Nanosensor detection of reactive oxygen and nitrogen species leakage in frustrated phagocytosis of nanofibres

Exposure to widely used inert fibrous nanomaterials (for example, glass fibres or carbon nanotubes) may result in asbestos-like lung pathologies, becoming an important environmental and health concern. However, the origin of the pathogenesis of such fibres has not yet been clearly established. Here we report an electrochemical nanosensor that is used to monitor and quantitatively characterize the flux and dynamics of reactive species release during the frustrated phagocytosis of glass nanofibres by single macrophages. We show the existence of an intense prolonged release of reactive oxygen and nitrogen species by single macrophages near their phagocytic cups. This continued massive leakage of reactive oxygen and nitrogen species damages peripheral cells and eventually translates into chronic inflammation and lung injury, as seen during in vitro co-culture and in vivo experiments.

[The mechanism of NRF2 inhibiting ROS induced autophagy to reduce ovarian granulosa cells damage]

This study explores the effects and possible mechanisms of nuclear factor E2 related factor 2 (NRF2) on ovarian granulosa cells, providing a scientific basis to prevent premature ovarian failure. An ovarian cell injury model was constructed by treating human ovarian granulosa cell (KGN cell) with 4-Vinylcyclohexene dioxide (VCD). Firstly, KGN cells were treated with different concentrations of VCD, and cell counting kit 8 (CCK-8) was used to detect ovarian cell proliferation. After determining IC50 by CCK8, the levels of estradiol and progesterone in the cell supernatant were detected using enzyme-linked immunosorbent assay (ELISA), reactive oxygen species (ROS) assay kit was used to detect the content of ROS in ovarian cells, real-time fluorescence quantitative polymerase chain reaction (qRT PCR) was used to detect the mRNA expression level of NRF2, and Western blot was used to detect the protein expression level of NRF2. Further, NRF2 silence (siNRF2) and overexpression (NRF2-OE) cell models were constructed through lentivirus transfection, and the effects of regulating NRF2 on VCD treated cell models were investigated by detecting hormone levels, oxidative stress indicators (ROS, SOD, GSH-Px), and autophagy (LC3B level). The results showed that VCD intervention inhibited the proliferation of ovarian granulosa cells in a time-dependent and dose-dependent manner (F>100, P<0.05), with an IC50 of 1.2 mmol/L at 24 hours. After VCD treatment, the level of estradiol in the cell supernatant decreased from (56.32±10.18) ng/ml to (24.59±8.75) ng/ml (t=5.78, P<0.05). Progesterone decreased from (50.25±7.03) ng/ml to (25.13±6.67) ng/ml (t=6.54, P<0.05). After VCD treatment, the SOD of cells decreased from (44.47±7.71) ng/ml to (30.92±4.97) ng/ml (t=3.61, P<0.05). GSH-Px decreased from (68.51±10.17) ng/ml to (35.19±6.59) ng/ml (t=5.73, P<0.05). Simultaneously accompanied by an increase in autophagy and a decrease in NRF2. This study successfully constructed KGN cell models that silenced NRF2 and overexpressed NRF2. Subsequently, this study treated each group of cells with VCD and found that the cell proliferation activity of the siNRF2 group was significantly reduced (t=8.37, P<0.05), while NRF2-OE could reverse the cell activity damage caused by VCD (t=3.37, P<0.05). The siNRF2 group had the lowest level of estradiol (t=5.78, P<0.05), while NRF2-OE could reverse the decrease in cellular estradiol levels caused by VCD (t=5.58, P<0.05). The siNRF2 group had the lowest progesterone levels (t=3.02, P<0.05), while NRF2-OE could reverse the decrease in cellular progesterone levels caused by VCD (t=2.41, P<0.05). The ROS level in the siNRF2 group was the highest (t=2.86, P<0.05), NRF2-OE could reverse the increase in ROS caused by VCD (t=3.14, P<0.05), the SOD enzyme content in the siNRF2 group was the lowest (t=2.98, P<0.05), and NRF2-OE could reverse the decrease in SOD enzyme content caused by VCD (t=4.72, P<0.05). The GSH-Px enzyme content in the siNRF2 group was the lowest (t=3.67, P<0.05), and NRF2-OE could reverse the decrease in antioxidant enzyme content caused by VCD (t=2.71, P<0.05). The LC3B level was highest in the siNRF2 group (t=2.45, P<0.05), and NRF2-OE was able to reverse the LC3B elevation caused by VCD (t=9.64, P<0.05). In conclusion, NRF2 inhibits ROS induced autophagy, thereby playing a role in reducing ovarian granulosa cell damage, which may be a potential target for premature ovarian failure.

[Clinicopathological characteristics of Klinefelter syndrome: a testicular biopsy analysis of 87 cases]

Objective: To investigate the clinicopathological characteristics of testicular biopsies from Klinefelter syndrome (KS) patients. Methods: The testicular biopsy specimens of 87 patients with KS (a total of 107 biopsy specimens) were collected from the Department of Pathology, Peking University Third Hospital, Beijing, China from January 2017 to July 2022. All patients were diagnosed as KS by peripheral blood karyotyping analysis. The testicular histopathologic features, testicular volume and hormone levels were evaluated retrospectively. The histopathologic analysis was used to assess the quantity and morphology of Leydig cells, the spermatogenic state of seminiferous tubules, the thickening of the basement membrane of seminiferous tubules and the changes of stroma. Results: Leydig cell proliferative nodules were seen in 95.3% (102/107) of KS testicular biopsy tissues. The eosinophilic inclusion bodies and lipofuscin in Leydig cells were found in 52.3% (56/107) and 57.9% (62/107) of specimens, respectively. The Sertoli cell only seminiferous tubules and the hyalinized tubules were found in 66.4% (71/107) and 76.6% (82/107) of the examined tissues, respectively. The tubules with complete spermatogenic arrest were found in 15.9% (17/107) of specimens, and 5.6% (6/107) of the specimens showed low spermatogenesis or incomplete spermatogenic arrest. In 85.0% (91/107) of the specimens, increased thick-walled small vessels with hyaline degeneration were identified. Conclusions: The most common features of KS testicular specimens are Leydig cell proliferative nodules, hyaline degeneration of seminiferous tubules and proliferation of thick-walled blood vessels. Testicular biopsy specimens of KS are rare. The pathologists can make a tentative diagnosis of KS based on the histological findings, combined with the ultrasound and laboratory results, which is helpful for further diagnosis and treatment of KS.

MOFs-based Fe@YAU-101/GCE electrochemical sensor platform for highly selective detecting trace multiplex heavy metal ions

The construction of sensors with specific recognition functions can easily, sensitively and efficiently detect heavy metal ions, which is a demand in the field of electrochemical sensing and an important topic in the detection of environmental pollutants. An electrochemical sensor based on MOFs composites was developed for sensing of multiplex metal ions. The large surface area, adjustable porosities and channels in MOFs facilitate successful loading of sufficient quantities highly active units. The active units and pore structures of MOFs are regulated and synergetic with each other to enhance the electrochemical activity of MOFs composites. Thus, the selectivity, sensitivity and reproducibility of MOFs composites have been improved. Fortunately, after characterization, Fe@YAU-101/GCE sensor with strong signal was successfully constructed. In the presence of target metal ions in solution, the Fe@YAU-101/GCE can efficiently and synchronously identify Hg²⁺, Pb²⁺, and Cd²⁺. The detection limits (LOD) are 6.67 × 10^-10 M(Cd²⁺), 3.33 × 10^-10 M(Pb²⁺) and 1.33 × 10^-8 M (Hg²⁺), and are superior to the permissible limits set by the National Environmental Protection Agency. The electrochemical sensor is simple without sophisticated instrumentation and testing processes, hence promising for practical applications.

Ginseng-derived panaxadiol ameliorates STZ-induced type 1 diabetes through inhibiting RORγ/IL-17A axis

Retinoic-acid-receptor-related orphan receptor γ (RORγ) is a major transcription factor for proinflammatory IL-17A production. Here, we revealed that the RORγ deficiency protects mice from STZ-induced Type 1 diabetes (T1D) through inhibiting IL-17A production, leading to improved pancreatic islet β cell function, thereby uncovering a potential novel therapeutic target for treating T1D. We further identified a novel RORγ inverse agonist, ginseng-derived panaxadiol, which selectively inhibits RORγ transcriptional activity with a distinct cofactor recruitment profile from known RORγ ligands. Structural and functional studies of receptor-ligand interactions reveal the molecular basis for a unique binding mode for panaxadiol in the RORγ ligand-binding pocket. Despite its inverse agonist activity, panaxadiol induced the C-terminal AF-2 helix of RORγ to adopt a canonical active conformation. Interestingly, panaxadiol ameliorates mice from STZ-induced T1D through inhibiting IL-17A production in a RORγ-dependent manner. This study demonstrates a novel regulatory function of RORγ with linkage of the IL-17A pathway in pancreatic β cells, and provides a valuable molecule for further investigating RORγ functions in treating T1D.

[α-lipoic acid ameliorates liver injury in rats with type 2 diabetes mellitus via activating AMPK/mTOR pathway]

OBJECTIVE

To investigate the effect of α-lipoic acid in ameliorating liver injury in rats with type 2 diabetes mellitus via activating adenosine 5'-monophosphate-activate protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway.

METHODS

The T2DM rat models were established by feeding with high-fat, high-sucrose diet and intraperitoneal injection of 27.5 mg/(kg·d) streptozotocin. The 32 rats with T2DM were randomly divided into 4 groups: T2DM group, α-lipoic acid group (LA), Compound C group (Comp C, an inhibitor of AMPK) and LA+Comp C group, with 8 rats in each group. Additionally, 8 Sprague-Dawlay (SD) rats without diabetes were set as normal control. The rats received α-lipoic acid at a dosage of 100 mg/(kg·d) or Compound C at a dosage of 20 mg/(kg·d) by intraperitoneal injection for 8 weeks as needed. The levels of relevant biochemical indexes were detected. The weight of liver was recorded to calculate liver weight index (LWI), and the pathological changes of liver tissues were detected by light and electron microscopy. The levels of AMPK, p-AMPK, mTOR, p-mTOR in rat liver were detected by Western blot.

RESULTS

Compared with control group, the levels of LWI, homeostasis model assessment of insulin resistance, fasting blood glucose, alanine transaminase, aspartate transaminase, gamma glutamyl transferase and triglyceride in T2DM group were increased significantly (all P＜0.05). The liver tissue lesions were more serious and hepatic steatosis grade was higher. The expression of p-AMPK was decreased (P＜0.05) and the expression of p-mTOR was increased significantly(P＜0.05). α-lipoic acid could reverse the above-mentioned changes, ameliorate insulin resistance (all P＜0.05), protect the structure and function of liver, and activate the AMPK/mTOR pathway (P＜0.05). The protection of α-lipoic acid was weakened by the inhibition of AMPK with Compound C (P＜0.05).

CONCLUSION

α-lipoic acid could protect the liver of rats with T2DM by activating AMPK/mTOR pathway.

Homeostasis inside Single Activated Phagolysosomes: Quantitative and Selective Measurements of Submillisecond Dynamics of Reactive Oxygen and Nitrogen Species Production with a Nanoelectrochemical Sensor

Reactive oxygen and nitrogen species (ROS/RNS) are generated by macrophages inside their phagolysosomes. This production is essential for phagocytosis of damaged cells and pathogens, i.e., protecting the organism and maintaining immune homeostasis. The ability to quantitatively and individually monitor the four primary ROS/RNS (ONOO^-, H₂O₂, NO, and NO₂^-) with submillisecond resolution is clearly warranted to elucidate the still unclear mechanisms of their rapid generation and to track their concentration variations over time inside phagolysosomes, in particular, to document the origin of ROS/RNS homeostasis during phagocytosis. A novel nanowire electrode has been specifically developed for this purpose. It consisted of wrapping a SiC nanowire with a mat of 3 nm platinum nanoparticles whose high electrocatalytic performances allow the characterization and individual measurements of each of the four primary ROS/RNS. This allowed, for the first time, a quantitative, selective, and statistically robust determination of the individual amounts of ROS/RNS present in single dormant phagolysosomes. Additionally, the submillisecond resolution of the nanosensor allowed confirmation and measurement of the rapid ability of phagolysosomes to differentially mobilize their enzyme pools of NADPH oxidases and inducible nitric oxide synthases to finely regulate their homeostasis. This reveals an essential key to immune responses and immunotherapies and rationalizes its biomolecular origin.

Elevated expression of the leptin receptor ob‑R may contribute to inflammation in patients with ulcerative colitis

The effect of leptin on ulcerative colitis (UC) has been controversial. The present study aimed to investigate the role of leptin and its receptor ob‑R in UC and the underlying mechanism of this role. The level of serum leptin and the protein expression of the leptin receptor ob‑R in the colonic mucosa were determined in patients with UC. Experimental colitis was induced through intrarectal administration of 2,4,6‑trinitrobenzene sulfonic acid (TNBS) in leptin receptor‑deficient Zucker rats (LR‑D). The body weight, disease activity index, colon length, and macroscopic and histopathological appearance were evaluated. Furthermore, the myeloperoxidase (MPO) enzyme activity and cytokine levels in colon tissues were also determined. The expression of the signal transducer and activator of transcription 3 (STAT3), phosphorylated STAT3 (p‑STAT3), nuclear factor (NF)‑κB‑p65, and Ras homolog gene family member A (RhoA) proteins in colon tissues was assessed. The results revealed that the expression of the leptin receptor ob‑R was increased in the colonic mucosa but the serum leptin level was not altered in patients with UC compared with healthy volunteers. The severity of experimental colitis, represented by body weight loss, disease activity index, colon length, and macroscopic and histological changes, was ameliorated in LR‑D rats compared with the wild‑type (WT) rats. Moreover, the MPO activity; levels of cytokines including interleukin (IL)‑1β, IL‑6, and tumor necrosis factor‑α; and expression of p‑STAT3, NF‑κB, and RhoA proteins were reduced in colon tissues of LR‑D rats compared with WT rats. In conclusion, activation of the leptin receptor ob‑R is an important pathogenic mechanism of UC, and leptin receptor deficiency may provide resistance against TNBS‑induced colitis by inhibiting the NF‑κB and RhoA signaling pathways.

[Demographic characteristics and canalith repositioning efficacy in 907 patients with typical benign paroxysmal positional vertigo]

AbstractObjective:To review the demographic characteristics and canalith repositioning efficacy in 907 patients with typical benign paroxysmal positional vertigo(BPPV). Method: The demographic characteristics of 907 patients with typical BPPV were statistically analyzed. According to the type of BPPV, patients were treated with the appropriate repositioning maneuver, and the clinical efficacy of repositioning maneuver was analyzed and summarized. Result: Nine hundred and seven patients of BPPV with typical nystagmus were elected in this study. 585 out of 907 were female and 322 out of were male, and the mean age was 53.10±14.25(13 to 89) years. The lesion located to the posterior semiCIrcular canal was 489 patients(53.9%), horizontal semiCIrcular canal was 312 patients(34.4%), anterior semiCIrcular was 63 patients(6.9%), and multiple semiCIrcular was 43 patients(4.8%). According to Kaplan-Meier survival analysis curve, the median cure time for the modified Semont and Epley repositioning maneuver in PC-BPPV groups was 3 days, and there was no significant difference in survival curves between the two repositioning maneuver. Meanwhile, the median cure time for Barbecue and Li horizontal canal quick repositioning maneuver groups was 3 days, and 1 day for Gufoni repositioning maneuver group in HC-BPPV groups. And there was no significant difference in survival curves among the three repositioning maneuver. In the AC-BPPV, 7 cases, 31 cases, 57 cases, 58 cases were cured with the Li anterior canal quick repositioning maneuver in the 1st day, the 3rd day, 1 week later, and 1 month later, and 5 cases lost to be follow-up. According to Kaplan-Meier survival analysis curve, the median cure time for the Li anterior canal quick repositioning maneuver in AC-BPPV groups was 3 days. Conclusion:Repositioning maneuver represents a simple, safe, rapid and effective approach to the treatment of BPPV. Therefore, repositioning maneuver should be choice for the BPPV treatment.

[Treatment of patients with probable benign paroxysmal positional vertigot]

Objective:To study the treatment and outcome of the patients with probable BPPV who lacked typical nystagmus.Method： Nine hundred and twenty-two patients with posterior canal BPPV or lateral canal BPPV were selected from the database of our department. There were 801 patients with typical nystagmus during positional testing and 121 patients lacked of typical nystagmus. Manual reposition (Eply,modified Semount,Barbecue and Li manuve) were used and the follow-up was（3.7±2.5）days.Result：In the patients with probable BPPV,there were 44 patients affected by posterior canal and 77 patients had been affected by lateral canal.In the patients with definite BPPV,there were 489 patients affected by posterior canal and 312 by horizontal canal.There was no statistic difference in the result of the treatment (cure,relief and no response) between the probable BPPV and definite BPPV (P>0.05).However,the rate of 'cure' and 'relief' in the probable BPPV was higher than the definite BPPV in lateral canal (P=0.023).Conclusion:A few patients with probable BPPV may develop to definite BPPV or other disease with dizziness.Maneuver of reposition is meaningful for probable BPPV,especially for patients with lateral canal probable BPPV.

[A randomized controlled trial on short-term efficacy of the modified Semont maneuver for the treatment of posterior canal benign paroxysmal positional vertigo]

Objective:To observe the short-term efficacy of modified Semont maneuver for posterior canal benign paroxysmal positional vertigo (PC-BPPV)Method:This was a prospective randomized controlled trial on 130 PC-BPPV patients. Subjects were randomized divided into two groups: modified Semont (65 patients),and Epley(65 patients).Each maneuver was repeated twice,and the presence of sequelae,nystagmus and vertigo on positional testing were evaluated 3rd day and 1 week after treatment.Result:Five patients were lost to follow up (all five in the modified Semont group),and three patients failed to complete treatment (all three in the Epley group). The sequelae at the 3rd day and one week after modified Semont maneuver were 27 and 9,while 41 and 15 in Epley group. The efficacy rates at the 3rd day and one week after modified Semont maneuver were 91.7% and 98.3%,and 91.9% and 96.8% in Epley group retrospectively. The sequelae and short-term effective rate of patients in modified Semont group was no difference when compared with that in Epley group (P>0.05).Conclusion:Modified Semont maneuver represents a simple rapid and effective approach to the treatment of posterior canal benign paroxysmal positional vertigo.

Chronic Intermittent Hypobaric Hypoxia Improves Cardiac Function through Inhibition of Endoplasmic Reticulum Stress

We investigated the role of endoplasmic reticulum stress (ERS) in chronic intermittent hypobaric hypoxia (CIHH)-induced cardiac protection. Adult male Sprague-Dawley rats were exposed to CIHH treatment simulating 5000 m altitude for 28 days, 6 hours per day. The heart was isolated and perfused with Langendorff apparatus and subjected to 30-min ischemia followed by 60-min reperfusion. Cardiac function, infarct size, and lactate dehydrogenase (LDH) activity were assessed. Expression of ERS molecular chaperones (GRP78, CHOP and caspase-12) was assayed by western blot analysis. CIHH treatment improved the recovery of left ventricular function and decreased cardiac infarct size and activity of LDH after I/R compared to control rats. Furthermore, CIHH treatment inhibited over-expression of ERS-related factors including GRP78, CHOP and caspase-12. CIHH-induced cardioprotection and inhibition of ERS were eliminated by application of dithiothreitol, an ERS inducer, and chelerythrine, a protein kinase C (PKC) inhibitor. In conclusion CIHH treatment exerts cardiac protection against I/R injury through inhibition of ERS via PKC signaling pathway.

[Current status of treatment of laryngeal contact granuloma]

Laryngeal contact granuloma, also known as vocal cord granuloma, is the non-neoplastic inflammatory granulation tissue occurring in the vocal cord around. The cause is unclear, morbidity and cure rate is low, the recurrence rate is high, leading to a poor clinical treatment. But some symptoms of the sound disorder, pharyngeal foreign body sensation seriously affect the quality of life of patients, increase the psychological burden of patients. With the increasing awareness of the disease, the deepening of the research, there have been different treatment methods. This paper reviews the previous literatures, and summarizes LCG treatment for the status.

[Impact of apical preparation diameter on fracture resistance of mandibular premolar roots]

OBJECTIVE

To compare the fracture resistance of roots of mandibular premolar with different apical preparation diameters.

METHODS

Sixty single-rooted single canal permanent mandibular premolar teeth extracted newly for orthodontic reason without immatureness, fracture or cracks were selected, with a curvature less than 10°, and internal length: short diameter of less than 2 at a level 5 mm from the apex. All the teeth were decoronated, leaving roots 13 mm in length. The initial apical file size for the teeth was ≤15#. The roots were assigned to 6 groups based on weights with random block design. Group A: blank control group, no instrumentation was performed. Groups B-F: the master apical file (MAF) was 40#, 45#, 50#, 55# and 60#, respectively. In the five experimental groups the roots were instrumented using hand files with step-back technique at 1 mm increments, resulting in a taper of 0.05. The irrigant used was distilled water. After mounted in acrylic resin, all the teeth were subject to vertical loading using an Instron testing machine until fractured. The occurrence of fractures was detected when the applied load suddenly decreased. The fracture load values and fracture modes were recorded. One-way ANOVA and post-hoc Tukey test were used to determine the difference of fracture load values between the groups (P<0.05). Chi-square tests were used to compare the modes of root fracture.

RESULTS

Five experimental groups exhibited lower fracture load values than that of control group [(1 444±155) N]. The mean fracture load values for roots instrumented to an apical diameter of 50# [(1 027±128) N], 55# [(994±150) N] and 60# [(983±166) N] were significantly lower than that of control group and 40# group [(1 339±131) N] and 45# [(1 287±144) N] (P<0.05). Buccal-lingual fracture, mesio-distal fracture and compound fracture occurred 55%, 13% and 32%, respectively. No difference of fracture mode was detected in the six groups.

CONCLUSION

The fracture resistance reduced significantly when the roots were instrumented to an apical diameter of 50# or larger.

[Diagnosis and management of pharyngeal dysphagia]

Objective:To evaluate the effects of different managements on the patients with pharyngeal dysphagia.Method:One hundred patients with pharyngeal dysphagia were recruited for this study.They were divided into three groups after evaluation of swallow function. Then the patients in each groups received treatments include oropharyngeal strengthening exercises, esophageal entrance balloon dilation and cricopharyngeal myotomy, respectively.After 3 months of treatment,the swallow function of the patients was evaluated again to determine the efficacy of the treatments.Result:Seventyfive patients received oropharyngeal strengthening exercises,21 patients received esophageal entrance balloon dilation and 4 patients received cricopharyngeal myotomy. After 3 months of treatment, the effective rates of three groups were 65.33%,76.19% and 75.00%, respectively, with a total efficacy of 68.00%. There was no significant difference of the treatment efficacy among three groups（χ²=0.983，P＞0.05）.Conclusion:Pharyngeal dysphagia can be improved after selected treatments according to the causes and severity of the disease.