The effect of maize-alfalfa intercropping on the physiological characteristics, nitrogen uptake and yield of maize

In Northeastern China, the intensive cropping system and increased use of chemical fertilizer has caused severe problems in terms of sustainable agricultural development. Therefore, to improve agricultural sustainability and crop productivity the farming system needs to be modified in the region. A pot experiment was conducted to evaluate the effect of maize-alfalfa intercropping on the physiological characteristics, nitrogen (N) uptake and yield of the maize crops in northeast China in 2017-2018. The study findings showed that intercropping under N fertilization progressively improved the physio-agronomic indices of the maize crop as compared to mono-cropping. The grain yield, 100 seed weight and biomass dry matter of maize crop improved in intercropping when it was practiced with N fertilizer. Furthermore, intercropping with N fertilization increased the chlorophyll content of the maize crop at bell-mouthed, silking, filing and mature stages by 19%, 44%, 12%, and 9% in 2017 and by 23%, 43%, 15%, and 11% in 2018, respectively, as compared with the monocropping system. Unlike monocropping, intercropping with N fertilization increased the photosynthesis rate (14% and 15%), stomatal conductance (74% and 98%) and transpiration rate (74% and 75%) in 2017 and 2018, respectively. However, intercropping reduced intercellular CO₂ (C_i ). Moreover, intercropping with N fertilization increased the maize N content of grain and leaves as well as total N uptake by 49%, 31% and 93% in 2017 and 53%, 34% and 132%, respectively, in 2018 as compared to monocropping. In conclusion, our results suggest that maize-alfalfa intercropping with optimal N fertilization provides a practical method for improving growth, yield and N accumulation in the maize crop.

Targeting SKP2/Bcr-Abl pathway with Diosmetin suppresses chronic myeloid leukemia proliferation

Bcr-Abl is the primary cause as well as currently key therapeutic target of chronic myeloid leukemia (CML). SKP2, an E3 ligase, is a downstream factor of Bcr-Abl to motivate the cell cycle transition of CML and also found to bind and activate Bcr-Abl in reverse. Therefore, SKP2/Bcr-Abl pathway is an attractive target for CML treatment. This study aims to identify an inhibitor of the SKP2/Bcr-Abl pathway based on a large screening of the natural products. We demonstrate that Diosmetin, a kind of phytoestrogens, notably downregulates the expression of SKP2, Bcr-Abl phosphorylation, and moderately downregulates the Bcr-Abl level. Furthermore, Diosmetin displays a favorable anti-tumor activity in CML cells and xenograft models. Collectively, our study reveals a natural compound in the treatment of CML on the basis of SKP2/Bcr-Abl signaling pathway.

Targeting ERα degradation by L-Tetrahydropalmatine provides a novel strategy for breast cancer treatment

The incidence and mortality of breast cancer (BCa) are the highest among female cancers. There are approximate 70% BCa that are classified as estrogen receptor alpha (ERα) positive. Therefore, targeting ERα is the most significantly therapeutic schedule. However, patients with breast cancer develop resistance to ERα or estrogen (E2) antagonists such as fulvestrant and tamoxifen. In the present study, we found that L-Tetrahydropalmatine (L-THP) significantly suppressed cell proliferation in ERα⁺ BCa cells via inducing cell cycle arrest rather than apoptosis. Additionally, L-THP enhanced the sensitivity of ERα⁺ BCa cells to tamoxifen and fulvestrant. Mechanically, the application of L-THP promotes ERα degradation through accumulating ubiquitin chains on ERα. Overexpressing ERα abrogates L-THP induced-antiproliferation in ERα⁺ BCa cells. Collectively, our work indicates that L-THP may represent a potentially novel therapeutic medicine for ERα⁺ breast cancer patient.

Targeting GRP78-dependent AR-V7 protein degradation overcomes castration-resistance in prostate cancer therapy

Rationale: Androgen receptor splice variant 7 (AR-V7) is a leading cause of the development of castration-resistant prostate cancer (CRPC). However, the regulation and function of AR-V7 at levels of post-translational modifications in prostate cancer therapy remain poorly understood. Here, we conducted a library screen of natural products to identify potential small molecules responsible for AR-V7 protein degradation in human prostate cancer cell lines.

Methods: A natural product library was used to screen the inhibitor of AR-V7. Co-IP and biomass spectrum assays were used to identify the AR-V7-interacting proteins, whereas western blot, confocal microscopy, RNA interfering, and gene transfection were used to validate these interactions. Cell viability, EDU staining, and colony formation assays were employed to detect cell growth and proliferation. Flowcytometry assays were used to detect the distribution of cell cycle. Mouse xenograft models were used to study the anti-CRPC effects in vivo.

Results: This screen identified rutaecarpine, one of the major components of the Chinese medicine Evodia rutaecarpa, as a novel chemical that selectively induces AR-V7 protein degradation via K48-linked ubiquitination. Mechanically, this effect relies on rutaecarpine inducing the formation of a GRP78-AR-V7 protein complex, which further recruits the E3 ligase SIAH2 to directly promote the ubiquitination of AR-V7. Consequently, the genetic and pharmacological activation of the GRP78-dependent AR-V7 protein degradation restores the sensitivity of castration-resistant prostate cancer to anti-androgen therapy in cell culture and animal models.

Conclusions: These findings not only provide a new approach for overcoming castration-resistance in prostate cancer therapy, but also increase our understanding about the interplay between molecular chaperones and ubiquitin ligase in shaping protein stability.

TGF-β signaling in intervertebral disc health and disease

OBJECTIVE

This paper aims to provide a comprehensive review of the changing role of transforming growth factor-β (TGF-β) signaling in intervertebral disc (IVD) health and disease.

METHODS

A comprehensive literature search was performed using PubMed terms 'TGF-β' and 'IVD'.

RESULTS

TGF-β signaling is necessary for the development and growth of IVD, and can play a protective role in the restoration of IVD tissues by stimulating matrix synthesis, inhibiting matrix catabolism, inflammatory response and cell loss. However, excessive activation of TGF-β signaling is detrimental to the IVD, and inhibition of the aberrant TGF-β signaling can delay IVD degeneration.

CONCLUSIONS

Activation of TGF-β signaling has a promising treatment prospect for IVD degeneration, while excessive activation of TGF-β signaling may contribute to the progression of IVD degeneration. Studies aimed at elucidating the changing role of TGF-β signaling in IVD at different pathophysiological stages and its specific molecular mechanisms are needed, and these studies will contribute to safe and effective TGF-β signaling-based treatments for IVD degeneration.

Mandibular reconstruction using the deep circumflex iliac artery free flap: effect of the length of bone harvested on donor site morbidity

The aim of this study was to assess the amounts of pain and morbidity that are associated with the length of the harvested anterior iliac bone graft (cm), and their effect on the contour of the donor site and activities of daily life. A total of 62 patients who had mandibular reconstruction using an iliac bone graft were enrolled in this study at the Wuhan University Hospital. The same surgical standards were used throughout. We divided the patients into two groups depending to the length of the graft (<9cm or 9cm or more). The amount and duration of the pain, the time necessary to walk normally, abnormalities of sensation, contour of the donor site, length of the scar, and the patients' satisfaction with the donor site were evaluated, and outcomes in the two groups compared. The worst pain after operation (p=0.001) the length of the scar (p=0.001), and the time needed before the patients were able to walk (p=0.001) differed significantly between the two groups. There was no significant difference between the two groups regarding other complications. The anterior iliac crest might still be considered to be an ideal donor site for large mandibular defects.

[Analysis of prognostic factors for hyperamylasemia following pancreaticoduodenectomy]

Objective: To investigate the prognostic factors of hyperamylasemia following pancreaticoduodenectomy (PD) . Methods: Clinical data of 359 patients were collected prospectively who underwent PD by the same group at Changhai Hospital of Navy Medical University from January 2017 to June 2018.There were 212 males and 147 females.The median age was 63 years old (range: 23 to 82 years old) .According to whether the patient's serum amylase was greater than 120 U/L at 0 or 1 day after surgery,the patients were divided into hyperamylasemia group and non-hyperamylasemia group. Univariate analysis and multivariate analysis were used to find out the prognostic factors of hyperamylasemia after PD. Results: Of the 359 patients, 238 cases (66.3%) developed hyperamylasemia.The incidence rate of clinically related pancreatic fistula (15.1% vs.2.5%, P<0.01) , grade B/C post pancreatectomy hemorrhage (8.8% vs. 2.5%, P<0.01) , and surgical site infection (9.2% vs. 3.3%, P=0.04) was significantly higher in the hyperamylasemia group.The severity of complications (CD grade≥Ⅲ: 11.3% vs.4.1%, P=0.023) and postoperative hospital stay (11 days vs. 9 days, P=0.001) were higher in the hyperamylasemia group.In the multivariate analysis, the main pancreatic duct diameter (MPD) ≤3 mm (OR=4.469, 95% CI: 2.563-7.793, P<0.01) , pathological type of disease (pancreatic cancer or pancreatitis) (OR=0.230, 95% CI: 0.122-0.436, P<0.01) and soft texture of pancreas (OR=3.297, 95%CI: 1.930-5.635, P<0.01) were independent prognostic factors for hyperamylasemia. Conclusions: Post-PD hyperamylasemia increased the incidence and severity of postoperative complications after PD.MPD≤3 mm, soft texture of pancreas and pathological type of disease were independent prognostic factors of hyperamylasemia.

Resection of liver metastases from breast cancer: a multicentre analysis

BACKGROUND

Surgery is becoming more practical and effective than conservative treatment in improving the poor outcomes of patients with breast cancer liver metastasis (BCLM). However, there is no generally acknowledged set of standards for identifying BCLM candidates who will benefit from surgery.

METHODS

Between January 2011 and September 2018, 67 female BCLM patients who underwent partial hepatectomy were selected for analysis in the present study. Prognostic factors after hepatectomy were determined. Univariate and multivariate analyses were performed to identify predictors of overall survival (OS) and intrahepatic recurrence-free survival (IHRFS).

RESULTS

The 1-, 3- and 5-year OS of patients treated with surgery was 93.5%, 73.7% and 32.2%, respectively, with a median survival time of 57.59 months. The Pringle manoeuvre [hazard radio (HR) = 0.117, 95% CI0.015-0.942, p = 0.044] and an increased interval between breast surgery and BCLM diagnosis (HR0.178, 95% CI 0.037-0.869, p = 0.033) independently predicted improved overall survival for BCLM patients. The 1-, 2- and 3-year IHRFS of patients who underwent surgery was 62.8, 32.6% and 10.9%, respectively, with a median intrahepatic recurrence-free survival time of 13.47 months. Moderately differentiated tumours (HR  0.259, 95% CI 0.078-0.857, p = 0.027) and the development of liver metastasis more than 2 years after breast surgery (HR  0.270, 95% CI 0.108-0.675, p = 0.005) might be predictors of increased IHRFS.

CONCLUSIONS

An interval of more than 2 years between breast cancer surgery and liver metastasis seems to be an indication of liver surgery in BCLM patients. The Pringle manoeuvre and moderately differentiated tumours are potential predictors associated with OS and IHRFS, respectively, as benefits from liver resection. Studies with increased sample sizes are warranted to validate our results.

Abstract P6-17-17: Pertuzumab, trastuzumab, and docetaxel for HER2-positive early or locally advanced breast cancer in the neoadjuvant setting: Efficacy and safety analysis of a randomized phase III study in Asian patients (PEONY)

Background

Pertuzumab and trastuzumab (P and H; F. Hoffmann-La Roche Ltd, Basel, CH) bind to distinct HER2 subdomains and have complementary modes of anticancer activity in HER2-positive breast cancer (BC). A global Phase II study (NeoSphere) reported that neoadjuvant treatment with P+H+docetaxel (D) significantly increased breast pathologic complete response (bpCR) vs H+D in patients (pts) with early/locally advanced/inflammatory HER2-positive BC (Gianni et al. Lancet Oncol 2012). PEONY (NCT02586025), a randomized, multicenter, double-blind, placebo-controlled, Phase III trial conducted in an Asian population (mainland China, Taiwan, Korea, Thailand), primarily compared the efficacy, safety, and tolerability of P+H+D vs placebo (Pla)+H+D in the neoadjuvant setting. We present data from the primary analysis.

Methods

Pts with centrally confirmed HER2-positive early (T2–3, N0–1)/locally advanced (T2–3, N2 or N3; T4, any N) BC were randomized 2:1 to 4 cycles of P+H+D or Pla+H+D every 3 weeks, before surgery: P, 840 mg loading/420 mg maintenance doses (or Pla); H, 8 mg/kg loading/6 mg/kg maintenance; D, 75 mg/m2. Post-surgery, pts received 3 cycles of fluorouracil, epirubicin, and cyclophosphamide followed by 13 cycles of P+H or Pla+H for up to 1 year (total of 17 HER2-targeted therapy cycles). The primary endpoint was total pCR rate (tpCR; absence of any residual invasive cancer in the breast and lymph nodes [ypT0/is, ypN0]) assessed by independent review committee (IRC) when pts completed surgery with a tpCR assessment. Missing/invalid assessments were considered residual disease.

Results

A total of 329 pts were randomized: 219 to P, 110 to Pla. Baseline characteristics were well balanced. Most pts had early BC (69.6%) and were from mainland China (79.3%). In the intention-to-treat population, the tpCR rate by IRC was 39.3% in the P arm and 21.8% in the Pla arm; a clinically and statistically significant difference of 17.5% (95% CI 6.9–28.0; p=0.0014). The local pathologist-assessed tpCR rates were 39.3% and 20.9%, respectively. A consistent treatment benefit of P vs Pla was observed in subgroups. Incidences of grade ≥3 adverse events (Aes) were 48.6% in the P arm and 41.8% in the Pla arm. Of the most common grade 3 Aes (≥3% of pts), neutropenia was higher in the P arm (38.1% vs 32.7%). Of the most common any-grade Aes (≥5%), diarrhea was higher in the P arm (38.5% vs 16.4%). No heart failure (New York Heart Association Functional Classification III or IV) or significant left ventricular ejection fraction decline events (≥10 percentage points from baseline and to &lt;50%) were observed during neoadjuvant therapy.

Conclusions

PEONY met its primary endpoint: P+H+D resulted in a clinically meaningful and statistically significant improvement in the tpCR rate by IRC vs Pla+H+D for the neoadjuvant treatment of HER2-positive early/locally advanced BC in Asian pts. Safety data were in line with the known P safety profile and generally comparable between treatment arms. Results were similar to NeoSphere, and confirm that P+H+D provides superior anticancer activity to H+D alone.

Citation Format: Shao Z, Pang D, Yang H, Li W, Wang S, Cui S, Liao N, Wang Y, Wang C, Chang Y-C, Wang H, Kang SY, Jiang Z, Li J, Zhou J, Althaus B, Mao Y, Eng-Wong J. Pertuzumab, trastuzumab, and docetaxel for HER2-positive early or locally advanced breast cancer in the neoadjuvant setting: Efficacy and safety analysis of a randomized phase III study in Asian patients (PEONY) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-17.

Abstract P4-08-18: Not presented

This abstract was not presented at the conference.

Citation Format: Liu Y, Chen S, Jiang Y, Wu J, Shao Z. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-18.

Abstract P1-06-10: Combined tandem affinity purification mass-spectrometry technique with genome-editing CRISPR-Cas9 knockout screening to identify potential subunits in the BRCA1 complex

Background: Genomic instability is one of tumor characteristics. Enhancing the DNA damage load or impairing the ability of DNA damage repair has been therapeutics of cancer. Breast cancer type 1 susceptibility gene (BRCA1) has been studied a lot about the DNA damage and repair in breast cancer and ovarian cancer. BRCA1 mutation increases the risk of developing breast cancer by an eighth to tenth. The C terminal domain of BRCA1 can associates with three proteins Abraxas, Bach1 and CtIP in a phosphorylation-dependent manner forming mutually exclusive complexes, namely BRCA1-A, B, and C complexes. The BRCA1-A complex is necessary in DNA damage repair, and study implicates the complex play roles in chemotherapy resistance.

Methods: We explored tandem affinity purification mass-spectrometry (TAP-MAS) technique to identify potential subunits associated with NBA1(one component of BRCA1-A complex). Then we made the genome-editing CRISPR-Cas9 sgRNA library into lentivirus to infect U2OS cells. And 5 Gy dose of Ionizing radiation (IR) was used to induce DNA damage on the cell. After 14 days cultivation, we extracted the DNA from the cells, performed polymerase chain reaction (PCR) and analyzed the correlation between potential genes and DNA damage-repair passage by bioinformatics methods. We generated 200 breast cancer patient tissue samples in our cancer center and performed immunostaining assay.

Results: By the TAP-MAS technique of NBA1 tagged with HA and Flag, we found 93 potential subunits except those known subunits in BRCA1-A complex. Combined with CRISPR-Cas9 sgRNA library screening, we scored the relativity of DNA damage and repair passageway of identified 93 potential subunits. We found that nucleoside-triphosphatase, cancer-related (NTPCR) as a new potential subunit of BRCA1-A complex (P value=0.0034) had the highest score. Endogenous and exogenous co-IP validated NTPCR physically associates with subunits within BRCA1-A complex. Besides, we found that NTPCR associated with the same domain of NBA1 as the other subunits in BRCA1-A complex. Immunohistochemistry of patient tissue samples indicated that high levels of NTPCR expression was correlated with poor prognosis in multivariate analysis (HR: 4.990; 95%CI: 1.433-17.378; p value: 0.012).

Conclusion: NTPCR is a new subunit in BRCA1-A complex. And high expression of NTPCR is a negative prognostic factor in breast cancer patients.

Citation Format: Zhao H, Jiang H, Sun W, Shao Z, Hu X. Combined tandem affinity purification mass-spectrometry technique with genome-editing CRISPR-Cas9 knockout screening to identify potential subunits in the BRCA1 complex [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-06-10.

Abstract P2-08-33: A novel seven-gene signature predicts prognosis in early-stage triple-negative breast cancer

Purpose:

Chemotherapy remains the only systemic treatment option for patients with triple-negative breast cancer (TNBC). However, due to the heterogeneity of TNBC, not all patients benefit from chemotherapy, especially those with early-stage disease. In order to improve prognostic assessment and reduce unnecessary adjuvant systemic therapy in these patients, we have developed a novel seven-gene signature.

Experimental Design:

With the ComBat method, we integrated the results from 150 transcriptome microarrays samples and 246 RNA-seq samples of early-stage TNBC patients, and identified mRNAs associated with recurrence-free survival (RFS) using Lasso-Cox model, We further analyzed these TNBC samples and compared them with 60 paired normal breast tissues (40 samples from RNA-seq and 20 samples from microarrays) to identify tumor-specific mRNAs. Twenty-one overlapped mRNAs of the RFS-associated mRNAs and the tumor-specific mRNAs are selected as candidate mRNAs. An additional 371 samples of frozen primary tumors were then collected from early-stage TNBC patients (mean follow-up of 45 months) and randomly divided into two sets: a training set (n = 186) and a validation (n = 185) set. Expression level of candidate mRNAs in these samples were measured using RT-qPCR assays, and a seven-gene signature was built through all subset regression in the training set. The prognostic and predictive accuracy of our signature was tested in the validation set and other public databases (GSE5327, GSE2034 and METABRIC).

Results:

Twenty-one candidate mRNAs were identified in early-stage TNBC patients, from which we developed a novel seven-gene signature (recurrence risk score [mRNA signature] = 1.108*TMEM101 - 0.213*KRT5 - 0.315*ACAN - 0.464*LCA5 + 0.446*RPP40 - 0.373*LAGE3 - 0.257*CDKL2). Patients in the training set were classified into high- or low-risk group based on our seven-gene signature and an optimum cut-off score derived from x-tile. The patients in high-risk group were more likely to suffer from recurrence (HR, 2.718; 95% confidence interval [CI], 1.928–3.726, P= 0.001), and a time-dependent receiver operating curve showed that the seven-gene mRNA signature had a better prognostic value than the clinicopathologic risk factors in both training set and validation set. The prognostic and predictive accuracy of the signature was also validated in the METABRIC and two other public GEO databases (GSE5327 and GSE2034). The time-dependent receiver operating curve showed that this signature had an area under the curve (AUC) of 0.742 (95% CI, 0.705-0.773) in METABRIC, 0.716 (95% CI, 0.682-0.739) and 0.723 (95% CI, 0.683-0.756) in GSE5327 and GSE2034 respectively.

Conclusion:

In this study, we developed a novel seven-gene signature which can provide additional prognostic information and may guidance in identifying early-stage TNBC patients eligible for adjuvant therapy or reduction of chemotherapy. To our knowledge, this is the first study investigating the prognostic potential of mRNA signature in early-stage triple-negative breast cancer. Our novel signature may provide an opportunity for de-escalating treatment in early-stage TNBC patients in the future.

Citation Format: Ren Y, Jiang Y, Zuo W, Xu X, Jin X, Ma D, Shao Z. A novel seven-gene signature predicts prognosis in early-stage triple-negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-33.

Mechanisms of endogenous repair failure during intervertebral disc degeneration

Intervertebral disc (IVD) degeneration is frequently associated with Low back pain (LBP), which can severely reduce the quality of human life and cause enormous economic loss. However, there is a lack of long-lasting and effective therapies for IVD degeneration at present. Recently, stem cell based tissue engineering techniques have provided novel and promising treatment for the repair of degenerative IVDs. Numerous studies showed that stem/progenitor cells exist naturally in IVDs and could migrate from their niche to the IVD to maintain the quantity of nucleus pulposus (NP) cells. Unfortunately, these endogenous repair processes cannot prevent IVD degeneration as effectively as expected. Therefore, theoretical basis for regeneration of the NP in situ can be obtained from studying the mechanisms of endogenous repair failure during IVD degeneration. Although there have been few researches to study the mechanism of cell death and migration of stem/progenitor cells in IVD so far, studies demonstrated that the major inducing factors (compression and hypoxia) of IVD degeneration could decrease the number of NP cells by regulating apoptosis, autophagy, and necroptosis, and the particular chemokines and their receptors played a vital role in the migration of mesenchymal stem cells (MSCs). These studies provide a clue for revealing the mechanisms of endogenous repair failure during IVD degeneration. This article reviewed the current research situation and progress of the mechanisms through which IVD stem/progenitor cells failed to repair IVD tissues during IVD degeneration. Such studies provide an innovative research direction for endogenous repair and a new potential treatment strategy for IVD degeneration.

Carboxypeptidase B2 and N play different roles in regulation of activated complements C3a and C5a in mice

Essentials Two basic carboxypeptidases are present in plasma, B2 (CPB2) and N (CPN). Cpb2-/- and Cpn-/- mice were challenged in a hemolytic uremic syndrome (HUS) model vs. wild type. Cpb2-/- exacerbates HUS while Cpn-/- exacerbates cobra venom factor challenge vs. wild type mice. CPB2 and CPN have overlapping but non-redundant roles.

SUMMARY

Background There are two basic carboxypeptidases in plasma. Carboxypeptidase B2 (CPB2) is activated from a circulating zymogen, proCPB2, and carboxypeptidase N (CPN) is constitutively active with both inactivating complement C3a and C5a. Aims To test the roles of CPB2 and CPN in complement-driven mouse models of cobra venom factor (CVF) challenge and hemolytic-uremic syndrome (HUS). Methods Cpb2-/- , Cpn-/- and wild-type (WT) mice were compared in an HUS model induced by Shiga toxin and lipopolysaccharide administration and following CVF administration. Results HUS was exacerbated in Cpb2-/- mice more than in Cpn-/- mice, compared with WT mice. Cpb2-/- mice developed the HUS clinical triad of microangiopathic hemolytic anemia, uremia and thrombocytopenia. Treatment with anti-C5 antibody improved survival of both Cpb2-/- and Cpn-/- mice. In contrast, when challenged acutely with CVF, the reverse phenotype was observed. Cpn-/- mice had markedly worse disease than Cpb2-/- mice, whereas the WT mice were resistant. Conclusions CPN and CPB2 play overlapping but non-redundant roles in regulating complement activation in vivo. The constitutively active CPN is key for inactivation of systemic C5a, whereas CPB2 functions as an on-demand supplementary anaphylatoxin inhibitor in inactivating excessive C5a formed locally.