Myeloid CD34+CD13+ Precursor Cells Transdifferentiate into Chondrocyte-Like Cells in Atherosclerotic Intimal Calcification

Chondrogenic differentiation is pivotal in the active regulation of artery calcification. We investigated the cellular origin of chondrocyte-like cells in atherosclerotic intimal calcification of C57BL/6 LDLr^−/− mice using bone marrow transplantation to trace ROSA26-LacZ-labeled cells. Immunohistochemical costaining of collagen type II with LacZ and leukocyte defining surface antigens was performed and analyzed by high-resolution confocal microscopy. Chondrocyte-like cells were detected in medium and advanced atherosclerotic plaques accounting for 7.1 ± 1.6% and 14.1 ± 1.7% of the total plaque cellularity, respectively. Chimera analysis exhibited a mean of 89.8% LacZ⁺ cells in peripheral blood and collagen type II costaining with LcZ revealed an average 88.8 ± 7.6% cytoplasmatic LacZ⁺ evidence within the chondrocyte-like cells. To examine whether hematopoietic stem cells contribute to the phenotype, stem cell marker CD34 and myeloid progenitor-associated antigen CD13 were analyzed. CD34⁺ was detectable in 86.9 ± 8.1% and CD13⁺ evidence in 54.2 ± 7.6% of chondrocyte-like cells, attributable most likely because of loss of surface markers during transdifferentiation. Chondrocyte differentiation factor Sox-9 was detected in association with chondrocyte-like cells, whereas Sm22α, a marker for smooth muscle cells, could not be demonstrated. The results show that the majority of chondrocyte-like cells were of bone marrow origin, whereas CD34⁺/CD13⁺ myeloid precursors appeared to infiltrate the plaque actively and transdifferentiated into chondrocytes-like cells in the progression of atherosclerosis.Vascular calcification continues to be a major cause of death and disability in the developed nations.¹ The extent of the calcification process is associated with atherosclerotic plaque burden and a heightened risk of myocardial infarction² resulting in significant morbidity and mortality. Long considered as a passive degenerative process, converging evidence from both in vitro and in vivo analysis provide considerable evidence that vascular calcification shares intriguing similarities with bone formation.³ Chondrocyte and osteoblastic metaplasia within sites of arterial calcification has been reported in humans and mice.⁴ Evidence is overwhelming that osteoblasts and chondrocyte-like cells actively promote the calcification process analogous to endochondral bone formation.⁵ The origin of cells differentiating into chondrocytes or osteoblasts has long remained unknown. Three hypotheses have been postulated: local pericytes from the tunica adventitia, vascular smooth muscle cells (VSMC) from the tunica media, or progenitor cells derived from bone marrow.⁶Media calcification is found mainly in patients with diabetes mellitus type 2 and chronic kidney disease⁷ and is associated with an increased risk of amputation and higher cardiovascular mortality.⁸ In an elegant work Speer et al⁹ recently demonstrated that chondrocyte-like cells in MGP^−/− mice, a mouse model of medial artery calcification were derived from transdifferentiation of mature smooth muscle cells.Intimal arterial calcification is the most common form of calcific vasculopathy with chronic inflammation as fundamental pathophysiological mechanism of the disease.¹⁰ The high-fat fed LDLR^−/− mouse develops in a sequential fashion both medial and atherosclerotic calcification, the latter pronounced after 2 months and worsened by uremia.¹¹ Recently, Duer et al¹² examined the nanostructure of calcium deposits within calcified human atherosclerotic plaques and demonstrated marked morphological similarities compared with skeletal bone emphasizing the active regulation of the process. Morony et al¹³ demonstrated that atherosclerotic intimal calcification could significantly be reduced in C57BL/6 LDLr^−/− mice by treatment with recombinant osteoprotegerin (Fc-OPG). Although leaving the atherosclerosis progression untouched, vascular intimal calcification as induced by chondrocyte-like cells was decreased, suggesting that the process of atherosclerosis and vascular calcification can be uncoupled. The authors hypothesized that the attenuation of vascular calcification was achieved by systemic long-term receptor activator of NF-κB ligand (RANKL) inhibition via OPG treatment. OPG is a known inhibitor of bone resorption and OPG serum levels displayed a positive correlation with the progression of atherosclerosis, coronary artery disease, stroke, and cardiovascular morbidity and mortality.¹⁴ OPG is a decoy receptor for RANKL, which is known to be a considerable mediator in osteoclastogenesis.¹⁵ Moreover, RANKL involvement is needed in lymph node genesis, activation, and survival of leukocytes from myeloid origin as well as differentiation of leukocytes.¹⁶An in vitro study with adult pluripotent cells derived from human peripheral blood monocytes showed transdifferentiation from a monocyte-like structure to a chondrocyte-like structure, indicating that these myeloid cells have the potential to differentiate into collagen type II synthesizing chondrocytes.¹⁷ Moreover, Shafer et al¹⁸ recently demonstrated that early chondrocyte progenitors were of myeloid origin in a mouse model of chondrocyte differentiation.Here we report that contrary to medial artery calcification in MGP^−/− mice, where chondrocyte metaplasia is based on smooth muscle cell transdifferentiation, chondrocyte-like cells emerging in this mouse model examining atherosclerotic intimal calcification are of bone marrow- derived myeloid origin. Moreover, we provide evidence that the differentiation process is mediated by induction of the NF-κB ligand RANKL.     

Silencing of hypoxia-inducible tumor suppressor lysyl oxidase gene by promoter methylation activates carbonic anhydrase IX in nasopharyngeal carcinoma

Lysyl oxidase (LOX) is an oxidative enzyme known to initiate the cross-linking of collagens and elastin, and suggested recently as a tumor suppressor for several tumor types including lung, pancreatic and gastric cancers. Previously we showed that LOX is strongly induced upon hypoxia in nasopharyngeal carcinoma (NPC) cell lines CNE2 and HONE1 but only slightly in HK1 and not in C666-1. Here, we further studied the regulatory mechanism and functions of LOX in NPC. LOX is widely expressed in human normal tissues with variations in expression levels. LOX was expressed in most NPC cell lines except for C666-1, while HK1 and FaDu (laryngeal cancer) only expressed low level of LOX. Methylation analysis showed that the LOX promoter was methylated in C666-1 and partially methylated in HK1. After demethylation with 5-aza-2’-deoxycytidine, LOX expression was reactivated along with increased unmethylated alleles. LOX promoter methylation was detected in 42/49 (85.7%) of NPC primary tumors but only 3/16 (18.75%) of nose swab samples from NPC patients. LOX overexpression reduced the clonogenicity and cell growth of NPC cells, and also inhibited the migration and invasion of the NPC cells. Carbonic anhydrase IX (CA9) mRNA level was obviously decreased in HK1 cells after transfection with LOX. The elevation of CA9 protein upon hypoxia was inhibited in LOX-transfected HK1 cells. The protein levels of an apoptosis marker cPARP were increased in LOX-transfected HK1 cells upon hypoxia treatment. Our data showed that silencing or down-regulation of LOX in NPC was due to its promoter methylation and LOX acts as a tumor suppressor in NPC. LOX silencing would facilitate NPC cells to escape from hypoxia-induced apoptosis and maintains a malignant and metastatic phenotype.     

A novel system for providing compatible blood to patients during surgery: "self-service" electronic blood banking by nursing staff

BACKGROUND: A good blood bank must be able to provide compatible blood units promptly to operating room patients with minimal wastage. A "self- service" by nursing staff blood banking system that is safe, efficient, and well-accepted has been developed. STUDY DESIGN AND METHODS: Specific blood units are no longer assigned to surgical patients who have a negative pretransfusion antibody screen, irrespective of the type of surgery. A computer-generated list of the serial numbers of all group-identical blood units currently in the blood bank inventory is provided for each patient. The units themselves are not labeled with a patient's name. The group O list will be provided for group O patients, the group A list for group A patients, and so forth. Should the patient require transfusion during surgery, the operating room nurses go to the refrigerator, remove any group-identical unit, and check the serial number of the unit against the serial numbers on the patient's list. If the serial number is on that list, the blood bank will accept responsibility for compatibility. The system was implemented in 1995. RESULTS: Since implementation, a total of 2154 patients have undergone operations at this hospital. Thirty-two patients received more than 10 units of red cells each. There were no transfusion errors. The crossmatch-to-transfusion ratio was reduced from 1.67 to 1.12. Turnaround time for supplying additional or urgent units to patients in operating room was shortened from 33 to 2.5 minutes. There was no incidence of a blood unit's serial number not being on the list. Work by nurses and technical staff was reduced by nearly 50 percent. CONCLUSION: The "self-service" (by nursing staff) blood banking system described is safe and efficient. It saves staff time and can be easily set up.     

整合蛋白α5亚基表达与肝癌恶性表型

目的探讨整合蛋白α５亚基与原发性肝癌的关系。方法应用免疫组化技术（ＡＢＣ法）和Ｎｏｒｔｈｅｒｎｂｌｏｔ杂交检测整合蛋白α５亚基在原发性肝癌中的表达。结果发现在７９例癌与癌周组织α５阳性率分别为３２．９％和８１．０％，两者间差异有显著性（Ｐ＜０．０１）。直径≤５ｃｍ的肝癌α５阳性率高于直径＞１０ｃｍ的肝癌（５５．６％比１０．０％，Ｐ＜０．０１），分化较好的肝癌α５阳性率高于分化不良者（４０．６％比１６．０％，Ｐ＜０．０５），已发生明确肝内转移（包括肝内播散和门静脉癌栓形成）的肝癌α５阳性率低于未发生肝内转移者（２０．６％比４２．２％，Ｐ＜０．０５）。α５亚基表达与患者年龄、血清甲胎蛋白水平、乙型肝炎病毒感染、肝硬化有无等因素均无明显相关（Ｐ＞０．０５）。Ｎｏｒｔｈｅｒｎｂｌｏｔ杂交结果也同时显示，非侵袭性肝癌α５表达高于侵袭性肝癌。结论整合蛋白α５低表达与肝癌增大、分化程度低、侵袭转移发生等恶性表型相关，可能对这些恶性表型起负性调节作用。     

Role of routine imaging in detecting recurrent lymphoma: A review of 258 patients with relapsed aggressive non‐Hodgkin and Hodgkin lymphoma

After first‐line therapy, patients with Hodgkin lymphoma (HL) and aggressive non‐HL are followed up closely for early signs of relapse. The current follow‐up practice with frequent use of surveillance imaging is highly controversial and warrants a critical evaluation. Therefore, a retrospective multicenter study of relapsed HL and aggressive non‐HL (nodal T‐cell and diffuse large B‐cell lymphomas) was conducted. All included patients had been diagnosed during the period 2002–2011 and relapsed after achieving complete remission on first‐line therapy. Characteristics and outcome of imaging‐detected relapses were compared with other relapses. A total of 258 patients with recurrent lymphoma were included in the study. Relapse investigations were initiated outside preplanned visits in 52% of the patients. Relapse detection could be attributed to patient‐reported symptoms alone or in combination with abnormal blood tests or physical examination in 64% of the patients. Routine imaging prompted relapse investigations in 27% of the patients. The estimated number of routine scans per relapse was 91–255 depending on the lymphoma subtype. Patients with imaging‐detected relapse had lower disease burden (P = 0.045) and reduced risk of death following relapse (hazard ratio = 0.62, P = 0.02 in multivariate analysis). Patient‐reported symptoms are still the most common factor for detecting lymphoma relapse and the high number of scans per relapse calls for improved criteria for use of surveillance imaging. However, imaging‐detected relapse was associated with lower disease burden and a possible survival advantage. The future role of routine surveillance imaging should be defined in a randomized trial. Am. J. Hematol. 89:575–580, 2014. © 2014 Wiley Periodicals, Inc.     

Effect of direct-acting oral anticoagulants (DOACs) on bleeding and blood product usage in cardiac surgery compared to warfarin and controls

In this retrospective, single-centre, observational study, we assessed (i) use of anticoagulant and antiplatelet (AP) therapy, (ii) the duration of direct-acting oral anticoagulant (DOAC) discontinuation, (iii) renal function and (iv) PT and APTT as predictors of bleeding and blood product usage; in adults (>18 years) undergoing major cardiac surgery from 01.01.2015 to 31.12.2018. Comparisons were made between each treatment group (warfarin, DOAC and DOAC + AP) and untreated controls, and between warfarin and DOAC. A total of 2928 patients were included for analysis. Median (range) of DOAC discontinuation prior to surgery was five days (1–22) for DOAC and five days (2–7) for DOAC + AP. There were no differences in bleeding between anticoagulant groups versus control, or DOAC versus warfarin. There were no differences in blood product use between DOAC and warfarin patients. The duration of DOAC discontinuation but not the creatinine clearance influenced bleeding and blood products use. Thrombosis occurred in 0·7% and 3·1% in controls and patients on warfarin respectively (P = 0·099) with none among patients on DOAC or DOAC + AP. The PT/APTT had no predictive value. Median five-day discontinuation of DOAC +/− AP irrespective of renal function prevents an increase in bleeding compared to patients on warfarin or controls with no increase in thrombosis.