Programmed cell death 1 ligand 1 (PD-L1) is an important immunosuppressive molecule, which inhibits the function of T cells and other immune cells by binding to the receptor programmed cell death-1. The PD-L1 expression disorder plays an important role in the occurrence, development, and treatment of sepsis or other inflammatory diseases, and has become an important target for the treatment of these diseases. Mesenchymal stem cells (MSCs) are a kind of pluripotent stem cells with multiple differentiation potential. In recent years, MSCs have been found to have a strong immunosuppressive ability and are used to treat various inflammatory insults caused by hyperimmune diseases. Moreover, PD-L1 is deeply involved in the immunosuppressive events of MSCs and plays an important role in the treatment of various diseases. In this review, we will summarize the main regulatory mechanism of PD-L1 expression, and discuss various biological functions of PD-L1 in the immune regulation of MSCs.

mRNA gene therapy has attracted much attention due to its advantages such as scalability, modification, no need to enter the nucleus and no integration of host genes. In gene therapy, safe and effective delivery of mRNA into cells is critical for the success of gene therapy. In this study, we designed and synthesized an amphiphilic cationic lipopeptide gene vector (dendritic arginine & disulfide bond-containing cationic lipopeptide, RLS) enriched with branched arginine. We achieved a 1.5-fold higher mRNA transfection efficiency in zebrafish compared to the commercial reagent Lipofectamine 2000, and confirmed its good biosafety by in vitro cytotoxicity and in vivo biosafety. First, we characterized the chemical composition of the cationic lipid peptides by nuclear magnetic resonance hydrogen spectroscopy (¹H NMR) and time-of-flight mass spectrometry (MS). The results of particle size and potential tested by dynamic light scattering particle size analysis showed that at a nitrogen/phosphorus (N/P) ratio of 20, the RLS/mRNA composite assemblies formed homogeneous nanoparticles with an average particle size of about 220 nm and a surface ζ potential of about +21 mV. In vitro gene transfection, the transfection experiments demonstrated that RLS exhibited 1.2-fold higher transfection efficiency in human embryonic kidney 293 cells (HEK293) and 3-fold higher transfection efficiency in rat mesenchymal stem cells (MSC) compared to Lipofectamine 2000. In addition, after microinjection of RLS into zebrafish embryos, we evaluated the survival, hatching, and teratogenicity rates, all of which confirmed its favorable in vivo safety profile. Thus, this amphiphilic cationic lipid peptide RLS, enriched with branched arginine, exhibits excellent mRNA delivery properties and safety. These findings highlight its potential as a promising gene therapy tool.

Isocitrate dehydrogenase 1 (IDH1) R132H is the most common mutated gene in grade II-III gliomas and oligodendrogliomas. Instead of activating telomerase (a reverse transcriptase which using RNA as a template to extend telomere length), the majority of IDH1^R132H mutant glioma maintain telomere length through an alternative mechanism that relies on homologous recombination (HR), which is known as alterative lengthening of telomere (ALT).The phenotype of ALT mechanism include: ALT associated promyelocytic leukemia protein (PML) bodies (APBs); extrachromosomal telomeric DNA repeats such as C- and T-loops; telomeric sister chromatid exchange (T-SCE), etc. The mechanism of ALT activation is not fully understood. Recent studies have shown that mutation IDH1 contributes to ALT phenotype in glioma cells in at least three key ways. Firstly, the IDH1^R132H mutation mediates RAP1 down-regulation leading to telomere dysfunction, thus ensuring persistent endogenous telomeric DNA damage, which is important for ALT activation. Spontaneous DNA damage at telomeres may provide a substrate for mutation break-induced replication (BIR)‑mediated ALT telomere lengthening, and it has been demonstrated that RAP1 inhibits telomeric repeat-containing RNA, transcribed from telomeric DNA repeat sequences (TERRA) transcription to down-regulate ALT telomere DNA replication stress and telomeric DNA damage, thereby inhibiting ALT telomere synthesis. Similarly, in ALT cells, knockdown of telomere-specific RNaseH1 nuclease triggers TERRA accumulation, which leads to increased replication pressure. Overexpression of RNaseH1, on the other hand, attenuates the recombination capacity of ALT telomeres, leading to telomere depletion, suggesting that RAP1 can regulate the level of replication pressure and thus ALT activity by controlling TERRA expression. Secondly, the IDH1^R132H also alters the preference of the telomere damage repair pathway by down-regulating XRCC1, which inhibits the alternative non-homologous end joining (A-NHEJ) pathway at telomeres and alters cellular preference for the HR pathway to promote ALT. Finally, the IDH1^R132H has a decreased affinity for isocitric acid and NADP+ and an increased affinity for α ketoglutarate (α‑KG) and NADPH, so that the mutant IDH1^R132H catalyzes the hydrogenation of α‑KG to produce 2-hydroxyglutarate (2-HG)in a NADPH-dependent manner. Because 2-HG is structurally similar to α‑KG, which maintains the trimethylation level of H3k9me3 by competitively inhibiting the activity of the α‑KG-dependent histone demethylase KDM4B, and recruits heterochromatin protein HP1α to heterochromatinize telomeres, and promote ALT phenotypes in cooperation with the inactivating of ATRX. In addition, it has been shown that APBs contain telomeric chromatin, which is essentially heterochromatin, and HP1α is directly involved in the formation of APBs. Based on these studies, this article reviews the mechanism of IDH1^R132H mediated telomere dysfunction and the preference of DNA repair pathway at telomeres in cooperate with ATRX loss to promote ALT, which may provide references for clinical targeted therapy of IDH1^R132H mutant glioma.

China ; History of Medicine ; Medicine/standards*

OBJECTIVE: This study was aimed at investigating the carrier rate of, and molecular variation in, α- and β-globin gene mutations in Hunan Province. METHODS: We recruited 25,946 individuals attending premarital screening from 42 districts and counties in all 14 cities of Hunan Province. Hematological screening was performed, and molecular parameters were assessed. RESULTS: The overall carrier rate of thalassemia was 7.1%, including 4.83% for α-thalassemia, 2.15% for β-thalassemia, and 0.12% for both α- and β-thalassemia. The highest carrier rate of thalassemia was in Yongzhou (14.57%). The most abundant genotype of α-thalassemia and β-thalassemia was -α ^3.7/αα (50.23%) and β ^IVS-II-654/β ^N (28.23%), respectively. Four α-globin mutations [CD108 (ACC>AAC), CAP +29 (G>C), Hb Agrinio and Hb Cervantes] and six β-globin mutations [CAP +8 (C>T), IVS-II-848 (C>T), -56 (G>C), beta nt-77 (G>C), codon 20/21 (-TGGA) and Hb Knossos] had not previously been identified in China. Furthermore, this study provides the first report of the carrier rates of abnormal hemoglobin variants and α-globin triplication in Hunan Province, which were 0.49% and 1.99%, respectively. CONCLUSION Our study demonstrates the high complexity and diversity of thalassemia gene mutations in the Hunan population. The results should facilitate genetic counselling and the prevention of severe thalassemia in this region.
Humans ; beta-Thalassemia/genetics* ; alpha-Thalassemia/genetics* ; Hemoglobinopathies/genetics* ; China/epidemiology* ; High-Throughput Nucleotide Sequencing

AIM: To investigate the efficacy and safety of intravitreal injection of Conbercept combined with 25G minimally invasive pars plana vitrectomy(PPV)at the end of surgery for early proliferative diabetic retinopathy(PDR)with vitreous hemorrhage.METHODS: A total of 60 patients(60 eyes)with PDR complicated with vitreous hemorrhage requiring PPV at the Affiliated Eye Hospital of Nanjing Medical University were retrospectively analyzed. Based on the injection timing of Conbercept, the patients were divided into 3 groups: 20 patients(20 eyes)injected at the end of the surgery(group A), 20 patients(20 eyes)injected preoperatively(group B), and 20 patients(20 eyes)without injection(group C). The differences in pre- and post-operative visual acuity, intraocular pressure, intraoperative conditions, prognosis, and complications were analyzed among the 3 groups.RESULTS: There were no significant differences in the preoperative conditions and operation time among the patients. There was no iatrogenic retinal hole or silicone oil tamponade during the operation in the 3 groups, and no recurrent retinal detachment occurred after the operations. Best corrected visual acuity(BCVA)at 1, 3 and 6mo of all groups were improved compared with those before the surgery(P<0.05), and the injection groups(group A and group B)had a significantly better postoperative improvement than the non-injection group(group C), and there were significant differences(P<0.05). The incidence of postoperative late vitreous hemorrhage(1mo after operation)in group A was significantly lower than those in groups B and C(P<0.05). The central retinal thickness of the operated eyes in the injection groups(groups A and B)was significantly lower than that in the non-injection group(group C)at 1, 3 and 6mo after operation(P<0.05).CONCLUSION: Conbercept injection at the end of the surgery and preoperative injection are both safe and effective for early PDR and can significantly improve postoperative visual acuity. However, Conbercept injection at the end of surgery can reduce the risk of late vitreous hemorrhage recurrence, leading to better PPV outcomes and improving patients' retinal and visual function and quality of life.

Aim To explore the effect of boschniakia rossica polysaccharides ( BRPS ) on cardiomyocyte damage induced by hypoxia/reoxygenation (H/R) and its possible mechanism. Methods H/R was used to induce rat cardiomyocyte H9c2 to establish a cell inju¬ry model, and different doses of BRPS were used to treat H9c2 cells. ELISA method was used to detect the level of MDA and the activity of SOD and GSH-Px. Flow cytometry was used to detect the rate of apopto-sis. qRT-PCR was used to detect the expression of miR-302a-3p. anti-miR-NC and anti-miR-302a-3p were respectively transfected into H9c2 cells and then subjected to H/R treatment. miR-NC and miR-302a-3p mimics were respectively transfected into H9c2 cells and treated with 100 mg • L

OBJECTIVE: To investigate risk factors of acute cerebrovascular events and effects on the prognosis within 1 year after hip fracture surgery. METHODS: A retrospective analysis was performed on 320 elderly patients with hip fracture treated from July 2017 to December 2020, including 111 males and 209 females, aged from 60 to 101 years old with an average of (79.05±8.48) years old. According to whether acute cerebrovascular events occurred within 1 year after surgery, patients were divided into cerebrovascular events and non-cerebrovascular events group. Clinical data of patients were collected, including age, sex, comorbidities, fracture type, white blood cell count, hemoglobin, albumin, activities of daily living (ADL) score, walking ability, type of anesthesia, type of surgery, and length of hospital stay, Univariate analysis and multivariate Logistic regression were used to analyze the independent risk factors of acute cerebrovascular events within 1 year after hip fracture in elderly patients. ADL, walking ability and mortality were compared between the two groups 1 year after surgery. RESULTS: Acute cerebrovascular events occurred in 38 patients (11.9%) within 1 year after surgery. In the cerebrovascular events group, there were 20 males and 18 females, aged (82.53±7.91) years. In the non-cerebrovascular event group, there were 91 males and 191 females, aged with an average of (78.59±8.46) years old . Univariate analysis showed that acute cerebrovascular events were associated with age (t=2.712, P=0.007), male (χ²=6.129, P=0.013), hypertension (χ²=8.449, P=0.004), arrhythmia (χ²=6.360, P=0.012), stroke history (χ²=34.887, P=0.000), diabetes mellitus (χ²=4.574, P=0.032) and length of hospital stay (t=2.249, P=0.025) were closely related. Multivariate Logistic regression analysis showed age (OR=1.068, P=0.018), male (OR=2.875, P=0.008), arrhythmia (OR=2.722, P=0.017) and stroke history (OR=7.382, P=0.000) was an independent risk factor for acute cerebrovascular events 1 year after surgery. The patients with cerebrovascular events died at 1 year after surgery (11 cases) compared with those without cerebrovascular events (41 cases), and the difference was statistically significant(χ²=5.108, P=0.024). ADL scores of patients with cerebrovascular events at 1 year after operation were (58.70±14.45) points compared with those without cerebrovascular events (67.83±10.45) points, and the difference was statistically significant(t=4.122, P=0.000). Independent walking, assisted walking and bed rest were 3, 17 and 7 cases in cerebrovascular event group, and 54, 174 and 13 cases in non-cerebrovascular event group, respectively;and the difference was statistically significant(χ²=11.030, P=0.003). CONCLUSION Acute cerebrovascular events were common in elderly patients 1 year after hip fracture. Age, male, arrhythmia and stroke history were independent risk factors for acute stroke. The patients in the cerebrovascular event group had higher mortality and worse self-care ability and walking ability one year after operation.
Female ; Humans ; Male ; Aged ; Middle Aged ; Aged, 80 and over ; Retrospective Studies ; Activities of Daily Living ; Hip Fractures ; Risk Factors ; Prognosis ; Stroke ; Arrhythmias, Cardiac

Objective: To investigate the expression of glycoprotein non metastatic melanoma protein B (GPNMB) in renal eosinophilic tumors and to compare the value of GPNMB with CK20, CK7 and CD117 in the differential diagnosis of renal eosinophilic tumors. Methods: Traditional renal tumor eosinophil subtypes, including 22 cases of renal clear cell carcinoma eosinophil subtype (e-ccRCC), 19 cases of renal papillary cell carcinoma eosinophil subtype (e-papRCC), 17 cases of renal chromophobe cell carcinoma eosinophil subtype (e-chRCC), 12 cases of renal oncocytoma (RO) and emerging renal tumor types with eosinophil characteristics [3 cases of eosinophilic solid cystic renal cell carcinoma (ESC RCC), 3 cases of renal low-grade eosinophil tumor (LOT), 4 cases of fumarate hydratase-deficient renal cell carcinoma (FH-dRCC) and 5 cases of renal epithelioid angiomyolipoma (E-AML)], were collected at the Affiliated Drum Tower Hospital of Nanjing University Medical School from January 2017 to March 2022. The expression of GPNMB, CK20, CK7 and CD117 was detected by immunohistochemistry and statistically analyzed. Results: GPNMB was expressed in all emerging renal tumor types with eosinophil characteristics (ESC RCC, LOT, FH-dRCC) and E-AML, while the expression rates in traditional renal eosinophil subtypes e-papRCC, e-chRCC, e-ccRCC and RO were very low or zero (1/19, 1/17, 0/22 and 0/12, respectively); the expression rate of CK7 in LOT (3/3), e-chRCC (15/17), e-ccRCC (4/22), e-papRCC (2/19), ESC RCC (0/3), RO (4/12), E-AML(1/5), and FH-dRCC (2/4) variedly; the expression of CK20 was different in ESC RCC (3/3), LOT(3/3), e-chRCC(1/17), RO(9/12), e-papRCC(4/19), FH-dRCC(1/4), e-ccRCC(0/22) and E-AML(0/5), and so did that of CD117 in e-ccRCC(2/22), e-papRCC(1/19), e-chRCC(16/17), RO(10/12), ESC RCC(0/3), LOT(1/3), E-AML(2/5) and FH-dRCC(1/4). GPNMB had 100% sensitivity and 97.1% specificity in distinguishing E-AML and emerging renal tumor types (such as ESC RCC, LOT, FH-dRCC) from traditional renal tumor types (such as e-ccRCC, e-papRCC, e-chRCC, RO),respectively. Compared with CK7, CK20 and CD117 antibodies, GPNMB was more effective in the differential diagnosis (P<0.05). Conclusion: As a new renal tumor marker, GPNMB can effectively distinguish E-AML and emerging renal tumor types with eosinophil characteristics such as ESC RCC, LOT, FH-dRCC from traditional renal tumor eosinophil subtypes such as e-ccRCC, e-papRCC, e-chRCC and RO, which is helpful for the differential diagnosis of renal eosinophilic tumors.
Humans ; Kidney Neoplasms/pathology* ; Carcinoma, Renal Cell/pathology* ; Diagnosis, Differential ; Angiomyolipoma/diagnosis* ; Biomarkers, Tumor/metabolism* ; Leukemia, Myeloid, Acute/diagnosis* ; Membrane Glycoproteins

During coronavirus disease 2019 epidemic, the treatment of severe trauma has been impacted. The Consensus on emergency surgery and infection prevention and control for severe trauma patients with 2019 novel corona virus pneumonia was published online on February 12, 2020, providing a strong guidance for the emergency treatment of severe trauma and the self-protection of medical staffs in the early stage of the epidemic. With the Joint Prevention and Control Mechanism of the State Council renaming "novel coronavirus pneumonia" to "novel coronavirus infection" and the infection being managed with measures against class B infectious diseases since January 8, 2023, the consensus published in 2020 is no longer applicable to the emergency treatment of severe trauma in the new stage of epidemic prevention and control. In this context, led by the Chinese Traumatology Association, Chinese Trauma Surgeon Association, Trauma Medicine Branch of Chinese International Exchange and Promotive Association for Medical and Health Care, and Editorial Board of Chinese Journal of Traumatology, the Chinese expert consensus on emergency surgery for severe trauma and infection prevention during coronavirus disease 2019 epidemic ( version 2023) is formulated to ensure the effectiveness and safety in the treatment of severe trauma in the new stage. Based on the policy of the Joint Prevention and Control Mechanism of the State Council and by using evidence-based medical evidence as well as Delphi expert consultation and voting, 16 recommendations are put forward from the four aspects of the related definitions, infection prevention, preoperative assessment and preparation, emergency operation and postoperative management, hoping to provide a reference for severe trauma care in the new stage of the epidemic prevention and control.