High-Density Genetic Map Construction and Identification of QTLs Controlling Oleic and Linoleic Acid in Peanut using SLAF-seq and SSRs

The cultivated peanut, A. hypogaea L., is an important oil and food crop globally.High-density genetic linkage mapping is a valuable and effective method for exploring complex quantitative traits. In this context, a recombinant inbred line (RIL) of 146 lines was developed by crossing Huayu28 and P76. We developed 433,679 high-quality SLAFs, of which 29,075 were polymorphic. 4,817 SLAFs were encoded and grouped into different segregation patterns. A high-resolution genetic map containing 2,334 markers (68 SSRs and 2,266 SNPs) on 20 linkage groups (LGs) spanning 2586.37 cM was constructed for peanut. The average distance between adjacent markers was 2.25 cM. Based on phenotyping in seven environments, QTLs for oleic acid (C18:1), linoleic acid (C18:2) and the ratio of oleic acid to linoleic acid (O/L) were identified and positioned on linkage groups A03, A04, A09, B09 and B10. Marker2575339 and Marker2379598 in B09 were associated with C18:1, C18:2 and O/L in seven environments, Marker4391589 and Marker4463600 in A09 were associated with C18:1, C18:2 and O/L in six environments. This map exhibits high resolution and accuracy, which will facilitate QTL discovery for essential agronomic traits in peanut.

Fibroblast drug scavenging increases intratumoural gemcitabine accumulation in murine pancreas cancer

OBJECTIVE

Desmoplasia and hypovascularity are thought to impede drug delivery in pancreatic ductal adenocarcinoma (PDAC). However, stromal depletion approaches have failed to show clinical responses in patients. Here, we aimed to revisit the role of the tumour microenvironment as a physical barrier for gemcitabine delivery.

DESIGN

Gemcitabine metabolites were analysed in LSL-KrasG12D/+ ; LSL-Trp53R172H/+ ; Pdx-1-Cre (KPC) murine tumours and matched liver metastases, primary tumour cell lines, cancer-associated fibroblasts (CAFs) and pancreatic stellate cells (PSCs) by liquid chromatography-mass spectrometry/mass spectrometry. Functional and preclinical experiments, as well as expression analysis of stromal markers and gemcitabine metabolism pathways were performed in murine and human specimen to investigate the preclinical implications and the mechanism of gemcitabine accumulation.

RESULTS

Gemcitabine accumulation was significantly enhanced in fibroblast-rich tumours compared with liver metastases and normal liver. In vitro, significantly increased concentrations of activated 2',2'-difluorodeoxycytidine-5'-triphosphate (dFdCTP) and greatly reduced amounts of the inactive gemcitabine metabolite 2',2'-difluorodeoxyuridine were detected in PSCs and CAFs. Mechanistically, key metabolic enzymes involved in gemcitabine inactivation such as hydrolytic cytosolic 5'-nucleotidases (Nt5c1A, Nt5c3) were expressed at low levels in CAFs in vitro and in vivo, and recombinant expression of Nt5c1A resulted in decreased intracellular dFdCTP concentrations in vitro. Moreover, gemcitabine treatment in KPC mice reduced the number of liver metastases by >50%.

CONCLUSIONS

Our findings suggest that fibroblast drug scavenging may contribute to the clinical failure of gemcitabine in desmoplastic PDAC. Metabolic targeting of CAFs may thus be a promising strategy to enhance the antiproliferative effects of gemcitabine.

[The clinicopathological characteristics of diabetic nephropathy and non-diabetic renal diseases in diabetic patients]

Objective: To analyze the clinicopathological characteristics of renal lesions in type 2 diabetic patients and to differentiate diabetic nephropathy (DN) from non-diabetic renal diseases(NDRD). Methods: Type 2 diabetic patients who received renal biopsy in Ruijin Hospital from January 2011 to December 2015 were recruited in this study. Clinical history, laboratory results and pathological data were retrospectively collected. According to the pathological findings, the patients were divided into 3 groups: DN, NDRD, DN+NDRD. Logistic model was applied to explore the independent clinical predictive factors in differentiating DN from NDRD. Results: A total of 207 type 2 diabetic patients received renal biopsy, accounting for 6.82% of all biopsy population. Fifty-one patients were diagnosed with DN, 142 with NDRD and 14 with both DN and NDRD. In NDRD, membranous nephropathy(MN)(34.5%) was the most common finding, followed by IgA nephropathy(19.7%).By contrast, NDRD patients manifested a shorter diabetic course, a higher baseline hemoglobin level, a lower baseline serum creatinine, a higher prevalence of hematuria, a lower prevalence of hypertension and diabetic retinopathy, a better control of blood glucose, better compliance of monitoring blood glucose and less family history of diabetes. In multivariate logistic model, diabetic family history(OR=4.68, P=0.04) and long history of diabetes(OR=1.01, P=0.02) were risk factors of DN. Conclusion: There is a high prevalence of NDRD in diabetic patients with renal lesions. Family history of diabetes and duration of diabetes are independent predictors of DN.

TIGAR mediates the inhibitory role of hypoxia on ROS production and apoptosis in rat nucleus pulposus cells

OBJECTIVE

Hypoxia has been shown to inhibit reactive oxygen species (ROS) production in nucleus pulposus (NP) cells. The TP53-induced glycolysis and apoptosis regulator (TIGAR) has been reported to suppress oxidative stress. We sought to explore the role of TIGAR in the effect of hypoxia on ROS production and apoptosis.

METHODS

An intervertebral disc degeneration (IDD) model of Sprague-Dawley (SD) rat caudal spine was established by puncturing the Co_6-7 disc. TIGAR expression was detected by immunohistochemistry and western blotting in human and SD rat NP tissues of degenerated discs. Rat primary NP cells treated with hypoxia and cobalt chloride (CoCl₂) were analyzed by western blotting for TIGAR expression. After TIGAR silence with TIGAR siRNA transfection, apoptosis percentage, mitochondrial and total intracellular ROS levels were measured. H₂O₂ was used to further check the effects of TIGAR on oxidative stress. Finally, NADPH/NADP⁺ and GSH/GSSH ratio were examined after TIGAR silencing under hypoxic conditions and after H₂O₂ treatment.

RESULTS

A degree-dependent increase in TIGAR expression was observed in human and rat degenerated NP tissues. Hypoxia and hypoxia-inducer CoCl₂ enhanced TIGAR and P53 expressions in rat NP cells. TIGAR silence reversed the inhibitory effects of hypoxia on intracellular and mitochondrial ROS production, as well as apoptosis percentage. However, TIGAR silence aggravated H₂O₂-induced ROS production. In addition, TIGAR increased NADPH/NADP⁺ and GSH/GSSH ratio in NP cells.

CONCLUSIONS

These results suggested that TIGAR appears to mediate the protective role of hypoxia on ROS production and apoptosis percentage by enhancing NADPH/NADP⁺ and GSH/GSSH ratio.

[Expression of serum IgG4 in patients with different diseases]

OBJECTIVE

To investigate serum IgG4 levels in different diseases and the changes of serum IgG4 levels in post treatment of IgG4 related disease.

METHODS

Clinical data of 620 patients who received investigation of serum IgG4 in Peking University People's Hospital from January 1, 2015 to March 31, 2016 were collected retrospectively. According to the difference of the diseases, they were divided into common group of diseases, autoimmune diseases and IgG4 related diseases; pancreatic disease patients were divided into autoimmune pancreatitis and pancreatic cancer group; According to different treatment stages of the disease, the patients with IgG4 related diseases were divided into pretreatment group and post treatment group. And the expressions of the patients'serum IgG4 levels in different groups were analyzed.

RESULTS

The median serum IgG4 level in the group of the patients with common diseases was 0.480(0.005, 50.400) g/L, in the group of autoimmune disease was 0.406 (0.003, 18.700) g/L , in the group of IgG4 related diseases was 5.200(0.046, 46.000)g/L, which was signi-ficantly higher in the group of IgG4 related diseases than the other two groups, and there was obvious statistical significance in serum IgG4 levels between the group of IgG4 related diseases and the other two groups (P<0.01); There was no obvious difference in serum IgG4 levels between the common disease group and the autoimmune disease group, and there was no obvious statistical difference in serum IgG4 levels between the two groups (P>0.05). In the patients with IgG4 related diseases, the median serum IgG4 level in the group of pretreatment patients was 6.540 (1.330, 34.100) g/L, and 3.735 (0.063, 46.000) g/L in the post treatment patients. Serum IgG4 levels decreased in post treatment group, signi-ficantly lower than in pretreatment, there was obvious statistical difference in serum IgG4 levels between the two groups (P<0.01). The median serum IgG4 level in the group of patients with autoimmune pancreatitis was 3.735 (0.063, 46.000) g/L ,and 0.438 (0.056, 1.130) g/L in the group of patients with pancreatic cancer,which was significantly higher in the group of patients with autoimmune pancreatitis than the others, and there was obvious statistical difference in serum IgG4 levels between the two groups (P<0.01).

CONCLUSION

Serum IgG4 levels in patients with different diseases were different, and were significantly higher in patients with autoimmune pancreatitis and IgG4 related diseases, so serum IgG4 levels can provide the basis for the differential diagnosis of different diseases; Serum IgG4 levels in patients with IgG4 related diseases decrease significantly after treatment, so it can be used as an important index to evaluate the curative effect of IgG4 related diseases.

[Observation of clinical and electrophysiological features in patients with distal myasthenia gravis]

Objective: To explore the clinical and electrophysiological features and prognosis of distal myasthenia gravis (MG). Methods: Data of MG patients in Beijing Tiantan Hospital from October 2016 to March 2017 were reviewed, including thorough neurological examinations, nerve conduction studies, repetitive nerve stimulations (RNS) and needle electromyographies. Distal MG patients were included and were analyzed as to their clinical and electrophysiological features and response to treatments. Results: Four patients (7.7%) could be classified as distal type among 52 definitely diagnosed MG patients. They had initial symptoms at age 36 to 64 and developed distal limb muscle weakness in the first month to 6 years after the onset of this disease. Hand muscles were preferentially involved in a non-uniform way. And one patient also had leg weakness on his tibialis anterior muscles. RNS showed a more significant decrement at slow rates in distal muscles, compared with proximal muscles. The baseline compound muscle action potentials (CMAP) of the distal affected muscles presented with slightly decreased or fluctuating amplitudes. Their weakness of ocular, bulbar, proximal and distal limb muscles improved generally after administration of acetylcholinesterase inhibitors or steroids plus acetylcholinesterase inhibitors. Electrophysiological reexaminations revealed increased baseline CMAPs, reduced decrement on RNS, and relief of myogenic changes on needle electromyography. Conclusions: Relatively prominent distal limb muscle weakness can be found in a minority of MG patients. Besides profound decrement on slow rate RNS, the involved distal muscles may have a characteristic decreased baseline CMAP, sometimes with a diurnal fluctuation. Distal MG responds well to regular treatments. Its short-term prognosis seems similar to that of common MG with proximal predominance.

Genetic diversity and paternal origin of domestic donkeys

Numerous studies have been conducted to investigate genetic diversity, origins and domestication of donkey using autosomal microsatellites and the mitochondrial genome, whereas the male-specific region of the Y chromosome of modern donkeys is largely uncharacterized. In the current study, 14 published equine Y chromosome-specific microsatellites (Y-STR) were investigated in 395 male donkey samples from China, Egypt, Spain and Peru using fluorescent labeled microsatellite markers. The results showed that seven Y-STRs-EcaYP9, EcaYM2, EcaYE2, EcaYE3, EcaYNO1, EcaYNO2 and EcaYNO4-were male specific and polymorphic, showing two to eight alleles in the donkeys studied. A total of 21 haplotypes corresponding to three haplogroups were identified, indicating three independent patrilines in domestic donkey. These markers are useful for the study the Y-chromosome diversity and population genetics of donkeys in Africa, Europe, South America and China.