Background and Aims:Endovascular repair of aortic arch diseases poses a major challenge in vascular surgery due to the need to both effectively exclude the lesion and preserve perfusion of supra-aortic branch vessels.The Castor branched aortic covered stent,with its integrated design and ability to maintain left subclavian artery(LSA)patency,offers potential advantages.When combined with the chimney technique for the left common carotid artery(LCCA),it may provide a minimally invasive and feasible solution for patients with insufficient proximal landing zones.This study aims to evaluate the preliminary feasibility and safety of this combined approach and provide clinical reference for the endovascular management of complex aortic arch pathologies.Methods:A retrospective analysis was conducted on 15 patients with aortic arch diseases who underwent treatment with the Castor branched stent-graft combined with LCCA chimney stenting at the Second Xiangya Hospital of Central South University between February 2023 and December 2024.Baseline characteristics,surgical procedures,perioperative complications,and follow-up outcomes were analyzed to assess technical success,complication rates,and branch vessel patency.Results:Among the 15 patients(11 males,average age 63.8 years),primary diagnoses included aortic dissection(33.4%),aortic arch aneurysm(53.3%),and penetrating aortic ulcer(13.3%).The technical success rate was 100%,with no perioperative deaths or major complications.During the follow-up period(4-26 months,mean 12.9 months),no adverse events such as stroke,paralysis,endoleak,or stent migration occurred.The patency rate of both the LCCA and LSA remained 100%.Conclusion:The Castor branched aortic stent-graft combined with LCCA chimney technique appears to be a technically feasible and safe short-term option for treating aortic arch diseases with insufficient proximal landing zones.It may serve as a promising alternative for complex aortic arch repair;however,large-scale,multicenter studies with long-term follow-up are needed to further validate its efficacy and safety.

Objective:To evaluate the prognosis of Hall technique and traditional performed metal crown (PMC) restoration technique, and to follow up the occlusal changes before and after treatment with Hall technique, providing references for the promotion of Hall technique.Methods:Children who visited the Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University from May 2021 to December 2022 were screened according to the inclusion and exclusion criteria. The therapeutic effects of the two groups were followed up at three time points: 1, 2 and 3 months after operation. The observation results were divided into three outcomes: success (crown in place, no symptoms of pulpitis or periapical periodontitis, no obvious abnormality in occlusion, no need for further treatment), partial failure (crown falling off or crown broken, tooth defect can be repaired, reversible pulpitis) and complete failure (irreversible pulpitis or periapical periodontitis, crown falling off and tooth defect irreparable), and statistical analysis was made. At the same time, the Hall technique group was followed up at five time points as before operation, immediately after operation, 2 weeks after operation, 4 weeks after operation and 8 weeks after operation respectively, in which the occlusion was analyzed by Dental Prescale Ⅱ system. The vertical dimension of occlusion (VDO), overbite and coverage, and canine relationship were recorded and compared. Three-dimensional finite element method was used to model and analyze the stress of the teeth treated with traditional PMC treatment and Hall technique, and the differences between them were compared.Results:Finally, 21 children were included in the Hall technique group, including 12 boys and 9 girls, with age of (5.0±1.4) years. Meanwhile, 22 children including 15 boys and 7 girls were in the traditional PMC group, with age of (5.1±1.3) years. There were 0 cases of complete failure and 0 cases of partial failure both in the Hall technique group and in the traditional PMC group within 1 month. There were 0 cases of complete failure and 1 case of partial failure in the Hall technique group, while 0 cases of complete failure and 0 cases of partial failure in the traditional PMC group within 2 months after operation. Hall technique group failed completely in 1 case and partially in 1 case, while the traditional pre-crown group failed completely in 0 cases and partially in 0 cases 3 months after operation. There was no significant difference in the incidence of primary index/complete failure and secondary index/partial failure between Hall technique group and traditional PMC group (all P>0.05). The occlusal area and occlusal force of children treated with Hall technique decreased immediately after operation compared with those before operation, but gradually recovered to the preoperative level at 2, 4 and 8 weeks after operation. To elaborate, the occlusal area decreased significantly from (14.79±3.55) mm 2 before operation to (10.15±3.17) mm 2 immediately after operation ( P=0.001), and recovered to (15.58±3.39) mm 2 at 8 weeks after operation ( P>0.05 compared with pre-operation). The occlusal force decreased significantly from (436.94±109.59) N before operation to (292.70±96.05) N immediately after operation ( P=0.001), and recovered to (441.86±104.31) N at 8 weeks after operation ( P>0.05 compared with pre-operation). Overbite decreased significantly from (2.54±1.05) mm before operation to (1.80±0.94) mm immediately after operation ( P=0.044) and then recovered to (2.35±1.02) mm ( P>0.05 compared with pre-operation). The coverage changed from (2.41±0.66) mm before operation to (2.27±0.61) mm immediately after operation ( P>0.05) and then recovered to (2.48±0.62) mm ( P>0.05 compared with pre-operation). The canine relationship was (3.12±0.54) mm before operation, and decreased significantly immediately after operation (2.17±0.89) mm ( P=0.001), and recovered to (3.05±0.61) mm after 8 weeks ( P>0.05 compared with pre-operation). In the three-dimensional finite element analysis, the maximum stress of all parts of the affected tooth increased immediately after Hall technique treatment, but with occlusal adjustment, the maximum stress of all parts of the affected tooth decreased, which was similar to that of the traditional metal pre-crown group. The vertical load and oblique load of pre-crown decreased from 180.11 and 496.16 MPa to 108.05 and 297.69 MPa, respectively. The vertical load and oblique load of enamel decreased from 94.83 and 255.94 MPa to 57.21 and 156.44 MPa, respectively. The vertical load and oblique load of dentin decreased from 55.19 and 124.77 MPa to 33.19 and 74.59 MPa, respectively. Conclusions:During the experimental observation period, there is no obvious difference between Hall technique and traditional PMC treatment technology in terms of post-treatment occlusion and clinical prognosis, which supports clinical application.

Objective:To explore the safety and efficacy of intraosseous regional administration (IORA) of vancomycin for preventing infection in primary total knee arthroplasty (TKA).Methods:A total of 124 patients with knee osteoarthritis undergoing TKA between February 2024 and May 2024 at nine hospitals were enrolled. Preoperative infection prophylaxis involved either IORA (0.5 g vancomycin administered via intraosseous regional infusion before incision) or intravenous infusion (1 g vancomycin via peripheral vein). The IORA group included 15 males and 47 females with a median age of 66.5 years (range, 60.0-70.0 years), while the intravenous group included 14 males and 48 females with a median age of 66.0 years (range, 61.8-70.3 years) years. Intraoperative samples were collected including fat and synovium tissues after incision, before prosthesis placement, and after tourniquet release; distal femoral cancellous bone during femoral osteotomy; proximal tibial cancellous bone during tibial osteotomy; proximal intercondylar cancellous bone before prosthesis placement; and peripheral blood from non-infused arms at surgery initiation and after tourniquet release. Vancomycin concentrations were measured using liquid chromatography-tandem mass spectrometry. Vital sign changes were recorded from admission to 5~10 minutes post-IORA (IORA group) or post-incision (intravenous group). Follow-ups were conducted on postoperative day 1 and 3, and at 1 and 3 months, to document complications including IORA-related adverse events, periprosthetic joint infections, surgical site infections, red man syndrome, acute kidney injury, deep vein thrombosis and so on.Results:Vancomycin concentrations in bone, fat, and synovial tissue samples were significantly higher in the IORA group than in the intravenous group ( P<0.05), while vancomycin concentrations in blood samples were significantly lower in the IORA group than in the intravenous group ( P<0.05). Only 7.3%(41/558) of tissue samples in the IORA group had vancomycin concentrations below 2.0 μg/g (the minimum inhibitory concentration of vancomycin against coagulase-negative staphylococcus), compared to 59.3%(331/558) in the intravenous group (χ 2=11.285, P<0.001). In the intravenous group, 16.9%(21/124) of blood samples had vancomycin concentrations exceeding 15.0 mg/L (the threshold associated with a significantly increased risk of nephrotoxicity), while all concentrations in the IORA group were below this threshold, the difference was statistically significant (χ 2=22.943, P<0.001). There were no statistically significant difference ( P>0.05) in vital signs changes before and after vancomycin administration between the two groups. Two patients in the intravenous group experienced incision exudate, while no other related complications occurred in either group. Conclusions:Compared to the traditional intravenous infusion of 1 g vancomycin, intraosseous injection of a low dose (0.5 g) of vancomycin achieves higher local tissue concentrations in the knee joint with a lower incidence of adverse reactions and is safe for infection prophylaxis. Despite guidelines not recommending the routine use of vancomycin for preventing infection after primary TKA, intraosseous injection of 0.5 g vancomycin may be considered intraoperatively for primary TKA in the following scenarios: patients in medical institutions with a high prevalence of methicillin-resistant staphylococcus aureus (MRSA) infections, patients with potential preoperative MRSA colonization, or patients with cephalosporin allergy.

OBJECTIVES: Ruptured abdominal aortic aneurysm (rAAA) is a life-threatening vascular emergency with extremely high in-hospital mortality. Open surgical repair (OSR) was historically the only treatment option but is associated with substantial trauma and perioperative risk. In recent years, endovascular repair (EVAR) has gained widespread use due to its minimally invasive nature and faster recovery, becoming the preferred option for anatomically suitable patients in many centers. However, controversy remains regarding the long-term survival benefits of EVAR compared with OSR and key prognostic factors affecting outcomes. This study aims to evaluate the clinical efficacy of OSR and EVAR for rAAA and identify independent predictors of postoperative survival to guide clinical decision-making. METHODS: A retrospective analysis was conducted on 83 patients diagnosed with rAAA and treated surgically in the Department of Vascular Surgery, the Second Xiangya Hospital of Central South University, between January 2013 and December 2022. Patients were divided into an OSR group and an EVAR group based on surgical approach. Baseline clinical characteristics, perioperative data, and follow-up outcomes were compared between groups. Long-term survival was analyzed, and univariate and multivariate Cox proportional hazards regression models were used to determine independent prognostic factors. RESULTS: Among the 83 patients, 32 (38.6%) underwent OSR and 51 (61.4%) received EVAR, with the proportion of EVAR steadily increasing to nearly 80% in the most recent 5 years. Patients in the EVAR group were older [(68.76±8.57) years vs (60.59±13.24) years, P=0.012], and had a lower proportion of males (76.5% vs 96.9%, P=0.013). EVAR significantly reduced operating time [(181.86±69.87) min vs (291.09±60.33) min] and hospital stay [(12.14±6.31) days vs (16.22±7.89) days (P<0.05)], but total hospitalization costs were markedly higher [(208 735.84±101 394.19) yuan vs (84 893.35±40 668.56) yuan, P<0.001]. There were no significant differences between groups in 30-day mortality (15.6% vs 15.7%), aneurysm-related mortality (9.4% vs 11.7%), overall mortality (28.1% vs 29.4%), or re-intervention rate (0 vs 5.9%) (P>0.05). The median follow-up time was 54.6 months (range, 12-144 months). Kaplan-Meier survival analysis showed comparable cumulative survival rates between OSR and EVAR (82.7% vs 76.2%, P=0.420). Cox regression identified hyperlipidemia [hazard ratio (HR)=2.32, 95% confidence interval (CI) 1.28 to 4.19, P=0.005] and elevated preoperative serum creatinine (HR=3.33, 95% CI 1.69 to 6.55, P<0.001) as significant predictors of poor prognosis. Both factors remained independently associated with mortality in the multivariate model (hyperlipidemia: HR=2.02, 95% CI 1.10 to 3.70; elevated serum creatinine: HR=2.77, 95% CI 1.40 to 5.47; P<0.05). CONCLUSIONS EVAR offeres advantages in operative and recovery times, though its long-term survival outcomes are comparable to OSR. A history of hyperlipidemia and elevated preoperative creatinine levels are independent predictors of poor prognosis. Surgical approach should be chosen based on anatomical feasibility and patient condition, with close management of lipid levels and renal function to improve outcomes.
Humans ; Aortic Aneurysm, Abdominal/mortality* ; Endovascular Procedures/methods* ; Retrospective Studies ; Male ; Female ; Prognosis ; Aged ; Aortic Rupture/mortality* ; Middle Aged ; Treatment Outcome ; Aged, 80 and over

Fractional flow reserve (FFR), an established modality for functionally assessing coronary artery disease, is increasingly applied to diagnose and manage lower extremity arterial disease. By incorporating functional parameters, FFR enhances revascularization precision by quantifying the hemodynamic impact of stenotic lesions, thereby overcoming limitations of conventional imaging. Key clinical applications in lower extremity disease include functional assessment in moderate intermittent claudication, post-vascular preparation strategy optimization, and predicting revascularization outcomes and complications. Advances in pressure wire and microcatheter systems, alongside non-invasive imaging-derived FFR techniques, are improving its feasibility and applicability. However, widespread adoption is challenged by the complex anatomy of the lower extremity arterial system, frequent severe calcification and diffuse disease, and a current lack of standardized FFR cutoff values. Promoting the standardized use of FFR is crucial for shifting the clinical management paradigm from anatomy-based repair toward functional reconstruction.
Humans ; Lower Extremity/blood supply* ; Peripheral Arterial Disease/diagnosis* ; Fractional Flow Reserve, Myocardial ; Endovascular Procedures/methods* ; Intermittent Claudication/physiopathology*

BACKGROUND: T cell dysfunction, which includes exhaustion, anergy, and senescence, is a distinct T cell differentiation state that occurs after antigen exposure. Although T cell dysfunction has been a cornerstone of cancer immunotherapy, its potential in transplant research, while not yet as extensively explored, is attracting growing interest. Interferon regulatory factor 4 (IRF4) has been shown to play a pivotal role in inducing T cell dysfunction. METHODS: A novel ultra-low-dose combination of Trametinib and Rapamycin, targeting IRF4 inhibition, was employed to investigate T cell proliferation, apoptosis, cytokine secretion, expression of T-cell dysfunction-associated molecules, effects of mitogen-activated protein kinase (MAPK) and mammalian target of rapamycin (mTOR) signaling pathways, and allograft survival in both in vitro and BALB/c to C57BL/6 mouse cardiac transplantation models. RESULTS: In vitro , blockade of IRF4 in T cells effectively inhibited T cell proliferation, increased apoptosis, and significantly upregulated the expression of programmed cell death protein 1 (PD-1), Helios, CD160, and cytotoxic T lymphocyte-associated antigen (CTLA-4), markers of T cell dysfunction. Furthermore, it suppressed the secretion of pro-inflammatory cytokines interferon (IFN)-γ and interleukin (IL)-17. Combining ultra-low-dose Trametinib (0.1 mg·kg -1 ·day -1 ) and Rapamycin (0.1 mg·kg -1 ·day -1 ) demonstrably extended graft survival, with 4 out of 5 mice exceeding 100 days post-transplantation. Moreover, analysis of grafts at day 7 confirmed sustained IFN regulatory factor 4 (IRF4) inhibition, enhanced PD-1 expression, and suppressed IFN-γ secretion, reinforcing the in vivo efficacy of this IRF4-targeting approach. The combination of Trametinib and Rapamycin synergistically inhibited the MAPK and mTOR signaling network, leading to a more pronounced suppression of IRF4 expression. CONCLUSIONS Targeting IRF4, a key regulator of T cell dysfunction, presents a promising avenue for inducing transplant immune tolerance. In this study, we demonstrate that a novel ultra-low-dose combination of Trametinib and Rapamycin synergistically suppresses the MAPK and mTOR signaling network, leading to profound IRF4 inhibition, promoting allograft acceptance, and offering a potential new therapeutic strategy for improved transplant outcomes. However, further research is necessary to elucidate the underlying pharmacological mechanisms and facilitate translation to clinical practice.
Animals ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Interferon Regulatory Factors/metabolism* ; Heart Transplantation/methods* ; T-Lymphocytes/immunology* ; Sirolimus/therapeutic use* ; Pyridones/therapeutic use* ; Graft Survival/drug effects* ; Pyrimidinones/therapeutic use* ; Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Male ; Signal Transduction/drug effects*

Objective:To evaluate the prognosis of Hall technique and traditional performed metal crown (PMC) restoration technique, and to follow up the occlusal changes before and after treatment with Hall technique, providing references for the promotion of Hall technique.Methods:Children who visited the Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University from May 2021 to December 2022 were screened according to the inclusion and exclusion criteria. The therapeutic effects of the two groups were followed up at three time points: 1, 2 and 3 months after operation. The observation results were divided into three outcomes: success (crown in place, no symptoms of pulpitis or periapical periodontitis, no obvious abnormality in occlusion, no need for further treatment), partial failure (crown falling off or crown broken, tooth defect can be repaired, reversible pulpitis) and complete failure (irreversible pulpitis or periapical periodontitis, crown falling off and tooth defect irreparable), and statistical analysis was made. At the same time, the Hall technique group was followed up at five time points as before operation, immediately after operation, 2 weeks after operation, 4 weeks after operation and 8 weeks after operation respectively, in which the occlusion was analyzed by Dental Prescale Ⅱ system. The vertical dimension of occlusion (VDO), overbite and coverage, and canine relationship were recorded and compared. Three-dimensional finite element method was used to model and analyze the stress of the teeth treated with traditional PMC treatment and Hall technique, and the differences between them were compared.Results:Finally, 21 children were included in the Hall technique group, including 12 boys and 9 girls, with age of (5.0±1.4) years. Meanwhile, 22 children including 15 boys and 7 girls were in the traditional PMC group, with age of (5.1±1.3) years. There were 0 cases of complete failure and 0 cases of partial failure both in the Hall technique group and in the traditional PMC group within 1 month. There were 0 cases of complete failure and 1 case of partial failure in the Hall technique group, while 0 cases of complete failure and 0 cases of partial failure in the traditional PMC group within 2 months after operation. Hall technique group failed completely in 1 case and partially in 1 case, while the traditional pre-crown group failed completely in 0 cases and partially in 0 cases 3 months after operation. There was no significant difference in the incidence of primary index/complete failure and secondary index/partial failure between Hall technique group and traditional PMC group (all P>0.05). The occlusal area and occlusal force of children treated with Hall technique decreased immediately after operation compared with those before operation, but gradually recovered to the preoperative level at 2, 4 and 8 weeks after operation. To elaborate, the occlusal area decreased significantly from (14.79±3.55) mm 2 before operation to (10.15±3.17) mm 2 immediately after operation ( P=0.001), and recovered to (15.58±3.39) mm 2 at 8 weeks after operation ( P>0.05 compared with pre-operation). The occlusal force decreased significantly from (436.94±109.59) N before operation to (292.70±96.05) N immediately after operation ( P=0.001), and recovered to (441.86±104.31) N at 8 weeks after operation ( P>0.05 compared with pre-operation). Overbite decreased significantly from (2.54±1.05) mm before operation to (1.80±0.94) mm immediately after operation ( P=0.044) and then recovered to (2.35±1.02) mm ( P>0.05 compared with pre-operation). The coverage changed from (2.41±0.66) mm before operation to (2.27±0.61) mm immediately after operation ( P>0.05) and then recovered to (2.48±0.62) mm ( P>0.05 compared with pre-operation). The canine relationship was (3.12±0.54) mm before operation, and decreased significantly immediately after operation (2.17±0.89) mm ( P=0.001), and recovered to (3.05±0.61) mm after 8 weeks ( P>0.05 compared with pre-operation). In the three-dimensional finite element analysis, the maximum stress of all parts of the affected tooth increased immediately after Hall technique treatment, but with occlusal adjustment, the maximum stress of all parts of the affected tooth decreased, which was similar to that of the traditional metal pre-crown group. The vertical load and oblique load of pre-crown decreased from 180.11 and 496.16 MPa to 108.05 and 297.69 MPa, respectively. The vertical load and oblique load of enamel decreased from 94.83 and 255.94 MPa to 57.21 and 156.44 MPa, respectively. The vertical load and oblique load of dentin decreased from 55.19 and 124.77 MPa to 33.19 and 74.59 MPa, respectively. Conclusions:During the experimental observation period, there is no obvious difference between Hall technique and traditional PMC treatment technology in terms of post-treatment occlusion and clinical prognosis, which supports clinical application.

Objective:To explore the safety and efficacy of intraosseous regional administration (IORA) of vancomycin for preventing infection in primary total knee arthroplasty (TKA).Methods:A total of 124 patients with knee osteoarthritis undergoing TKA between February 2024 and May 2024 at nine hospitals were enrolled. Preoperative infection prophylaxis involved either IORA (0.5 g vancomycin administered via intraosseous regional infusion before incision) or intravenous infusion (1 g vancomycin via peripheral vein). The IORA group included 15 males and 47 females with a median age of 66.5 years (range, 60.0-70.0 years), while the intravenous group included 14 males and 48 females with a median age of 66.0 years (range, 61.8-70.3 years) years. Intraoperative samples were collected including fat and synovium tissues after incision, before prosthesis placement, and after tourniquet release; distal femoral cancellous bone during femoral osteotomy; proximal tibial cancellous bone during tibial osteotomy; proximal intercondylar cancellous bone before prosthesis placement; and peripheral blood from non-infused arms at surgery initiation and after tourniquet release. Vancomycin concentrations were measured using liquid chromatography-tandem mass spectrometry. Vital sign changes were recorded from admission to 5~10 minutes post-IORA (IORA group) or post-incision (intravenous group). Follow-ups were conducted on postoperative day 1 and 3, and at 1 and 3 months, to document complications including IORA-related adverse events, periprosthetic joint infections, surgical site infections, red man syndrome, acute kidney injury, deep vein thrombosis and so on.Results:Vancomycin concentrations in bone, fat, and synovial tissue samples were significantly higher in the IORA group than in the intravenous group ( P<0.05), while vancomycin concentrations in blood samples were significantly lower in the IORA group than in the intravenous group ( P<0.05). Only 7.3%(41/558) of tissue samples in the IORA group had vancomycin concentrations below 2.0 μg/g (the minimum inhibitory concentration of vancomycin against coagulase-negative staphylococcus), compared to 59.3%(331/558) in the intravenous group (χ 2=11.285, P<0.001). In the intravenous group, 16.9%(21/124) of blood samples had vancomycin concentrations exceeding 15.0 mg/L (the threshold associated with a significantly increased risk of nephrotoxicity), while all concentrations in the IORA group were below this threshold, the difference was statistically significant (χ 2=22.943, P<0.001). There were no statistically significant difference ( P>0.05) in vital signs changes before and after vancomycin administration between the two groups. Two patients in the intravenous group experienced incision exudate, while no other related complications occurred in either group. Conclusions:Compared to the traditional intravenous infusion of 1 g vancomycin, intraosseous injection of a low dose (0.5 g) of vancomycin achieves higher local tissue concentrations in the knee joint with a lower incidence of adverse reactions and is safe for infection prophylaxis. Despite guidelines not recommending the routine use of vancomycin for preventing infection after primary TKA, intraosseous injection of 0.5 g vancomycin may be considered intraoperatively for primary TKA in the following scenarios: patients in medical institutions with a high prevalence of methicillin-resistant staphylococcus aureus (MRSA) infections, patients with potential preoperative MRSA colonization, or patients with cephalosporin allergy.

Severe open tibiofibular fractures account for approximately 28.1% of all open fractures. Among them, Gustilo-Anderson type IIIB/C fractures present significant clinical challenges due to associated bone and soft tissue defects, high infection rates, and risk of amputation. Inadequate preoperative assessment may lead to suboptimal emergency surgical planning or intraoperative complications. Historically, external fixation was often preferred, but this approach has been associated with limitations such as restricted joint mobility, delayed bone union, joint stiffness, and disuse osteoporosis, resulting in poor functional recovery. With advancements of debridement techniques, standardization of antibiotic use, and popularization of early soft tissue coverage, early internal fixation has gained broader acceptance. Nevertheless, controversies persist regarding the choice of fixation method, timing of definitive fixation, use of reamed versus unreamed intramedullary nailing, and necessity of fibular fixation. To standardize the diagnosis and early management of severe open tibiofibular fractures, reduce complication rates, and improve functional recovery, the Society of Microsurgery of the Chinese Medical Association organized a panel of domestic experts to develop the Evidence-based guideline for the diagnosis and early fixation of severe open tibiofibular fractures ( version 2025), using evidence-based methodology. The guidelines provided 12 recommendations covering diagnostic and early fixation strategies of severe open tibiofibular fractures, aiming to provide clinicians with scientifically grounded and standardized guidance.

Hormesis effect has been observed in the secondary metabolite synthesis of microorganisms induced by rare earth elements. However, the underlying molecular mechanism remains unclear. To analyze the molecular mechanism of the regulatory effect of Rhodotorula mucilaginosa in the presence of lanthanum chloride, different concentrations of lanthanum chloride were added to the fermentation medium of Rhodotorula mucilaginosa, and the carotenoid content was subsequently measured. It was found that the concentrations of La³⁺ exerting the promotional and inhibitory effects were 0-100 mg/L and 100-400 mg/L, respectively. Furthermore, the expression of 33 genes and the synthesis of 55 metabolites were observed to be up-regulated, while the expression of 85 genes and the synthesis of 123 metabolites were found to be down-regulated at the concentration range of the promotional effect. Notably, the expression of carotenoid synthesis-related genes except AL1 was up-regulated. Additionally, the content of β-carotene, lycopene, and astaxanthin demonstrated increases of 10.74%, 5.02%, and 3.22%, respectively. The expression of 5 genes and the synthesis of 91 metabolites were up-regulated, while the expression of 35 genes and the synthesis of 138 metabolites were down-regulated at the concentration range of the inhibitory effect. Meanwhile, the content of β-carotene, lycopene, and astaxanthin decreased by 21.73%, 34.81%, and 35.51%, respectively. In summary, appropriate concentrations of rare earth ions can regulate the synthesis of secondary metabolites by modulating the activities of various enzymes involved in metabolic pathways, thereby exerting the hormesis effect. The findings of this study not only contribute to our comprehension for the mechanism of rare earth elements in organisms but also offer a promising avenue for the utilization of rare earth elements in diverse fields, including agriculture, pharmaceuticals, and healthcare.
Lanthanum/pharmacology* ; Rhodotorula/genetics* ; Carotenoids/metabolism* ; Hormesis/drug effects* ; Fermentation ; Multiomics