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1.
J Am Chem Soc ; 146(4): 2445-2451, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38230586

RESUMO

Spontaneous generation of H2O2 in sub-10 µm-sized water microdroplets has received increasing interest since its first discovery in 2019. On the other hand, due to the short lifetime of these microdroplets (rapid evaporation) and lack of suitable tools to real-time monitor the generation of H2O2 in individual microdroplets, such a seemingly thermodynamically unfavorable process has also raised vigorous debates on the origin of H2O2 and the underlying mechanism. Herein, we prepared water microdroplets with a long lifetime (>1 h) by virtue of microwell confinement and dynamically monitored the spontaneous generation of H2O2 in individual microdroplets via time-lapsed fluorescence imaging. It was unveiled that H2O2 was continuously generated in the as-prepared water microdroplets and an apparent equilibrium concentration of ∼3 µM of H2O2 in the presence of a H2O2-consuming reaction can be obtained. Through engineering the geometry of these microdroplets, we further revealed that the generation rates of H2O2 in individual microdroplets were positively proportional to their surface-to-volume ratios. This also allowed us to extract a maximal H2O2 generation rate of 7.7 nmol m-2 min-1 in the presence of a H2O2-consuming reaction and derive the corresponding probability of spontaneous conversion of interfacial H2O into H2O2 for the first time, that is, ∼1 of 65,000 water molecules in 1 s. These findings delivered strong evidence that the spontaneous generation of H2O2 indeed occurs at the surface of microdroplets and provided us with an important starting point to further enhance the yield of H2O2 in water microdroplets for future applications.

2.
Development ; 148(7)2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33674260

RESUMO

Mitochondria play a crucial role in spermatogenesis and are regulated by several mitochondrial fusion proteins. However, their functional importance associated with their structure formation and mRNA fate regulation during spermatogenesis remains unclear. Here, we show that mitofusin 2 (MFN2), a mitochondrial fusion protein, interacts with nuage-associated proteins (including MIWI, DDX4, TDRKH and GASZ) in mice. Conditional mutation of Mfn2 in postnatal germ cells results in male sterility due to germ cell developmental defects. Moreover, MFN2 interacts with MFN1, another mitochondrial fusion protein with a high-sequence similarity to MFN2, in testes to facilitate spermatogenesis. Simultaneous mutation of Mfn1 and Mfn2 in testes causes very severe infertile phenotypes. Importantly, we show that MFN2 is enriched in polysome fractions of testes and interacts with MSY2, a germ cell-specific DNA/RNA-binding protein, to control gamete-specific mRNA (such as Spata19) translational activity during spermatogenesis. Collectively, our findings demonstrate that MFN2 interacts with nuage-associated proteins and MSY2 to regulate male germ cell development by controlling several gamete-specific mRNA fates.


Assuntos
Diferenciação Celular/fisiologia , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Células Germinativas/metabolismo , RNA Mensageiro/metabolismo , Espermatogênese/genética , Espermatogênese/fisiologia , Animais , Proteínas Argonautas , RNA Helicases DEAD-box , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fertilidade , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Inativação de Genes , Células Germinativas/patologia , Células HEK293 , Humanos , Infertilidade Masculina/genética , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Mitocôndrias/metabolismo , Dinâmica Mitocondrial , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Mutação , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Testículo/metabolismo , Testículo/patologia
3.
Small ; 20(16): e2307366, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38039446

RESUMO

Restoring immune tolerance is the ultimate goal for rheumatoid arthritis (RA) treatment. The most reported oral or intravenous injection routes for the immunization of autoantigens cause gastrointestinal side effects, low patient compliance, and unsatisfied immune tolerance induction. Herein, the use of a transdermal microneedle patch is for the first time investigated to codeliver CII peptide autoantigen and rapamycin for reversing immune disorders of RA. The immunized microneedles efficiently recruit antigen-presenting cells particularly Langerhans cells, and induce tolerogenic dendritic cells at the administration skin site. The tolerogenic dendritic cells further homing to lymph nodes to activate systemic Treg cell differentiation, which upregulates the expression of anti-inflammatory mediators while inhibiting the polarization of Th1/2 and Th17 T cell phenotypes and the expression of inflammatory profiles. As a result, the optimized microneedles nearly completely eliminate RA symptoms and inflammatory infiltrations. Furthermore, it is demonstrated that a low dose of rapamycin is crucial for the successful induction of immune tolerance. The results indicate that a rationally designed microneedle patch is a promising strategy for immune balance restoration with increased immune tolerance induction efficiency and patient compliance.


Assuntos
Artrite Reumatoide , Células de Langerhans , Humanos , Células Th17 , Artrite Reumatoide/terapia , Tolerância Imunológica , Sirolimo/farmacologia
4.
Opt Express ; 32(4): 6190-6203, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38439328

RESUMO

In order to broaden the sensing bandwidth of surface plasmon resonance (SPR) sensors, we propose and demonstrate a dual-channel SPR fiber optic sensor with wide bandwidth. The sensor is fabricated using no-core fiber (NCF), in which the film consists of a silver film and a ZnO film. The sensing characteristics are investigated by simulation and experiment. The resonance wavelength range of the SPR sensor can be significantly tuned by varying the thickness of the ZnO film. In the experiments, a dual-channel SPR sensor that can be used for simultaneous detection of temperature and refractive index was realized by cascading ZnO/Ag film with Ag film. The experimental results show that the two sensing channels are independent without crosstalk. The sensitivity of this sensor is 3512 nm/RIU in the range of 1.333 ∼ 1.385 and 4.6 nm/°C in the range of 0 ∼ 60 °C, which is better than most of the current dual-channel SPR sensors. In addition, the experimental results show that this sensor has good stability in use. The sensor proposed in this work has the advantages of a wide operating wavelength range, simple and compact structure, and high sensitivity. It has a broad application prospect in the simultaneous measurement of refractive index and temperature of liquids.

5.
Opt Lett ; 49(4): 907-910, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38359213

RESUMO

A mirrored transformation optics (MTO) approach is presented to overcome the material mismatch in transformation optics. It makes good use of the reflection behavior and introduces a mirrored medium to offset the phase discontinuities. Using this approach, a high-performance planar focusing lens of transmission type is designed, which has a larger concentration ratio than the other focusing lens obtained by the generalized Snell's law. The MTO will not change any functionality of the original lens and has promising potential applications in imaging and light energy harvesting.

6.
FASEB J ; 37(5): e22908, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37039784

RESUMO

Peroxisomal fatty acyl-CoA reductase 1 (FAR1) is a rate-limiting enzyme for ether lipid (EL) synthesis. Gene mutations in FAR1 cause a rare human disease. Furthermore, altered EL homeostasis has also been associated with various prevalent human diseases. Despite their importance in human health, the exact cellular functions of FAR1 and EL are not well-understood. Here, we report the generation and initial characterization of the first Far1 knockout (KO) mouse model. Far1 KO mice were subviable and displayed growth retardation. The adult KO male mice had smaller testes and were infertile. H&E and immunofluorescent staining showed fewer germ cells in seminiferous tubules. Round spermatids were present but no elongated spermatids or spermatozoa were observed, suggesting a spermatogenesis arrest at this stage. Large multi-nucleated giant cells (MGC) were found lining the lumen of seminiferous tubules with many of them undergoing apoptosis. The immunofluorescent signal of TEX14, an essential component of intercellular bridges (ICB) between developing germ cells, was greatly reduced and mislocalized in KO testis, suggesting the disrupted ICBs as an underlying cause of MGC formation. Integrative analysis of our total testis RNA-sequencing results and published single-cell RNA-sequencing data unveiled cell type-specific molecular alterations underlying the spermatogenesis arrest. Many genes essential for late germ cell development showed dramatic downregulation, whereas genes essential for extracellular matrix dynamics and cell-cell interactions were among the most upregulated genes. Together, this work identified the cell type-specific requirement of ELs in spermatogenesis and suggested a critical role of Far1/ELs in the formation/maintenance of ICB during meiosis.


Assuntos
Azoospermia , Éter , Camundongos , Animais , Masculino , Humanos , Camundongos Knockout , Espermatogênese/genética , Espermátides , Éteres , Etil-Éteres , Lipídeos , RNA , Fatores de Transcrição/genética
7.
Langmuir ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38990556

RESUMO

Encapsulation technology is well established for entrapping active ingredients within an outer shell for their protection and controlled release. However, many solutions employed industrially use nondegradable cross-linked synthetic polymers for shell formation. To curb rising microplastic pollution, regulatory policies are forcing industries to substitute the use of such intentionally added microplastics with environmentally friendly alternatives. This work demonstrates a one-pot process to make microplastic-free microcapsules using supramolecular self-assembly of bis-ureas. Molecular bis-urea species generated in-situ spontaneously self-assemble at the interface of an oil-in-water emulsion via hydrogen bonding to form a shell held together by noncovalent bonds. In addition, Laponite nanodiscs were introduced in the formulation to restrict aggregation observed during the self-assembly and to reduce the porosity of the shell, leading to well-dispersed microcapsules (mean Sauter diameter d [3,2] ∼ 5 µm) with high encapsulation efficiency (∼99%). Accelerated release tests revealed an increase in characteristic release time of the active by more than an order of magnitude after encapsulation. The mechanical strength parameters of these capsules were comparable to some of the commercial, nondegradable melamine-formaldehyde microcapsules. With mild operating conditions in an aqueous environment, this technology has real potential to offer an industrially viable method for producing microplastic-free microcapsules.

8.
Genesis ; 61(3-4): e23512, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37058328

RESUMO

Mouse sperm-associated antigen 6 like (SPAG6L) is an axoneme central apparatus protein, essential for the normal function of the ependymal cell and lung cilia, and sperm flagella. Accumulated evidence has disclosed multiple biological functions of SPAG6L, including ciliary/flagellar biogenesis and polarization, neurogenesis, and neuronal migration. Conventional Spag6l knockout mice died of hydrocephalus, which impedes further investigation of the function of the gene in vivo. To overcome the limitation of the short lifespan of conventional knockout mice, we developed a conditional allele by inserting two loxP sites in the genome flanking exon 3 of the Spag6l gene. By crossing the floxed Spag6l mice to a Hrpt-Cre line which expresses Cre recombinase ubiquitously in vivo, mutant mice that are missing SPAG6L globally were obtained. Homozygous mutant Spag6l mice showed normal appearance within the first week after birth, but reduced body size was observed after 1 week, and all developed hydrocephalus and died within 4 weeks of age. The phenotype mirrored that of the conventional Spag6l knockout mice. The newly established floxed Spag6l model provides a powerful tool to further investigate the role of the Spag6l gene in individual cell types and tissues.


Assuntos
Hidrocefalia , Animais , Camundongos , Hidrocefalia/genética , Integrases/genética , Camundongos Knockout
9.
Dev Biol ; 485: 50-60, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35257720

RESUMO

Sperm flagella formation is a complex process that requires cargo transport systems to deliver structural proteins for sperm flagella assembly. Two cargo transport systems, the intramanchette transport (IMT) and intraflagellar transport (IFT), have been shown to play critical roles in spermatogenesis and sperm flagella formation. IMT exists only in elongating spermatids, while IFT is responsible for delivering cargo proteins in the developing cilia/flagella. Our laboratory discovered that mouse meiosis expressed gene 1 (MEIG1), a gene essential for sperm flagella formation, is present in the manchette of elongating spermatids. IFT complex components, IFT20 and IFT88, are also present in the manchette of the elongating spermatids. Given that the three proteins have the same localization in elongating spermatids and are essential for normal spermatogenesis and sperm flagella formation, we hypothesize that they are in the same complex, which is supported by co-immunoprecipitation assay using mouse testis extracts. In the Meig1 knockout mice, neither IFT20 nor IFT88 was present in the manchette in the elongating spermatids even though their localizations were normal in spermatocytes and round spermatids. However, MEIG1 was still present in the manchette in elongating spermatids of the conditional Ift20 knockout mice. In the sucrose gradient assay, both IFT20 and IFT88 proteins drifted from higher density fractions to lighter ones in the Meig1 knockout mice. MEIG1 distribution was not changed in the conditional Ift20 knockout mice. Finally, testicular IFT20 and IFT88 protein and mRNA levels were significantly reduced in Meig1 knockout mice. Our data suggests that MEIG1 is a key protein in determining the manchette localization of certain IFT components, including IFT20 and IFT88, in male germ cells.


Assuntos
Espermátides , Espermatogênese , Proteínas Supressoras de Tumor/metabolismo , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/metabolismo , Masculino , Meiose , Camundongos , Camundongos Knockout , Proteínas Nucleares/metabolismo , Fosfoproteínas/genética , Proteínas/metabolismo , Cauda do Espermatozoide/metabolismo , Espermátides/metabolismo , Espermatócitos , Espermatogênese/genética
10.
Proteins ; 91(4): 555-566, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36444670

RESUMO

Interactions between the meiosis-expressed gene 1 (MEIG1) and Parkin co-regulated gene (PACRG) protein are critical in the formation of mature sperm cells. Targeting either MEIG1 or PACRG protein could be a contraceptive strategy. The W50A and Y68A mutations on MEIG1 are known to interrupt the MEIG1-PACRG interactions resulting in defective sperm cells. However, the details about how the mutants disrupt the protein-protein binding are not clear. In this study, we reveal insights on MEIG1 and PACRG protein dynamics by applying Gaussian-accelerated molecular dynamics (GaMD) simulations and post-GaMD analysis. Our results show that the mutations destabilize the protein-protein interfacial interaction. The effect of the Y68A mutation is more significant than W50A as Y68 forms stronger polar interactions with PACRG. Because both human and mouse models demonstrate similar dynamic properties, the findings from mouse proteins can be applied to the human system. Moreover, we report a potential ligand binding pocket on the MEIG1 and PACRG interaction surface that could be a target for future drug design to inhibit the MEIG1-PACRG interaction. PACRG shows more qualified pockets along the protein-protein interface, implying that it is a better target than MEIG1. Our work provides a fundamental understanding of MEIG1 and PACRG protein dynamics, paving the way for drug discovery in male-based contraception.


Assuntos
Chaperonas Moleculares , Simulação de Dinâmica Molecular , Camundongos , Animais , Masculino , Humanos , Chaperonas Moleculares/genética , Sêmen/metabolismo , Ubiquitina-Proteína Ligases/genética , Meiose , Proteínas dos Microfilamentos/genética , Proteínas Nucleares/genética , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Proteínas de Ciclo Celular/metabolismo
11.
Langmuir ; 39(40): 14451-14458, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37773886

RESUMO

Polyamines have emerged as a promising class of CO2 absorbents due to their remarkable sequestration capacity. However, their potential industrial application as aqueous absorbents is significantly hindered by a low regeneration efficiency and high energy consumption. To address these issues, this study investigates the use of triethylenetetramine (TETA) and ethylene glycol (EG) to develop a nonaqueous absorbent. The incorporation of EG enhances absorption performance and reduces the regeneration energy needed for TETA, whereas the high viscosity of the absorbent impedes absorption rate, amine efficiency, and regeneration efficiency. In order to enhance CO2 capture, micron-sized reaction units (SiO2@TETA-EG) were developed by encapsulating TETA solution with nanosilica. The SiO2@TETA-EG composite exhibits a large specific surface area (99 m2/g), with a porous shell structure and improved fluidity, which effectively counteracts the negative effects caused by high viscosity. Notably, SiO2@TETA-EG indicates a noticeably higher apparent rate constant of 4.29 min-1 at 323.2 K compared to the TETA-EG solution. Furthermore, SiO2@TETA-EG displays a 28.4% boost in regeneration efficiency while maintaining favorable stability in pore size and shape after regeneration.

12.
Org Biomol Chem ; 21(31): 6410-6418, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37505192

RESUMO

Expensive rhodium (Rh)-based catalysts have been widely used for the hydroformylation of propene. To find a cheaper and effective alternative to these Rh-based catalysts, herein, a series of phosphine ligands were used to coordinate with iridium, and their catalytic reactivities for the hydroformylation of propene were systematically investigated in this study. The effects of different phosphine ligands, pressures, temperatures, and catalyst dosages on the hydroformylation of propene were investigated. Tripyridyl phosphine iridium Ir2(cod)2Cl2-P(3-py)3 (Ir(I)-L5) and its derivatives exhibit the highest catalytic reactivity. Surprisingly, the catalytic reactivity of Ir(I)-L5 is higher than that of Rh2(cod)2Cl2-P(3-py)3 (Rh(I)-L5). When the Ir(I)-L5 complex is used as the catalyst, reactions performed in a polar solvent gave higher turnover number (TON) values than those in a non-polar solvent. Up to a TON of 503 can be obtained. Different n-butyraldehyde/iso-butyraldehyde (n/i) ratios can be obtained by adjusting the phosphine ligands or the proportion of gas pressure. The catalyst showed good reusability in five recycling experiments. Furthermore, based on DFT theoretical calculations, a probable reaction mechanism was proposed. It is reliable that an Ir-based catalyst can be considered as a highly effective catalyst for the hydroformylation of propylene with CO.

13.
Skin Res Technol ; 29(11): e13507, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38009042

RESUMO

BACKGROUND: The Stratum Corneum (SC) is the first barrier of the skin. The properties of individual cells are crucial in understanding how the SC at different anatomical regions maintains a healthy mechanical barrier. The aim of the current study is to present a comprehensive description of the maturation and mechanical properties of superficial corneocytes at different anatomical sites in the nominal dry state. MATERIALS AND METHODS: Corneocytes were collected from five anatomical sites: forearm, cheek, neck, sacrum and medial heel of 10 healthy young participants. The surface topography was analysed using Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). The level of positive-involucrin cornified envelopes (CEs) and desmoglein-1 (Dsg1) were used as indirect measures of immature CEs and corneodesmosomes, respectively. In addition, AFM nanoindentation and stress-relaxation experiments were performed to characterise the mechanical properties. RESULTS: Volar forearm, neck and sacrum corneocytes presented similar topographies (ridges and valleys) and levels of Dsg1 (13-37%). In contrast, cheek cells exhibited circular nano-objects, while medial heel cells were characterized by villi-like structures. Additionally, medial heel samples also showed the greatest level of immature CEs (32-56%, p < 0.001) and Dsg1 (59-78%, p < 0.001). A large degree of inter-subject variability was found for the Young's moduli of the cells (0.19-2.03 GPa), which was correlated with the level of immature CEs at the cheek, neck and sacrum (p < 0.05). CONCLUSION: It is concluded that a comprehensive study of the mechanical and maturation properties of corneocytes may be used to understand the barrier functions of the SC at different anatomical sites.


Assuntos
Epiderme , Pele , Humanos , Epiderme/química , Queratinócitos , Células Epidérmicas , Antebraço
14.
J Tissue Viability ; 32(2): 305-313, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36813598

RESUMO

INTRODUCTION: During the COVID-19 pandemic healthcare workers (HCWs) have used respiratory protective equipment for prolonged periods, which has been associated with detrimental effects on the underlying skin. The present study aims to evaluate changes in the main cells (corneocytes) of the stratum corneum (SC) following prolonged and consecutive use of respirators. METHODS: 17 HCWs who wore respirators daily during routine hospital practice were recruited to a longitudinal cohort study. Corneocytes were collected via tape stripping from a negative control site (area outside the respirator) and from the cheek which was in contact with the device. Corneocytes were sampled on three occasions and analysed for the level of positive-involucrin cornified envelopes (CEs) and the amount of desmoglein-1 (Dsg1), as indirect measurements of immature CEs and corneodesmosomes (CDs), respectively. These were compared to biophysical measurements (Transepidermal water loss, TEWL, and SC hydration) at the same investigation sites. RESULTS: A large degree of inter-subject variability was observed, with maximum coefficients of variation of 43% and 30% for the level of immature CEs and Dsg1, respectively. Although it was observed that there was not an effect of prolonged respirator usage on the properties of corneocytes, the level of CDs was greater at the cheek than the negative control site (p < 0.05). Furthermore, low levels of immature CEs correlated with greater TEWL values after prolonged respirator application (p < 0.01). It was also noted that a smaller proportion of immature CEs and CDs was associated with a reduced incidence of self-reported skin adverse reactions (p < 0.001). CONCLUSIONS: This is the first study that investigated changes in corneocyte properties in the context of prolonged mechanical loading following respirator application. Although differences were not recorded over time, the levels of CDs and immature CEs were consistently higher in the loaded cheek compared to the negative control site and were positively correlated with a greater number of self-reported skin adverse reactions. Further studies are required to evaluate the role of corneocyte characteristics in the evaluation of both healthy and damaged skin sites.


Assuntos
COVID-19 , Pandemias , Humanos , Estudos Longitudinais , COVID-19/prevenção & controle , Ventiladores Mecânicos , Atenção à Saúde
15.
Dev Biol ; 477: 164-176, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34023333

RESUMO

Intraflagellar transport (IFT) is an evolutionarily conserved mechanism essential for the assembly and maintenance of most eukaryotic cilia and flagella, including mammalian sperm tails. Depletion of IFT27, a component of the IFT complex, in male germ cells results in infertility associated with disrupted sperm flagella structure and motility. Leucine zipper transcription factor-like 1 (LZTFL1) is an IFT27 associated protein. LZTFL1, also known as BBS17, is a Bardet-Biedl syndrome (BBS) associated protein. Patients carrying biallelic variants of LZTFL1 gene exhibit the common BBS phenotypes. The global Lztfl1 knockout mice showed abnormal growth rate and retinal degeneration, typical of BBS phenotype. However, it is not clear if Lztfl1 has a role in male fertility. The LZTFL1 protein is highly and predominantly expressed in mouse testis. During the first wave of spermatogenesis, the protein is only expressed during spermiogenesis phase from the round spermatid stage and displays a cytoplasmic localization with a vesicular distribution pattern. At the elongated spermatid stage, LZTFL1 is present in the developing flagella and appears also close to the manchette. Fertility of Lztfl1 knockout mice was significantly reduced and associated with low sperm motility and a high level of abnormal sperm (astheno-teratozoospermia). In vitro assessment of fertility revealed reduced fertilization and embryonic development when using sperm from homozygous mutant mice. In addition, we observed a significant decrease of the testicular IFT27 protein level in Lztfl1 mutant mice contrasting with a stable expression levels of other IFT proteins, including IFT20, IFT81, IFT88 and IFT140. Overall, our results support strongly the important role of LZTFL1 in mouse spermatogenesis and male fertility.


Assuntos
Fertilidade/fisiologia , Espermatozoides/fisiologia , Fatores de Transcrição/fisiologia , Animais , Células CHO , Células COS , Chlorocebus aethiops , Cricetulus , Feminino , Fertilidade/genética , Células HEK293 , Humanos , Masculino , Camundongos Knockout , Ligação Proteica , RNA Mensageiro/metabolismo , Espermatogênese/genética , Espermatogênese/fisiologia , Fatores de Transcrição/genética , Proteínas rab de Ligação ao GTP/fisiologia
16.
J Biol Chem ; 297(5): 101312, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34673028

RESUMO

Mammalian spermatogenesis is a highly coordinated process that requires cooperation between specific proteins to coordinate diverse biological functions. For example, mouse Parkin coregulated gene (PACRG) recruits meiosis-expressed gene 1 (MEIG1) to the manchette during normal spermiogenesis. Here we mutated Y68 of MEIG1 using the CRISPR/cas9 system and examined the biological and physiological consequences in mice. All homozygous mutant males examined were completely infertile, and sperm count was dramatically reduced. The few developed sperm were immotile and displayed multiple abnormalities. Histological staining showed impaired spermiogenesis in these mutant mice. Immunofluorescent staining further revealed that this mutant MEIG1 was still present in the cell body of spermatocytes, but also that more MEIG1 accumulated in the acrosome region of round spermatids. The mutant MEIG1 and a cargo protein of the MEIG1/PACRG complex, sperm-associated antigen 16L (SPAG16L), were no longer found to be present in the manchette; however, localization of the PACRG component was not changed in the mutants. These findings demonstrate that Y68 of MEIG1 is a key amino acid required for PACRG to recruit MEIG1 to the manchette to transport cargo proteins during sperm flagella formation. Given that MEIG1 and PACRG are conserved in humans, small molecules that block MEIG1/PACRG interaction are likely ideal targets for the development of male contraconception drugs.


Assuntos
Acrossomo/metabolismo , Proteínas de Ciclo Celular/metabolismo , Mutação de Sentido Incorreto , Proteínas Nucleares/metabolismo , Fosfoproteínas/metabolismo , Espermatócitos/metabolismo , Substituição de Aminoácidos , Animais , Transporte Biológico Ativo/genética , Proteínas de Ciclo Celular/genética , Masculino , Camundongos , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Proteínas Nucleares/genética , Fosfoproteínas/genética
17.
Org Biomol Chem ; 20(16): 3413, 2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-35403655

RESUMO

Correction for 'Metal-free oxidative synthesis of benzimidazole compounds by dehydrogenative coupling of diamines and alcohols' by Jiaming Hu et al., Org. Biomol. Chem., 2022, DOI: 10.1039/d2ob00165a.

18.
Org Biomol Chem ; 20(14): 2852-2856, 2022 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-35297458

RESUMO

We report a novel metal-free synthesis of benzimidazole compounds by dehydrogenative coupling of diamines and alcohols. Using NHPI as a nonmetallic catalyst combined with molecular oxygen or air as the oxidant, this transformation represents a widely applicable protocol to N-heterocycles, such as benzimidazoles, benzothiophenes, benzooxazoles and quinazolines. Flow microreactors operating under optimized conditions enabled this reaction with higher efficiency, and the total residence time was 30 min compared with the batch bubbling reactor (10 h). Moreover, a possible reaction mechanism is proposed according to the control experiments.


Assuntos
Álcoois , Diaminas , Benzimidazóis , Metais , Estrutura Molecular , Estresse Oxidativo
19.
Molecules ; 27(21)2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36364038

RESUMO

Fast-moving consumer goods (FMCG) industry has long included many appealing essential oils in products to meet consumers' needs. Among all, the demand for limonene (LM) has recently surged due to its broad-spectrum health benefits, with applications in cosmetic, detergent, and food products. However, LM is extremely volatile, hence has often been encapsulated for a longer shelf-life. To date, mostly non-biodegradable synthetic polymers have been exploited to fabricate the microcapsule shells, and the resulting microcapsules contribute to the accumulation of microplastic in the environment. So far, information on LM-entrapping microcapsules with a natural microplastic-free shell and their mechanism of formation is limited, and there is lack of an in-depth characterisation of their mechanical and adhesive properties, which are crucial for understanding their potential performance at end-use applications. The present research aims towards developing safe microcapsules with a core of LM fabricated via complex coacervation (CC) using gum Arabic (GA) and fungally sourced chitosan (fCh) as shell precursors. The encapsulation efficiency (EE) for LM was quantified by gas chromatography (GC) separation method. The morphology of microcapsules was investigated via bright-field optical microscopy and scanning electron microscopy, and their mechanical properties were characterised using a micromanipulation technique. Moreover, the adhesive properties of the resulting microcapsules were studied via a bespoke microfluidic device fitted with a polyethylene-terephthalate (PET) substrate and operating at increasingly hydrodynamic shear stress (HSS). Spherical core-shell microcapsules (EE ~45%) with a mean size of 38 ± 2 µm and a relatively smooth surface were obtained. Their mean rupture force and nominal rupture stress were 0.9 ± 0.1 mN and 2.1 ± 0.2 MPa, respectively, which are comparable to those of other microcapsules with synthetic shells, e.g., urea- and melamine-formaldehyde. It was also found that the fCh-GA complexed shell provided promising adhesive properties onto PET films, leading to a microcapsule retention of ~85% and ~60% at low (≤50 mPa) and high shear stress (0.9 Pa), respectively. Interestingly, these values are similar to the adhesion data available in literature for microplastic-based microcapsules, such as melamine-formaldehyde (50-90%). Overall, these findings suggest that microplastics-free microcapsules with a core of oil have been successfully fabricated, and can offer a potential for more sustainable, consumer- and environmentally friendly applications in FMCGs.


Assuntos
Goma Arábica , Microplásticos , Cápsulas/química , Limoneno , Composição de Medicamentos/métodos , Goma Arábica/química , Formaldeído
20.
Am J Physiol Cell Physiol ; 320(1): C132-C141, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33175573

RESUMO

Spag6 encodes an axoneme central apparatus protein that is required for normal flagellar and cilia motility. Recent findings suggest that Spag6 also plays a role in ciliogenesis, orientation of cilia basal feet, and planar polarity. Sensory cells of the inner ear display unique structural features that underlie their mechanosensitivity. They represent a distinctive form of cellular polarity, known as planar cell polarity (PCP). However, a role for Spag6 in the inner ear has not yet been explored. In the present study, the function of Spag6 in the inner ear was examined using Spag6-deficient mice. Our results demonstrate hearing loss in the Spag6 mutants, associated with abnormalities in cellular patterning, cell shape, stereocilia bundles, and basal bodies, as well as abnormally distributed Frizzled class receptor 6 (FZD6), suggesting that Spag6 participates in PCP regulation. Moreover, we found that the subapical microtubule meshwork was disrupted. Our observations suggest new functions for Spag6 in hearing and PCP in the inner ear.


Assuntos
Polaridade Celular , Células Ciliadas Auditivas Internas/metabolismo , Perda Auditiva/metabolismo , Audição , Proteínas dos Microtúbulos/deficiência , Microtúbulos/metabolismo , Animais , Feminino , Receptores Frizzled/metabolismo , Células Ciliadas Auditivas Internas/ultraestrutura , Perda Auditiva/genética , Perda Auditiva/patologia , Perda Auditiva/fisiopatologia , Masculino , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas dos Microtúbulos/genética , Microtúbulos/ultraestrutura
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