Imidazolium-Functionalized Conjugated Polymer for On-Site Visual and Ultrasensitive Detection of Toxic Hexavalent Chromium.

Hexavalent chromium [Cr(VI)] is considered a serious environmental pollutant that possesses a hazardous effect on humans even at low concentrations. Thus, the development of a bifunctional material for ultratrace-selective detection and effective elimination of Cr(VI) from the environment remains highly desirable and scarcely reported. In this work, we explore an imidazolium-appended polyfluorene derivative PF-DBT-Im as a highly sensitive/selective optical probe and a smart adsorbent for Cr(VI) ions with an ultralow detection limit of 1.77 nM and removal efficiency up to 93.7%. In an aqueous medium, PF-DBT-Im displays obvious transformation in its emission color from blue to magenta on exclusively introducing Cr(VI), facilitating naked-eye colorimetric detection. Consequently, a portable sensory device integrated with a smartphone is fabricated for realizing real-time and on-site visual detection of Cr(VI). Besides, the imidazolium groups attached onto side chains of PF-DBT-Im are found to be highly beneficial for achieving selective and efficient elimination of Cr(VI) with capacity as high as 128.71 mg g-1. More interestingly, PF-DBT-Im could be easily regenerated following treatment with KBr and can be recycled at least five times in a row. The main factor behind ultrasensitive response and excellent removal efficiency is found to be anion-exchange-induced formation of a unique ground-state complex between PF-DBT-Im and Cr(VI), as evident by FT-IR, XPS, and simulation studies. Thus, taking advantage of the excellent signal amplification property and rich ion-exchange sites, a dual-functional-conjugated polymer PF-DBT-Im is presented for the concurrent recognition and elimination of Cr(VI) ions proficiently and promptly with great prospects in environmental monitoring and water decontamination.

Retinopathy as a predictive indicator for significant hepatic fibrosis according to T2DM status: A cross-sectional study based on the national health and nutrition examination survey data.

INTRODUCTION AND OBJECTIVES: Type 2 Diabetes Mellitus (T2DM), a prevalent metabolic disorder, often coexists with a range of complications, with retinopathy being particularly common. Recent studies have shed light on a potential connection between diabetic retinopathy (DR) and hepatic fibrosis, indicating a possible shared pathophysiological foundation in T2DM. This study investigates the correlation between retinopathy and hepatic fibrosis among individuals with T2DM, as well as evaluates the diagnostic value of DR for significant hepatic fibrosis. MATERIALS AND METHODS: Our cross-sectional analysis incorporated 5413 participants from the National Health and Nutrition Examination Survey (NHANES) 2005-2008. The Fibrosis-4 score (FIB-4) classified hepatic fibrosis into different grades (F0-F4), with significant hepatic fibrosis marked as F2 or higher. Retinopathy severity was determined using retinal imaging and categorized into four levels. The analysis of variance or Chi-square tests facilitated group comparisons. Additionally, the receiver operating characteristic (ROC) analysis appraised the predictive accuracy of retinopathy for significant hepatic fibrosis in the T2DM population. RESULTS: Among 5413 participants, the mean age was 59.56 ± 12.41, with 50.2% male. And 20.6% were diagnosed with T2DM. Hepatic fibrosis grading was positively associated with retinopathy severity (OR [odds ratio]: 1.521, 95%CI [confidence interval]: 1.152-2.008, P = 0.003) across the entire population. The association was amplified in the T2DM population according to Pearson's analysis results. The ROC curve demonstrated retinopathy's diagnostic capacity for significant hepatic fibrosis in the T2DM population (AUC [area under curve] = 0.72, 95%CI: 0.651-0.793, P < 0.001). CONCLUSIONS: Retinopathy could serve as an independent predictor of significant hepatic fibrosis in T2DM population. Ophthalmologists are advised to closely monitor T2DM patients with retinopathy.

A Robust Switchable Oil-In-Water Emulsion Stabilized by Electrostatic Repulsions between Surfactant and Similarly Charged Carbon Dots.

How to control the stability of oil-in-water (O/W) emulsions is one of the main topics for scientists working in colloidal systems. Recently, carbon dots (CDs) have received great interest as smart materials because of their excellent physicochemical properties and versatile applications. Herein, for the first time, advanced and switchable O/W emulsions are presented that are stabilized by the synergistic effect of cationic surfactant cetyltrimethylammonium bromide CTAB (emulsifier) and similarly charged CDs (stabilizer). In the formulated emulsion, the cationic surfactant molecules are adsorbed at the oil and water interface to decrease the interfacial tension and enrich the drops with a positive charge to ensure intensive electrostatic repulsions among them. On the contrary, cationic CDs are distributed in the water phase among the droplets to reduce the water secretion and prevent flocculation and droplet coalescence. The stabilizing effect is found to be universal for emulsions of a range of oil phases. Furthermore, the formulated emulsion is found to be switchable between "stable" and "unstable" modes by adding an equivalent of anionic surfactant sodium dodecyl benzene sulphonate (SDBS). The stabilized and switchable O/W emulsions are believed to have wide practical applications in water purification, pharmaceuticals, protein recognition, as well as catalysis.

Phosphine-Catalyzed Stereoselective Ring-Opening Addition of Cyclopropenones with Nucleophiles.

A phosphine-catalyzed ring-opening addition reaction of cyclopropenones with a variety of nucleophiles (NuH), including oxygen-, nitrogen-, sulfur-, and carbon-based ones, has been investigated, which produces potentially useful α,ß-unsaturated carbonyl derivatives in high yields (up to 99%), high regioselectivity, and exclusive E-selectivity. The reaction proceeds in high efficiency under very mild conditions using only 1 mol % PPh3 as the catalyst at room temperature. The method is also amenable for the synthesis of deuterated alkenes when deuterated nucleophiles (NuD) are employed. The mechanism is investigated by experiments and DFT calculations, which suggests an α-ketenyl phosphorus ylide as a key intermediate in the catalytic cycle that captures the nucleophiles in a stereoselective manner.

Aggregation and Binding-Directed FRET Modulation of Conjugated Polymer Materials for Selective and Point-of-Care Monitoring of Serum Albumins.

Nonspecific interactions of conjugated polymers (CPs) with various proteins prove to be a major impediment for researchers when designing a suitable CP-based probe for the amplified and selective recognition of particular proteins in complex body fluids. Herein, a new strategy is presented for the precise and specific monitoring of clinically important serum albumin (SA) proteins at the nanomolar level using fluorescence resonance energy transfer (FRET)-modulated CP-surfactant ensembles as superior sensing materials. In brief, the newly designed color-tunable CP PF-DBT-Im undergoes intense aggregation with the surfactant sodium dodecyl sulfate (SDS), enabling drastic change in the emission color from violet to deep red due to intermolecular FRET. The emission of PF-DBT-Im/SDS ensembles then changed from deep red to magenta specifically on addition of SAs owing to the exclusive reverse FRET facilitated by synergistic effects of electrostatic interactions, hydrophobic forces, and the comparatively high intrinsic quantum yield of SAs. Interestingly, PF-DBT-Im itself could not differentiate SAs from other proteins, demonstrating the superiority of the PF-DBT-Im/SDS self-assembly over PF-DBT-Im. Finally, an affordable smartphone-integrated point-of-care (PoC) device is also fabricated as a proof-of-concept for the on-site and rapid monitoring of SAs, validating the potential of the system in long-term clinical applications.

Downregulation of exosomal miR-7-5p promotes breast cancer migration and invasion by targeting RYK and participating in the atypical WNT signalling pathway.

BACKGROUND: Current studies show that exosomal miRNAs become an important factor in cancer metastasis. Among the many miRNA studies, miR-7-5p has not been thoroughly investigated in breast cancer metastasis. METHODS: Bioinformatic screening was performed using extant data from the GEO database, and miR-7-5p expression levels in breast cancer cell lines and exosomes were further examined using real-time quantitative PCR (qRT-PCR). The extracted exosomes were characterised by transmission electron microscopy (TEM), particle size analysis and marker protein determination. Cell migration and invasion were then examined using wound healing assays and Transwell assays, respectively. Correlation between miR-7-5p and receptor-like tyrosine kinase (RYK) was analysed by luciferase reporter. The effect of miR-7-5p against RYK-related downstream factors was verified using western blot assays. RESULTS: In this study, we found that the expression of miR-7-5p was significantly different in exosomes secreted from breast cancer cell lines with different high and low invasiveness. Further experiments revealed that miR-7-5p has an important role in inhibiting the migration and invasion of breast cancer. In terms of mechanism of action, miR-7-5p was found to target the RYK, leading to its reduced expression, which in turn caused a reduction in the phosphorylation level of the downstream factor JNK. Reduced levels of phosphorylated JNK factors lead to reduced levels of phosphorylation of c-Jun protein, which in turn leads to increased expression of EMT transcription factors, thereby inhibiting the epithelial-mesenchymal transition (EMT) process to suppress the invasion of breast cancer. CONCLUSION: Thus, we demonstrated that exosomes loaded with high levels of miR-7-5p emitted from less aggressive breast cancers can participate in the atypical WNT pathway by targeting the RYK gene and thus inhibit breast cancer metastasis.

Conjugated polymer nanoparticles and their nanohybrids as smart photoluminescent and photoresponsive material for biosensing, imaging, and theranostics.

The emergence of conjugated polymers (CPs) has provided a pathway to attain smart multifunctional conjugated polymer nanoparticles (CPNs) with enhanced properties and diverse applications. CPNs based on π-extended CPs exhibit high fluorescence brightness, low cytotoxicity, excellent photostability, reactive oxygen species (ROS) generation ability, high photothermal conversion efficiency (PCE), etc. which endorse them as an excellent theranostic tool. Furthermore, the unique light-harvesting and energy transfer properties of CPNs enables their transformation into smart functional nanohybrids with augmented performance. Owing to such numerous features, simple preparation method and an easy separation process, the CPNs and their hybrids have been constantly rising as a frontrunner in the domain of medicine and much work has been done in the respective research area. This review summarizes the recent progress that has been made in the field of CPNs for biological and biomedical applications with special emphasis on biosensing, imaging, and theranostics. Following an introduction into the field, a first large section provides overview of the conventional as well as recently established synthetic methods for various types of CPNs. Then, the CPNs-based fluorometric assays for biomolecules based on different detection strategies have been described. Later on, examples of CPNs-based probes for imaging, both in vitro and in vivo using cancer cells and animal models have been explored. The next section highlighted the vital theranostic applications of CPNs and corresponding nanohybrids, mainly via imaging-guided photodynamic therapy (PDT), photothermal therapy (PTT) and drug delivery. The last section summarizes the current challenges and gives an outlook on the potential future trends on CPNs as advanced healthcare material.

Oridonin inhibits epithelial-mesenchymal transition of human nasopharyngeal carcinoma cells by negatively regulating AKT/STAT3 signaling pathway.

Oridonin, derived from Rabdosia rubescens, has exhibited anticancer activity in a variety of cancers. However, few studies have explored the effect of oridonin (ORI) on migration, invasion and epithelial-mesenchymal transition (EMT) in nasopharyngeal carcinoma. In our study, the results demonstrated that oridonin significantly inhibited migration and invasion of human nasopharyngeal carcinoma CNE-2Z and HNE-1 cell lines, as depicted by wound healing and Transwell assays. In addition, oridonin increased the expression of E-Cadherin while decreased the expressions of vimentin and twist1 at the mRNA and protein levels in a dose-dependent manner. Interestingly, oridonin also decreased cell mobility in nasopharyngeal carcinoma. The subsequent results of western blotting uncovered that the phosphorylation levels of AKT and signal transducer and activator of transcription 3 (STAT3) were decreased upon oridonin treatment. Furthermore, co-treatment with the AKT activator SC-79 attenuated the anti-metastatic effect of oridonin on nasopharyngeal carcinoma and partially abolished the high expression of E-cadherin and the low expression of twist1 mediated by oridonin. In conclusion, the results revealed that oridonin could repress metastatic phenotype and reverse epithelial-mesenchymal transition (EMT) in nasopharyngeal carcinoma by negatively regulating AKT/STAT3 signaling pathway, suggesting that AKT/STAT3 signaling may be the potential therapeutic target of oridonin against nasopharyngeal carcinoma.

Magnetic imprinted nanoparticles with synergistic tailoring of covalent and non-covalent interactions for purification and detection of procyanidin B2.

A synergistic imprinting strategy of covalent and non-covalent interactions is proposed to prepare magnetic molecularly imprinted polymers (DI-MMIPs) for highly selective separation of procyanidin B2 (PC) from grape seed samples. Dopamine and 3-amino-phenylboronic acid as cooperative functional monomers endow the imprinted sites with synergistic tailoring. Benefiting from the synergistic effect, the DI-MMIPs exhibit enhanced imprinting performance with high adsorption capacity (27.71 mg g-1), fast kinetic equilibrium time (within 30 min), outstanding selectivity (IF = 5.8, SC > 3.2), and satisfactory regeneration ability. In addition, the DI-MMIPs possess good magnetism, uniform morphology with typical core-shell structure, and stable crystallization. Furthermore, the established DI-MMIPs coupled with HPLC-UV (~ 280 nm) method has a wide linearity range of 0.05-200 µg mL-1 with correlation coefficient of 0.9997, high recoveries (> 93.1%) with RSDs from 2.9 to 5.5%, and low LOD (0.0008 µg mL-1). Consequently, this work provides an effective and easily tailored way to fabricate magnetic imprinted nanomaterials with both rapid recognition rate and high selectivity and thus holds great promise to realize the extraction and detection of PC from real samples.

Porous γ-Fe2O3 spheres coated with N-doped carbon from polydopamine as Li-ion battery anode materials.

Nitrogen doping has been demonstrated to play a crucial role in controlling the electronic properties of carbon-based composites. In this paper, nitrogen-doped carbon coated γ-Fe2O3 (NC@γ-Fe2O3) composite was successfully fabricated through a facile and high-yield strategy, including a hydrothermal reaction process for porous γ-Fe2O3 and a subsequent coating of nitrogen-doped carbon by using dopamine as precursor. The resulting composite combines the superior properties of porous Fe2O3 and heteroatom-doped conductive carbon layer derived from polydopamine. When used as the anode material of the lithium-ion battery, the as-prepared NC@γ-Fe2O3 composite exhibits excellent lithium storage properties in terms of high capacity, stable cycling performance (869.6 mAh g(-1) at the current density of 0.5 A g(-1) after 150 cycles) and excellent rate capability.

Preparation and application of magnetic molecularly imprinted nanoparticles for the selective extraction of osthole in Libanotis Buchtomensis herbal extract.

In this work, novel magnetic molecularly imprinted polymers were prepared for the selective extraction of osthole from Libanotis Buchtomensis herbal extract. During the synthesis process, double bonds grafted on the surface of Fe3 O4 nanoparticles could not only drive the temple molecules to locate onto the surface of vinyl-functionalized magnetic nanoparticles by π-π conjugation, which makes the distribution of binding sites ordered, but also direct the occurrence of imprinting polymerization at the surface of magnetic nanoparticles by the copolymerization of vinyl terminal groups with functional monomers and cross-linking agent. The characteristics of the resulting polymers were evaluated by transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and vibrating sample magnetometry. Adsorption kinetics, isotherms, selectivity, reproducibility, and reusability were discussed, which suggest that the obtained nanomaterials possess rapid binding kinetics, high adsorption capacity of 17.65 mg/g, and favorable selectivity for the target molecule. Satisfactory reproducibility and reusability were verified as well. Meanwhile, the resultant imprinted nanoparticles were successfully applied to selectively separate osthole from the herbal extract, which show great potential in extracting active ingredients from traditional Chinese medicine.

Selective adsorption of protein by a high-efficiency Cu(2+) -cooperated magnetic imprinted nanomaterial.

We report a core-shell magnetic molecularly imprinted polymer with high affinity through a facile sol-gel method for the selective adsorption of bovine hemoglobin from real bovine blood. Copper ions grafted on the surface of the matrix could immobilize template protein through chelation, which greatly enhances the orderliness of imprinted cavities and affinity of polymers. The obtained products exhibit a desired level of magnetic susceptibility, resulting in the highly efficient adsorption process. The results of adsorption experiments show that the saturation adsorption capacity of imprinted products could reach 116.3 mg/g within 30 min. Meanwhile, the specific binding experiment demonstrates the high selectivity of polymers for bovine hemoglobin. Furthermore, satisfactory reusability is demonstrated by ten adsorption-desorption cycles with no obvious deterioration in binding capacity. Electrophoretic analysis suggests the polymer could be used successfully in separation and enrichment of bovine hemoglobin from the bovine blood sample, which exhibits potential application in pretreatment of proteomics.

Preparation of magnetic glycoprotein-imprinted nanoparticles with dendritic polyethyleneimine as a monomer for the specific recognition of ovalbumin from egg white.

Glycoproteins are crucial in massive physiological events and clinical application. It is necessary to prepare new materials to isolate the specific glycoprotein. New and simple core-shell molecularly imprinted polymers were prepared by surface imprinting. The polymers are synthesized with magnetic nanoparticles as the core, water-soluble dendritic polyethyleneimine as the monomer and the ovalbumin as the template. The prepared imprinted polymers showed thin imprinted shell, biocompatibility and superparamagnetic properties. The resultant materials exhibited fast kinetics, high adsorption capacity, perfect selectivity and reusability. More important, they can absorb the template glycoprotein from the neutral solution and successfully be applied to recognize the ovalbumin from egg white, which means that they can provide an alternate method to isolate glycoprotein from bodily fluids.

Selective extraction of gallic acid in pomegranate rind using surface imprinting polymers over magnetic carbon nanotubes.

A novel surface imprinting polymer based on magnetic carbon nanotubes was prepared using dendritic polyethyleneimine as functional monomer to amplify the number of imprinted cavities. The characteristics of resulting polymers were evaluated by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM). Results suggest that magnetic nanoparticles are deposited onto the surface of multiwalled carbon nanotubes and the imprinted shell is coated on the surface of magnetic carbon nanotubes with a thickness of approximately 8 nm. Magnetic imprinted polymers are sensitive to magnetic fields and can be easily separated within 3 s using an external magnet. The adsorption results indicate that the obtained imprinted polymers have fast kinetics, an ultrahigh adsorption capacity of 479.9 mg g(-1), and satisfactory selectivity towards the template molecule. The prepared materials have excellent stability with no obvious deterioration after six adsorption-regeneration cycles. In addition, a method for determination of gallic acid (GA) in pomegranate rind was developed, using a combination of the prepared polymers used as solid-phase extraction (SPE) sorbents and high-performance liquid chromatography (HPLC) for rapid isolation and determination of GA. The limit of detection of the proposed method is 0.001 µg mL(-1), and the intra and inter-day relative standard deviations (RSDs) are lower than 3.8% and 5.3%, respectively. The recoveries of GA from pomegranate rind extract are in the range 98.2-103.6% with RSDs lower than 4.3%.

Synthesis of magnetic dual-template molecularly imprinted nanoparticles for the specific removal of two high-abundance proteins simultaneously in blood plasma.

Novel core-shell dual-template molecularly imprinted superparamagnetic nanoparticles were synthesized using bovine hemoglobin and bovine serum albumin as the templates for the efficient depletion of these two high-abundance proteins from blood plasma for the first time. The preparation process combined surface imprinting technique and a two-step immobilized template strategy. The obtained polymers were fully characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. The results showed that the as-synthesized nanomaterials possessed homogeneous and thin imprinted shells with a thickness of about 5 nm, stable crystalline phase, and superparamagnetism. The binding performance of the imprinted polymers was investigated through a series of adsorption experiments, which indicated that the products had satisfactory recognition ability for bovine hemoglobin and bovine serum albumin. The resultant nanoparticles were also successfully applied to simultaneously selective removal of two proteins from a real bovine blood sample.

One-step preparation of magnetic imprinted nanoparticles adopting dopamine-cupric ion as a co-monomer for the specific recognition of bovine hemoglobin.

A novel magnetic core-shell polydopamine-cupric ion complex imprinted polymer was prepared in one-step through surface imprinting technology, which could specifically recognize bovine hemoglobin from the real blood samples. The polymerization conditions and adsorption performance of the resultant nanomaterials were investigated in detail. The results showed that the cupric ion played an important role in the recognition of template proteins. The saturating adsorption capacity of this kind of imprinted polymers was 2.23 times greater than those of imprinted polymers without cupric ion. The imprinting factor of the imprinted materials was as high as 4.23 for the template molecule. The selective separation bovine hemoglobin from the real blood sample is successfully applied. In addition, the prepared materials had excellent stability and no obvious deterioration after five adsorption-regeneration cycles. Easy preparation, rapid separation, high binding capacity and satisfactory selectivity for the template protein make this polymer attractive in the separation of high-abundance proteins.

Actinoplanes lutulentus sp. nov., isolated from mucky soil in China.

A novel actinomycete, designated strain NEAU-GRX6T, was isolated from mucky soil collected from a stream of Jinlong Mountain in Harbin, Heilongjiang Province, north China, and characterized using a polyphasic approach. The isolate formed irregular sporangia containing motile sporangiospores on the substrate mycelium. The whole-cell sugars were xylose, glucose and galactose. The predominant menaquinones were MK-9(H6), MK-10(H4) and MK-9(H4). The major fatty acids were C16:0, C15:0, C18:1ω9c, C17:1ω7c and C18:0. The phospholipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol. The DNA G+C content was 67 mol%. 16S rRNA gene sequence similarity studies showed that strain NEAU-GRX6T belonged to the genus Actinoplanes, being most closely related to Actinoplanes palleronii IFO 14916T (97.80% similarity) and Actinoplanes missouriensis NBRC 102363T (97.76%). However, the low observed levels of DNA-DNA relatedness allowed the isolate to be differentiated from the above-mentioned species of the genus Actinoplanes. Moreover, strain NEAU-GRX6T could also be distinguished from A. palleronii IFO 14916T and A. missouriensis NBRC 102363T by phenotypic characteristics. Therefore, it is proposed that strain NEAU-GRX6T represents a novel species of the genus Actinoplanes, for which the name Actinoplanes lutulentus sp. nov. is proposed. The type strain is strain NEAU-GRX6T (=CGMCC 4.7090T=DSM 45883T).

Micromonospora jinlongensis sp. nov., isolated from muddy soil in China and emended description of the genus Micromonospora.

A novel actinomycete, designated strain NEAU-GRX11(T), was isolated from muddy soil collected from a stream of Jinlong Mountain in Harbin, north China. The organism was found to have morphological and chemotaxonomic characteristics typical of the genus Micromonospora. The 16S rRNA gene sequence of strain NEAU-GRX11(T) showed highest similarity to Micromonospora zamorensis CR38(T) (99.2 %), Micromonospora saelicesensis Lupac 09(T) (99.0 %), Micromonospora chokoriensis 2-19/6(T) (98.7 %), Micromonospora coxensis 2-30-b/28(T) (98.5 %), Micromonospora aurantiaca ATCC 27029(T) (98.4 %) and Micromonospora lupini lupac 14N(T) (98.3 %). Phylogenetic analysis based on the 16S rRNA gene and gyrB gene demonstrated that strain NEAU-GRX11(T) was a member of the genus Micromonospora and supported the closest phylogenetic relationship to M. zamorensis CR38(T), M. saelicesensis Lupac 09(T), M. chokoriensis 2-19/6(T) and M. lupini lupac 14N(T). A combination of DNA-DNA hybridization and some phenotypic characteristics indicated that the novel strain could be readily distinguished from these closest phylogenetic relatives. Therefore, it is proposed that NEAU-GRX11(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora jinlongensis sp. nov. is proposed. The type strain is NEAU-GRX11(T) (=CGMCC 4.7103(T)=DSM 45876(T)).

Micromonospora maoerensis sp. nov., isolated from a Chinese pine forest soil.

A novel actinomycete, designated strain NEAU-MES19(T), was isolated from pine forest soil in Heilongjiang province, China. A polyphasic study was carried out to establish the taxonomic position of this strain. The organism was found to have morphological and chemotaxonomic characteristics typical of the genus Micromonospora. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain NEAU-MES19(T) was most closely related to Micromonospora matsumotoense IMSNU 22003(T). However, phylogenetic analysis based on the gyrB gene sequence showed that the isolate was more closely related to Micromonospora cremea CR30(T) than M. matsumotoense IMSNU 22003(T). The low level of DNA-DNA relatedness allowed the isolate to be differentiated from M. matsumotoense IMSNU 22003(T) and M. cremea CR30(T). Moreover, strain NEAU-MES19(T) could also be distinguished from its closest phylogenetic relatives by morphological, physiological and biochemical characteristics. Therefore, it is proposed that strain NEAU-MES19(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora maoerensis sp. nov. is proposed. The type strain is NEAU-MES19(T) (=CGMCC 4.7091(T) = DSM 45884(T)).

LEP Gene Promotes Milk Fat Synthesis via the JAK2-STAT3 and mTOR Signaling Pathways in Buffalo Mammary Epithelial Cells.

Leptin (LEP), a protein hormone well-known for its role in metabolic regulation, has recently been linked to lipid metabolism in cattle. However, its function in buffalo mammary glands remains unclear. To address this issue, we isolated and identified the LEP gene and conducted experiments to investigate its function in buffalo mammary epithelial cells (BuMECs). In this study, two transcript variants of LEP, designated as LEP_X1 and LEP_X2, were identified. The coding sequences (CDS) of LEP_X1 and LEP_X2 are 504 bp and 579 bp in length, encoding 167 and 192 amino acid residues, respectively. Bioinformatics analysis revealed that LEP_X2 is a hydrophobic protein with an isoelectric point below 7 and contains a signal peptide, while LEP_X1 is hydrophilic and lacks a signal peptide. Our study found that LEP gene expression in lactating BuMECs was significantly higher than in non-lactating cells, with LEP_X2 expression remarkably higher than LEP_X1 in lactating BuMECs. Overexpression of both LEP_X1 and LEP_X2 significantly promoted the expression of genes related to milk fat synthesis in lactating BuMECs, including STAT3, PI3K, mTOR, SCD, and SREBF1, accompanied by an increase in cellular triglycerides (TG). Interestingly, LEP_X2 overexpression significantly suppressed LEP_X1 expression while increasing intracellular TG concentration by 12.10-fold compared to LEP_X1 overexpression, suggesting an antagonistic relationship between the two variants and supposing LEP_X2 plays a dominant role in milk fat synthesis in lactating BuMECs. Additionally, four nucleotide substitutions were identified in the buffalo LEP CDS, including a nonsynonymous substitution c.148C>T (p.Arg50Cys), which was predicted to decrease the stability of the LEP protein without affecting its function. These results collectively underscore the significant role of LEP in milk fat synthesis and can provide a basis for molecular breeding strategies of buffalo.