Adenylate kinase phosphate energy shuttle underlies energetic communication in flagellar axonemes.

The complexities of energy transfer mechanisms in the flagella of mammalian sperm flagella have been intensively investigated and demonstrate significant diversity across species. Enzymatic shuttles, particularly adenylate kinase (AK) and creatine kinase (CK), are pivotal in the efficient transfer of intracellular ATP, showing distinct tissue- and species-specificity. Here, the expression profiles of AK and CK were investigated in mice and found to fall into four subgroups, of which Subgroup III AKs were observed to be unique to the male reproductive system and conserved across chordates. Both AK8 and AK9 were found to be indispensable to male reproduction after analysis of an infertile male cohort. Knockout mouse models showed that AK8 and AK9 were central to promoting sperm motility. Immunoprecipitation combined with mass spectrometry revealed that AK8 and AK9 interact with the radial spoke (RS) of the axoneme. Examination of various human and mouse sperm samples with substructural damage, including the presence of multiple RS subunits, showed that the head of radial spoke 3 acts as an adapter for AK9 in the flagellar axoneme. Using an ATP probe together with metabolomic analysis, it was found that AK8 and AK9 cooperatively regulated ATP transfer in the axoneme, and were concentrated at sites associated with energy consumption in the flagellum. These findings indicate a novel function for RS beyond its structural role, namely, the regulation of ATP transfer. In conclusion, the results expand the functional spectrum of AK proteins and suggest a fresh model regarding ATP transfer within mammalian flagella.

LRRC23 deficiency causes male infertility with idiopathic asthenozoospermia by disrupting the assembly of radial spokes.

Asthenozoospermia (AZS) is the primary cause of infertility in males. The radial spoke (RS) is an axonemal structure, connecting the peripheral doublet microtubules with the central pair of microtubules. This T-shaped multiprotein complex functions as a mechanochemical sensor to promote sperm motility. LRRC23 is a novel subunit of the RS complex that is necessary for flagellar assembly and movement in mice. However, the importance of LRRC23 in modulating RS formation in humans remains unclear. Here, we identified a homozygous nonsense mutation in LRRC23 (c.376C>T:p. Arg126X) in an infertile AZS patient whose parents were consanguineous. We verified the adversity of this novel mutation because of its ability to disrupt LRRC23 synthesis and impair RSs integrity. Furthermore, we demonstrated an interaction between LRRC23 and RSPH3 in vitro, indicating that LCCR23 is associated with RS in humans. Meanwhile, the LRRC23-mutant patient had a good prognosis following intracytoplasmic sperm injection. This study provides strong preliminary evidence that LRRC23 defects are potential causative factors of AZS in humans, which expands our knowledge for improved genetic counseling and better reproductive recommendations for patients with AZS.

ACROSIN deficiency causes total fertilization failure in humans by preventing the sperm from penetrating the zona pellucida.

STUDY QUESTION: Does a homozygous nonsense mutation in ACR lead to total fertilization failure (TFF) resulting in male infertility in humans? SUMMARY ANSWER: A novel homozygous nonsense mutation of ACR (c.167G>A, p.Trp56X) was identified in two infertile brothers and shown to cause human TFF. WHAT IS KNOWN ALREADY: ACROSIN, encoded by ACR, is a major acrosomal enzyme expressed only in the acrosome of the sperm head. Inhibition of acrosin prevents sperm penetration of the zona pellucida (ZP) in several species, including humans. Acr-knockout in hamsters causes male infertility with completely blocked fertilization. Of note, there are no reports of ACR mutations associated with TFF in humans. STUDY DESIGN, SIZE, DURATION: Whole-exome sequencing (WES) was used for the identification of pathogenic genes for male factor TFF in eight involved couples. PARTICIPANTS/MATERIALS, SETTING, METHODS: Data from eight infertile couples who had experienced TFF during their IVF or ICSI attempts were collected. Functional assays were used to verify the pathogenicity of the potential genetic factors identified by WES. Subzonal insemination (SUZI) and IVF assays were performed to determine the exact pathogenesis of TFF caused by deficiencies in ACROSIN. MAIN RESULTS AND THE ROLE OF CHANCE: A novel homozygous nonsense mutation in ACR, c.167G>A, p.Trp56X, was identified in two additional primary infertile brothers whose parents were first cousins. This rare mutation caused ACROSIN deficiency and acrosomal ultrastructural defects in the affected sperm. Spermatozoa lacking ACROSIN were unable to penetrate the ZP, rather than hampering sperm binding, disrupting gamete fusion, or preventing oocyte activation. These findings were supported by the fertilization success of SUZI and ICSI attempts, as well as the normal expression of ACTL7A and PLCζ in the mutant sperm, suggesting that ICSI without remedial assisted oocyte activation is an optimal treatment for ARCOSIN-deficient TFF. LIMITATIONS, REASONS FOR CAUTION: The absence of another independent pedigree to support our argument is a limitation of this study. WIDER IMPLICATIONS OF THE FINDINGS: The findings expand our understanding of the genes involved in human TFF, providing information for appropriate genetic counseling and fertility guidance for these patients. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the National Natural Science Foundation of China (grant no. 82201803, 81901541, 82271639, and 32000584), University Synergy Innovation Program of Anhui Province (GXXT-2019-044), and the Nonprofit Central Research Institute Fund of the Chinese Academy of Medical Sciences (grant no. 2019PT310002). The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Nickel-Catalyzed Reductive Dicarbofunctionalizations of Alkenes for the Synthesis of Difluorocarbonyl Oxindoles and Isoquinoline-1,3-diones.

A novel and efficient strategy for the construction of difluorocarbonyl-oxindole and difluorocarbonyl-isoquinoline-1,3-dione derivatives involving nickel-catalyzed intramolecular Heck-type cyclizations followed by intermolecular cross-couplings has been developed. This approach features high functional group tolerance, broad substrate scope, and operational simplicity under mild conditions, thus providing a new method for the rapid difluorocarbonyl-functionalization of alkenes to construct the structurally diversified five- and six-membered heterocycles.

Pro-efferocytic macrophage membrane biomimetic nanoparticles for the synergistic treatment of atherosclerosis via competition effect.

Macrophages participate in many links in the pathological process of atherosclerosis (AS) and the regulation of influence of macrophages at the molecular level might be a new avenue for AS treatment. For this aim, the macrophage membrane biomimetic nanoparticles, derived from macrophage membrane coated SHP1i-loaded liposome NPs (MM@Lips-SHP1i) was designed. Due to the reservation of intrinsic membrane proteins and function from macrophages, the biomimic nanoparticles could effectively evade clearance by the immune system, prolong blood circulation time and actively tend and aggregate to atherosclerotic plaques. More importantly, in the plaque area, MM@Lips-SHP1i nanoparticles could compete with macrophages in vivo to bind with oxidized low-density lipoprotein (oxLDL) and lipopolysaccharide (LPS), reduce uptake of new lipids by macrophages, reduce foam cell formation, and inhibit the expression of pro-inflammatory cytokines. In addition, small molecule inhibitor of SHP-1, the downstream effector molecule of CD47 loaded in macrophage membrane biomimetic nanoparticles could interrupt CD47-SIRPα signal transduction in monocytes and macrophages, thereby enhancing the efferocytosis of macrophages, inhibiting the progression of plaque, achieving synergistic treatment of atherosclerosis. This work focuses on the key process in the formation of AS, macrophage foaming and chronic inflammation, and is based on the fact that macrophage membrane biomimetic nanoparticles can preserve the key surface proteins of macrophages closely related to the formation of AS, providing a new avenue to inhibit the progression of AS by utilizing the biological characteristics of macrophage membrane in macrophage membrane biomimetic nanoparticles.

Targeted Therapy of Atherosclerosis Vulnerable Plaque by ROS-Scavenging Nanoparticles and MR/Fluorescence Dual-Modality Imaging Tracing.

Purpose: Early diagnosis and treatment of atherosclerosis (AS) vulnerable plaque has important clinical significance for the prognosis of patients. In this work, the integrated diagnosis and treatment nanoparticles based on Gd-doped Prussian blue (GPB) were constructed for the fluorescence/MR dual-mode imaging and anti-ROS treatment of vulnerable AS plaques in vitro and in vivo. Methods: To fabricate the theranostic NPs, GPB was modified with water-soluble polymer polyethyleneimine (PEI), fluorescence molecule rhodamine (Rd), and targeted molecule dextran sulfate (DS) step by step via electrostatic adsorption to construct GPRD NPs. The fluorescence/MR imaging ability and various nano-enzymes activity of GPRD NPs were detected, and the biocompatibility and safety of GPRD were also evaluated. Subsequently, RAW264.7 cells and ApoE -/- model mice were used to evaluate the effect of GPRD NPs on the targeted dual-mode imaging and anti-ROS treatment of vulnerable plaque in vitro and in vivo. Results: The experimental results showed that our fabricated GPRD NPs not only displayed excellent MR/fluorescence dual-modality imaging of vulnerable plaque in vivo but also effectively utilized the nano-enzyme activity of GPB to inhibit the AS progress by ROS scavenging and the following reduction of inflammation, apoptosis, and foam cells' formation, providing a new avenue for the diagnosis and treatment of AS vulnerable plaque. Conclusion: The fabricated multimodal imaging nanoparticles with ROS-scavenging ability provided a new avenue for the diagnosis and treatment of AS vulnerable plaques.

DNA aptamer-based dual-responsive nanoplatform for targeted MRI and combination therapy for cancer.

Accurate drug delivery is a common topic, and it has always been an aim that scientists strive to achieve. To address this need, multifunctional and stimulus-sensitive nanoplatforms have attracted significant attention. Here we fabricated a glutathione (GSH) and adenosine-5'-triphosphate (ATP) dual-sensitive nanoplatform for controlled drug release and activatable MRI of tumors based on DNA aptamer and manganese dioxide (MnO2) nanosheets. Cleverly utilizing the DNA tunability, AS1411 aptamer which binds nucleolin, a protein specifically expressed on tumor-associated endothelial cells, was designed with ATP aptamer and its cDNA to load the anticancer drug, doxorubicin (Dox). The formed DNA-Dox complex was delivered to the tumor region with the help of MnO2 nanosheets and AS1411 aptamer. Then, the on-demand drug release in tumor cells was realized with the co-effect of the ATP aptamer and GSH reduction. It was found that without the structure of the MnO2 nanosheets being broken by GSH, Dox almost could not be released even in the presence of ATP. Similarly, without ATP, Dox was still maintained in the duplex even with GSH. Further combining the MRI ability and chemodynamic therapy of the produced Mn2+, an improved effect of the inhibition of tumor growth and imaging was achieved. Our designed DNA aptamer-based dual-responsive nanoplatform can realize the targeted drug delivery and MRI of breast tumor cells both in vitro and in vivo.

Theranostic nanoplatform to target macrophages enables the inhibition of atherosclerosis progression and fluorescence imaging of plaque in ApoE(-/-) mice.

BACKGROUND: Rupture of atherosclerotic plaque can cause acute malignant heart and cerebrovascular events, such as acute coronary heart disease, stroke and so on, which seriously threaten the safety of human life and property. Therefore, the early diagnosis and inhibition of atherosclerotic plaque progress still be a vital task. RESULTS: In this study, we presented the development of composite mesoporous silica nanoparticle (Ru(bpy)3@SiO2-mSiO2, CMSN)-based nanomedicines (NMs) (Ru(bpy)3@SiO2-mSiO2@SRT1720@AntiCD36, CMSN@SRT@Anti) for accurate diagnosis and treatment of atherosclerosis (AS). In vitro cell experiments showed that both RAW264.7 and oxidized low density lipoprotein (ox-LDL)-stimulated RAW264.7 cells could significantly uptake CMSN@SRT@Anti. Conversely, little fluorescence signal could be observed in CMSN@SRT group, showing the excellent targeting ability of CMSN@SRT@Anti to Class II scavenger receptor, CD36 on macrophage. Additionally, such fluorescence signal was significantly stronger in ox-LDL-stimulated RAW264.7 cells, which might benefit from the upregulated expression of CD36 on macrophages after ox-LDL treatment. For another, compared with free SRT1720, CMSN@SRT@Anti had a better and more significant effect on the inhibition of macrophage foaming process, which indicated that drug-carrying mesoporous silicon with targeting ability could enhance the efficacy of SRT1720. Animal experimental results showed that after the abdominal injection of CMSN@SRT@Anti, the aortic lesions of ApoE-/-mice could be observed with obvious and persistent fluorescence signals. After 4 weeks post-treatment, the serum total cholesterol, aortic plaque status and area were significantly improved in the mouse, and the effect was better than that in the free SRT1720 group or the CMSN@SRT group. CONCLUSIONS: The designed CMSN@SRT@Anti with excellent biocompatibility, high-performance and superior atherosclerosis-targeting ability has great potential for accurate identification and targeted therapy of atherosclerotic diseases.

Detection of Soluble Mercury in Cinnabar Using a CV-Ag NPs SERS Probe.

In the current work a uniform morphological Ag nanoparticles (Ag NPs) were prepared with ascorbic acid as a reducing agent and citrate as a stabilizer. The surface of Ag NPs modified by crystal violet (CV) and potassium iodide (KI) was used as an aggregation agent to obtain CV modified Ag NPs (CV-Ag NPs) probes for detecting mercury ions. The mercury ions could be reduced to mercury molecules by citrate, and then deposited on the surface of Ag NPs, leading to the separation of CV molecules from the surface of Ag NPs. Therefore, the SERS signal intensity of CV decreased with the increase of the Hg2+ concentration and the concentration of Hg2+ was in the range of 1 × 10-11 to 1 × 10-5 M. Taking the change of the characteristic peak intensity of CV at 913 cm-1 as a reference, the SERS spectrum intensity of CV has a linear relationship with the Hg2+ concentration. The equation is y = -333.55x + 1343.05, where the linear correlation coefficient is R2 = 0.980, and the recovery rate is between 84.20 to 105.60%. Finally, the CV-Ag NPs probe was used to quickly detect soluble mercury in cinnabar. Compared with the conventional large-scale instrument detection method, this simple and fast method, can be applied for rapid detection of soluble mercury, and has a certain significance for concerning the research of mineral medicine processing mechanism.

The Opportunities and Challenges of Silica Nanomaterial for Atherosclerosis.

Atherosclerosis (AS) as the leading cause of cardiovascular and cerebrovascular events has been paid much attention all the time. With the continuous development of modern medical drug treatment, surgical treatment, interventional treatment and other methods, the mortality rate of AS has shown a downward trend, while the morbidity rate is still increasing. Oral lipid-lowering or anti-inflammatory drugs are generally used for early AS, but the relatively low accumulation efficiency in lesions and the unavoidable side effects required researchers to develop more effective drug delivery approaches for the therapy of AS. Mesoporous silica nanoparticles as nanocarrier for drug delivery have received extensive attentions due to their flexible size, high specific surface area, controlled pore volume, high drug loading capacity and excellent biocompatibility. Series of good reviews about the mesoporous silica nanoparticles loaded drugs for cancer therapy have been well documented. However, their roles as nanocarrier for drug delivery to treat AS have few reports. In this review, the applications and challenges of mesoporous silica nanomaterials in the field of the diagnosis and therapy of AS have been summarized. The classification, synthesis, formation mechanism, surface modification and functionalization of mesoporous silica nanomaterials which were closely related to the theranostic effect of AS have also been included. Last but not the least, the future prospects' suggestions of mesoporous silica nanomaterial-based drug delivery system for AS are also provided.

Detection of Chlortetracycline Hydrochloride in Milk with a Solid SERS Substrate Based on Self-assembled Gold Nanobipyramids.

This paper described how a high-yield, monodisperse Au nanobipyramids (Au NBs) sol was prepared by a seed-mediated method, and gold nanoparticles were assembled on the surface of a silicon wafer by self-assembly technology to obtain a solid SERS substrate. Scanning electron microscopy (SEM) showed that the average length of Au NBs was 34.31 nm, and the analysis enhancement factor (AEF) was approximately 7.3 × 105 with rhodamine 6G (R6G) used as a probe. SERS detection of chlortetracycline hydrochloride (CCH) in milk was performed utilizing the prepared Au NBs substrate, and the limit of detection was 0.01 mg/mL. In the range of 0.01 - 1 mg/mL, the mass concentration of CCH and the SERS signal intensity satisfied the linear relationship y = 258.467x + 150.501; the value of the correlation coefficient was 0.9785. In addition, the recovery of spiked samples fluctuated between 96.80 to 111.38%. These results proved that the method is simple and fast, and it is promising to be applied to the field detection of antibiotics in milk.

Detection of Scopolamine Hydrobromide via Surface-enhanced Raman Spectroscopy.

Surface-enhanced Raman spectroscopy (SERS) was used to measure scopolamine hydrobromide. First, the Raman characteristic peaks of scopolamine hydrobromide were assigned, and the characteristic peaks were determined. The optimal aggregation agent was potassium iodide based on a comparative experimental study. Finally, the SERS spectrum of scopolamine hydrobromide was detected in aqueous solution, and the semi-quantitative analysis and the recovery rate were determined via a linear fitting. The detection limit of scopolamine hydrobromide in aqueous solution was 0.5 µg/mL. From 0 - 10 µg/mL, the curve of the intensity of the Raman characteristic peak of scopolamine hydrobromide at 1002 cm-1 is y = 4017.76 + 642.47x. The correlation coefficient was R2 = 0.983, the recovery was 98.5 - 109.7%, and the relative standard deviation (RSD) was about 5.5%. This method is fast, accurate, non-destructive and simple for the detection of scopolamine hydrobromide.