1.Long-term safety and effectiveness of roxadustat in Chinese patients with chronic kidney disease-associated anemia: The ROXSTAR registry.
Xiaoying DU ; Yaomin WANG ; Haifeng YU ; Jurong YANG ; Weiming HE ; Zunsong WANG ; Dongwen ZHENG ; Xiaowei LI ; Shuijuan SHEN ; Dong SUN ; Weimin YU ; Detian LI ; Changyun QIAN ; Yiqing WU ; Shuting PAN ; Jianghua CHEN
Chinese Medical Journal 2025;138(12):1465-1476
BACKGROUND:
Chronic kidney disease (CKD)-associated anemia (CKD-anemia) is associated with poor survival, and hemoglobin targets are often not achieved with current therapies. Phase 3 trials have demonstrated the treatment efficacy of roxadustat for CKD-anemia. This phase 4 study aims to evaluate the long-term (52-week) safety and effectiveness of roxadustat in a broad real-world patient population with CKD-anemia with and without dialysis in China.
METHODS:
This Phase 4 multicenter, open-label, prospective study, conducted from 24 November 2020 to 11 November 2022, evaluated the long-term safety and effectiveness of roxadustat for CKD-anemia in China. Patients aged ≥18 years with CKD-anemia with or without dialysis were included. The initial oral dose was 70-120 mg (weight-based followed by dose adjustment) over 52 weeks. The primary endpoint was safety based on adverse events (AEs). The secondary endpoints were hemoglobin changes from baseline and the proportion of patients who achieved mean hemoglobin ≥100 g/L. Effectiveness evaluable populations 1 (EE1) and EE2 included roxadustat-naïve and previously roxadustat-treated patients, respectively. The safety analysis set (SAF) included all patients who received ≥1 occasion.
RESULTS:
The EE1, EE2, and SAF populations included 1804, 193, and 2021 patients, respectively. In the SAF, the mean age was 50 ± 14 years, and 1087 patients (53.8%) were male. Mean baseline hemoglobin was 96.9 ± 14.0 g/L in EE1 and 100.3 ± 12.9 g/L in EE2. In EE1, the mean (95% confidence interval) hemoglobin changes from baseline over weeks 24-36 and 36-52 were 14.2 (13.5-14.9) g/L and 14.3 (13.5-15.0) g/L, respectively. Over weeks 24-36 and 36-52, 83.3% and 86.1% of patients in EE1 and 82.7% and 84.7% in EE2 achieved mean hemoglobin ≥100 g/L, respectively. In the SAF, 1643 (81.3%) patients experienced treatment-emergent AEs (TEAEs). Overall, 219 (10.8%) patients experienced drug-related TEAEs. Thirty-eight (1.9%) patients died of TEAEs (unrelated to the study drug). Vascular access thrombosis was uncommon.
CONCLUSIONS:
Roxadustat (52 weeks) increased hemoglobin and maintained the treatment target in Chinese patients with CKD-anemia with acceptable safety, supporting its use in real-world settings.
REGISTRATION
Chinese Clinical Trial Registry ( www.chictr.org.cn ) ChiCTR2100046322; CDE ( www.chinadrugtrials.org.cn ) CTR20201568.
Humans
;
Male
;
Female
;
Anemia/etiology*
;
Middle Aged
;
Renal Insufficiency, Chronic/complications*
;
Glycine/adverse effects*
;
Isoquinolines/adverse effects*
;
Aged
;
Prospective Studies
;
Adult
;
Hemoglobins/metabolism*
;
Treatment Outcome
;
China
;
Registries
;
East Asian People
2.Hematological Characteristics of Neonates with Abnormal Hemoglobin and Their Parents in Guangzhou Area.
Yan-Fen GE ; Yue ZHAO ; Ya-Xuan HUANG ; Jun-Ru LIU ; Ting LIN ; Lu-Hua XIAN
Journal of Experimental Hematology 2025;33(1):180-186
OBJECTIVE:
To analyze the incidence of abnormal hemoglobin (Hb) in neonates in Guangzhou area, as well as the results of quantitative analysis of Hb in neonatal umbilical cord blood and genetic diagnosis of thalassemia in neonates with abnormal Hb; And to explore the hematological phenotypes and clinical characteristics of neonates with abnormal Hb and their parents, providing a reference for eugenics and childcare.
METHODS:
650 neonates born at Guangdong Provincial People's Hospital who underwent Hb electrophoresis were included in this study. The results of routine blood test of umbilical cord blood , Hb electrophoresis and α-, β-thalassemia gene detection of the neonates were collected. The genotype distribution of thalassemia in the neonates was analyzed. Additionally, the abnormal Hb content of α and β variants was studied. Furthermore, the differences in hematological parameters between abnormal Hb neonates and normal neonates and α-thalassemia neonates, as well as between the parents of abnormal Hb neonates and normal adults were compared.
RESULTS:
Among the 650 neonates, 332 (51.08%) were diagnosed with thalassemia, including 235 cases of α-thalassemia (36.15%), 79 cases of β-thalassemia (12.15%), and 18 cases of compound αβ-thalassemia (2.77%). Among all the α-thalassemia genotypes, the most prevalent one was -- SEA/αα (48.94%), followed by -α3.7/αα (20.00%), -α4.2/αα (11.06%), and ααCS/αα (8.94%). The four most common genotypes of β-thalassemia were βCD41-42 (32.91%), βIVS-Ⅱ-654 (26.58%), β-28 (21.52%), and βE (10.13%), respectively. 275 cases of abnormal bands were found in Hb electrophoresis of umbilical cord blood, with a detection rate of 42.31%. The abnormal Hb content of α-variant in the neonates was significantly higher than that of β-variant (P < 0.001). The levels of Hb, MCV, MCH, Hb A, and Hb F in neonates with abnormal Hb were lower than those in normal neonates, while the RDW-CV was higher than that in normal neonates, with statistical significantce (P < 0.05). The levels of RBC and Hb A in neonates with abnormal Hb were lower than those in neonates with α-thalassemia, while the level of MCH was higher than that in neonats with α-thalassemia, with statistical significance (P < 0.05). The levels of Hb, MCV, MCH, and Hb A in parents of neonates with abnormal Hb were lower than those in normal adults, while the RDW-CV was higher than that in normal adults, and the differences were statistically significant (P < 0.05).
CONCLUSION
The abnormal Hb content of α-variant in the neonates is significantly higher than that of β-variant in the neonates in Guangzhou, which can help to presume whether it is α chain or β chain based on the abnormal Hb content, providing a reference for globin gene sequencing. Meanwhile, analysis of various hematological screening-related indicators in neonates in the early stage is beneficial for early warning of the occurrence of abnormal Hb combined with thalassemia, reducing missed diagnoses to a certain extent.
Humans
;
Infant, Newborn
;
Genotype
;
Hemoglobins, Abnormal/genetics*
;
China/epidemiology*
;
alpha-Thalassemia/epidemiology*
;
beta-Thalassemia/genetics*
;
Parents
;
Female
;
Male
;
Fetal Blood
3.Serum proteomics and machine learning unveil new diagnostic biomarkers for tuberculosis in adolescents and young adults.
Yu CHEN ; Hongxiang XU ; Yao TIAN ; Qian HE ; Xiaoyun ZHAO ; Guobin ZHANG ; Jianping XIE
Chinese Journal of Biotechnology 2025;41(4):1478-1489
Adolescents and young adults (AYAs) are one of the major populations susceptible to tuberculosis. However, little is known about the unique characteristics and diagnostic biomarkers of tuberculosis in this population. In this study, 81 AYAs were recruited, and the high-quality serum proteome of the AYAs with tuberculosis was profiled by quantitative proteomics. The data of serum proteomics indicated that the relative abundance of hemoglobin and apolipoprotein was significantly reduced in the patients with active tuberculosis (ATB). The pathway enrichment analysis showed that the downregulated proteins in the ATB group were mainly involved in the antioxidant and cell detoxification pathways, indicating extensive oxidative stress damage. Random forest (RF) and extreme gradient boosting (XGBoost) were employed to evaluate protein importance, which yielded a set of candidate proteins that can distinguish between ATB and non-ATB. The analysis with the support vector machine algorithm (recursive feature elimination) suggested that the combination of apolipoprotein A-I (APOA1), hemoglobin subunit beta (HBB), and hemoglobin subunit alpha-1 (HBA1) had the highest accuracy and sensitivity in diagnosing ATB. Meanwhile, the levels of hemoglobin (HGB) and albumin (ALB) can be used as blood biochemical indicators to evaluate changes in the protein levels of APOA1 and HBB. This study established the serum proteome landscape of AYAs with tuberculosis and identified new biomarkers for the diagnosis of tuberculosis in this population.
Humans
;
Proteomics/methods*
;
Biomarkers/blood*
;
Adolescent
;
Young Adult
;
Apolipoprotein A-I/blood*
;
Machine Learning
;
Tuberculosis/blood*
;
Proteome/analysis*
;
Male
;
Hemoglobins/analysis*
;
Female
;
Blood Proteins/analysis*
;
Adult
4.Screening and characterization of camelid-derived nanobodies against hemoglobin.
Ning ZHONG ; Wenhui LEI ; Zuying LIU ; Xiaoxiao XIE ; Lingjing ZHANG ; Tengchuan JIN ; Minjie CAO ; Yulei CHEN
Chinese Journal of Biotechnology 2025;41(4):1515-1534
Hemoglobin, the principal protein in red blood cells, is crucial for oxygen transport in the bloodstream. The quantification of hemoglobin concentration is indispensable in medical diagnostics and health management, which encompass the diagnosis of anemia and the screening of various blood disorders. Immunological methods, based on antigen-antibody interactions, are distinguished by their high sensitivity and accuracy. Consequently, it is necessary to develop hemoglobin-specific antibodies characterized by high specificity and affinity to enhance detection accuracy. In this study, we immunized a Bactrian camel (Camelus bactrianus) with human hemoglobin and subsequently constructed a nanobody library. Utilizing a solid-phase screening method, we selected nanobodies and evaluated the binding activity of the screened nanobodies to hemoglobin. Initially, human hemoglobin was used to immunize a Bactrian camel. Following four immunization sessions, blood was withdrawn from the jugular vein, and a nanobody library with a capacity of 2.85×108 colony forming units (CFU) was generated. Subsequently, ten hemoglobin-specific nanobody sequences were identified through three rounds of adsorption-elution-enrichment assays, and these nanobodies were subjected to eukaryotic expression. Finally, enzyme-linked immunosorbent assay and biolayer interferometry were employed to evaluate the stability, binding activity, and specificity of these nanobodies. The results demonstrated that the nanobodies maintained robust binding activity within the temperature range of 20-40 ℃ and exhibited the highest binding activity at pH 7.0. Furthermore, the nanobodies were capable of tolerating a 10% methanol solution. Notably, among the nanobodies tested, VHH-12 displayed the highest binding activity to hemoglobin, with a half maximal effective concentration (EC50) of 10.63 nmol/L and a equilibrium dissociation constant (KD) of 2.94×10-7 mol/L. VHH-12 exhibited no cross-reactivity with a panel of eight proteins, such as ovalbumin and bovine serum albumin, while demonstrating partial cross-reactivity with hemoglobin derived from porcine, goat, rabbit, and bovine sources. In this study, a hemoglobin-specific high-affinity nanobody was successfully isolated, demonstrating potential applications in disease diagnosis and health monitoring.
Animals
;
Camelus/immunology*
;
Single-Domain Antibodies/immunology*
;
Hemoglobins/immunology*
;
Humans
;
Peptide Library
5.Prognostic value of pretreatment peripheral blood hemoglobin×lymphocyte/monocyte ratio in patients with nasopharyngeal carcinoma.
Chao DENG ; Zui CHEN ; Jie LING ; Yangchun XIE ; Xiayan ZHAO ; Chunhong HU ; Xianling LIU ; Yuhua FENG ; Tao HOU
Journal of Central South University(Medical Sciences) 2024;49(12):1909-1918
OBJECTIVES:
Peripheral whole blood cell counts have been used as prognostic indicators for various cancers, but their predictive value in nasopharyngeal carcinoma remain unclear. This study aims to evaluate the prognostic significance of the pretreatment hemoglobin×lymphocyte/monocyte ratio (HLMR) in non-recurrent, non-metastatic NPC patients undergoing definitive radiotherapy.
METHODS:
Clinical and follow-up data from 805 NPC patients who completed definitive radiotherapy or chemoradiotherapy were retrospectively analyzed. Pretreatment hemoglobin, lymphocyte count, and monocyte count were collected to calculate HLMR. Receiver operating characteristic (ROC) curves were used to determine the optimal cut-off value of HLMR. Patients were then classified into high and low HLMR groups. The association between HLMR and clinicopathological characteristic was assessed using chi-square tests. Independent prognostic factors for overall survival (OS) and progression-free survival (PFS) were identified using Cox proportional hazards models. A nomogram was constructed based on the independent predictors to estimate patient survival rates, and internal validation was performed using a validation cohort.
RESULTS:
The ROC curve identified 605.5 as the optimal HLMR cut-off value for predicting 5-year survival. Multivariate Cox regression analysis revealed that T stage (HR=1.886, 95% CI 1.331 to 2.673, P<0.001), N stage (HR=2.021, 95% CI 1.267 to 3.225, P=0.003), Eastern Cooperative Oncology Group (ECOG) score (HR=3.991, 95% CI 1.257 to 12.677, P=0.019), concurrent chemoradiotherapy regimen (HR=0.338, 95% CI 0.156 to 0.731, P=0.006), and HLMR (HR=0.648, 95% CI 0.460 to 0.912, P=0.013) were independent prognostic factors for OS. A nomogram including T stage, N stage, and HLMR in the training cohort was constructed to predict 3-, 5-, and 7-year OS, with a C-index of 0.713. The area under the curves for predicting 3-, 5-, and 7-year OS were 0.744, 0.665, and 0.682, respectively. Calibration curves showed good agreement between predicted and observed survival rates. The above results were further confirmed in the validation cohort.
CONCLUSIONS
Pretreatment HLMR may serve as a promising prognostic biomarker for patients with nasopharyngeal carcinoma.
Humans
;
Nasopharyngeal Carcinoma/mortality*
;
Prognosis
;
Hemoglobins/analysis*
;
Nasopharyngeal Neoplasms/pathology*
;
Monocytes/cytology*
;
Female
;
Male
;
Retrospective Studies
;
Middle Aged
;
Adult
;
Aged
;
Nomograms
;
Chemoradiotherapy
;
ROC Curve
6.Individualized red-cell transfusion strategy for non-cardiac surgery in adults: a randomized controlled trial.
Ren LIAO ; Jin LIU ; Wei ZHANG ; Hong ZHENG ; Zhaoqiong ZHU ; Haorui SUN ; Zhangsheng YU ; Huiqun JIA ; Yanyuan SUN ; Li QIN ; Wenli YU ; Zhen LUO ; Yanqing CHEN ; Kexian ZHANG ; Lulu MA ; Hui YANG ; Hong WU ; Limin LIU ; Fang YUAN ; Hongwei XU ; Jianwen ZHANG ; Lei ZHANG ; Dexing LIU ; Han HUANG
Chinese Medical Journal 2023;136(23):2857-2866
BACKGROUND:
Red-cell transfusion is critical for surgery during the peri-operative period; however, the transfusion threshold remains controversial mainly owing to the diversity among patients. The patient's medical status should be evaluated before making a transfusion decision. Herein, we developed an individualized transfusion strategy using the West-China-Liu's Score based on the physiology of oxygen delivery/consumption balance and designed an open-label, multicenter, randomized clinical trial to verify whether it reduced red cell requirement as compared with that associated with restrictive and liberal strategies safely and effectively, providing valid evidence for peri-operative transfusion.
METHODS:
Patients aged >14 years undergoing elective non-cardiac surgery with estimated blood loss > 1000 mL or 20% blood volume and hemoglobin concentration <10 g/dL were randomly assigned to an individualized strategy, a restrictive strategy following China's guideline or a liberal strategy with a transfusion threshold of hemoglobin concentration <9.5 g/dL. We evaluated two primary outcomes: the proportion of patients who received red blood cells (superiority test) and a composite of in-hospital complications and all-cause mortality by day 30 (non-inferiority test).
RESULTS:
We enrolled 1182 patients: 379, 419, and 384 received individualized, restrictive, and liberal strategies, respectively. Approximately 30.6% (116/379) of patients in the individualized strategy received a red-cell transfusion, less than 62.5% (262/419) in the restrictive strategy (absolute risk difference, 31.92%; 97.5% confidence interval [CI]: 24.42-39.42%; odds ratio, 3.78%; 97.5% CI: 2.70-5.30%; P <0.001), and 89.8% (345/384) in the liberal strategy (absolute risk difference, 59.24%; 97.5% CI: 52.91-65.57%; odds ratio, 20.06; 97.5% CI: 12.74-31.57; P <0.001). No statistically significant differences were found in the composite of in-hospital complications and mortality by day 30 among the three strategies.
CONCLUSION:
The individualized red-cell transfusion strategy using the West-China-Liu's Score reduced red-cell transfusion without increasing in-hospital complications and mortality by day 30 when compared with restrictive and liberal strategies in elective non-cardiac surgeries.
TRIAL REGISTRATION
ClinicalTrials.gov, NCT01597232.
Humans
;
Adult
;
Postoperative Complications
;
Erythrocyte Transfusion/adverse effects*
;
Blood Transfusion
;
Hospitals
;
Hemoglobins/analysis*
7.Analysis of management efficacy in patients with heavy menstrual bleeding associated with antithrombotic therapy.
Xiao Lin JIANG ; Xin YAN ; Hui Na SU ; Yan Hua LIU ; Ru Xue HAN ; Zi Yi SONG ; Xiao Wan SUN ; De Hui SU ; Xin YANG
Chinese Journal of Obstetrics and Gynecology 2023;58(4):286-292
Objective: To evaluate different methods' efficacy of controlling acute bleeding and managing long-term menstruation in patients with heavy menstrual bleeding (HMB) associated with antithrombotic therapy. Methods: The clinical data of 22 cases with HMB associated with antithrombotic therapy admitted to Peking University People's Hospital from January 2010 to August 2022 were analyzed, aged 39 years old (26-46 years). Changes in menstrual volume, hemoglobin (Hb), and quality of life were collected after control of acute bleeding and long-term menstrual management. Menstrual volume was assessed by pictorial blood assessment chart (PBAC), and quality of life was assessed by menorrhagia multi-attribute scale (MMAS). Results: (1) Treatment of acute bleeding: of the 22 cases with HMB associated with antithrombotic therapy, 16 cases were treated in our hospital and 6 in other hospital for emergency bleeding; of the 16 cases treated in our hospital, 3 underwent emergency intrauterine Foley catheter balloon compression due to severe bleeding (Hb decreased by 20 to 40 g/L within 12 hours). Of the 22 cases with antithrombotic therapy-related HMB, 15 (including 2 cases with severe bleeding) underwent emergency aspiration or endometrial resection, and intraoperative placement of levonorgestrel-releasing intrauterine system (LNG-IUS) followed by a significant reduction in bleeding volume; 3 cases had controlled acute bleeding after rivaroxaban dose reduction and continued observation; 2 cases were given gonadotropin-releasing hormone agonists to control acute bleeding in other hospital, of which 1 case was temporarily treated with periodic blood transfusion, and the other one patient underwent total hysterectomy; and 2 cases had temporary amenorrhea with oral mifepristone after intrauterine balloon compression or oral norethindrone. (2) Long-term menstrual management: of the 22 cases with antithrombotic therapy-related HMB, 15 had LNG-IUS placement and 12 had LNG-IUS placement for 6 months, and menstrual volume was significantly reduced [PBAC scores were 365.0 (272.5-460.0) vs 25.0 (12.5-37.5), respectively; Z=4.593, P<0.001], Hb was significantly increased [91.5 g/L (71.8-108.2 g/L) vs 128.5 g/L (121.2-142.5 g/L); Z=4.695, P<0.001], and quality of life was significantly improved [MMAS scores were 415.0 (327.5-472.5) vs 580.0 (570.0-580.0), respectively; Z=-3.062, P=0.002] before placement compared with 6 months after placement. Three rivaroxaban dose reduction patients' PBAC scores decreased by 20 to 35 but remained >100, and perceived quality of life did not change significantly. Two cases with temporary amenorrhea treated with oral mifepristone felt significantly improved quality of life, and the MMAS scores increased by 220 and 180, respectively. Conclusion: Intrauterine Foley catheter balloon compression, aspiration or endometrial ablation could be used to control acute bleeding in patients with antithrombotic therapy-related HMB, and LNG-IUS for long-term management could reduce menstrual volume, increase hemoglobin, and improve the quality of life of patients.
Female
;
Humans
;
Adult
;
Menorrhagia/etiology*
;
Fibrinolytic Agents/adverse effects*
;
Levonorgestrel/adverse effects*
;
Amenorrhea/drug therapy*
;
Mifepristone/therapeutic use*
;
Quality of Life
;
Rivaroxaban/therapeutic use*
;
Hemoglobins
;
Intrauterine Devices, Medicated/adverse effects*
;
Contraceptive Agents, Female
9.Association between blood pressure during 12-28 weeks gestation and pre-eclampsia: predictive value of blood pressure trajectories constructed by latent class growth modeling.
Wei CAI ; Xin ZHOU ; Ning YANG ; Xiu Long NIU ; Guo Hong YANG ; Xin ZHANG ; Wei WANG ; Shao Bo CHEN ; Yu Ming LI
Chinese Journal of Cardiology 2023;51(2):164-171
Objective: To explore the associations between blood pressure trajectories during pregnancy and risk of future pre-eclampsia in a large cohort enrolling pregnant women at gestational age of ~12 weeks from community hospitals in Tianjin. Latent class growth modeling (LCGM) was used to model the blood pressure trajectories. Methods: This was a large prospective cohort study. The study enrolled pregnant women of ~12 weeks of gestation in 19 community hospitals in Tianjin from November 1, 2016 to May 30, 2018. We obtained related information during 5 antepartum examinations before gestational week 28, i.e., week 12, week 16, week 20, week 24 and week 28. LCGM was used to model longitudinal systolic (SBP) and diastolic blood pressure (DBP) trajectories. For the association study, the predictors were set as SBP and DBP trajectory membership (built separately), the outcome was defined as the occurrence of preeclampsia after 28 weeks of gestation. Results: A total of 5 809 cases with known pregnant outcomes were documented. After excluding 249 cases per exclusion criteria, 5 560 cases with singleton pregnancy were included for final analysis. There were 128 cases preeclampsia and 106 cases gestational hypertension in this cohort. Univariate logistic regression and multivariate logistic regression showed the higher baseline SBP level and DBP level were related with increased risk of preeclampsia. Four distinctive SBP trajectories and DBP trajectories from 12 weeks to 28 weeks of gestation were identified by LCGM. After controlling for potential confounders (baseline BMI, being primipara or not, white blood cell counts, hemoglobin level, platelet counts and alanine aminotransferase level), the OR for SBP latent classification trajectory_ 4 was 4.023 (95%CI: 2.368 to 6.835, P<0.001), and the OR for SBP latent classification trajectory_3 was 1.854 (95%CI: 1.223 to 2.811, P=0.004). Logistic regression showed that: using the DBP latent classification trajectory_1 as the reference group, the OR for DBP latent classification trajectory_4 was 4.100 (95%CI: 2.571 to 6.538, P<0.001), and 2.632 (95%CI: 1.570 to 4.414, P<0.001) for DBP latent classification trajectory_2. After controlling for potential confounders (baseline BMI, being primipara or not, white blood cell counts, hemoglobin level, platelet counts and alanine aminotransferase level), the OR for DBP_traj_4 was 2.527 (95%CI: 1.534 to 4.162, P<0.001), and the OR for DBP_traj_3 was 1.297 (95%CI: 0.790 to 2.128, P=0.303), and 2.238 (95%CI: 1.328 to 3.772, P=0.002) for DBP_traj_2. Therefore, BP trajectories from 12 weeks to 28 weeks identified by LCGM served as novel risk factors that independently associated with the occurrence of preeclampsia. Receiver operating characteristic (ROC) curve analysis showed incremental diagnostic performance by combing baseline blood pressure levels with blood pressure trajectories. Conclusion: By applying LCGM, we for the first time identified distinctive BP trajectories from gestational week 12 to 28, which can independently predict the development of preeclampsia after 28 weeks of gestation.
Female
;
Humans
;
Pregnancy
;
Infant
;
Blood Pressure
;
Pre-Eclampsia/diagnosis*
;
Prospective Studies
;
Gestational Age
;
Alanine Transaminase
;
Hemoglobins
10.Responses of blood parameters and hemoglobin subtypes in plateau zokors and plateau pikas to different altitude habitats.
Cong-Hui GAO ; Ji-Mei LI ; Bo XU ; Zhi-Fan AN ; Zhi-Jie WANG ; Xiao-Qi CHEN ; Jia-Yu ZHANG ; Deng-Bang WEI
Acta Physiologica Sinica 2023;75(1):69-81
The plateau zokor (Myospalax baileyi) and plateau pika (Ochotona curzoniae) are native species unique to the Qinghai-Tibetan Plateau with successful adaptation to the hypoxic environment. In this study, the number of red blood cells, hemoglobin concentration, mean hematocrit and mean volume of red blood cells were measured in plateau zokors and plateau pikas at different altitudes. Hemoglobin subtypes of two plateau animals were identified by mass spectrometry sequencing. The forward selection sites in two animals' hemoglobin subunits were analyzed by PAML4.8 program. Homologous modeling was used to analyze the effect of forward selection sites on the affinity of hemoglobin to oxygen. The adapting strategies of plateau zokors and plateau pikas to hypoxia at different altitudes were analyzed through comparing blood parameters between the two species. The results indicated that, with increasing altitudes, plateau zokors responded to hypoxia by increasing red blood cell count and decreasing red blood cell volume, while plateau pikas took the opposite strategies to plateau zokors. In erythrocytes of plateau pikas, both adult α2β2 and fetal α2ε2 hemoglobins were identified, while erythrocytes of plateau zokors only had adult α2β2 hemoglobin, however the affinities and the allosteric effects of the hemoglobin of plateau zokors were significantly higher than those of plateau pikas. Mechanistically, in the α and β subunits of hemoglobin of plateau zokors and pikas, the numbers and the sites of the positively selected amino acids as well as the side chain groups polarities and orientations of the amino acids differed significantly, which may result in the difference of the affinities to oxygen of hemoglobin between plateau zokors and pikas. In conclusion, the adaptive mechanisms to respond to hypoxia in blood properties of plateau zokors and plateau pikas are species-specific.
Animals
;
Altitude
;
Amino Acids
;
Hemoglobins
;
Hypoxia
;
Lagomorpha

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