Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective:To investigate the mechanism by which microRNA-183 (miR-183) regulates the progression of diabetic nephropathy (DN) through targeting phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and modulating the AKT signaling pathway, and to identify potential therapeutic targets for DN.Methods:(1) Bioinformatic analysis of miRNA expression: MiRNA expression datasets from diabetic nephropathy (DN) and control samples were obtained from the Gene Expression Omnibus database. Differential expression analysis was performed, and differentially expressed miRNAs (DEmiRNAs) were identified using thresholds of an absolute log 2 (fold changes) >1 and an adjusted P-value<0.05. The results were visualized in a volcano plot and a heatmap. (2) Animal model establishment and in vivo interventional studies: A DN rat model was induced by administration of a high-fat/high-sucrose diet combined with an intraperitoneal injection of streptozotocin. Rats were randomly assigned into four groups ( n=10 per group) using a random number table: control group, DN model group, miR-183 inhibitor negative control (NC) group, and miR-183 inhibitor group. The latter two groups received tail vein injections of the miR-183 inhibitor NC or the miR-183 inhibitor, respectively, for eight consecutive weeks. Parameters including fasting blood glucose, 24-hour urinary protein excretion, urinary albumin excretion rate (UAER), serum creatinine, and blood urea nitrogen (BUN) were measured. Renal histopathological changes were assessed by HE and PAS staining. Furthermore, the expression of candidate miRNAs from patient data was validated, and the mechanism of action of miR-183 was investigated using quantitative real-time PCR and Western blotting. (3) In vitro mechanistic investigations in cultured podocytes: Mouse podocyte clone-5 (MPC5) cells were cultured in vitro and subjected to the following conditions: normal glucose (5.3 mmol/L glucose), high glucose (30 mmol/L glucose), and osmotic control (5.3 mmol/L glucose+19.5 mmol/L mannitol). Cells in the logarithmic growth phase were transfected with the miR-183 inhibitor (100 nmol/L), miR-183 mimic (50 nmol/L), or their corresponding negative controls. A dual-luciferase reporter assay was conducted to validate the binding interaction between miR-183 and the 3'-untranslated region (3'UTR) of PTEN. The effects of miR-183 on the AKT signaling pathway, apoptosis-related proteins, and cell viability were evaluated by quantitative real-time PCR, Western blotting, and the cell counting kit-8 assay, respectively. Results:MiR-183 expression was markedly upregulated in renal tissues from DN patients and DN model rats (both P<0.05). Inhibition of miR-183 significantly reduced renal miR-183 levels by 90.2% ( P<0.01), decreased fasting blood glucose by 65.3% ( P<0.01), and improved renal function parameters, including reductions in urinary protein (40.3%), blood urea nitrogen (32.1%), urinary albumin excretion rate (22.5%), and serum creatinine (40.2%) (all P<0.01). Histological analyses showed attenuation of glomerular lesions and glycogen accumulation. Bioinformatic prediction and experimental validation identified PTEN as a direct target of miR-183, confirmed by dual-luciferase assays. In vitro, miR-183 inhibition increased PTEN expression, reduced AKT phosphorylation, promoted podocyte proliferation, and suppressed apoptosis (upregulation of Bcl-2 and downregulation of cleaved-caspase-3). These effects were abolished upon PTEN knockdown. Conclusions:miR-183 aggravates DN by targeting PTEN and activating the AKT signaling pathway. Inhibition of miR-183 improves renal function and reduces podocyte apoptosis, suggesting miR-183 as a potential therapeutic target for DN.

Objective To explore the effects of different glucose concentrations on the synthesis and secretion of bone collagen in osteoblasts and the impact of diabetes on bone quality in mice.Methods(1)Primary osteoblasts were extracted from the skulls of neonatal mice via collagenase digestion and cultured in four groups under different glucose concentrations:normal glucose(5.5 mmol/L),moderate glucose(11.5 mmol/L),moderate-high glucose(16.5 mmol/L),and high glucose(25 mmol/L).EdU staining was performed to evaluate cell proliferation,while the Transwell assay was used to assess cell migration.Immunofluorescence and Western blotting were performed to detect and quantitatively analyze the content of type Ⅰ collagen(Col-1).Alizarin red S(ARS)staining and alkaline phosphatase(ALP)staining were applied to assess the effects of different glucose concentrations on osteogenic differentiation.(2)Six-week-old male C57BL/6 mice were randomly divided into control group and model group(5 in each group).The model group was fed a high-fat diet for 4 weeks followed by streptozotocin(STZ)injection to establish a diabetic mouse model.The osteogenic differentiation capacity of primary osteoblasts from both groups was assessed.(3)Micro-computed tomography(Micro-CT)was employed to analyze femoral bone mineral density(BMD),bone volume/tissue volume(BV/TV),trabecular number(Tb.N),and trabecular separation(Tb.Sp).Three-point bending test was conducted to evaluate mechanical parameters including maximum load,Young's modulus,fracture energy,and stiffness.RT-qPCR was employed to assess the expression of osteogenic differentiation genes(Alp,Opn,Col1a1,and Lox).Masson staining and Mallory staining were used to evaluate Col-1 content in trabecular bone.Results(1)EdU and Transwell assay results demonstrated that with the gradual increase in glucose concentration,the proliferation and migration abilities of osteoblasts were significantly decreased(P<0.001),and the protein expression levels of Col-1 and lysyl oxidase(LOX)were significantly reduced(P<0.01 or P<0.001).ARS and ALP staining revealed that calcium salt deposition and ALP activity in osteoblasts were significantly decreased with increasing glucose concentration(P<0.05 or P<0.001).(2)Compared with control group,mice in model group exhibited typical"three polies and one weight loss"symptoms(polyuria,polydipsia,polyphagia,and weight loss)of diabetes,and ARS and ALP staining showed a significant reduction in osteoblasts(P<0.001).(3)Micro-CT and three-point bending test results indicated that,compared with control group,mice in model group showed microarchitectural deterioration of bone,decreased Tb.N,increased Tb.Sp,and significantly reduced maximum load,Young's modulus,fracture energy,and stiffness(P<0.05).RT-qPCR results showed that the relative mRNA expression levels of osteogenic differentiation genes(Alp,Opn,Col1a1,and Lox)were significantly decreased in model group compared with control group(P<0.01 or P<0.001).Masson and Mallory staining indicated a significant reduction in collagen content in model group compared with control group(P<0.01).Conclusions High-glucose environment inhibits osteoblast proliferation,differentiation,and migration.Diabetic mice exhibit reduced bone quality and increased bone fragility,potentially mediated by decreased lysyl oxidase and collagen levels.

Objective To investigate the effects of ischemia time and storage periods on RNA quality in fresh-frozen breast cancer(BC)and esophageal cancer(EC)tissue samples in order to establish evidence-based protocols for biobank sample management.Methods The tumor(T)and paired normal(N)tissue samples from 6 cases of BC and 6 cases of EC were collected and cryopreserved in Biobank,Shantou Central Hospital.Mirror paraffin-embedded tissues were simultaneously prepared into sections for morphological analysis.The samples were divided into two groups of<15 min and 15-30 min according to ischemia time,and RNA quality was analyzed at 4 storage periods of 8-10 months(T1),14-16 months(T2),26-28 months(T3)and 38-40 months(T4).Results In 96 analyzed samples,93.8%(90/96)exhibited high quality(RIN≥6),with 89.6%(43/48)in BC and 97.9%(47/48)in EC.Significant differences in RIN were observed between BC group and EC group(8.050 vs.8.600,P=0.009).In EC group,RIN value was significantly negatively correlated with RNA yield(P<0.001).Moreover,RIN values of tumor-normal pairs exhibited markedly significant differences(7.550 vs.9.000,P<0.001).In contrast,no significant difference was detected in BC group(8.200 vs.7.700,P=0.348).Statistical analysis showed that RIN value was positively correlated with 28S/18S(P<0.001),but had no correlation with tumor content(P=0.676)and necrotic content(P=0.055).Neither ischemia time(<15 min vs.15-30 min:8.200 vs.8.300,P=0.932)nor storage periods(T1-T4:8.400,7.700,8.450,8.600,P=0.163)compromised RNA quality.Conclusion Organ origin and tissue type could influence RNA quality of fresh-frozen tissue samples.However,limited ischemia time(≤30 min)and long-term storage period(38-40 months)do not adversely affect RNA quality in fresh-frozen breast cancer and esophageal cancer tissue samples.

Aim To investigate the anti-acute lung injury(ALI)effect of Sterculiae Lychnophorae Semen(SLS)and its mechanism.Methods The main ac-tive components of SLS and their core targets and path-ways of action against ALI were obtained by network pharmacology methods.Subsequently,molecular doc-king technology and in vitro cellular experiments were applied for validation.Results A total of 19 core tar-gets were obtained,including HSP90AA1,CASP3,TNF,MAPK8 and MAPK14.The mechanisms may in-volve signaling pathways such as cancer,PI3K/Akt and MAPK.Molecular docking confirmed that the key targets of SLS formed a better binding activity with the relevant active ingredients.The in vitro results showed that SLS was able to protect the PM2.5-contaminated BEAS-2B cells,inhibit their NO,IL-1β and TNF-αlevels,and reduce the expression of p-p38 MAPK and p-JNK proteins.Conclusions The study successfully predicts the active ingredients,targets and signaling pathways of SLS against ALI,and in vitro experiments demonstrate that SLS might protect BEAS-2B cells from PM2.5 stimulus-induced inflammation and apoptosis by inhibiting the over-activation of p38 MAPK and JNK signaling pathways.

Streptococcus equinus is a zoonotic disease that can cause illness in various animals under specific environmental condi-tions.No reports have described isolation of this bacterium from the liver in affected sheep.This study successfully isolated and identi-fied a strain of Streptococcus equinus through bacterial isolation and culture,Gram staining,drug sensitivity testing,mouse sensitivity testing,bacterial biochemical testing,and whole genome sequencing.The strain was found to have pathogenicity toward Kunming white mice,and to be sensitive to four antibiotics(penicillin,ampicillin,ceftiofur sodium,and ceftriaxone sodium)but resistant to four antibiotics(streptomycin,amoxicillin,tetracycline,and gentamicin).On the basis of drug sensitivity testing,targeted treatment of the affected sheep flock with ceftiofur sodium effectively controlled the disease within 2 days,and no new cases occurred.This study provides a reference for biological characterization of ovine Streptococcus equinus;public health;and the investigation of disease pre-vention,control,and epidemiology.

The femoral vein is the primary venous trunk of the lower limbs and is commonly used for central venous catheterization in clinical practice.Traditional textbooks lack summarizes of the different types of anatomical variations of the femoral vein,making it more challenging for operators to perform punctures.Ultrasound-guided catheterization provides visualization,but there are still frequent instances of failed punctures and various complications.Operators usually use ultrasound equipment according to personal habits,but may not reach its full potential.This review summarizes recent researches on anatomical variations of the femoral vein and ultrasound-guided femoral vein catheterization,offering reference for medical professionals in clinical practice.

Nano liquid chromatography-high resolution tandem mass spectrometry(LC-HRMS/MS)is widely used for body fluid peptidome analysis,yet the impact of replicate analyses remains overlooked.Using salivary peptidome,in this work,10 replicate analyses of the same sample were conducted.It was found that although m/z and molecular weight ranges were consistent across replicates,single runs identified only 348-576 unique peptides from 32-39 degraded proteins.Merging all replicates revealed 1237 peptides from 77 proteins,a 2.5 folds increase in peptides and 2 folds increase in proteins.Instrument stability was confirmed via intensity/retention time of 12 peptides.Merged peptides primarily derived from high-abundance proteins(e.g.,Statherin,PRP1/2).Analysis of 20 peptides showed that the some peptides were detected in single analysis but confidence varying(19%-99%),low-confidence peptides(<95%)exceeded 95%after replicate.signal intensity alone didn't determine confidence and peptides spanning the sequence region between the longest and the shortest detected fragments could be identified.The above findings suggested that single-run LC-MS peptidomics analysis carried inherent false negatives and uncertainties.However,by integrating the results of a single analysis with the mechanism of enzymatic hydrolysis for endogenous peptides,it was possible to make reasonable inferences and extrapolations regarding peptides derived from highly abundant degraded proteins.