BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) risk prediction models established in patients with chronic hepatitis B receiving nucleos(t)ide analogue (NA) rarely include viral factors because of mediocre predictability of traditional viral markers. Here, we investigate the role of serum hepatitis B virus (HBV) RNA, a novel biomarker, in predicting HCC risk in NA-treated patients. METHODS: A total of 1374 NA-treated patients were enrolled from 2 prospective chronic hepatitis B cohorts. Serum HBV RNA was detected at baseline, year 1, 2 and 3 of treatment. Cox proportional- hazard model was used to investigate the association of HBV RNA kinetics with HCC risk. RESULTS: After a median follow-up of 5.4 years, 76 patients developed HCC. HBV RNA declines at year 1 (adjusted hazard ratio, 0.70; P = .009) and 2 (adjusted hazard ratio, 0.71; P = .016) were independently associated with HCC risk. Patients with less HBV RNA decline at year 1 (<= 0.4 log10 copies/mL) or 2 (<= 0.6 log10 copies/mL) had 2.22- and 2.09-folds higher HCC risk, respectively, than those with more declines. When incorporating these early on-treatment HBV RNA declines into existing HCC risk scores, including PAGE-B (age, sex, and platelets), modified PAGE-B (mPAGE-B) (age, sex, platelets, and albumin), and aMAP (age, sex, platelets, and albumin-bilirubin score) score, they could enhance their predictive performance (ie, C-index 0.814 vs 0.78 [model (PAGE-B D year-1 HBV RNA decline) vs PAGE-B score based on baseline parameters]). CONCLUSIONS: Serum HBV RNA declines at year 1 and 2 were significantly associated with on-treatment HCC risk. Incorporating early on-treatment HBV RNA declines into HCC risk prediction models can be useful tools to guide appropriate surveillance strategies in NA-treated patients.

Summary Background Obesity is typically associated with metabolic dysfunction, but its impact on hepatocellular carcinoma (HCC) remains unclear in patients with chronic hepatitis B (CHB). Aim To study the effect of obesity on HCC development in patients with CHB receiving antiviral therapy. Methods We included patients from a Chinese multicentre, prospective, observational, treated CHB cohort in this study. General obesity was evaluated by body‐mass index (BMI). Central obesity was evaluated by waist circumference, waist‐to‐hip ratio and waist‐to‐height ratio. Results A total of 5754 nucleos(t)ide analogue treated patients were enrolled in the analysis. The 5‐year cumulative incidence of HCC was 2.9%. Waist‐to‐height ratio performed better in predicting HCC development than BMI, waist circumference or waist‐to‐hip ratio. Patients with central obesity (defined as waist‐to‐height ratio >0.5) had significantly higher 5‐year incidence of HCC than those without central obesity in the overall population (3.9% vs 2.1%, hazard ratio [HR]: 2.06, P = 0.0001) and 745 propensity score matched pairs (4.7% vs 2.3%, HR: 2.04, P = 0.026), respectively. Besides cirrhosis status and aMAP HCC risk score, central obesity was also independently associated with HCC risk (HR: 1.63, P = 0.013). Waist‐to‐height ratio gain within 1 year was associated with a significantly higher HCC risk with an adjusted HR value of 1.88 (95% confidence interval: 1.12‐3.13, P = 0.017). Conclusions Central obesity, evaluated by the waist‐to‐height ratio, was associated with a twofold increase in HCC risk among CHB patients receiving antiviral treatment, highlighting the important role of abnormal metabolic function in the progression of liver disease.

目的:构建可用于预测乙型肝炎病毒相关慢加急性肝衰竭患者结局的风险模型.方法:以国家"十二五"科技重大专项课题"慢加急性肝衰竭中西医结合治疗方案优化研究"入组的乙型肝炎病毒相关慢加急性肝衰竭患者为研究对象,按照2:1分为训练集、测试集.在训练集人群中建立死亡风险模型并通过Cox回归分析,在测试集中验证模型的区分度与一致性.结果:年龄(HR=1.02,95％CI 1.01～1.04)、总胆红素(HR=1.04,95％CI 1.02～1.07)、国际标准化比值(HR=2.58,95％CI 1.98～3.37)、肝性脑病(Ⅰ/Ⅱ期:HR=2.20,95％CI 1.25～3.87;Ⅲ/Ⅳ期:HR=23.67,95％CI 7.74～72.37)、肝肾综合征(HR=3.64,95％CI 1.69～7.82)、低钠血症(HR=1.86,95％CI 1.22～2.84)、血小板计数(20～60:HR=1.42,95％CI 1.89～2.27;>60:HR=2.42,95％CI 1.94～6.20)是预后的独立影响因素;基于上述7项因素建立的列线图可以准确预测乙型肝炎病毒相关慢加急性肝衰竭人群结局;列线图在预测28、336 d结局方面优于终末期肝病模型(MELD)及MELD-Na评分(0.87 vs 0.79/0.80,0.82 vs 0.73/0.75);在预测90 d结局时优于MELD评分(0.86 vs 0.79,P=0.042),但与MELD-Na评分差异无统计学意义(0.86 vs 0.82,P=0.140).结论:以年龄、总胆红素、国际标准化比值、肝性脑病、肝肾综合征、低钠血症、血小板计数等7个关键因素构建而成的列线图,在预测乙型肝炎病毒相关慢加急性肝衰竭患者死亡风险方面具有一定的价值.

Background & Aims: Hepatocellular carcinoma (HCC) is the leading cause of death in patients with chronic hepatitis. In this international collaboration, we sought to develop a global universal HCC risk score to predict the HCC development for patients with chronic hepatitis. Methods: A total of 17,374 patients, comprising 10,578 treated Asian patients with chronic hepatitis B (CHB), 2,510 treated Caucasian patients with CHB, 3,566 treated patients with hepatitis C virus (including 2,489 patients with cirrhosis achieving a sustained virological response) and 720 patients with non-viral hepatitis (NVH) from 11 international prospective observational cohorts or randomised controlled trials, were divided into a training cohort (3,688 Asian patients with CHB) and 9 validation cohorts with different aetiologies and ethnicities (n = 13,686). Results: We developed an HCC risk score, called the aMAP score (ranging from 0 to 100), that involves only age, male, albumin-bilirubin and platelets. This metric performed excellently in assessing HCC risk not only in patients with hepatitis of different aetiologies, but also in those with different ethnicities (C-index: 0.82-0.87). Cut-off values of 50 and 60 were best for discriminating HCC risk. The 3- or 5-year cumulative incidences of HCC were 0-0.8%, 1.5-4.8%, and 8.1-19.9% in the low- (n = 7,413, 43.6%), medium- (n = 6,529, 38.4%), and high-risk (n = 3,044, 17.9%) groups, respectively. The cut-off value of 50 was associated with a sensitivity of 85.7-100% and a negative predictive value of 99.3-100%. The cut-off value of 60 resulted in a specificity of 56.6-95.8% and a positive predictive value of 6.6-15.7%. Conclusions: This objective, simple, reliable risk score based on 5 common parameters accurately predicted HCC development, regardless of aetiology and ethnicity, which could help to establish a risk score-guided HCC surveillance strategy worldwide. Lay summary: In this international collaboration, we developed and externally validated a simple, objective and accurate prognostic tool (called the aMAP score), that involves only age, male, albumin-bilirubin and platelets. The aMAP score (ranged from 0 to 100) satisfactorily predicted the risk of hepatocellular carcinoma (HCC) development among over 17,000 patients with viral and non-viral hepatitis from 11 global prospective studies. Our findings show that the aMAP score had excellent discrimination and calibration in assessing the 5-year HCC risk among all the cohorts irrespective of aetiology and ethnicity. (C) 2020 European Association for the Study of the Liver. Published by Elsevier B.V.

目的:分析高迁移率族蛋白B1(high mobility group protein,HMGB1)与降钙素原(procalcitionin,PCT)水平在急性胰腺炎(acute pancreatitis,AP)病情程度评估中的临床应用价值.方法:回顾性分析2014年5月-2016年9月本院收治的79例AP患者的临床资料,根据AP患者病情严重程度将其分为三组,包括轻度AP(mild AP,MAP)患者21例、中度AP(moderately severe AP,MSAP)患者17例、重度AP(severe AP,SAP)患者41例.均进行入院24 h内BISAP与APACHEⅡ评分、SOFA评分,分析血清HMGB1、PCT水平与三种评分之间的相关性.结果:三组血清HMGB1、PCT水平比较,差异均有统计学意义(P<0.05);SAP组的血清HMGB1、PCT水平均显著高于MSAP组和MAP组,MSAP组均显著高于MAP组,差异均有统计学意义(P<0.05).三组BISAP、APACHEⅡ和SOFA评分比较,差异均有统计学意义(P<0.05);SAP组BISAP、APACHEⅡ和SOFA评分均显著高于MSAP组和MAP组,MSAP组均显著高于MAP组,差异均有统计学意义(P<0.05).血清HMGB1、PCT水平均与BISAP评分呈正相关(r=0.728、0.674,P<0.05),血清HMGB1、PCT水平均与APACHEⅡ评分呈正相关(r=0.892、0.817,P<0.05),血清HMGB1、PCT水平均与SOFA评分呈正相关(r=0.698、0.545,P<0.05).结论:血清HMGB1、PCT水平与AP病情严重程度呈正相关,对判断AP患者病情严重程度具有重要的应用价值.

目的:比较中西医结合治疗与单纯西药治疗方案对48周乙型肝炎病毒(HBV)相关慢加急性肝衰竭(ACLF)患者病死率的影响.方法:934例HBV-ACLF患者为研究对象,按照实际接受的治疗方案分为中西医结合治疗组(593例)、西药治疗组(341例),采用Kaplan-Meier方法及log-rank检验比较两组患者4、8、12、24、48周终点事件累积发生率,通过Cox比例风险回归计算分析影响HBV ACLF预后的独立因素.结果:中西医结合治疗组患者4、8、12、24、48周病死率分别为11.6％、17.9％、20.6％、24.5％、27.0％,显著低于西药治疗组的19.1％、25.5％、27.3％、31.4％、32.0％ (P ＜0.05);经校正混杂因素后,中西医结合治疗组患者4、8、12、24、48周时死亡风险分别是西药组的0.57、0.63、0.72、0.65、0.73倍(P＜0.05);年龄、总胆红素、国际标准化比值、肝性脑病、肝肾综合征、血小板计数是影响HBV ACLF预后的独立因素.结论:中西医结合治疗方案能降低HBV-ACLF人群的4～ 48周病死率;与西药治疗方案相比,中西医结合治疗方案在改善HBV-ACLF患者预后方面具有优势作用.

ObjectiveTo investigate the 8-week mortality rate of patients with hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF) complicated by hepatic encephalopathy (HE) treated with integrated traditional Chinese and Western medicine therapy, as well as independent prognostic factors. MethodsA total of 125 HBV-ACLF patients with HE who were admitted to 18 hospitals from January 2012 to February 2015 were enrolled and divided into trial group and control group using a randomized controlled design. The patients in the trial group were given integrated traditional Chinese and Western medicine therapy, and those in the control group were given Western medicine therapy alone. The 8-week mortality rate was observed for both groups. The t-test or the Mann-Whitney U test was used for comparison of continuous data between groups; the chi-square test was used for comparison of categorical data between groups; the Kaplan-Meier method and the log-rank test were used for survival analysis; the Cox proportional hazards regression model was used for the analysis of risk factors. ResultsThe 8-week mortality rate was 27.5% in the trial group and 50.0% in the control group (χ2=5.630, P=0.018), the median survival time was 41.2 days in the trial group and 28.4 days in the control group, and the 8-week cumulative probability of survival was 60.4% in the trial group and 32.5% in the control group (χ2=6.187, P=0.013). The Cox regression analysis showed that compared with the control group, the trial group was a protective factor in patients with HBV-ACLF complicated by HE (hazard ratio ［HR］=0.424, 95% confidence interval ［CI］: 0.208-0.864, P=0.018). There were significant differences between the two groups in total bilirubin (TBil) (HR=1.063, 95%CI: 1.002-1.128, P=0.042), prothrombin activity (PTA) (HR=0.942, 95%CI: 0.890-0.998, P=0.044), ACLF stage (HR=2.737, 95%CI: 1.287-5.818, P=0.009), and the presence or absence of gastrointestinal hemorrhage (HR=5.291, 95%CI: 1.736-16.126, P=0.003). ConclusionTraditional Chinese medicine treatment can significantly reduce the 8-week mortality rate of HBV-ACLF patients with HE, increase their 8-week survival probability, and prolong survival time. TBil, PTA, ACLF stage, and gastrointestinal hemorrhage are independent prognostic factors.

Objective:To study the effect of genotype 3 hepatitis E virus ORF3 protein onthe production of type Ⅰ interferon and ISG15 protein in Human hepatocellular carcinoma cells.Methods:Hepatocellular carcinoma cell line PLC-PRF-5 was respectively transfected with the genotype Ⅲ hepatitis E virus ORF3 plasmid and the empty plasmid.At different time points after transfection(0h,8h,12h,24h,48h,72h,120h),the production of IFN Ⅰ in supernatants was measured by ELISA and the expression of ISG15 protein was assayed by Western blot.Results:The levels of IFN α and β3 in the ORF3 plasmid groupsupernatant were obviously higher than those in the empty plasmid group and blank group,but there was no significant change in the empty plasmid group and blank group.And the expression of ISG15 protein was increased in ORF3 plasmid group,but there was no significant change in the empty plasmid group and blank group.Conclusion:Genotype Ⅲ HEV ORF3 protein promotes the expression of type Ⅰ interferon (IFN α and IFN β) and ISG15 protein.

Intraflagellar transport (IFT) is a conserved mechanism essential for the assembly andmaintenance of most eukaryotic cilia and flagella. However, IFT25, a component of the IFT complex, is not required for the formation of cilia in somatic tissues. In mice, the gene is highly expressed in the testis, and its expression is upregulated during the final phase when sperm flagella are formed.To investigate the role of IFT25 in sperm flagella formation, the gene was specifically disrupted in male germ cells. All homozygous knockout mice survived to adulthood and did not show any gross abnormalities. However, all homozygous knockout males were completely infertile. Sperm numbers were reduced and these sperm were completely immotile. Multiple morphological abnormalities were observed in sperm, including round heads, short and bent tails, with some tails showing branched flagella and others with frequent abnormal thicknesses, as well as swollen tips of the tail. Transmission electron microscopy revealed that flagellar accessory structures, including the fibrous sheath and outer dense fibers, were disorganized, and most sperm had also lost the "9+2" microtubule structure. In the testis, IFT25 forms a complex with other IFT proteins. In Ift25 knockout testes, IFT27, an IFT25 binding partner, was missing, and IFT20 and IFT81 levels were also reduced. Our findings suggest that IFT25, although not necessary for the formation of cilia in somatic cells, is indispensable for sperm flagellum formation and male fertility in mice.

Although rare, acute liver failure (ALF) is associated with high levels of mortality, warranting the development of novel therapies. Nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) play roles in ALF. Lipoxin A4 (LXA4) has been shown to alleviate inflammation in non-hepatic tissues. In the present study, we explored whether LXA4 exerted hepatoprotective effects in a rat model of ALF. A rat model of ALF was generated by intraperitoneal injections of D-galactosamine (300 mg/kg) and lipopolysaccharide (50 µg/kg). Animals were randomly assigned to: control group (no ALF); model group (ALF); and the groups treated with a low dose (0.5 µg/kg), medium dose (1 µg/kg), and high dose (2 µg/kg) of LXA4 (all with ALF); and pyrrolidine dithiocarbamate (PDTC)-treated group (ALF and 100 mg/kg PDTC, an inhibitor of NF-κB). Liver histology was measured using H&E staining, serum levels by ELISA, and liver mRNA expression was measured by RT-PCR for the detection of the pro‑inflammatory cytokines TNF-α and IL-6. Liver cell apoptosis (as measured using the TUNEL method and examining caspase-3 activity), and Kupffer cell NF-κB activity [using an electrophoretic mobility shift assay (EMSA)] were examined. Serum levels of transaminases, TNF-α and interleukin-6 (IL-6) were substantially higher in the model group compared to controls. In the model group, significant increases in TNF-α and IL-6 mRNA expression, TUNEL‑positive cells, and caspase-3 activity in the liver tissue were noted. LXA4 improved liver pathology and significantly decreased the indicators of inflammatory response and apoptosis in a dose-dependent manner. High-dose LXA4 provided better protection than PDTC. LXA4 administration significantly decreased NF-κB expression in hepatocytes and Kupffer cells. These results indicated that LXA4 inhibited NF-κB activation, reduced the secretion of pro-inflammatory cytokines, and inhibited apoptosis of liver cells, thereby exerting protective effects against ALF.

重型肝炎是肝细胞短期内大片坏死或严重变性导致肝功能衰竭的一类危重综合征,包括黄疸进行性加深、凝血功能障碍、肝性脑病和腹水等,其特点是进展迅速、病情凶险、并发症多、预后差,常可导致多器官功能衰竭而死亡,病死率高达50％～80％[1].为和国际接轨,我国已将重型肝炎更名为肝衰竭,包括急性肝衰竭、亚急性肝衰竭、慢加急性肝衰竭和慢性肝衰竭四种类型.

Objective:To investigate non-bioartificial liver's influence on clinical efficacy and prognosis of patients with chronic hepatitis B related liver failure,and explore its intervention time for liver failure.Methods:Three hundred and eight cases of patients who hospitalized in Tongji Hospital ( Wuhan) were analyzed in perspective clinical study.Patients who accepted non-bioartificial liver and standard medical treatment were defined as ALSS group.The ones who only accepted standard medical therapy were defined as SMT group.Both of the two groups were divided into three groups of early,medium and advanced stage respectively.Results:At 8-week,the difference of clinical efficien-cy of ALSS group was better than SMT group (52.07%vs 34.07%, P=0.004).The difference of 12-week cumulative survival rate of ALSS group and SMT group was not statistical significant (50.4%vs42.1 %,P>0.05).The result was similar to 48-week cumulative survival rate (44.3%vs 40.7%, P>0.05) .12-week cumulative survival rate of early,medium and advanced stage patients in ALSS group was 81.8%, 62.3%and 14.9%respectively,while 48-week cumulative survival rate of them was 72.7%,56.7%and 9.6%respectively.12-week cumu-lative survival rate of early,medium and advanced stage patients in SMT group was 79.4%,42.9%and 15.3% respectively,while 48-week cumulative survival rate of them was 73.3%,42.9%and 12.3%respectively.Comparing ALSS with SMT group,12-week cumulative survival rate of early stage patients was no statistical significant difference (P>0.05), while the difference of 48-week cumulative survival rate was&nbsp;no statistical significant (P>0.05).The results were the same to advanced stage patients.However,both 12-week cumulative survival rate and 48-week cumulative survival rate of medium-term patients in ALSS group were higher than that of SMT group ( P<0.05) .Conclusion:Non-bioartificial liver could improve clinical efficiency and increase survival rate of patients with liver failure in medium term.But to patients in early stage or advanced liver failure,the value of non-bioartificial liver was little.

Objective To investigate non-bioartificial liver’s influence on clinical efficacy and prognosis of patients with chronic hepatitis B related liver failure.Methods 308 cases of patients who hospitalized in Tongji Hospital(Wuhan)were analyzed in perspective clinical study.Patients who accepted both non-bioartificial liver and standard medical treatment were defined as ALSS group.The ones who accepted standard medical therapy only were defined as SMT group.Taking 8-week as an observation point,we recorded patients’symptoms and biochemical parameters,such as liver function and clotting function.According to them,we could determine the clinical efficacy of patients.Taking the time when patients admitted to hospital and accepted treatment as a starting point,and we took 48 weeks as ending point and recorded the survival time of cases.We took advantage of SPSS 17.0 statistical software to make survival curve and by which to determine the prognosis of our patients with liver failure.The difference of survival rate between two groups was compared by Log Rank test.Results Non-bioartificial liver could improve clinical symptoms and signs,liver function and coagulation function of patients with liver failure (comparing with pre-artificial liver,the level of ALT、TBil were reduced by 63.6 U /L and 34.17 μmol/L respectively,PTA was increased by 7.71% average,P <0.01 ).At 8-week,the difference of clinical efficiency between ALSS group and SMT group was of statistical significance(52.07% vs 34.07%,P <0.01).12-week cumulative survival rate of ALSS group and SMT group were 50.4% and 42.1% respec-tively,the difference between them was not statistical significant(P >0.05).After following up one year, the average survival time of patients in ALSS group was(186.2 ±11.5)days while it was(160.3 ±19.0) days in SMT group patients.The difference of one year cumulative survival rate between two groups was not statistical significant (44.3% vs 40.7%,P >0.05 ).Conclusion Non-bioartificial liver could improve clinical efficiency,while it could not improve prognosis.

RC/BTB2 is a binding partner of sperm associated antigen 16S (SPAG16S), which is a regulator of spermiogenesis in mice, a process during which sperm flagella are formed. The expression of Rc/btb2 is also regulated by multicilin, a protein that controls ciliogenesis. Given that mouse Rc/btb2 mRNA is not only expressed in tissues bearing motile cilia, but also in tissues without motile cilia, we investigated whether RC/BTB2 plays a role in the general process of ciliogenesis by studying two cell lines that have primary cilia, NIH3T3, and IMCD3. We discovered that the subcellular localization of RC/BTB2 in the NIH3T3 and IMCD3 cells encompasses the pathway for ciliogenesis. RC/BTB2 was found in the Golgi bodies and centrosomes, two key structures essential for normal ciliogenesis. Knockdown of Rc/btb2 gene expression in these cell lines disrupted ciliogenesis. The percentage of cells with primary cilia was significantly reduced in stable cell lines transduced with specific Rc/btb2 shRNA viruses as compared to the control cells. When cilia were formed in the knockdown cells, they were significantly shorter than those in the control cells. Knockdown of Rc/btb2 expression did not affect cell proliferation and the cell cycle. Exogenous expression of RC/BTB2 in these stable knockdown cells restored ciliogenesis. These findings suggest that RC/BTB2 is a necessary component of the process of formation of primary cilia in somatic cells, perhaps through the transportation of cargos from Golgi bodies to centrosomes for cilia assembling. © 2015 Wiley Periodicals, Inc.

A key event in the process of spermiogenesis is the formation of the flagella, which enables sperm to reach eggs for fertilization. Yeast two-hybrid studies revealed that meiosis-expressed gene 1 (MEIG1) and Parkin co-regulated gene (PACRG) interact, and that sperm-associated antigen 16, which encodes an axoneme central apparatus protein, is also a binding partner of MEIG1. In spermatocytes of wild-type mice, MEIG1 is expressed in the whole germ cell bodies, but the protein migrates to the manchette, a unique structure at the base of elongating spermatid that directs formation of the flagella. In the elongating spermatids of wild-type mice, PACRG colocalizes with α-tubulin, a marker for the manchette, whereas this localization was not changed in the few remaining elongating spermatids of Meig1-deficient mice. In addition, MEIG1 no longer localizes to the manchette in the remaining elongating spermatids of Pacrg-deficient mice, indicating that PACRG recruits MEIG1 to the manchette. PACRG is not stable in mammalian cells, but can be stabilized by MEIG1 or by inhibition of proteasome function. SPAG16L is present in the spermatocyte cytoplasm of wild-type mice, and in the manchette of elongating spermatids, but in the Meig1 or Pacrg-deficient mice, SPAG16L no longer localizes to the manchette. By contrast, MEIG1 and PACRG are still present in the manchette of Spag16L-deficient mice, indicating that SPAG16L is a downstream partner of these two proteins. Together, our studies demonstrate that MEIG1/PACRG forms a complex in the manchette and that this complex is necessary to transport cargos, such as SPAG16L, to build the sperm flagella.

A key event in the process of spermiogenesis is the formation of the flagella, which enables sperm to reach eggs for fertilization. Yeast two-hybrid studies revealed that meiosis-expressed gene 1 (MEIG1) and Parkin co-regulated gene (PACRG) interact, and that spermassociated antigen 16, which encodes an axoneme central apparatus protein, is also a binding partner of MEIG1. In spermatocytes of wildtype mice, MEIG1 is expressed in the whole germ cell bodies, but the protein migrates to the manchette, a unique structure at the base of elongating spermatid that directs formation of the flagella. In the elongating spermatids of wild-type mice, PACRG colocalizes with α-tubulin, a marker for the manchette, whereas this localization was not changed in the few remaining elongating spermatids of Meig1deficient mice. In addition, MEIG1 no longer localizes to the manchette in the remaining elongating spermatids of Pacrgdeficient mice, indicating that PACRG recruits MEIG1 to the manchette. PACRG is not stable in mammalian cells, but can be stabilized by MEIG1 or by inhibition of proteasome function. SPAG16L is present in the spermatocyte cytoplasm of wild-type mice, and in the manchette of elongating spermatids, but in theMeig1 or Pacrg-deficient mice, SPAG16L no longer localizes to the manchette. By contrast, MEIG1 and PACRG are still present in the manchette of Spag16L-deficient mice, indicating that SPAG16L is a downstream partner of these two proteins. Together, our studies demonstrate that MEIG1/PACRG forms a complex in the manchette and that this complex is necessary to transport cargos, such as SPAG16L, to build the sperm flagella.