Endothelial dysfunction in vascular complications of diabetes: a comprehensive review of mechanisms and implications

Diabetic vascular complications are prevalent and severe among diabetic patients, profoundly affecting both their quality of life and long-term prospects. These complications can be classified into macrovascular and microvascular complications. Under the impact of risk factors such as elevated blood glucose, blood pressure, and cholesterol lipids, the vascular endothelium undergoes endothelial dysfunction, characterized by increased inflammation and oxidative stress, decreased NO biosynthesis, endothelial-mesenchymal transition, senescence, and even cell death. These processes will ultimately lead to macrovascular and microvascular diseases, with macrovascular diseases mainly characterized by atherosclerosis (AS) and microvascular diseases mainly characterized by thickening of the basement membrane. It further indicates a primary contributor to the elevated morbidity and mortality observed in individuals with diabetes. In this review, we will delve into the intricate mechanisms that drive endothelial dysfunction during diabetes progression and its associated vascular complications. Furthermore, we will outline various pharmacotherapies targeting diabetic endothelial dysfunction in the hope of accelerating effective therapeutic drug discovery for early control of diabetes and its vascular complications.

Association of Gut Microbiota and Biochemical Features in a Chinese Population With Renal Uric Acid Stone

Previous studies suggest that patients with nephrolithiasis exhibit dysbiosis in their gut microbiota, but those studies were conducted in calcium oxalate stone patients. We aimed to explore the association of gut microbiota and biochemical features of renal uric acid stone (UAS) patients in a Chinese population and identify the related bacteria that may affect the pathopoiesis of UAS. A case-control study of 117 patients with UAS, 123 patients with gout, and 135 healthy controls were included from January 2014 to October 2020. For each subject, data on demographics, biochemical parameters of blood and urine were analyzed. Fifteen patients with gout, 16 patients with UAS, 17 UAS patients with gout, and 17 healthy subjects were enrolled and provided fecal samples. The characteristics of gut microbiota were explored by using 16S ribosomal RNA (rRNA) gene sequencing and analyzed by using a combination of software mother and R. Hyperuricemia was the main risk factor for the development of gout and UAS. Obesity, dyslipidemia, and aciduria were unique risk factors for UAS patients. The richness, diversity, and relative abundance of dominant bacteria at the phylum and genus levels of gut microbiota in UAS patients were significantly distinct from other subjects. Abundance of Bacteroides and Fusobacterium was significantly positively correlated with the serum uric acid (UA) level of UAS patients. Fusobacteria was involved in the metabolism and degradation of certain short-chain fatty acids, amino acids, and sugars in pathopoiesis of UAS, and inhibited their synthesis pathways. Fusobacteria may be related to the pathogenesis of UAS, and this finding contributes to the personalized treatment of UAS from the perspective of maintaining micro-ecological equilibrium in gut.

A case report of acute testicular pain secondary to segmental testicular infarction

BACKGROUND

Segmental testicular infarction is a rare condition that often occurs in the upper pole of the left testicle and usually presents with acute onset of scrotal pain. Contrast-enhanced ultrasound and MR are essential for diagnosing and differentiating segmental testicular infarction in clinical practice, and conservative treatment can only be adopted after a definitive diagnosis. In the present case, after conservative treatment, the infarct volume was reduced, the blood flow around the infarct was increased, and blood flow signals appeared in the infarct. We performed a correlation analysis to investigate the causes of these changes.

CASE PRESENTATION

A 33-year-old male, without any specific disease history, was admitted to the hospital with a 5-day history of left testicular pain, and the imaging showed focal necrosis of the left testicle with hemorrhage. He was diagnosed with segmental testicular infarction after differentiating and excluding it from malignant tumors. Conservative medical treatment was given, and the symptoms of testicular pain were relieved after treatment. After discharge, regular reexamination at follow-ups showed that the infarct's size was reduced, the blood flow around the infarct was increased, and blood flow signals appeared in the infarct.

CONCLUSION

Conservative treatment has become the standard treatment currently adopted after confirming the diagnosis of segmental testicular infarction through contrast-enhanced ultrasound and MR. The blood flow changes in and around the focus of testicular infarction can be related to various factors. At present, relevant conclusions of the underlying mechanisms were mainly deduced from infarction studies of other related organs such as the heart and brain; thus, the specific pathological mechanism needs further experimental verification.

Combined inhibition of JAK1,2/Stat3‑PD‑L1 signaling pathway suppresses the immune escape of castration‑resistant prostate cancer to NK cells in hypoxia

Castration‑resistant prostate cancer (CRPC) is difficult to treat in current clinical practice. Hypoxia is an important feature of the CRPC microenvironment and is closely associated with the progress of CRPC invasion. However, no research has been performed on the immune escape of CRPC from NK cells. The present study focused on this subject. Firstly, when the CRPC cell lines C4‑2 and CWR22Rv1 were induced by hypoxia, the expression of the UL16 binding protein (ULBP) ligand family of natural killer (NK) group 2D (NKG2D; ULBP‑1, ULBP‑2 and ULBP‑3) and MHC class I chain‑related proteins A and B (MICA/MICB) decreased. NKG2D is the main activating receptor of NK cells. Tumor cells were then co‑cultured with NK cells to conduct NK cell‑mediated cytotoxicity experiments, which revealed the decreased immune cytolytic activity of NK cells on hypoxia‑induced CRPC cells. In exploring the mechanism behind this observation, an increase in programmed death‑ligand 1 (PD‑L1) expression in CRPC cells induced by hypoxia was observed, while the addition of PD‑L1 antibody effectively reversed the expression of NKG2D ligand and enhanced the cytotoxic effect of NK cells on CRPC cells. In the process of exploring the upstream regulatory factors of PD‑L1, inhibition of the Janus kinase (JAK)1,2/signal transducer and activator of transcription 3 (Stat3) signaling pathway decreased the expression of PD‑L1 in CRPC cells. Finally, it was observed that combined inhibition of JAK1,2/PD‑L1 or Stat3/PD‑L1 was more effective than inhibition of a single pathway in enhancing the immune cytolytic activity of NK cells. Taking these results together, it is thought that combined inhibition of the JAK1,2/PD‑L1 and Stat3/PD‑L1 signaling pathways may enhance the immune cytolytic activity of NK cells toward hypoxia‑induced CRPC cells, which is expected to provide novel ideas and targets for the immunotherapy of CRPC.

Preclinical studies using miR-32-5p to suppress clear cell renal cell carcinoma metastasis via altering the miR-32-5p/TR4/HGF/Met signaling

While testicular nuclear receptor 4 (TR4) may promote prostate cancer (PCa) metastasis, its role in the clear cell renal cell carcinoma (ccRCC) remains unclear. Here we found a higher expression of TR4 in ccRCC tumors from patients with distant metastases than those from metastasis-free patients, suggesting TR4 may play positive roles in the ccRCC metastasis. Results from multiple in vitro ccRCC cell lines also confirmed TR4's positive roles in promoting ccRCC cell invasion/migration via altering the microRNA (miR-32-5p)/TR4/HGF/Met/MMP2-MMP9 signaling. Mechanism dissection revealed that miR-32-5p could suppress TR4 protein expression levels via direct binding to the 3'UTR of TR4 mRNA, and TR4 might then alter the HGF/Met signaling at the transcriptional level via direct binding to the TR4-response-elements (TR4RE) on the HGF promoter. Then the in vitro data also demonstrated the efficacy of Sunitinib, a currently used drug to treat ccRCC, could be increased after targeting this newly identified miR-32-5p/TR4/HGF/Met signaling. The preclinical study using the in vivo mouse model with xenografted ccRCC cells confirmed the in vitro cell lines data. Together, these findings suggest that TR4 is a key player to promote ccRCC metastasis and targeting this miR-32-5p/TR4/HGF/Met signaling with small molecules including TR4-shRNA or miR-32-5p may help to develop a new therapy to better suppress the ccRCC metastasis.

Adipocytes affect castration-resistant prostate cancer cells to develop the resistance to cytotoxic action of NK cells with alterations of PD-L1/NKG2D ligand levels in tumor cells

BACKGROUND

Obesity affects prostate cancer (PCa) progression, and the periprostatic adipose tissue adjacent to the prostate is considered a driving force of disease progression. Adipocytes are the main cell population in adipose tissues and their paracrine role contributes to PCa progression, however its implication in modulating immune reactions remains largely unknown. We investigated the adipocyte role in controlling the susceptibility of castration-resistant PCa (CRPC) cells to the cytotoxic action of natural killer (NK) cells.

METHODS

Using primary NK cells as the NK cell source, NK cell cytotoxicities to CRPC cells, either control media treated or adipocyte-conditioned media (CM) treated, were tested in lactate dehydrogenase (LDH) release-based assays. The levels of programmed death receptor ligand (PD-L1) and NK group 2D (NKG2D) ligands in adipocyte CM-treated CRPC cells were analyzed in qPCR analyses. Effects of blocking adipocyte action on altering PD-L1/NKG2D ligand levels and the susceptibility of CRPC cells to NK cell cytotoxicity were investigated.

RESULTS

We found NK cell cytotoxicity to CRPC cells decreases when tumor cells are treated with adipocyte CM associated with PD-L1 and NKG2D ligand level alterations. Further, we discovered that the JAK/Stat3 signaling pathway was responsible for the adipocyte CM effect. Two adipokine molecules, IL-6 and leptin, were shown to be important in activation of the JAK/Stat3 signaling in CRPC cells to modulate the PD-L1/NKG2D ligand level alteration. Adding the inhibitors of JAK/Stat3 signaling or neutralizing antibodies of IL-6 or leptin increased the susceptibility of CRPC cells to NK cell action.

CONCLUSIONS

Blocking the adipocyte effect by inhibiting the IL-6/leptin-JAK/Stat3 signaling axis may enhance NK cell mediated immunity to CRPC cells and this strategy may help to develop future therapeutics to treat obese PCa patients.

[Low-concentration hydrogen peroxide solution for continuous bladder irrigation after transurethral resection of the prostate]

OBJECTIVE

To evaluate the effectiveness and safety of low-concentration hydrogen peroxide solution (HPS) for continuous bladder irrigation after transurethral resection of the prostate (TURP).

METHODS

We retrospectively analyzed the clinical data about 148 cases of benign prostatic hyperplasia (BPH) treated by TURP from January 2013 to January 2016. Seventy-six of the patients received postoperative continuous bladder irrigation with 0.15% HPS (group A) and the other 72 with normal saline (group B). We compared the two groups of patients in their postoperative hemoglobin (Hb) levels, duration of bladder irrigation, frequency of catheter blockage, time of catheterization, and length of hospital stay.

RESULTS

There were no statistically significant differences between the two groups of patients preoperatively in the prostate volume, International Prostate Symptoms Score, maximum urinary flow rate, postvoid residual urine, or levels of serum PSA and Hb (P > 0.05). At 48 hours after operation, a significantly less reduction was observed in the Hb level in group A than in group B (［3.38 ± 2.56］ vs ［7.29 ± 6.58］ g/L, P < 0.01). The patients of group A, in comparison with those of group B, also showed remarkably shorter duration of postoperative bladder irrigation (［32.57 ± 5.99］ vs ［46.10 ± 8.79］ h, P < 0.01), lower rate of catheter blockage (3.3% vs 11.8%, P < 0.01), shorter time of catheterization (［3.74 ± 0.79］ vs ［4.79 ± 0.93］ d, P < 0.01), and fewer days of postoperative hospital stay (［4.22 ± 0.81］ vs ［4.67 ± 0.88］ d, P < 0.01).

CONCLUSIONS

Low-concentration HPS for continuous bladder irrigation after TURP can reduce blood loss, catheter blockage, bladder irrigation duration, catheterization time, and hospital stay, and therefore deserves a wide clinical application.

ATM‑JAK‑PD‑L1 signaling pathway inhibition decreases EMT and metastasis of androgen‑independent prostate cancer

Castration-resistant prostate cancer (CRPC), also known as androgen-independent prostate cancer, frequently develops local and distant metastases, the underlying mechanisms of which remain undetermined. In the present study, surgical specimens obtained from patients with clinical prostate cancer were investigated, and it was revealed that the expression levels of ataxia telangiectasia mutated kinase (ATM) were significantly enhanced in prostate cancer tissues isolated from patients with CRPC compared with from patients with hormone-dependent prostate cancer. CRPC C4-2 and CWR22Rv1 cells lines were subsequently selected to establish prostate cancer models, and ATM knockout cells were established via lentivirus infection. The results of the present study demonstrated that the migration and epithelial-mesenchymal transition (EMT) of ATM knockout cells were significantly decreased, which suggested that ATM is closely associated with CRPC cell migration and EMT. To further investigate the mechanisms underlying this process, programmed cell death 1 ligand 1 (PD-L1) expression was investigated in ATM knockout cells. In addition, inhibitors of Janus kinase (JAK) and signal transducer and activator of transcription 3 (STAT3; Stattic) were added to C4-2-Sc and CWR22Rv1-Sc cells, and the results demonstrated that PD-L1 expression was significantly decreased following the addition of JAK inhibitor 1; however, no significant change was observed following the addition of Stattic. Furthermore, a PD-L1 antibody and JAK inhibitor 1 were added to C4-2-Sc and CWR22Rv1-Sc cells, and it was revealed that cell migration ability was significantly decreased and the expression of EMT-associated markers was effectively reversed. The results of the present study suggested that via inhibition of the ATM-JAK-PD-L1 signaling pathway, EMT, metastasis and progression of CRPC may be effectively suppressed, which may represent a novel therapeutic approach for targeted therapy for patients with CRPC.

In vitro-induced M2 type macrophages induces the resistance of prostate cancer cells to cytotoxic action of NK cells

Previous reports, including our experimental results, showed that macrophages migrate to prostate cancer (PCa) cells. We tested whether the migrated macrophages affect the susceptibility of castration-resistant PCa (CRPC) cells to cytotoxic actions of natural killer (NK) cells. We found treatment of tumor cells with the conditioned media (CM) of the PMA/IL-4 treated THP-1 cells (M2 type macrophages) (THP-1 CM) decreased the susceptibility of tumor cells to NK cell cytotoxicity, as a result of increased programmed death receptor ligand 1 (PD-L1) and decreased NK group 2D (NKG2D) ligands in CRPC cells. Meanwhile, the decreased susceptibility of tumor cells was also detected when NK cells were treated with THP-1 CM and used in NK cell cytotoxicity tests. Therefore, we observed higher resistance of CRPC cells when both tumor and NK cells were treated with THP-1 CM than when tumor cells or NK cells were individually treated. We further discovered that the PMA/IL-4 treated THP-1 cells secrete a high level of IL-6, so blocking the IL-6 action significantly decreased the PD-L1 level while recovering the NKG2D ligands, thus increasing the susceptibility of CRPC cells to NK cell action. Moreover, we discovered that JAK-Stat3 is the most critical IL-6 downstream signaling in triggering the THP-1 CM effect. Consequently, we found the susceptibility of CRPC cells to NK cells was increased when either JAK or Stat 3 inhibitor was added when tumor cells were treated with THP-1 CM, and that the best effect was observed when the JAK inhibitor and PD-L1 Ab were added together.

Inhibition of IL-6-JAK/Stat3 signaling in castration-resistant prostate cancer cells enhances the NK cell-mediated cytotoxicity via alteration of PD-L1/NKG2D ligand levels

To investigate whether IL‐6 signaling affects the susceptibility of castration‐resistant prostate cancer (CRPC) cells to cytotoxic action of natural killer (NK) cells, CRPC cell lines (having different IL‐6 levels) were developed by lentiviral transduction. While observing no secreted IL‐6 level in parental C4‐2 and CWR22Rv1 cells, we found the IL‐6 expression/secretion in these cells was induced after the transduction process and the IL‐6 level difference in C4‐2siIL‐6/sc and CWR22siIL‐6/sc cell CRPC cell sets could be detected. We then found that IL‐6‐knockdown cells were more susceptible to NK cell cytotoxicity than control cells due to lowered programmed death receptor ligand 1 (PD‐L1) and increased NK group 2D (NKG2D) ligand levels. In animal studies, to concur with the in vitro results, we found that IL‐6‐expressing cell‐derived tumors were more resistant to NK cell action than the tumors of IL‐6‐knockdown cells. Further, we discovered that JAK‐Stat3 is the most critical IL‐6 downstream signaling that modulates PD‐L1/NKG2D ligand levels in CRPC cells. Furthermore, inhibition of the JAK or Stat3 signaling effectively increased the susceptibility of C4‐2sc and CWRsc cells to NK cell cytotoxicity. We observed the most effective cytotoxicity when the PD‐L1 Ab and JAK inhibitor (or Stat 3 inhibitor) were used together. These results suggest that the strategy of targeting IL‐6 signaling (or its downstream signaling) may enhance the NK cell‐mediated immune action to CRPC tumors, thus yielding clinical implications in developing future immunotherapeutics of exploiting this strategy to treat patients with CRPC.

Transrectal real-time tissue elastography targeted biopsy coupled with peak strain index improves the detection of clinically important prostate cancer

The focus of the present study was to evaluate transrectal real-time tissue elastography (RTE)-targeted two-core biopsy coupled with peak strain index for the detection of prostate cancer (PCa) and to compare this method with 10-core systematic biopsy. A total of 141 patients were enrolled for evaluation. The diagnostic value of peak strain index was assessed using a receiver operating characteristic curve. The cancer detection rates of the two approaches and corresponding positive cores and Gleason score were compared. The cancer detection rate per core in the RTE-targeted biopsy (44%) was higher compared with that in systematic biopsy (30%). The peak strain index value of PCa was higher compared with that of the benign lesion. PCa was detected with the highest sensitivity (87.5%) and specificity (85.5%) using the threshold value of a peak strain index of ≥5.97 with an area under the curve value of 0.95. When the Gleason score was ≥7, RTE-targeted biopsy coupled with peak strain index detected 95.6% of PCa cases, but 84.4% were detected using systematic biopsy. Peak strain index as a quantitative parameter may improve the differentiation of PCa from benign lesions in the prostate peripheral zone. Transrectal RTE-targeted biopsy coupled with peak strain index may enhance the detection of clinically significant PCa, particularly when combined with systematic biopsy.

The Differential Effects of Anti-Diabetic Thiazolidinedione on Prostate Cancer Progression Are Linked to the TR4 Nuclear Receptor Expression Status

The insulin sensitizers, thiazolidinediones (TZDs), have been used as anti-diabetic drugs since the discovery of their ability to alter insulin resistance through transactivation of peroxisome proliferator-activated receptors (PPARs). However, their side effects in hepatitis, cardiovascular diseases, and bladder cancer resulted in some selling restrictions in the USA and Europe. Here, we found that the potential impact of TZDs on the prostate cancer (PCa) progression might be linked to the TR4 nuclear receptor expression. Clinical surveys found that 9% of PCa patients had one allele TR4 deletion in their tumors. TZD increased cell growth and invasion in PCa cells when TR4 was knocked down. In contrast, TZD decreased PCa progression in PCa cells with wild type TR4. Mechanism dissection found that the Harvey Rat Sarcoma (HRAS) oncogene increased on TZD treatment of the TR4 knocked-down CWR22Rv1 and C4-2 cells, and interruption with HRAS inhibitor resulted in reversal of TZD-induced PCa progression. Together, these results suggest that TZD treatment may promote PCa progression depending on the TR4 expression status that may be clinically relevant since extra caution may be needed for those diabetic PCa patients receiving TZD treatment who have one allele TR4 deletion.

In vivo determination of muscle-derived stem cells in rat corpus cavernosum

The aim of this in vivo study was to determine the existence of muscle-derived stem cells (MDSCs) in rat corpus cavernosum. Immunohistochemical and RT-PCR analyses were performed to determine the expression of the stem cell markers (Sca-1, Oct4, and desmin) in Sprague-Dawley (SD) rats in different age groups (10 rats in each group). Sca-1 was mainly expressed in blood vessels and cavernous sinus and demonstrated primarily cytoplasmic staining. Desmin was expressed mainly in muscle tissues and staining occurred mainly in the cytoplasm but also partially in the nucleus. An extremely small amount of double-positive stained cells (Sca-1/desmin) were detected near the cavernous sinus. Expression of the markers was significantly and negatively correlated with the age of the rats (P < 0.05). The RT-PCR results showed that the expression levels of Sca-1 and desmin significantly decreased with age (P < 0.05). Correlation analysis indicated that the expression of Sca-1 and desmin were significantly and negatively correlated with the age of rats (r = -0.929, P < 0.05). The present study provides evidence for the existence of MDSCs in rat corpus cavernosum. MDSCs may have therapeutic potential in the treatment of organic erectile dysfunction.

TR4 nuclear receptor increases prostate cancer invasion via decreasing the miR-373-3p expression to alter TGFβR2/p-Smad3 signals

Testicular nuclear receptor 4 (TR4), a member of the nuclear receptor superfamily, may play important roles to modulate the metabolic diseases and prostate tumorigenesis. Here we found TR4 could increase prostate cancer (PCa) cell invasion. Mechanism dissection revealed that TR4 might increase PCa cell invasion via decreasing the miR-373-3p expression that resulted in the activation of the TGFβR2/p-Smad3 signals. The in vivo mouse model using orthotopically xenografted CWR22Rv1 cell line transfected with luciferase-reporter confirmed in vitro cell line studies showing TR4 increased PCa metastasis via decreasing the miR-373-3p expression. Together, these data suggest that TR4 may increase PCa metastasis via a newly identified signal and targeting these TR4/miR-473-3p/TGFβR2/p-Smad3 signals using TR4 antagonist or TR4-siRNA or miR-373-3p may allow us to develop a new potential therapeutic approach to better suppress PCa metastasis.

TR4 Nuclear Receptor Alters the Prostate Cancer CD133+ Stem/Progenitor Cell Invasion via Modulating the EZH2-Related Metastasis Gene Expression

The testicular nuclear receptor 4 (TR4) is a member of the nuclear receptor superfamily that mediates various biologic functions with key impacts on metabolic disorders and tumor progression. Here, we demonstrate that TR4 may play a positive role in prostate cancer CD133(+) stem/progenitor (S/P) cell invasion. Targeting TR4 with lentiviral silencing RNA significantly suppressed prostate cancer CD133(+) S/P cell invasion both in vitro and in vivo. Mechanism dissection found that TR4 transcriptionally regulates the oncogene EZH2 via binding to its 5' promoter region. The consequences of targeting TR4 to suppress EZH2 expression may then suppress the expression of its downstream key metastasis-related genes, including NOTCH1, TGFβ1, SLUG, and MMP9. Rescue approaches via adding the EZH2 reversed the TR4-mediated prostate cancer S/P cell invasion. Together, these results suggest that the TR4→EZH2 signaling may play a critical role in the prostate cancer S/P cell invasion and may allow us to develop a better therapy to battle the prostate cancer metastasis.

TR4 nuclear receptor enhances prostate cancer initiation via altering the stem cell population and EMT signals in the PPARG-deleted prostate cells

A recent report indicated that the TR4 nuclear receptor might suppress the prostate cancer (PCa) initiation via modulating the DNA damage/repair system. Knocking-out peroxisome proliferator-activated receptor gamma (PPARG), a nuclear receptor that shares similar ligands/activators with TR4, promoted PCa initiation. Here we found 9% of PCa patients have one allele of PPARG deletion. Results from in vitro cell lines and in vivo mouse model indicated that during PCa initiation TR4 roles might switch from suppressor to enhancer in prostate cells when PPARG was deleted or suppressed (by antagonist GW9662). Mechanism dissection found targeting TR4 in the absence of PPARG might alter the stem cell population and epithelial-mesenchymal transition (EMT) signals. Together, these results suggest that whether TR4 can enhance or suppress PCa initiation may depend on the availability of PPARG and future potential therapy via targeting PPARG to battle PPARG-related diseases may need to consider the potential side effects of TR4 switched roles during the PCa initiation.

Targeting TR4 nuclear receptor suppresses prostate cancer invasion via reduction of infiltrating macrophages with alteration of the TIMP-1/MMP2/MMP9 signals

Background

TR4 nuclear receptor 4 (TR4) plays an important role in macrophages-associated foam cell formation of cardiovascular diseases and infiltrating macrophages are critical for prostate cancer (PCa) progression. However, the linkage of macrophages and TR4 and their impacts on PCa metastasis remains unclear.

Results

Knocking-down TR4 in human PCa cells (C4-2, CWR22Rv1), but not in human macrophages cells (THP-1), led to suppress the macrophages infiltration to PCa cells. The consequences of such suppression of the recruitment of macrophages toward PCa then resulted in suppressing the PCa cell invasion. Mechanism dissection found that knocking-down TR4 in PCa cells suppressed metastasis-related genes including MMP2, with induction of TIMP-1. Interruption assays using TIMP-1 neutralizing antibody could then reverse TR4-macrophage-mediated PCa invasion. IHC staining showed higher TR4 level, more macrophage infiltration, lower TIMP-1 and stronger MMP2/MMP9 in tumor tissues of the Gleason score 5 + 4 patients compared with the Gleason score 3 + 3 patients.

Conclusion

Targeting TR4 in prostate tumor microenvironment might represent a potential new therapeutic approach to better battle PCa metastasis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-014-0281-1) contains supplementary material, which is available to authorized users.

TR4 Nuclear Receptor Different Roles in Prostate Cancer Progression

Nuclear receptors are important to maintain the tissue homeostasis. Each receptor is tightly controlled and under a very complicated balance. In this review, we summarize the current findings regarding the nuclear receptor TR4 and its role in prostate cancer (PCa) progression. In general, TR4 can inhibit the PCa carcinogenesis. However, when PPARγ is knocked out, activation of TR4 can have an opposite effect to promote the PCa carcinogenesis. Clinical data also indicates that higher TR4 expression is found in PCa tissues with high Gleason scores compared to those tissues with low Gleason scores. In vitro and in vivo studies show that TR4 can promote PCa progression. Mechanism dissection indicates that TR4 inhibits PCa carcinogenesis through regulating the tumor suppressor ATM to reduce DNA damages. On the other hand, in the absence of PPARγ, TR4 tends to increase the stem cell population and epithelial-mesenchymal transition (EMT) via regulating CCL2, Oct4, EZH2, and miRNA-373-3p expression that results in increased PCa carcinogenesis. In opposition to PCa initiation, TR4 can increase PCa metastasis via modulating the CCL2 signals. Finally, targeting TR4 enhances the chemotherapy and radiation therapy sensitivity in PCa. Together, these data suggest TR4 is a key player to control PCa progression, and targeting TR4 with small molecules may provide us a new and better therapy to suppress PCa progression.

Nitroxide radical polymer/carbon-nanotube-array electrodes with improved C-rate performance in organic radical batteries

The intimate connection between carbon nanotubes and the current collector reduces electron-transfer resistance of the cathode and enhances the C-rate performance of the batteries.

TR4 nuclear receptor promotes prostate cancer metastasis via upregulation of CCL2/CCR2 signaling

Testicular nuclear receptor 4 (TR4) plays protective roles against oxidative stress and DNA damage and might contribute to aging. Our recent clinical tumor tissue staining results showed higher expression of TR4 in prostate cancer (PCa) patients with high Gleason scores compared to the tissues with the low Gleason scores. In vitro migration/invasion assays after manipulation of the TR4 expression in PCa cells showed that TR4 promoted PCa cells migration/invasion. Mechanism dissection found that the CCL2/CCR2 signal plays the key role in the mediation of TR4-promoted PCa cells migration/invasion. Chromatin immunoprecipitation and Luciferase assays further confirmed TR4 modulation of CCL2 at the transcriptional level and addition of the CCR2 antagonist led to interruption of the TR4-enhanced PCa cells migration/invasion. Finally, the orthotopic xenografted mice studies using the luciferase expressing CWR22Rv1 cells found that TR4 enhanced PCa metastasis and this increased metastasis was reversed when the CCR2 antagonist was injected into the mice. Together, these in vitro and in vivo results revealed a positive role of TR4 in PCa metastasis and demonstrated CCL2/CCR2 signaling as an important mediator in exerting TR4 action. This finding suggests that TR4 may represent a biomarker related to PCa metastasis and targeting the TR4-CCL2/CCR2 axis may become a new therapeutic approach to battle PCa metastasis.

Differential roles of PPARγ vs TR4 in prostate cancer and metabolic diseases

Peroxisome proliferator-activated receptor γ (PPARγ, NR1C3) and testicular receptor 4 nuclear receptor (TR4, NR2C2) are two members of the nuclear receptor (NR) superfamily that can be activated by several similar ligands/activators including polyunsaturated fatty acid metabolites, such as 13-hydroxyoctadecadienoic acid and 15-hydroxyeicosatetraenoic acid, as well as some anti-diabetic drugs such as thiazolidinediones (TZDs). However, the consequences of the transactivation of these ligands/activators via these two NRs are different, with at least three distinct phenotypes. First, activation of PPARγ increases insulin sensitivity yet activation of TR4 decreases insulin sensitivity. Second, PPARγ attenuates atherosclerosis but TR4 might increase the risk of atherosclerosis. Third, PPARγ suppresses prostate cancer (PCa) development and TR4 suppresses prostate carcinogenesis yet promotes PCa metastasis. Importantly, the deregulation of either PPARγ or TR4 in PCa alone might then alter the other receptor's influences on PCa progression. Knocking out PPARγ altered the ability of TR4 to promote prostate carcinogenesis and knocking down TR4 also resulted in TZD treatment promoting PCa development, indicating that both PPARγ and TR4 might coordinate with each other to regulate PCa initiation, and the loss of either one of them might switch the other one from a tumor suppressor to a tumor promoter. These results indicate that further and detailed studies of both receptors at the same time in the same cells/organs may help us to better dissect their distinct physiological roles and develop better drug(s) with fewer side effects to battle PPARγ- and TR4-related diseases including tumor and cardiovascular diseases as well as metabolic disorders.

Minireview: Pathophysiological roles of the TR4 nuclear receptor: lessons learned from mice lacking TR4

Testicular nuclear receptor 4 (TR4), also known as NR2C2, belongs to the nuclear receptor superfamily and shares high homology with the testicular nuclear receptor 2. The natural ligands of TR4 remained unclear until the recent discoveries of several energy/lipid sensors including the polyunsaturated fatty acid metabolites, 13-hydroxyoctadecadienoic acid and 15-hydroxyeicosatetraenoic acid, and their synthetic ligands, thiazolidinediones, used for treatment of diabetes. TR4 is widely expressed throughout the body and particularly concentrated in the testis, prostate, cerebellum, and hippocampus. It has been shown to play important roles in cerebellar development, forebrain myelination, folliculogenesis, gluconeogenesis, lipogenesis, muscle development, bone development, and prostate cancer progression. Here we provide a comprehensive summary of TR4 signaling including its upstream ligands/activators/suppressors, transcriptional coactivators/repressors, downstream targets, and their in vivo functions with potential impacts on TR4-related diseases. Importantly, TR4 shares similar ligands/activators with another key nuclear receptor, peroxisome proliferator-activated receptor γ, which raised several interesting questions about how these 2 nuclear receptors may collaborate with or counteract each other's function in their related diseases. Clear dissection of such molecular mechanisms and their differential roles in various diseases may help researchers to design new potential drugs with better efficacy and fewer side effects to battle TR4 and peroxisome proliferator-activated receptor γ involved diseases.

[Inhibition of stromal interaction molecule 1 and the expression of apoptosis-related proteins in prostate cancer PC-3 cells]

OBJECTIVE

To explore the effects of stromal interaction molecule 1 (STIM1) on the expression of apoptosis-related proteins in prostate cancer PC-3 cells.

METHODS

We transfected the lentivirus vector STIM1-pGCSIL-GFP carrying STIM shRNA into human hormone-independent prostate cancer PC-3 cells, and 3 days later observed the transfection efficiency by fluorescence microscopy. At 7 days after transfection, we determined the expression of STIM1 in the PC-3 cells by RT-PCR and Western blot and those of apoptosis-related proteins Bcl-2, Bax, survivin and activated Caspase-3 by Western blot.

RESULTS

At 3 days, inverted microscopy revealed a transfection efficiency of > 80%. At 7 days, the STIM1 expression was significantly inhibited at both mRNA and protein levels. The Bcl-2/Bax rate was remarkably decreased as compared with that of the control group (0. 31 vs 1.24 ) , and the survivin expression was markedly reduced, 0. 14 times that of the relative expression in the control. However, the Caspase-3 cleavage was significantly activated, 1.52 times that of the control (P <0.05).

CONCLUSION

STIM1 can be regarded as an oncogene in prostate cancer PC-3 cells. Inhibition of its expression can induce PC-3 cell apoptosis by reducing the Bcl-2/Bax rate, decreasing the survivin expression, and activating the Caspase-3 pathway.

TR4 nuclear receptor functions as a tumor suppressor for prostate tumorigenesis via modulation of DNA damage/repair system

Testicular nuclear receptor 4 (TR4), a member of the nuclear receptor superfamily, plays important roles in metabolism, fertility and aging. The linkage of TR4 functions in cancer progression, however, remains unclear. Using three different mouse models, we found TR4 could prevent or delay prostate cancer (PCa)/prostatic intraepithelial neoplasia development. Knocking down TR4 in human RWPE1 and mouse mPrE normal prostate cells promoted tumorigenesis under carcinogen challenge, suggesting TR4 may play a suppressor role in PCa initiation. Mechanism dissection in both in vitro cell lines and in vivo mice studies found that knocking down TR4 led to increased DNA damage with altered DNA repair system that involved the modulation of ATM expression at the transcriptional level, and addition of ATM partially interrupted the TR4 small interfering RNA-induced tumorigenesis in cell transformation assays. Immunohistochemical staining in human PCa tissue microarrays revealed ATM expression is highly correlated with TR4 expression. Together, these results suggest TR4 may function as a tumor suppressor to prevent or delay prostate tumorigenesis via regulating ATM expression at the transcriptional level.

Isolation and passage of muscle-derived stem cells from the rat penile corpora cavernosa and induction of differentiation into smooth muscle cells

This study treated the isolation and passage of muscle-derived stem cells (MDSCs) from rat penile corpora cavernosa, detection of stem cell marker expression, observation of their self-renewal and continuous proliferation, and demonstration of their potential to differentiate into smooth muscle cells in co-culture. Muscle-derived stem cells from the rat penile corpora cavernosa were isolated and purified. The expression of stem cell markers Sca-1 and desmin was detected in PP6 cells, thus confirming that the main components of PP6 cells are MDSCs. The expression of Sca-1 and desmin occurred both in PP6 cells and cells at passages 3, 6, and 8, and there was no significant decrease in the expression level with increasing passage number. The growth curves indicated that the cell doubling time was approximately 48 h. The cells entered the stationary phase after approximately 7 days of culture. The proliferative activity of the cells at passage 8 remained unchanged. After 2 days of co-culture with smooth muscle cells, the DAPI-labeled MDSCs tended to exhibit smooth muscle cell morphology and expression of α-SMA was detected. MDSCs exist in the rat penile corpora cavernosa and possess the potential to differentiate into smooth muscle cells. This discovery serves as the basis in view of the potential use of endogenous stem cells for the treatment of erectile dysfunction (ED).

TGFBR3 co-downregulated with GATA3 is associated with methylation of the GATA3 gene in bladder urothelial carcinoma

Bladder urothelial carcinoma (BUC) accounts for ∼90% of all cases of bladder cancer. Reduced expression of TGFBR3 has been frequently observed in several types of human cancers. However, little is known about whether expression of TGFBR3 reduced in BUC and the underlying mechanisms. In the present study, we performed quantitative real-time PCR to examine the mRNA expression of TGFBR3 and GATA3, and bisulfite genomic sequencing to evaluate the methylation status in TGFBR3 and GATA3 promoter regions in fresh tumor and the corresponding paracarcinoma tissues from 29 patients with BUC. As a result, the expression of TGFBR3 and GATA3, a transcriptional factor of the TGFBR3 gene, were found to be co-downregulated in BUC. Moreover, our findings indicated that GATA3 promoter methylation was one of the reasons for silencing of GATA3 and TGFBR3 in BUC, albeit TGFBR3 methylation and mutation were not associated with reduced expression of TGFBR3 mRNA in BUC. In summary, our findings suggest that methylation in the GATA3 promoter region may inhibit the expression of GATA3 mRNA, which leads to the reduced expression of TGFBR3 mRNA in BUC.

Increased chemosensitivity via targeting testicular nuclear receptor 4 (TR4)-Oct4-interleukin 1 receptor antagonist (IL1Ra) axis in prostate cancer CD133+ stem/progenitor cells to battle prostate cancer

Prostate cancer (PCa) stem/progenitor cells are known to have higher chemoresistance than non-stem/progenitor cells, but the underlying molecular mechanism remains unclear. We found the expression of testicular nuclear receptor 4 (TR4) is significantly higher in PCa CD133(+) stem/progenitor cells compared with CD133(-) non-stem/progenitor cells. Knockdown of TR4 levels in the established PCa stem/progenitor cells and the CD133(+) population of the C4-2 PCa cell line with lentiviral TR4 siRNA led to increased drug sensitivity to the two commonly used chemotherapeutic drugs, docetaxel and etoposide, judging from significantly reduced IC50 values and increased apoptosis in the TR4 knockdown cells. Mechanism dissection studies found that suppression of TR4 in these stem/progenitor cells led to down-regulation of Oct4 expression, which, in turn, down-regulated the IL-1 receptor antagonist (IL1Ra) expression. Neutralization experiments via adding these molecules into the TR4 knockdown PCa stem/progenitor cells reversed the chemoresistance, suggesting that the TR4-Oct4-IL1Ra axis may play a critical role in the development of chemoresistance in the PCa stem/progenitor cells. Together, these studies suggest that targeting TR4 may alter chemoresistance of PCa stem/progenitor cells, and this finding provides the possibility of targeting TR4 as a new and better approach to overcome the chemoresistance problem in PCa therapeutics.

Higher expression of peroxisome proliferator-activated receptor γ or its activation by agonist thiazolidinedione-rosiglitazone promotes bladder cancer cell migration and invasion

OBJECTIVE

To investigate the role of peroxisome proliferator-activated receptor γ (PPARγ) in bladder cancer (BCa) progression.

MATERIALS AND METHODS

The gene copy number of PPARγ in human BCa tissue samples was analyzed by fluorescence in situ hybridization. The migration and invasive ability of human BCa cell lines with different PPARγ expression levels or treated with thiazolidinedione-rosiglitazone, a PPARγ agonist and an antidiabetic drug, were investigated.

RESULTS

PPARγ amplification was increased dramatically in BCa tissue compared with normal urothelium (38.1% vs 4.3%, P = .0082) and in tumors with lymph node metastasis compared with those without metastasis (75.0% vs 15.4%, P = .0176). The human BCa cell line 5637 with strong PPARγ expression demonstrated a greater ability for cell migration and invasion than the UMUC-3 cell line with weak PPARγ expression. Knocking down PPARγ in BCa 5637 cells led to decreased cell migration, and activation of PPARγ with thiazolidinedione-rosiglitazone promoted their migration and invasive ability.

CONCLUSION

PPARγ amplification in BCa could play an important role in BCa cell migration and invasion. Alteration of PPARγ expression by PPARγ-small interfering ribonucleic acid or activation by its agonist rosiglitazone, a diabetic thiazolidinedione drug, could lead to alternation of BCa cell migration and invasion.

[Evaluation of 80-W and 120-W GreenLight laser vaporization for benign prostatic hyperplasia in high-risk patients]

OBJECTIVE

To investigate and compare the effectiveness and safety of 80-W GreenLight laser vaporization and GreenLight high-performance system (HPS) 120-W laser vaporization for the treatment of benign prostatic hyperplasia (BPH) in high-risk patients.

METHODS

We allocated 290 high-risk patients with BPH to two groups to receive 80-W (n = 220) and HPS 120-W GreenLight laser vaporization (n = 70). We recorded and compared the pre-, intra- and post-operative clinical data of the two groups.

RESULTS

The operations were successful in both of the groups. There were statistically significant differences in the prostate volume, IPSS, Qmax and PVR before and after surgery (P < 0.01), but not between the two groups (P > 0.05). The operation time, lasing time and energy consumption were (56.5 +/- 22.6) min, (31.2 +/- 10.3) min and (159.8 +/- 29.0) kJ in the 80-W group, as compared with (45.1 +/- 20.4) min, (24.6 +/- 8.3) min and (134.2 +/- 23.3) kJ in the 120 W group, with significant differences between the two (P < 0.01).

CONCLUSION

GreenLight laser vaporization of the prostate is a safe and effective procedure for the treatment of BPH, and the new HPS 120-W laser therapy, with its advantages of easier operation and shorter surgical time, is an even better minimally invasive option for elderly high-risk patients.

[Single trocar laparoscopic surgery: a report of 45 cases]

OBJECTIVE

To report the initial urological applications of single trocar laparoscopic surgery.

METHODS

From April to December 2010, a total of 45 urologic patients underwent single trocar laparoscopic surgery. The procedures included high ligations of spermatics vessels (n = 17), unroofing of renal cysts (n = 24) and ureterolithotomy (n = 4). Transperitoneal approach: A 15 mm incision was made in umbilicus and CO(2) pneumoperitoneum created. A 10-mm trocar was inserted into enterocoelia. After the installation of single punch laparoscope (STROZ), the operating instruments were guided through integrated working channel to complete operative procedures. Retroperitoneal approach: A 15 mm incision was made above the diseased-side crista iliaca for around 4 cm. Retroperitoneal cavity was prepared for retroperitoneoscopy with the IUPU (Institute of Urology, Peking University) technique. In the same way, a 10-mm trocar was inserted. And the single punch laparoscope was installed to complete operative procedures.

RESULTS

The procedures were successful in 41 cases. But the others (renal cysts, n = 2; ureteral calculus, n = 2) were successfully managed by adding a 5 mm trocar. Operation time: transperitoneal approach, 23 - 70 min; retroperitoneal approach, 45 - 175 min. The intra-operative volume of blood loss was minimal. And the hospital stay was 1 - 5 days. No significant postoperative complication occurred.

CONCLUSION

For some relatively simple procedures, a new and more minimally invasive approach of single trocar laparoscopic surgery may be attempted.

Study on mating ecology and sex ratio of three internally ovipositing fig wasps of Ficus curtipes

Studies on mating ecology and sex allocation in fig-parasitizing wasps ovipositing from outside the fig have given valuable insights into known factors that are responsible for the theory of sex ratio. Similarly, internally ovipositing fig-parasitizing wasps and fig-pollinating wasps provide interesting models for comparative analysis. In addition to the fig-pollinating wasp Eupristina sp., we found that Ficus curtipes hosts two species of internally ovipositing fig-parasitizing wasps: D. yangi and Lipothymus sp. Eupristina sp. males showed less aggression. Eupristina sp. has wingless males that mate only within the natal patch, providing excellent examples of full local-mate competition. D. yangi males showed high levels of aggression and lethal combat. D. yangi has winged males but mate mostly within the natal patch. Only a few matings occur after male dispersal. Its sex ratio was lower than the prediction of partial local mate competition theory. Wingless male Lipothymus sp., which mate partly after dispersal, did not present fatal fight. Therefore, the mating behaviour of D. yangi and Lipothymus sp. did not follow predicted patterns, based on wing morph. The mating pattern of D. yangi and Lipothymus sp. should follow the partial local mate competition theory. Furthermore, there was not a significant correlation between the proportion of males and the proportion of fruit parasitized in both winged D. yangi males and wingless Lipothymus sp. males.

[Construction of the recombinant adenovirus vector bearing dual-survivin shRNA]

OBJECTIVE

To construct a recombinant adenovirus vector bearing dual-survivin short hairpin RNA (shRNA).

METHODS

Dual-survivin shRNA was designed and synthesized respectively, both inserted into adenovirus DNA. The recombinant adenovirus vector was confirmed via both sequencing and restriction digestion analysis, and then linearized and transfected into the HEK 293 cell line to generate recombinant adenoviruses.

RESULTS

The recombinant adenovirus vector was constructed and the target sequence was obtained.

CONCLUSION

The construction of the recombinant adenovirus vector provides a basis for the research of potential gene therapy for prostate cancer.

Enhancement of cephalosporin C production by cultivation of Cephalosporium acremonium M25 using a mixture of inocula

AIMS

To enhance the productivity of Cephalosporin C (CPC) by cultivation of Cephalosporium acremonium M25 using a mixture of inocula.

METHODS AND RESULTS

Inoculum age was classified into three stages (early, intermediate and late) by image analysis. A mixture of inocula, according to the inoculum ages, was used for efficient production of CPC in the main culture. The most effective mixing ratio of inocula for CPC production in shake flasks was a 3 : 7 volume ratio of early- and late-stage inocula. This was also the case in a 1.5 l stirred-tank reactor. CPC productivity was enhanced by about 32% and 34% when using an inoculum mixture in the shake flask and 1.5 l stirred-tank reactor, respectively.

CONCLUSION

The morphological characteristics of C. acremonium M25 in the seed culture were quite different according to inoculum age. The compromise of different ages of inoculum showed better production of CPC.

SIGNIFICANCE AND IMPACT OF THE STUDY

The productivity of CPC was enhanced considerably when using mixed inocula. The results of this study can be applied to fungal cultures for efficient production of various metabolites.

[The phylogeny of 5 Chinese peculiar Parnassius butterflies using noninvasive sampling mtDNA sequences]

This paper employs nonivasive sampling DNA sequencing technique for estimating molecular phylogeny of 5 Chinese peculiar Parnassius Butterflies. Of 433bp mitochondrial cytochrome b DNA sequences, A% + T% was 75.4%, and 40 nucleotide sites were substituted (about 9.24%). The molecular phylogenetic tree constructed by parsimony method suggests that Parnassius acco is closely related to Parnassius baileyi; Parnassius apollo, Parnassius orlears, and Parnassius simo are independent branches respectively. Parnassius simo is divergent earlier. The result is identical with that of morphology.

Regulatory factors associated with synthesis of the osmolyte glycine betaine in the halophilic methanoarchaeon Methanohalophilus portucalensis

The halophilic methanoarchaeon Methanohalophilus portucalensis can synthesize de novo and accumulate beta-glutamine, Nepsilon-acetyl-beta-lysine, and glycine betaine (betaine) as compatible solutes (osmolytes) when grown at elevated salt concentrations. Both in vivo and in vitro betaine formation assays in this study confirmed previous nuclear magnetic resonance 13C-labelling studies showing that the de novo synthesis of betaine proceeded from glycine, sarcosine, and dimethylglycine to form betaine through threefold methylation. Exogenous sarcosine (1 mM) effectively suppressed the intracellular accumulation of betaine, and a higher level of sarcosine accumulation was accompanied by a lower level of betaine synthesis. Exogenous dimethylglycine has an effect similar to that of betaine addition, which increased the intracellular pool of betaine and suppressed the levels of Nepsilon-acetyl-beta-lysine and beta-glutamine. Both in vivo and in vitro betaine formation assays with glycine as the substrate showed only sarcosine and betaine, but no dimethylglycine. Dimethylglycine was detected only when it was added as a substrate in in vitro assays. A high level of potassium (400 mM and above) was necessary for betaine formation in vitro. Interestingly, no methylamines were detected without the addition of KCl. Also, high levels of NaCl and LiCl (800 mM) favored sarcosine accumulation, while a lower level (400 mM) favored betaine synthesis. The above observations indicate that a high sarcosine level suppressed multiple methylation while dimethylglycine was rapidly converted to betaine. Also, high levels of potassium led to greater amounts of betaine, while lower levels of potassium led to greater amounts of sarcosine. This finding suggests that the intracellular levels of both sarcosine and potassium are associated with the regulation of betaine synthesis in M. portucalensis.

Two newly identified mutations (Thr233Ile and Leu152Met) in partially adenosine deaminase-deficient (ADA-) individuals that result in differing biochemical and metabolic phenotypes

Deficiency of adenosine deaminase (ADA-) results in autosomal recessive immunodeficiency disease of varying severity. Partial ADA- [ADA deficiency in erythrocytes (RBCs) but substantial ADA in non-RBCs] has also been identified, primarily by population screening of healthy adults in Africa and newborns in New York State. Normal immune function and/or minimal elevations of toxic metabolites in childhood suggested that partial ADA deficiency was benign and therefore that six mutations identified in partially ADA-deficient newborns and expressing 8-80% of normal ADA in non-RBCs were not pathogenic. However, the lowest activity mutation (Arg211Cys) has now been reported in patients with adult-onset immunodeficiency. We have now molecularly and biochemically studied two additional individuals whom we found to represent opposite ends of the spectrum of partial ADA deficiency as to biochemical abnormalities and age of ascertainment. Homozygosity for a newly identified Leu152Met mutation expressing considerably less activity than the pathogenic Arg211Cys mutation was found in a currently healthy 10-year-old Afghanistani child (ascertained at birth). He had the highest accumulation of the metabolite dATP among 13 partially ADA-deficient patients studied, but considerably lower than in those with immunodeficiency. Homozygosity for a newly identified Thr233Ile mutation expressing somewhat greater ADA activity than Arg211Cys was found in a healthy young adult Kung individual, associated with very low metabolite concentrations. Biochemical findings and a family history suggestive of immunodeficiency in prior offspring support the idea that the Leu152Met mutation could result in disease in homozygous individuals challenged by severe environmental insult or in heterozygosity with a null mutation. The pathogenicity of the Thr233Ile mutation, as well as a previously described Ala215Thr mutation with relatively lower activity is less likely but will only be determined by long-term observation of individuals carrying these mutations. Although, in contrast to other partial mutations, neither of these two mutations are at CpG hot spots, the frequency of CpG mutations remains high for partial mutations but is also similarly high in ADA- immunodeficient patients (5/8 vs 12/21).

Spontaneous in vivo reversion to normal of an inherited mutation in a patient with adenosine deaminase deficiency

Somatic mosaicism in genetic disease generally results from a de novo deleterious mutation during embryogenesis. We now describe a somatic mosaicism due to the unusual mechanism of in vivo reversion to normal of an inherited mutation. The propositus was an adenosine deaminase-deficient (ADA-) child with progressive clinical improvement and unexpectedly mild biochemical and immunologic abnormalities. Mosaicism due to reversion was evidenced by absence of a maternally transmitted deleterious mutation in 13/15 authenticated B cell lines and in 17% of single alleles cloned from blood DNA, despite retention of a maternal 'private' ADA polymorphism linked to the mutation. Establishment of significant somatic mosaicism following reversion to normal could modify any disorder in which revertant cells have a selective advantage.

Somatic mosaicism for a newly identified splice-site mutation in a patient with adenosine deaminase-deficient immunodeficiency and spontaneous clinical recovery

Absent or severely reduced adenosine deaminase (ADA) activity produces inherited immunodeficiency of varying severity, with defects of both cellular and humoral immunity. We report somatic mosaicism as the basis for a delayed presentation and unusual course of a currently healthy young adult receiving no therapy. He was diagnosed at age 2 1/2 years because of life-threatening pneumonia, recurrent infections, failure of normal growth, and lymphopenia, but he retained significant cellular immune function. A fibroblast cell line and a B cell line, established at diagnosis, lacked ADA activity and were heteroallelic for splice-donor-site mutation in IVS 1 (+1GT-->CT) and a missense mutation (Arg101Gln). All clones (17/17) isolated from the B cell mRNA carried the missense mutation, indicating that the allele with the splice-site mutation produced unstable mRNA. In striking contrast, a B cell line established at age 16 years expressed 50% of normal ADA; 50% of ADA mRNA had normal sequence, and 50% had the missense mutation. Genomic DNA contained the missense mutation but not the splice-site mutation. All three cell lines were identical for multiple polymorphic markers and the presence of a Y chromosome. In vivo somatic mosaicism was demonstrated in genomic DNA from peripheral blood cells obtained at 16 years of age, in that less than half the DNA carried the splice-site mutation (P < .002, vs. original B cell line). Consistent with mosaicism, erythrocyte content of the toxic metabolite deoxyATP was only minimally elevated. Somatic mosaicism could have arisen either by somatic mutation or by reversion at the site of mutation. Selection in vivo for ADA normal hematopoietic cells may have played a role in the return to normal health, in the absence of therapy.

Homozygosity for a missense mutation (G20R) associated with neonatal onset adenosine deaminase-deficient severe combined immunodeficiency (ADA-SCID)

Mutations at the adenosine deaminase (ADA) locus can result in varying degrees of immunodeficiency, including rapidly fulminant severe combined immunodeficiency (SCID) as well as a slowly progressive immunodeficiency not diagnosed until later in childhood. Genetic heterogeneity is a factor in the clinical heterogeneity. We have now identified, by direct sequencing of PCR-amplified genomic DNA, a G to A transition at a CpG dinucleotide predicting a glycine to arginine substitution at codon 20 (G20R). The mutation, in homozygosity, was associated with neonatal-onset rapidly fatal SCID. Consistent with homozygosity, the child was derived from a small isolated inbred community in Newfoundland. The mutation abolishes a site for the restriction enzyme BamHI and can be simply detected by agarose gel electrophoresis following amplification of exon 2 from genomic DNA and digestion with BamHI. The majority of ADA missense mutations can now be detected by similar amplification and enzyme digestion. We demonstrated that the G20R mutation is deleterious since introduction of the mutation into a normal ADA minigene abolished enzyme activity, as determined by transient expression in monkey kidney (Cos) cells. The amino acid substitution occurs in an area of the molecule conserved from Escherichia coli to man and that, as shown by crystallographic analysis, is involved in the binding of Zn2+ at the catalytic site. Although the mutation is in a CpG dinucleotide, known "hotspots" for G to A transitions, it was not found in a series of 43 additional ADA- chromosomes. Identification of mutations in additional ADA- patients with immunodeficiency of varying severity should further define the role that genotype plays in determining the extent of immunologic dysfunction.

An Asp8Asn substitution results in the adenosine deaminase (ADA) genetic polymorphism (ADA 2 allozyme): occurrence on different chromosomal backgrounds and apparent intragenic crossover

We have now determined the molecular genetic basis for the common biochemical polymorphism at the adenosine deaminase (ADA) locus. The ADA*2 allele contains a G to A transition at nt22 (relative to the ATG) that results in substitution of asparagine for aspartic acid at codon 8 (Asp8Asn). Introduction of the nucleotide substitution into an ADA 1 cDNA and transfection into monkey kidney (Cos) cells confirmed that the mutation resulted in expression of an enzyme that comigrated with the naturally occurring ADA 2 allozyme. The substitution of neutral asparagine for anionic aspartic acid is consistent with the more cathodal electrophoretic migration of ADA 2 as compared with ADA 1. The nucleotide substitution was found on at least two different genetic backgrounds, suggesting independent recurrence of the mutation. Consistent with independent recurrence, the G to A transition is at a CpG dinucleotide and represents a type of mutation that occurs with high frequency. We have also unexpectedly identified a probable intragenic crossover in the very large first intron that is rich in repetitive DNA sequences.

Severe combined immunodeficiency of reduced severity due to homozygosity for an adenosine deaminase missense mutation (Arg253Pro)

Genetic deficiency of adenosine deaminase (ADA) results in varying degrees of immunodeficiency, including neonatal onset severe combined immunodeficiency (ADA- SCID) and milder, later onset immunodeficiency. We have determined the molecular basis of disease in a child from a consanguineous mating with ADA- SCID of clinically and biochemically reduced severity, diagnosed at 15 months of age and characterized by retention of more immunologic function than is typical of the fulminant neonatal onset type. The course was notable for an early predominance of bacterial infections and eosinophilia. In contrast to its absence in most ADA- SCIDs, residual ADA activity (1-2% of normal) could be detected in EBV-transformed B cells. Consistent with the increased residual ADA, excretion of the substrate deoxyadenosine and accumulation of the toxic metabolite deoxyATP were less than seen in ADA- SCID patients with fulminant disease. Sequence analysis of cDNA revealed a G853C transversion, predicting a substitution of proline for arginine at codon 253 (Arg253Pro). The parents were heterozygous and the child was homozygous for the mutation, as shown by sequence analysis of amplified genomic DNA. Transient expression of mutant cDNA in Cos cells revealed an electrophoretically abnormal, more negatively charged ADA with 1-2% of normal activity. These observations are consistent with replacement of positively charged arginine by proline, the lower accumulation of toxic metabolites, and the milder phenotype. By contrast, transient expression of a Gly216Arg mutant cDNA, associated, when homozygous, with neonatal onset ADA-SCID, did not reveal ADA activity. Mutations such as Arg253Pro, which retain residual activity of monomeric ADA, should be dominant for ameliorating the phenotype in patients carrying two different allelic mutations. Identification of additional similar mutations may be significant in evaluating the goals for and efficacy of current trials of gene and gene product replacement.

Novel deletion and a new missense mutation (Glu 217 Lys) at the catalytic site in two adenosine deaminase alleles of a patient with neonatal onset adenosine deaminase- severe combined immunodeficiency

Mutations at the adenosine deaminase (ADA) locus result in a spectrum of disorders, encompassing a fulminant neonatal onset severe combined immunodeficiency (SCID) and childhood onset immunodeficiency, as well as apparently normal immune function. The extent of accumulation of the toxic metabolite, deoxyATP, correlates directly with severity of disease. We have now determined the mutations on both alleles of a child with fulminant, neonatal onset ADA- SCID and accumulation of extremely high concentrations of deoxyATP. The genotype was consistent with the severely affected phenotype. One allele carried a large deletion that arose by non-homologous recombination and included the first five exons and promoter region. The second allele carried a missense mutation (G649A) resulting in replacement of Glu217, an amino acid involved in the catalytic site, by Lys and predicting a major alteration in charge. Expression of the mutant cDNA in Cos cells confirmed that the mutation abolished enzyme activity. We have previously reported that a missense mutation at the preceding codon is similarly associated with neonatal onset ADA- SCID and accumulation of extremely high deoxyATP. These findings suggest that genotype-phenotype correlations may be apparent for ADA- SCID, despite the role that random variation in exposure to environmental pathogens may play in the initial phenotype. Such genotype-phenotype correlations may be important to consider in evaluating results of ongoing trials of "gene" and enzyme replacement therapy.

Novel deletion and a new missense mutation (Glu 217 Lys) at the catalytic site in two adenosine deaminase alleles of a patient with neonatal onset adenosine deaminase- severe combined immunodeficiency

Mutations at the adenosine deaminase (ADA) locus result in a spectrum of disorders, encompassing a fulminant neonatal onset severe combined immunodeficiency (SCID) and childhood onset immunodeficiency, as well as apparently normal immune function. The extent of accumulation of the toxic metabolite, deoxyATP, correlates directly with severity of disease. We have now determined the mutations on both alleles of a child with fulminant, neonatal onset ADA- SCID and accumulation of extremely high concentrations of deoxyATP. The genotype was consistent with the severely affected phenotype. One allele carried a large deletion that arose by non-homologous recombination and included the first five exons and promoter region. The second allele carried a missense mutation (G649A) resulting in replacement of Glu217, an amino acid involved in the catalytic site, by Lys and predicting a major alteration in charge. Expression of the mutant cDNA in Cos cells confirmed that the mutation abolished enzyme activity. We have previously reported that a missense mutation at the preceding codon is similarly associated with neonatal onset ADA- SCID and accumulation of extremely high deoxyATP. These findings suggest that genotype-phenotype correlations may be apparent for ADA- SCID, despite the role that random variation in exposure to environmental pathogens may play in the initial phenotype. Such genotype-phenotype correlations may be important to consider in evaluating results of ongoing trials of "gene" and enzyme replacement therapy.