying mechanisms of the neuronal circuit in depression (for in vivo studies, n = 10; for in vitro studies, n = 5-10) using fiber photometry; optogenetic, chemogenetic, pharmacological, and molecular profiling techniques; and behavioral tests.

RESULTS

Both CSDS and CRS most significantly reduced TGR5 expression of hippocampal CA3 PyNs. Genetic overexpression of TGR5 in CA3 PyNs or intra-CA3 infusion of INT-777, a specific agonist, protected against CSDS and CRS, exerting significant antidepressant-like effects that were mediated via CA3 PyN activation. Conversely, genetic knockout or TGR5 knockdown in CA3 facilitated stress-induced depression-like behaviors. Re-expression of TGR5 in CA3 PyNs rather than infusion of INT-777 significantly improved depression-like behaviors in Tgr5 knockout mice exposed to CSDS or CRS. Silencing and stimulation of CA3 PyNs→somatostatin-GABAergic (gamma-aminobutyric acidergic) neurons of the dorsolateral septum circuit bidirectionally regulated depression-like behaviors, and blockade of this circuit abrogated the antidepressant-like effects from TGR5 activation of CA3 PyNs.

CONCLUSIONS

These findings indicate that TGR5 can regulate depression via CA3 PyNs→somatostatin-GABAergic neurons of dorsolateral septum transmission, suggesting that TGR5 could be a novel target for developing antidepressants.

Co-administration of combretastatin A4 nanoparticles and anti-PD-L1 for synergistic therapy of hepatocellular carcinoma

Background

According to data estimated by the WHO, primary liver cancer is currently the fourth most common malignant tumor and the second leading cause of death around the world. Hepatocellular carcinoma (HCC) is one of the most common primary liver malignancies, so effective therapy is highly desired for HCC.

Results

In this study, the use of poly(l-Aspartic acid)-poly(ethylene glycol)/combretastatin A4 (CA4-NPs) was aimed to significantly disrupt new blood vessels in tumor tissues for targeted hepatic tumor therapy. Here, PEG-b-PAsp-g-CA4 showed significantly prolonged retention in plasma and tumor tissue. Most importantly, CA4-NPs were mainly distributed at the tumor site because of the triple target effects—enhanced permeability and retention (EPR) effect, acid-sensitive (pH = 5.5) effect to the tumor microenvironment (TME), and good selectivity of CA4 for central tumor blood vessel. Considering that CA4-NPs might induce severe hypoxic conditions resulting in high expression of HIF-1α in tumor tissues, which could induce the overexpression of PD-L1, herein we also used a programmed death-ligand 1 antibody (aPD-L1) to prevent immunosuppression. This way of complementary combination is able to achieve an ideal treatment effect in tumor site where CA4-NPs and aPD-L1 could respond to the inner area and peripheral area, respectively. As a result, a significant decrease in tumor volume and weight was observed in the combination group of CA4-NPs plus aPD-L1 compared with CA4-NPs or aPD-L1 monotherapy in subcutaneous Hepa1-6 hepatic tumor models.

Conclusions

We presented a new idea that co-administration of CA4-NPs and aPD-L1 possessed notable anti-tumor efficacy for HCC treatment.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-00865-w.

Risk of hearing loss among multidrug-resistant tuberculosis patients according to cumulative aminoglycoside dose

SETTING: The ototoxic effects of aminoglycosides (AGs) lead to permanent hearing loss, which is one of the devastating consequences of multidrug-resistant tuberculosis (MDR-TB) treatment. As AG ototoxicity is dose-dependent, the impact of a surrogate measure of AG exposure on AG-induced hearing loss warrants close attention for settings with limited therapeutic drug monitoring.OBJECTIVE: To explore the prognostic impact of cumulative AG dose on AG ototoxicity in patients following initiation of AG-containing treatment for MDR-TB.DESIGN: This prospective cohort study was nested within an ongoing cluster-randomized trial of nurse case management intervention across 10 MDR-TB hospitals in South Africa.RESULTS: The adjusted hazard of AG regimen modification due to ototoxicity in the high-dose group (≥75 mg/kg/week) was 1.33 times higher than in the low-dose group (<75 mg/kg/week, 95%CI 1.09-1.64). The adjusted hazard of developing audiometric hearing loss was 1.34 times higher than in the low-dose group (95%CI 1.01-1.77). Pre-existing hearing loss (adjusted hazard ratio [aHR] 1.71, 95%CI 1.29-2.26) and age (aHR 1.16 per 10 years of age, 95%CI 1.01-1.33) were also associated with an increased risk of hearing loss.CONCLUSION: MDR-TB patients with high AG dose, advanced age and pre-existing hearing loss have a significantly higher risk of AG-induced hearing loss. Those at high risk may be candidates for more frequent monitoring or AG-sparing regimens.

Zhuyu Annao decoction promotes angiogenesis in mice with cerebral hemorrhage by inhibiting the activity of PHD3

Some traditional Chinese decoctions, such as Zhuyu Annao, exert favorable therapeutic effects on acute cerebral hemorrhage, hemorrhagic stroke, and other neurological diseases, but the underlying mechanism remains unclear. This study aimed to determine whether Zhuyu Annao decoction (ZYAND) protects the injured brain by promoting angiogenesis following intracerebral hemorrhage (ICH) and elucidate its specific mechanism. The effect of ZYAND on the nervous system of mice after ICH was explored through behavioral experiments, such as the Morris water maze and Rotarod tests, and its effects on oxidative stress were explored by detecting several oxidative stress markers, including malondialdehyde, nitric oxide, glutathione peroxidase, and superoxide dismutase. Real-time quantitative RT-PCR and WB were used to detect the effects of ZYAND on the levels of prolyl hydroxylase domain 3 (PHD3), hypoxia-inducible factor-1α (HIF-1α), and vascular endothelial growth factor (VEGF) in the brain tissues of mice. The effect of ZYAND on the NF-κB signaling pathway was detected using a luciferase reporter gene. A human umbilical cord vascular endothelial cell angiogenesis experiment was performed to determine whether ZYAND promotes angiogenesis. The Morris water maze test and other behavioral experiments verified that ZYAND improved the neurobehavior of mice after ICH. ZYAND activated the PHD3/HIF-1α signaling pathway, inhibiting the oxidative damage caused by ICH. In angiogenesis experiments, it was found that ZYAND promoted VEGF-induced angiogenesis by upregulating the expression of HIF-1α, and NF-κB signaling regulated the expression of HIF-1α by inhibiting PHD3. ZYAND exerts a reparative effect on brain tissue damaged after ICH through the NF-κB/ PHD3/HIF-1α/VEGF signaling axis.

The hierarchical folding dynamics of topologically associating domains are closely related to transcriptional abnormalities in cancers

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The hierarchical levels of TAD boundaries were tissue- and cell type-specific.

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The TAD nesting level of genes in tumors is different from that in normal tissue.

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Hierarchical TAD level of genes is related to abnormal transcription and prognosis in cancers.

Recent studies have shown that the three-dimensional (3D) structure of chromatin is associated with cancer progression. However, the roles of the 3D genome structure and its dynamics in cancer remains largely unknown. In this study, we investigated hierarchical topologically associating domain (TAD) structures in cancers and defined a “TAD hierarchical score (TH score)” for genes, which allowed us to assess the TAD nesting level of all genes in a simplified way. We demonstrated that the TAD nesting levels of genes in a tumor differ from those in normal tissue. Furthermore, the hierarchical TAD level dynamics were related to transcriptional changes in cancer, and some of the genes in which the hierarchical level was altered were significantly related to the prognosis of cancer patients. Overall, the results of this study suggest that the folding dynamics of TADs are closely related to transcriptional abnormalities in cancers, emphasizing that the function of hierarchical chromatin organization goes beyond simple chromatin packaging efficiency.

Unravelling a Zigzag Pathway for Hot Carrier Collection with Graphene Electrode

The capture of photoexcited deep-band hot carriers, excited by photons with energies far above the bandgap, is of significant importance for photovoltaic and photoelectronic applications because it is directly related to the quantum efficiency of photon-to-electron conversion. By employing time-resolved photoluminescence and state-of-the-art time-domain density functional theory, we reveal that photoexcited hot carriers in organic-inorganic hybrid perovskites prefer a zigzag interfacial charge-transfer pathway, i.e., the hot carriers transfer back and forth between CH₃NH₃PbI₃ and graphene electrode, before they reach a charge-separated state. Driven by quantum coherence and interlayer vibrational modes, this pathway at the semiconductor-graphene interface takes about 400 fs, much faster than the relaxation process within CH₃NH₃PbI₃ (several picoseconds). Our work provides new insight into the fundamental understanding and precise manipulation of hot carrier dynamics at the complex interfaces, paving the way for highly efficient photovoltaic and photoelectric device optimization.

Engineered Antibody Fragment against the Urokinase Plasminogen Activator for Fast Delineation of Triple-Negative Breast Cancer by Positron Emission Tomography

The urokinase plasminogen activator (uPA) and its cofactors are important regulators of tumor initiation and progression (including metastasis), and its overexpression is associated with unfavorable situations in cancer patients. We have previously used positron emission tomography (PET) imaging with a radiolabeled monoclonal antibody against the uPA (named ATN-291) to detect the uPA signaling activity in various cancer types; however, good tumor contrast can only be observed 24 h postinjection. To shorten the antibody circulation time and decrease interactions of ATN-291 with the mononuclear phagocyte system (MPS), our goal in this study is to develop an engineered antibody fragment (F(ab')₂) from the parent antibody. By pepsin digestion and chromatography purification, ATN-291 F(ab')₂ was obtained and characterized. Subsequently, it was conjugated with NOTA-Bn-NCS or fluorescein isothiocyanate (FITC) for PET imaging and fluorescence-mediated cellular analysis (i.e., flow cytometry or fluorescence microscopy). We confirmed that ATN-291 F(ab')₂ still maintained a good targeting efficacy for the uPA in MDA-MB-231 cells (uPA⁺) and it had a faster blood clearance speed compared with ATN-291, while its interaction with MPS has been significantly decreased. In rodent tumor xenografts, radiolabeled ATN-291 F(ab')₂ had a selective and persistent uptake in MDA-MB-231 tumors, with an early tumor-to-blood ratio of 1.3 ± 0.8 (n = 4) at 2 h postinjection from PET imaging. During our observation, radiolabeled ATN-291 F(ab')₂ was excreted from both renal and hepatobiliary pathways. Radiolabeled ATN-291 F(ab')₂ was also used for detecting uPA fluctuation during the tumor treatment in test animals. We concluded that radiolabeled ATN-291 F(ab')₂ could be used as fast as PET cancer diagnostics with versatile applicability.

Mapping COVID-19 with nuclear imaging: from infection to functional sequelae

The pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, or coronavirus disease 2019, COVID-19) has been raging all over the globe for more than one year. COVID-19 virus can attack multiple organs through binding to angiotensin-converting enzyme 2 (ACE2) receptors and further induce systemic inflammation and immune dysregulation. In the last issue of 2020 AJNMMI (http://www.ajnmmi.us), Lima et al. summarized current biological complications of COVID-19, their underlying mechanisms, and our options of mapping these functional sequelae using nuclear imaging techniques. Four major organs, including the lung, heart, kidney, and endothelium, were identified as most vulnerable to COVID-19 viruses in severe patients. Nuclear medicine proved accurate and sensitive in assessing the onset, progression, and treatment of COVID-19 patients. By choosing the most appropriate radiotracers and imaging methods, clinicians and researchers are able to analyze and monitor the presence of inflammation, fibrosis, and changes of metabolic rates in organs of interest. With these desirable nuclear imaging methods, systematic evaluation of COVID-19, from its onset to functional sequela, can be achieved with rational patient stratification and timely treatment monitoring, which we believe will eventually lead to full victory against the pandemic.

CRISPR/Cas9-mediated CysLT1R deletion reverses synaptic failure, amyloidosis and cognitive impairment in APP/PS1 mice

As a major pathological hallmark of Alzheimer's disease (AD), amyloid-β (Aβ) is regarded as a causative factor for cognitive impairment. Extensive studies have found Aβ induces a series of pathophysiological responses, finally leading to memory loss in AD. Our previous results demonstrated that cysteinyl leukotrienes receptor 1 (CysLT1R) antagonists improved exogenous Aβ-induced memory impairment. But the role of CysLT1R in AD and its underlying mechanisms still remain elusive. In this study, we investigated CysLT1R levels in AD patients and APP/PS1 mice. We also generated APP/PS1-CysLT1R-/- mice by clustered regulatory interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated CysLT1R deletion in APP/PS1 mice and studied the effect of CysLT1R knockout on amyloidogenesis, synapse structure and plasticity, cognition, neuroinflammation, and kynurenine pathway. These attributes were also studied after lentivirus-mediated knockdown of CysLT1R gene in APP/PS1 mice. We found that CysLT1R knockout or knockdown could conserve synaptic structure and plasticity, and improve cognition in APP/PS1 mice. These effects were associated with concurrent decreases in amyloid processing, reduced neuroinflammation and suppression of the kynurenine pathway. Our study demonstrates that CysLT1R deficiency can mediate several beneficial effects against AD pathogenesis, and genetic/pharmacological ablation of this protein could be a potential therapeutic option for AD.

2D Polarized Materials: Ferromagnetic, Ferrovalley, Ferroelectric Materials, and Related Heterostructures

The emergence of 2D polarized materials, including ferromagnetic, ferrovalley, and ferroelectric materials, has demonstrated unique quantum behaviors at atomic scales. These polarization behaviors are tightly bonded to the new degrees of freedom (DOFs) for next generation information storage and processing, which have been dramatically developed in the past few years. Here, the basic 2D polarized materials system and related devices' application in spintronics, valleytronics, and electronics are reviewed. Specifically, the underlying physical mechanism accompanied with symmetry broken theory and the modulation process through heterostructure engineering are highlighted. These summarized works focusing on the 2D polarization would continue to enrich the cognition of 2D quantum system and promising practical applications.

Computational methods for the prediction of chromatin interaction and organization using sequence and epigenomic profiles

The exploration of three-dimensional chromatin interaction and organization provides insight into mechanisms underlying gene regulation, cell differentiation and disease development. Advances in chromosome conformation capture technologies, such as high-throughput chromosome conformation capture (Hi-C) and chromatin interaction analysis by paired-end tag (ChIA-PET), have enabled the exploration of chromatin interaction and organization. However, high-resolution Hi-C and ChIA-PET data are only available for a limited number of cell lines, and their acquisition is costly, time consuming, laborious and affected by theoretical limitations. Increasing evidence shows that DNA sequence and epigenomic features are informative predictors of regulatory interaction and chromatin architecture. Based on these features, numerous computational methods have been developed for the prediction of chromatin interaction and organization, whereas they are not extensively applied in biomedical study. A systematical study to summarize and evaluate such methods is still needed to facilitate their application. Here, we summarize 48 computational methods for the prediction of chromatin interaction and organization using sequence and epigenomic profiles, categorize them and compare their performance. Besides, we provide a comprehensive guideline for the selection of suitable methods to predict chromatin interaction and organization based on available data and biological question of interest.