BACKGROUND:Forskolin,a diterpenoid natural compound extracted from Coleus forskohlii,has a crucial regulatory role in skeletal muscle repair.However,the regulatory role of forskolin on myogenic differentiation of C2C12 skeletal muscle cells has not been fully explored.OBJECTIVE:To explore the effects of forskolin on the differentiation of C2C12 myoblast cell line and probe into the underlying molecular mechanisms.METHODS:C2C12 cells were treated with 0,0.1,0.25,0.5,1,5,10 and 20 μmol/L forskolin during growth,and cell proliferation was detected by cell counting kit-8 and qRT-PCR.C2C12 cells were treated with 0,0.25,0.5 and 1 μmol/L forskolin during the induction of myogenic differentiation.Immunofluorescence staining and qRT-PCR were used to detect C2C12 cells differentiation.Western blot was used to detect the expression level of myogenic differentiation-related signaling pathway proteins.RESULTS AND CONCLUSION:(1)The viability of C2C12 cells was decreased and cell proliferation was inhibited after treatment with high concentrations(＞1 μmol/L)of forskolin.(2)The qRT-PCR results showed that forskolin up-regulated the expression of Myh2,Myh4,Myomaker,but down-regulated the expression of Myh7 compared with the 0 μmol/L group,when C2C12 cells were differentiated for 4 days.Immunofluorescence staining results showed that the fusion index and myotube diameter of C2C12 cells were increased after forskolin treatment,and the number of myotubes was also increased.(3)Western blot results showed that the phosphorylated extracellular signal-regulated kinase 1/2 expression was inhibited;however,the phosphorylated protein kinase B was promoted after treatment with forskolin.The protein expression level of the myogenic differentiation transcription factor Myogenin was significantly up-regulated after treatment with forskolin.The above results demonstrate that forskolin may promote myogenic differentiation of C2C12 skeletal muscle cells through the extracellular signal-regulated kinase 1/2 and protein kinase B signaling pathway.

BACKGROUND:Forskolin,a diterpenoid natural compound extracted from Coleus forskohlii,has a crucial regulatory role in skeletal muscle repair.However,the regulatory role of forskolin on myogenic differentiation of C2C12 skeletal muscle cells has not been fully explored.OBJECTIVE:To explore the effects of forskolin on the differentiation of C2C12 myoblast cell line and probe into the underlying molecular mechanisms.METHODS:C2C12 cells were treated with 0,0.1,0.25,0.5,1,5,10 and 20 μmol/L forskolin during growth,and cell proliferation was detected by cell counting kit-8 and qRT-PCR.C2C12 cells were treated with 0,0.25,0.5 and 1 μmol/L forskolin during the induction of myogenic differentiation.Immunofluorescence staining and qRT-PCR were used to detect C2C12 cells differentiation.Western blot was used to detect the expression level of myogenic differentiation-related signaling pathway proteins.RESULTS AND CONCLUSION:(1)The viability of C2C12 cells was decreased and cell proliferation was inhibited after treatment with high concentrations(＞1 μmol/L)of forskolin.(2)The qRT-PCR results showed that forskolin up-regulated the expression of Myh2,Myh4,Myomaker,but down-regulated the expression of Myh7 compared with the 0 μmol/L group,when C2C12 cells were differentiated for 4 days.Immunofluorescence staining results showed that the fusion index and myotube diameter of C2C12 cells were increased after forskolin treatment,and the number of myotubes was also increased.(3)Western blot results showed that the phosphorylated extracellular signal-regulated kinase 1/2 expression was inhibited;however,the phosphorylated protein kinase B was promoted after treatment with forskolin.The protein expression level of the myogenic differentiation transcription factor Myogenin was significantly up-regulated after treatment with forskolin.The above results demonstrate that forskolin may promote myogenic differentiation of C2C12 skeletal muscle cells through the extracellular signal-regulated kinase 1/2 and protein kinase B signaling pathway.

BACKGROUND: Recent studies have shown that sodium-glucose cotransporters-2 (SGLT2) inhibitors significantly improve major adverse cardiovascular events in heart failure with preserved ejection fraction (HFpEF) patients, but the exact mechanism is unknown. Ferritinophagy is a special form of selective autophagy that participates in ferroptosis. In this study, we aimed to investigate whether ferritinophagy was activated during the occurrence of HFpEF, and whether canagliflozin (CANA) could inhibite ferritinophagy. METHODS: We reared Dahl salt-sensitive (DSS) rats on a high-salt diet to construct a hypertensive HFpEF model, and simultaneously administered CANA intervention. Then we detected indicators related to ferritinophagy. RESULTS: The expression of nuclear receptor coactivator 4 (NCOA4), as well as microtubule-associated proteins light chain 3 (LC3), Bcl-2 interacting protein 1 (Beclin-1) and p62, were upregulated in HFpEF rats, accompanied by the downregulation of ferritin heavy chain 1 (FTH1), upregulation of mitochondrial iron transporter sideroflexin1 (SFXN1) and increased reactive oxygen species (ROS) production. Above changes were diminished by CANA. CONCLUSION Ferritinophagy is activated in HFpEF rats and then inhibited by CANA, leading to HFpEF benefits. The inhibition of ferritinophagy could provide new prospective targets for the prevention and treatment of HFpEF, and provide new ideas for investigating the mechanism of cardiovascular benefit of SGLT2 inhibitors.

Objective:The clinical significance of aural fullness in patients with vestibular migraine（VM） remains unclear, and it is yet to be determined whether VM with aural fullness represents a distinct subtype of VM; this study aimed to compare differences in demographic characteristics, clinical manifestations, audiological findings, and vestibular function tests between VM patients with and without aural fullness, and explore whether the former is a subtype of VM and whether it requires differentiated treatment. Methods:A total of 174 VM patients were enrolled, including 75 with aural fullness（aural fullness group） and 99 without aural fullness（non-aural fullness group）; demographic data, vertigo characteristics, medical history, family history, pure-tone audiometry, and vestibular function tests were thoroughly recorded, and independent samples t-test and chi-square test were used for inter-group comparisons. Results:①Regarding demographic characteristics, the age of the aural fullness group was significantly lower than that of the non-aural fullness group[（44.08±13.97） years vs. （49.45±16.05） years, P=0.020）, while the two groups showed consistent gender distribution（more females than males） with no statistically significant difference. ②For aural fullness characteristics, unilateral aural fullness accounted for 65.0% in the aural fullness group, significantly higher than bilateral aural fullness（35.0%, P<0.001）. ③In terms of vertigo characteristics, there were no statistically significant inter-group differences in the nature of attacks（rotational vertigo: 36.0% vs. 41.4%, P=0.463; dizziness: 21.3% vs. 11.1%, P=0.064; rotational vertigo or dizziness: 29.3% vs. 25.3%, P=0.548; dizziness with unsteady gait: 9.3% vs. 11.1%, Fisher P=0.806; visual oscillation with unsteady gait: 4.0% vs. 11.1%, Fisher P=0.086）, duration（several hours: 34.7% vs. 33.3%, P=0.841; several minutes: 22.7% vs. 21.2%, P=0.808; several seconds: 5.3% vs. 8.1%, Fisher P=0.557; several days: 9.3% vs. 9.1%, Fisher P=1.000; multiple combined patterns: 17.3% vs. 15.2%, P=0.686）, or incidence of nausea and vomiting（84.0% vs. 72.7%, P=0.071, no statistical significance）. ④No statistically significant inter-group differences were found in medical history and family history, including motion sickness history（8.0% vs. 4.0%, Fisher P=0.337）, headache history（22.7% vs. 34.3%, P=0.084）, and family history of dizziness（12.0% vs. 14.1%, P=0.666）. ⑤For audiological characteristics, 21.3%（16/75） of patients in the aural fullness group had low-frequency hearing loss, significantly higher than 5.1% in the non-aural fullness group（χ²=10.66, P=0.001）; among patients with unilateral aural fullness, 28.6%（14/49） had ipsilateral low-frequency hearing loss, significantly higher than 7.7%（2/26） of those with bilateral aural fullness（χ²=4.41, P=0.036）; however, there was no statistically significant difference in the rate of bilateral high-frequency hearing loss between the two groups（54.7%[41/75]vs. 50.5%[50/99], χ²=0.30, P=0.586）. ⑥In vestibular function tests, no statistically significant inter-group differences were observed in smooth pursuit type Ⅲ/Ⅳ（12.5% vs. 13.1%, P=0.913）, caloric test with CP>25%（31.2% vs. 37.4%, P=0.411）, abnormal video head impulse test（vHIT） rate（30.8% vs. 32.6%, P=0.865）, or abnormal vestibular evoked myogenic potential（VEMP） rate（53.8% vs. 38.9%, Fisher P=0.484）. Conclusion:VM patients with aural fullness have an earlier age of onset, with nearly 1/4 accompanied by low-frequency hearing loss; VM patients with and without aural fullness are highly consistent in gender distribution, nature/duration of vertigo, vestibular function impairment, and presence of bilateral high-frequency hearing loss, suggesting that the core clinical phenotypes of the two groups are consistent, while the former has an earlier age of onset and a higher proportion of unilateral hearing loss, which may be related to the pathological mechanism of VM and inner ear microcirculation disorders.
Humans ; Female ; Male ; Middle Aged ; Adult ; Migraine Disorders/classification* ; Young Adult ; Vertigo ; Age of Onset ; Aged ; Hearing Loss

Objective:To compare the clinical effects of restrictive transfusion strategy and liberal transfusion strategy for cardiac valve surgery.Methods:This study employed a prospective, randomized controlled superiority design, enrolling 439 patients undergoing non-emergency cardiac valve surgery with cardiopulmonary bypass at Department of Cardiovascular Surgery, Guangdong Provincial People′s Hospital, Southern Medical University from June 2023 to October 2024 who met the inclusion and exclusion criteria. While all the patients appeared hematocrit (Hct)≤24% or hemoglobin (Hb)≤80 g/L during the cardiopulmonary bypass. A simple random design was adopted to generate a random sequence and participants were randomized into a restrictive transfusion group (restrictive criteria: Hct≤18% or Hb≤60 g/L during cardiopulmonary bypass, and Hct≤21% or Hb≤70 g/L postoperatively) or a liberal transfusion group (liberal criteria: Hct≤24% or Hb≤80 g/L during cardiopulmonary bypass and Hct≤30% or Hb≤100 g/L postoperatively). If Hb or Hct fell below the respective thresholds, 2 units of red blood cells were transfused, followed by re-evaluation. If levels remained below the threshold, an additional 2 units were transfused until the criteria were met. The primary outcome was a composite of postoperative 3-month mortality, infection, ischemic events, and new-onset renal failure requiring dialysis. Secondary outcomes included blood product utilization, length of stay in the ICU and so on. Intergroup comparisons were performed using independent sample t-test, Mann-Whitney U test, χ2 test, or Fisher′s exact test, and analyses were conducted using a binary multivariable Logistic regression model. Results:A total of 439 patients were included in this study. The restrictive roup included 221 patients, including 75 males and 146 females, aged ( M(IQR)) 57.0 (14.0) years (range: 21 to 76 years). The liberal group included 218 patients, including 67 males and 151 females, aged 56.0 (20.0) years (range: 19 to 74 years). No statistically significant difference was observed in the incidence of primary outcome (restrictive group: 10.9%(24/221) vs. liberal group: 9.6%(21/218), χ2=0.180, P>0.05), 2 patints in the restrictive group died and 3 patints in liberal group died ( P=0.684). The transfusion rate was significantly lower in the restrictive group(19.0%(42/221) vs. 100%(218/218), P<0.01), with no significant differences in other secondary outcomes (all P>0.05). Subgroup analysis revealed an interaction between sex and transfusion strategy ( P=0.023), suggesting that using liberal transfusion strategy in male patients might increase the risk of the primary outcome. Conclusion:The mid-term results do not show that the restrictive transfusion strategy is superior to the liberal transfusion strategy in reducing the incidence of postoperative outcome events in patients undergoing cardiac valve surgery.

Objective To observe the difference of bone micro-structure in different regions of proximal femur,micro-CT scanning was performed on 30 proximal femur specimens to explain the mechanism of proximal femur fracture and to provide anatomical basis for prosthesis design.Methods Totally 30 intact proximal femur specimens were obtained from 60-80 year-old cadavers.Micro-CT scanning was used to measure the trabecular thickness(Tb.Th),trabecular number(Tb.N),trabecular space(Tb.Sp),connectivity(Conn)and bone mineral density(BMD)and other parameters in 7 regions of proximal femur,including proximal pressure trabecular(PPT),distal pressure trabecular(DPT),femoral head-neck junction(FHNJ),head and neck of femoral neck(HNFN),the base of femoral neck(BPFN),intertrochanteric line(IL)and greater trochanter(GT).Results The bone mineral density of IL and GT were higher than those of BPFN,FHNJ,DPT and PPT.The trabecular thickness of GT was the largest,followed by IL,BPFN and HNFN,and the smallest was FHNJ,DPT and PPT.The trabecular space of IL was larger than that of GT,and the data of both were larger than those of other parts,among which DPT and PPT were the smallest.The trabecular number of IL and GT were the smallest,BPFN,HNFN and FHNJ were larger,and DPT was the largest.The volume fraction of IL was the smallest,BPFN and HNFN were larger,DPT and PPT were the largest.Conclusion The bone density,trabecular thickness,bone volume,and total volume of GT and IL in the proximal femur of elderly patients are all relatively large,so the reason for the high incidence of fractures is not due to weak internal bone microstructure;The bone density,trabecular thickness,and trabecular gap at the proximal and distal ends of the vertical trabecular bone are relatively small.If it is necessary to perform core decompression for prosthesis filling at this location,the design should be conducive to the mechanical conduction of the prosthesis and the regeneration of surrounding bone tissue.

The efficient production of L-glutamate is dependent on the product's rapid efflux, hence researchers have recently concentrated on artificially modifying its transport system and cell membrane wall structure. Considering the unique composition and structure of the cell wall of Corynebacterium glutamicum, we investigated the effects of CmpLs on L-glutamate synthesis and transport in SCgGC7, a constitutive L-glutamate efflux strain. First, the knockout strains of CmpLs were constructed, and it was confirmed that the deletion of CmpL1 and CmpL4 significantly improved the performance of L-glutamate producers. Next, temperature-sensitive L-glutamate fermentation with the CmpL1 and CmpL4 knockout strains were carried out in 5 L bioreactors, where the knockout strains showcased temperature-sensitive characteristics and enhanced capacities for L-glutamate production under high temperatures. Notably, the CmpL1 knockout strain outperformed the control strain in terms of L-glutamate production, showing production and yield increases of 69.2% and 55.3%, respectively. Finally, the intracellular and extracellular metabolites collected at the end of the fermentation process were analyzed. The modification of CmpLs greatly improved the L-glutamate excretion and metabolic flux for both L-glutamate production and transport. Additionally, the CmpL1 knockout strain showed decreased accumulation of downstream metabolites of L-glutamate and intermediate metabolites of tricarboxylic acid (TCA) cycle, which were consistent with its high L-glutamate biosynthesis capacity. In addition to offering an ideal target for improving the stability and performance of the industrial strains for L-glutamate production, the functional complementarity and redundancy of CmpLs provide a novel target and method for improving the transport of other metabolites by modification of the cell membrane and cell wall structures in C. glutamicum.
Corynebacterium glutamicum/genetics* ; Glutamic Acid/biosynthesis* ; Fermentation ; Metabolic Engineering ; Bacterial Proteins/metabolism* ; Bioreactors/microbiology* ; Gene Knockout Techniques

Objective:To investigate the effects of 10° head up tilt bed rest (HUT) on human cardiac function via 3D speckle tracking echocardiography (3D-STE), and to study the difference in cardiac function under the submaximal exercise load between the horizontal position and 10° HUBR.Methods:Thirty young healthy volunteers were recruited as the subjects, who were randomly divided into an 10° HUT exercise group and horizontal exercise group with 15 subjects in each. Subjects in both groups were asked to ride the bicycle ergometer in the 10° HUBR position and supine position respectively. The load started with 50 W and was increased by 25 W every 3 min until it reached the maximum of 125 W. Before the exercise (resting state), 1 min after the load was increased each time, and 3 min after exercise (recovery period), the following indices were collected: ①basic cardiac function indices: heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP), ②conventional cardiac ultrasound indices: left ventricular ejection fraction (LVEF), stroke volume (SV) and cardiac output (CO), ③left ventricular strain indices: global longitudinal strain (GLS), global circumferential strain (GCS), and global area strain (GAS) measured by 3D-SET. The changes of these indices in the 2 groups of subjects under different exercise loads were observed.Results:The differences in the major effect of the basic heart indices (HR, SBP and DBP), conventional cardiac ultrasound indices (LVEF, SV and CO) and left ventricular strain indices (GLS, GCS and GAS) in response to the exercise load were statistically significant ( F=194.90, 113.66, 17.19, P=0.017, 0.018, 0.001). With the increase of the exercise load, the basic heart indices and conventional cardiac ultrasound indices kept rising, the left ventricular strain indices reached the minimum under a moderate exercise load (75 W), HR, SBP and CO were higher than those of the resting state ( P<0.05 or 0.01). Both LVEF under exercise loads of 75, 100, 125 W and during recovery, and SV under exercise loads of 100, 125 W and during recovery were significantly higher than those of the resting state ( P<0.05 or 0.01), while GLS and GCS under exercise loads of 50, 75, 125 W ( P<0.05 or 0.01), and GAS under exercise loads of 50, 75 W ( P<0.01) were significantly lower. There were statistically significant differences not only in GCS across the groups ( F=4.60, P=0.026) but also in DBP due to the interactions between the grouping and exercise loads ( F=3.13, P=0.031). DBP was higher than that of the resting state when the exercise load was 125 W in both groups. Conclusions:During submaximal exercise, myocardial contractility shows sustained enhancement with the increase of the exercise load. The results of GLS, GCS and GAS indicate that myocardial strain reaches its lowest value under a moderate exercise load, suggesting that moderate exercise can be used to evaluate cardiac function via 3D-SET. Under a simulated lunar gravity of 10° HUT, there is less deformation in the short axis direction of the myocardium, indicating that GCS can be used as a sensitive indicator to detect changes in cardiac function under different gravities.

Objective To observe the correlation between cortical thickness and pathological deposition of β-amyloid(Aβ)in patients with Alzheimer disease(AD)induced mild cognitive impairment(MCI)or dementia.Methods Totally 22 AD patients were prospectively enrolled and divided into dementia group(n=12)and MCI group(n=10)based on the degree of cognitive impairment,while 17 healthy individuals without cognitive impairment were recruited as control group.MR examination and 18F-florbutaben(18F-FBB)PET imaging were performed,the cortical thickness and Aβ deposition value(Centiloid[CL]value)were calculated and compared among 3 groups and between each 2 groups,then the correlation between the above two indexes was analyzed.Results The cortical thickness in dementia group,MCI group and control group was(2.18±0.14),(2.35±0.08)and(2.36±0.09)mm,respectively,with significant difference among 3 groups(P＜0.05).The cortical thickness in dementia group was significantly thinner than that in MCI group and control group(both P＜0.05).CL value in dementia group,MCI group and control group was 77.97(63.07,95.55),65.51(54.54,90.50)and-1.17(-9.66,4.88),respectively,with significant difference among 3 groups(P＜0.05).CL value in dementia group and MCI group were significantly higher than in control group(both P＜0.05).The cortical thickness was moderately negatively correlated with CL value in MCI group(r=-0.580,P=0.048)but not in the other 2 groups(both P＞0.05).Conclusion The cortical thickness was moderately negatively correlated with abnormal deposition of Aβ in patients with AD induced MCI,but was not during dementia.