Organ-specific microenvironment modifies diverse functional and phenotypic characteristics of leukemia-associated macrophages in mouse T cell acute lymphoblastic leukemia.

Tumor-associated macrophages are widely studied in solid tumors. The distribution of macrophages in lymph node samples was found to be associated with the prognosis of lymphoma patients. However, the role of macrophages in leukemia and their functional and phenotypic characteristics in hematopoietic malignancies have not been defined. In this study, we examined the distribution and functional and phenotypic characteristics of macrophages in a Notch1-induced mouse model of T cell acute lymphoblastic leukemia (T-ALL). The distribution of macrophages in bone marrow (BM) and spleen, which are proposed as BM and spleen leukemia-associated macrophages (LAMs), were different during the development of leukemia. LAMs stimulated the proliferation of T-ALL cells and had higher migration activity. RNA-sequencing analysis revealed that gene expression profiles of BM and spleen LAMs showed considerable differences. RT-PCR analysis showed that LAMs expressed both M1- and M2-associated phenotypic genes, but they expressed much lower levels of TGF-ß1, VEGF-A, and CSF-1 than did tumor-associated macrophages from B16 melanoma. Furthermore, spleen LAMs more potently stimulated the proliferation of T-ALL cells compared with BM LAMs. Moreover, LAMs could be subdivided into M1-like (CD206(-)) and M2-like (CD206(+)) groups. Both CD206(+) and CD206(-) LAMs stimulated the proliferation of T-ALL cells, although CD206(+) LAMs expressed higher levels of most M1- and M2-associated genes. These results suggested the functional and phenotypic characteristics of LAMs, which were modified by organ specific microenvironments. Our results broaden our knowledge about macrophages in malignant microenvironments from solid tumors to leukemia.

Potential role of Wnt/ß-catenin signaling in blastic transformation of chronic myeloid leukemia: cross talk between ß-catenin and BCR-ABL.

Chronic myeloid leukemia (CML) results from malignant transformation of hematopoietic stem cells induced by the BCR-ABL oncogene. Transformation from chronic to blastic phase is the lethal step in CML. Leukemic stem cells (LSCs) are the basic reason for blastic transformation. It has been shown that Wnt/ß-catenin signaling contributes to the self-renewal capacity and proliferation of LSCs in CML. However, the role of Wnt/ß-catenin signaling in blastic transformation of CML is still obscure. Here, we explored the relationship between BCR-ABL and ß-catenin signaling in vitro and in vivo. We found that BCR-ABL stimulated ß-catenin via activation of PI3K/AKT signaling in blastic phase CML cells. Inhibition of the kinase activity of BCR-ABL, PI3K, or AKT decreased the level of ß-catenin in both K562 cells and a CML mouse model and suppressed the transcription of downstream target genes (c-myc and cyclin D1). In addition, inhibition of the BCR-ABL/PI3K/AKT pathway delayed the disease progression in the CML mouse model. To further explore the role of ß-catenin in the self-renewal and survival of CML LSCs, we established a secondary transplantation CML mouse model. Our data revealed that inhibition of the BCR-ABL/PI3K/AKT pathway reduced the tumor-initiating ability of K562 cells, decreased leukemia cell infiltration into peripheral blood and bone marrow, and prolonged the survival of mice. In conclusion, our data indicate a close relationship between ß-catenin and BCR-ABL/PI3K/AKT in blastic phase CML. ß-Catenin inhibition may be of therapeutic value by targeting LSCs in combination with a tyrosine kinase inhibitor, which may delay blastic transformation of CML.

Cell-penetrating fusion peptides OD1 and OD2 interact with Bcr-Abl and influence the growth and apoptosis of K562 cells.

The Bcr-Abl oncoprotein is the cause of chronic myelogenous leukemia (CML). Crystal structure analysis suggests that Bcr30-63 is the core of the Bcr-Abl oligomerization interface for aberrant kinase activity; however, the precise role of other residues of Bcr1-72 excluding Bcr30-63 have not been evaluated. In this study, Bcr30-63 was named OD2 and other residues of Bcr1-72 were named OD1. Cytoplasmic transduction peptide (CTP) was used to carry molecules into cytoplasm. CTP-OD1 and CTP-OD2 fusion peptides were expressed from a cold-inducible expression system. Our results demonstrated that both fusion peptides could localize into the cytoplasm, specifically interact with the Bcr-Abl protein and further inhibit growth, induce apoptosis, and decrease the phosphorylation of Bcr-Abl in K562 cell lines. However, the viability of THP-1, a Bcr-Abl negative cell line, was unaffected. These results suggested that CTP-OD1 and CTP-OD2 may be an attractive therapeutic option to inhibit the activation of Bcr-Abl kinase in CML.

Gestational diabetes mellitus combined with fulminant type 1 diabetes mellitus, four cases of double diabetes: A case report.

BACKGROUND: Fulminant type 1 diabetes mellitus (FT1DM) that occurs during pregnancy or the perinatal period is known as pregnancy-related FT1DM (PF), always without history of abnormal glucose metabolism. Here, we present four patients who developed FT1DM during treatment but were first diagnosed with gestational diabetes mellitus (GDM). CASE SUMMARY: The clinical data of four patients with GDM combined with FT1DM admitted to our hospital between July 2018 and April 2021 were collected, and the patients and their infants were followed up. All patients were diagnosed with GDM during the second trimester and were treated. The blood glucose level elevated suddenly during the third trimester and then were diagnosed with FT1DM. Two patients had an insulin allergy, and two had symptoms of upper respiratory tract infection before onset. One patient developed ketoacidosis, and three developed ketosis. Two patients had cesarean section deliveries, and two had vaginal deliveries. The growth and development of the infants were normal. C-peptide levels were lower than those at onset, suggesting progressive impairment of islet function. The frequencies of the DRB1 09:01, DQB1 03: 03, DQA1 03:02, DPA1 01:03, DPA1 02:02, DPB1 05:01, DRB4 01:03, G 01:01, and G 01:04 human leukocyte antigen (HLA)-G alleles were high in the present study. CONCLUSION: In comparison with pregnancy-associated FT1DM (PF), patients with GDM combined with FT1DM had an older age of onset, higher body mass index, slower onset, fewer prodromal symptoms, and less acidosis. The pathogenesis may be due to various factors affecting the already fragile ß-cells of GDM patients with genetically susceptible class II HLA genotypes. We speculate that GDM combined with FT1DM during pregnancy, referred to as "double diabetes," is a subtype of PF with its own unique characteristics that should be investigated further.

TAT-CC fusion protein depresses the oncogenicity of BCR-ABL in vitro and in vivo through interrupting its oligomerization.

Chronic myeloid leukemia (CML) is a clonal hematologic malignancy characterized by the BCR-ABL protein. BCR-ABL is a constitutively active tyrosine kinase and plays a critical role in the pathogenesis of CML. Imatinib mesylate, a selective tyrosine kinase inhibitor, is effective in CML, but drug resistance and relapse occur. The coiled-coil (CC) domain located in BCR(1-72) mediates BCR-ABL tetramerization, which is essential for the activation of tyrosine kinase and transformation potential of BCR-ABL. CC domain is supposed to be a therapeutic target for CML. We purified a TAT-CC protein competively binding with the endogenous CC domain to reduce BCR-ABL kinase activity. We found that TAT-CC co-located and interacted with BCR-ABL in Ba/F3-p210 and K562 cells. It induced apoptosis and inhibited proliferation in these cells. It increased the sensitivity of these cells to imatinib and reduced the phosphorylation of BCR-ABL, CRKL and STAT5. We confirmed that TAT-CC could attenuate the oncogenicity of Ba/F3-p210 cells and diminish the volume of K562 solid tumor in mice. We conclude targeting the CC may provide a complementary therapy to inhibit BCR-ABL oncogenicity.

Linear porokeratosis of the foot with dermoscopic manifestations: A case report.

BACKGROUND: Porokeratosis (PK) is a common autosomal dominant chronic progressive dyskeratosis with various clinical manifestations. Based on clinical manifestations, porokeratosis can be classified as porokeratosis of mibelli, disseminated superficial porokeratosis, disseminated superficial actinic porokeratosis, linear porokeratosis (LP), porokeratosis palmaris et plantaris disseminata, porokeratosis punctata, popular PK, hyperkeratosis PK, inflammatory PK, verrucous PK, and mixed types. We report a case of LP in a child and describe its dermoscopic findings. CASE SUMMARY: Linear porokeratosis is a rare PK. The patient presented with unilateral keratinizing maculopapular rash of the foot in childhood. The patient underwent skin pathology and dermoscopy, and was treated with liquid nitrogen freezing and topical drugs. CONCLUSION: From this case we take-away that LP is a rare disease, by the dermoscopic we can identify it.

The intracellular stability of DLC1 is regulated by the 26S proteasome in human hepatocellular carcinoma cell line Hep3B.

Deleted in liver cancer 1 (DLC1), a tumor suppressor gene identified in a primary human hepatocellular carcinoma, encodes a Rho GTPase-activating protein (RhoGAP). Although DLC1 expression has been studied at the transcriptional level, little is known about its regulation at the protein level. Here we show that DLC1 is an unstable protein that is degraded by the 26S proteasome in human hepatocellular carcinoma Hep3B cells. In addition, five putative PEST motifs were identified in the N-terminus of DLC1. Unexpectedly, the N-terminus of DLC1 appeared to be stable. Furthermore, deletion of any one of the five PEST motifs except PEST2 decreased the stability of the N-terminus of DLC1, which suggests that the PEST motifs may play an unrevealed role in maintaining the stability of DLC1. These data indicated that the intracellular stability of DLC1 is regulated by the 26S proteasome via its PEST motifs.

Neuropathy and chloracne induced by 3,5,6-trichloropyridin-2-ol sodium: Report of three cases.

BACKGROUND: Chloracne is a rare skin condition that is caused by systemic exposure to halogenated aromatic compounds. The main characteristic of chloracne is blackhead, and in severe cases, it can be accompanied by systemic symptoms. Sodium 3,5,6-trichloropyridin-2-ol (STCP) is a necessary precursor compound for the production of chlorpyrifos and triclopyr, which are extensively used as a pesticide and herbicide, respectively. STCP is also a chlorophenol that has been associated with chloracne. STCP poisoning could induce mild myelin sheath damage. We herein report three cases with chloracne due to exposure to STCP. CASE SUMMARY: Three young men, aged 29, 33, and 26 years, respectively, in the same workplace had polymorphic skin lesions, characterized mainly by comedones and cysts, and one of them also had acne like lesions in the genital area. These clinical manifestations appeared when they were exposed to STCP for 3 d, 1 wk, and 2 wk, respectively. Among them, polyneuropathy and liver damage occurred. We performed dermoscopy and clinical and laboratory tests on these patients. Additionally, histopathology was used for further diagnosis in the serious patient. These patients were diagnosed with chloracne and separated from STCP. The patients were prescribed oral viaminate capsules, topical adapalene gel, and regular hematologic follow-up for aspartate transaminase and lipids. They are still under follow-up. There was no new lesions and the laboratory tests returned to normal in two patients. Pigmentation and shallow scars remained in the original areas of papules. However, in the most serious patient, new papules still appeared intermittently. All these remind us that the treatment of chloracne caused by STCP is difficult, and we should attach great importance to this new compound related with the neuropathy and chloracne. CONCLUSION: STCP is becoming a new chemical product to induce chloracne, which should attract the attention of all medical professionals, especially dermatologists. Due to the lack of knowledge on the new chemical, the diagnosis of chloracne cannot be made in time. Chloracne still deserves our attention.

Cloning, expression, purification and functional characterization of the oligomerization domain of Bcr-Abl oncoprotein fused to the cytoplasmic transduction peptide.

Protein-based cellular therapeutics have been limited by getting molecules into cells and the fact that many proteins require accurate cellular localization for function. Cytoplasmic transduction peptide (CTP) is a newly designed transduction peptide that carries molecules across the cell membrane with a preference to localize in the cytoplasmic compartment and is, therefore, applicable for cytoplasmic targeting. The Bcr-Abl fusion protein, playing major causative role in chronic myeloid leukemia (CML), is a cytoplasmic oncoprotein that contains an N-terminus oligomerization domain (OD) mediating homodimerization of Bcr-Abl proteins, and an intact OD in Bcr-Abl is required both for the activation of its transforming activity and tyrosine kinase. Therefore, disrupting Bcr-Abl oligomerization represents a potential therapeutic strategy for inhibiting Bcr-Abl oncogenicity. In this study, we explored the possible homodimerization-disrupting and tyrosine kinase inhibiting effect of the transduction of OD in Bcr-Abl positive K562 cells. By expressing in Escherichia coli a CTP-OD-HA fusion protein followed by Ni+-NTA affinity purification, immunoblot identification and enterokinase cleavage, we showed that the CTP-OD-HA protein was structurally and functionally active in that it potently transduced and primarily localized into the cytoplasmic compartment, heterodimerized with Bcr-Abl, and potently inhibited the phospho-tyrosine pathways of Bcr-Abl oncoprotein at a low concentration of 4 microM. These results delineate strategies for the expression and purification of therapeutic molecules for intracytoplasmic protein based therapeutics and the CTP-OD-HA-mediated killing strategy could be explored as a promising anti-leukemia agent or an adjuvant to the conventional therapeutic modalities in chronic myeloid leukemia, such as in vitro purging.

Cloning, expression, purification, distribution and kinetics characterization of the bacterial beta-galactosidase fused to the cytoplasmic transduction peptide in vitro and in vivo.

Cytoplasmic transduction peptide (CTP) offers exciting therapeutic opportunities for the treatment of many diseases caused by cytoplasmic functional molecules. It can transduce large, biologically active proteins into the cytoplasmic compartment of several mammalian cells. However, other intriguing features of CTP, including its activity in vitro, and distribution and tissue infiltration abilities in vivo, remain to be explored. The present study was initiated to (1) further confirm the cytoplasmic localization preference and the enzymatic activity of the transduced CTP-beta-gal in vitro and (2) examine the kinetics and tissue distribution of the CTP-beta-gal fusion protein in mice. A CTP-beta-gal fusion protein was expressed in Escherichia coli and either transduced into BaF3-BCR/ABL cells or administered intravenously into female Balb/C mice at a dose of 100 microg per mouse. Its localization in BaF3-BCR/ABL cells was evaluated by immunocytochemistry and in situ X-gal staining, and its distribution in various tissues was analyzed both by in situ X-gal staining and quantitative enzymatic activity assay. beta-Galactosidase enzyme activity was observed in BaF3-BCR/ABL cells and in all tissues tested, with peak activity occurring at 15 min in most tissues and at 24h in brain. These data will not only allow rational selection of delivery schedules for therapeutic CTP, but will also aid the use of CTP fusion protein transduction in the development of protein therapeutics targeting the cytoplasmic compartment both in vitro and in vivo.

[Distribution and Accumulation of Cadmium in Paddy Soil and Rice Affected by Pollutant Sources Control and Improvement Measures].

The objective of this study was to determine the effect of five scenarios on the accumulation of Cd in the soil-rice system, including the return of straw to the field and the lack of the return, atmospheric deposition control, use of clean water for irrigation, and the use of lime. For the field experiments, three typical paddies were selected and divided into five plots (5 m×6 m) in Xiangtan, Zhuzhou, and Liling in the Hunan province from April to October 2016. The results showed that the application of lime can increase pH by 0.87, while the available Cd concentration in the soil was decreased by 33.7%. The accumulations of Cd in roots, stems, and brown rice were decreased by 47.9%, 46.7%, and 54.8%, respectively, with a decrease in the corresponding bioconcentration factors. Irrigating with clean water and liming tended to increase the soil pH by 0.44 and 0.49, respectively, while the available Cd concentration in the soil was decreased by 18.2% and 14.5%, respectively. The Cd concentrations in roots, stems, and brown rice were decreased by 32.6%, 24.2%, and 18.0%, and 17.6%, 11.3%, and 25.4% with decreased bioconcentration factors under both treatments (irrigating with clean water and liming). The available Cd concentration in the soil was increased by 6.1% and the Cd accumulation in the rice plants also increased with the return of straw to the soil. The bioconcentration factors of the rice plants were also increased when the paddy straw was returned to the fields. The results showed that the measures, such as the use of lime, atmospheric deposition control, use of clean water for irrigation, and lack of the return of straw to the paddy soil, should be helpful for the safe production of brown rice. The possible long-term risks associated with returning straw to the paddy field should be evaluated scientifically.

CAR-T therapy for leukemia: progress and challenges.

Despite the rapid development of therapeutic strategies, leukemia remains a type of difficult-to-treat hematopoietic malignancy that necessitates introduction of more effective treatment options to improve life expectancy and quality of patients. Genetic engineering in adoptively transferred T cells to express antigen-specific chimeric antigen receptors (CARs) has proved highly powerful and efficacious in inducing sustained responses in patients with refractory malignancies, as exemplified by the success of CD19-targeting CAR-T treatment in patients with relapsed acute lymphoblastic leukemia. Recent strategies, including manipulating intracellular activating domains and transducing viral vectors, have resulted in better designed and optimized CAR-T cells. This is further facilitated by the rapid identification of an accumulating number of potential leukemic antigens that may serve as therapeutic targets for CAR-T cells. This review will provide a comprehensive background and scrutinize recent important breakthrough studies on anti-leukemia CAR-T cells, with focus on recently identified antigens for CAR-T therapy design and approaches to overcome critical challenges.

Depression of oncogenecity by dephosphorylating and degrading BCR-ABL.

Aberrant phosphorylation and overexpression of BCR-ABL fusion protein are responsible for the main pathogenesis in chronic myeloid leukemia (CML). Phosphorylated BCR-ABL Y177 recruits GRB2 adaptor and triggers leukemic RAS-MAPK and PI3K-AKT signals. In this study, we engineered a SPOA system to dephosphorylate and degrade BCR-ABL by targeting BCR-ABL Y177. We tested its effect on BCR-ABL phosphorylation and expression, as well as cell proliferation and apoptosis in CML cells. We found that SPOA remarkably dephosphorylated BCR-ABL Y177, prevented GRB2 recruitment, and uncoupled RAS-MAPK and PI3K-AKT signals. Meanwhile, SPOA degraded BCR-ABL oncoprotein in ubiquitin-independent manner and depressed the signal transduction of STAT5 and CRKL by BCR-ABL. Furthermore, SPOA inhibited proliferation and induced apoptosis in CML cells and depressed the oncogenecity of K562 cells in mice. These results provide evidence that dephosphorylating and degrading oncogenic BCR-ABL offer an alternative CML therapy.

[Effects of Sinopodophyllum hexundrum on apoptosis in K562 cells].

OBJECTIVE: To investigate the effects of Sinopodophyllum hexundrum on apoptosis in K562 cells. METHODS: K562 cells were treated with Sinopodophyllum hexundrum at different concentrations and for different lengths of time to determine the optimal conditions of SinoPodophyllum hexandrum treatment for K562 cells using CCK8 assay. The cell apoptotic rate was detected by flow cytometry, and the cell morphology and nuclear morphology of K562 cells were observed with Wright staining and DPAI staining, respectively. The protein expressions of BCR/ABL, p-BCR/ABL, STAT5, p-STAT5 and the apoptosis-related proteins PARP, caspase-3 and cleaved-caspase-3 were determined with Western blotting. RESULTS: The cell proliferation was inhibited in a concentration-and time-dependent manner by 1, 2, and 3 µg/mL Sinopodophyllum hexundrum. The treatment was optimal with a Sinopodophyllum hexundrum concentration of 2 µg/mL a treatment time of 48 h, and the cell apoptotic rate increased in a time-dependent manner and significantly increased at 48 h (P<0.001). The expression of apoptosis-related proteins PARP, caspase-3 and cleaved-caspase-3 were also activated in a time-dependent manner. The cells showed typical apoptotic changes after treatment with 2 µg/mL Sinopodophyllum hexundrum for 48 h with significantly reduced expressions of BCR/ABL, p-BCR/ABL, STAT5, AND p-STAT5. CONCLUSION: Sinopodophyllum hexundrum promotes K562 cell apoptosis possibly by inhibiting BCR/ABL-STAT5 survival signal pathways and activating the mitochondrion-associated apoptotic pathways.

[Research Progress on Expression and Function of P2 Purinergic Receptor in Blood Cells].

Nucleotides have unambiguously emerged as a family of mediators of intercellular communication, which bind a class of plasma membrane receptors, P2 purinergic receptors, to trigger intercellular signaling. P2 receptors can be further divided into two structurally and functionally different sub-famlies, the P2X and P2Y receptors. Different blood cells express diverse spectrum of P2 receptors at different levels. Extracellular adenosine triphosphate (ATP) exerts different effects on blood cells, regulating cell proliferation, differentiation, migration, chemotaxis, release of cytokines or lysosomal constituents, and generation of reactive oxygen or nitrogen species. The relationship between abnormal P2 receptors and human diseases attracts more and more attention. This review briefly discusses the expression and function of P2 receptors in hematopoietic system.

[Indomethacin Significantly Enhances Inhibitory Effect of Imatinib on Proliferation of KCL22 and K562/G01 Cells].

OBJECTIVE: To investigate the inhibitory effect of indomethacin combined with imatinib on proliferation of KCL22 and K562/G01 cells, and to elucidate the molecular mechanism of antiproliferative effect by Wnt/ß-Catenin signaling way. METHODS: Indomethacin was used in KCL22 and K562/G01 cells. The cell growth was detected by MTT assay to explore the optimal concentration and time. The effect of drugs on proliferation capacity was assessed by MTT assay and colony-forming assay. Flow cytometry was used to identify the cell cycle and apoptosis changes. The protein expression of pß-catenin (S33/37/T41), pGSK-3ß (Ser9) and C-MYC were analyzed by Western blot. RESULTS: The optimal concentration and time of indomethacin on KCL22 and K562/G01 were 80 µmol/L for 48 h. The inhibitory effect of 80 µmol/L indomethacin combined 2 µmol/L imatinib on cell proliferation was significantly better than a single drug treatment. Flow cytometry results showed that cell cycle was arrested in the G0/G1 phase in both combined treatment groups. The number of apoptosis cells in combined treatment groups was significantly higher than that in single drug treatment groups. Compared with the control group or single drug treatment groups, the protein level of pß-catenin, ß-catenin, pGSK-3ß (Ser9) and C-MYC decreased significantly. CONCLUSION: Indomethacin significantly enhances inhibitory effect of imatinib on proliferation of KCL22 and K562/G01 cells and regulate cell proliferation through Wnt/ß-Catenin signaling way.

[Effect of Recombinant Adenovirus AdE-SH2-Caspase 8 on the Apoptosis of Imatinib-resistant K562/G01 Cell Line].

OBJECTIVE: To investigate the effect of SH2-Caspase 8 fusion protein expressed by recombinant adenovirus AdE-SH2-Caspase8-HA-GFP (SC) on the apoptosis of K562/G01 cell line, which is a BCR/ABL positive chronic myeloid leukemia cell line and resistant to imatinib. METHODS: The K562/G01 cell line was infected with AdE-SH2-Caspase 8-HA-GFP adenovirus (SC), then the cells were divided into 3 groups: AdE-SH2m-Caspase 8-HA-GFP (SmC) group, AdE-GFP (CMV) group and PBS group as control. The infection efficiency was observed under fluorescent microscopy and by flow cytometry. The expression of fusion protein SH2-Caspase 8-HA was measured by Western blot. The morphology of the cells detected by Wright's staining. The apoptosis of the cells were detected by flow cytometry and DNA ladder. The expression of Caspase 3 and PARP were detected by Western blot. RESULT: The infection efficiency of SC on K562/G01 cells was high which was confirmed by fluorescent microscopy and FCM. SH2-Caspase 8-HA fusion protein were expressed correctly in K562/G01 cells. After treatment with SC the apoptosis of K562/G01 cells could be observed by microscopy. The result of FCM showed that early apoptosis of K562/G01 cells increased significantly as compared with control groups (P < 0.05). DNA ladder showed that the classic DNA ladders appeared in K562/G01 cells after treatment with SC. The wester blot detection showed that the expression level of apoptosis-related protein Caspase 3 and PARP increased. CONCLUSION: The recombinant adenovirus SC expressing SH2-Caspase 8 fusion protein can induces the apoptosis of K562/G01 cells.

Heat shock protein-70 neutralizes apoptosis inducing factor in Bcr/Abl expressing cells.

Bcr/Abl fusion protein is a hallmark of human chronic myeloid leukemia (CML). The protein can activate various signaling pathways to make normal cells transform malignantly and thus to facilitate tumorigenesis. It has been reported that heat shock protein-70 (HSP-70) can be served as an anti-apoptotic protein that suppresses Bax and Apo-2L/TRAIL. But it is unclear whether HSP-70 affects AIF-initiated apoptosis in Bcr/Abl expressing cells considering that HSP-70 is coincidentally over-regulated in these cells. Our findings supported that abundant HSP-70 in Bcr/Abl cells neutralizes AIF by segregating it from nucleus via direct interaction, leading to the failure of AIF initiating cell death and the silence of caspase-independent apoptotic pathway upon apoptotic induction. Moderate inhibition of HSP-70 expression by siRNA leads to Vp-16 triggered re-distribution of AIF in nucleus. In addition, AIF bears a HSP-70 binding domain allowing association with HSP-70. Therefore, disruption of the association using an AIF mutant lacking this domain can restore the potential of AIF importing into nucleus, and finally triggers cell death in a time dependent manner.

PMT1 deficiency enhances basal UPR activity and extends replicative lifespan of Saccharomyces cerevisiae.

Pmt1p is an important member of the protein O-mannosyltransferase (PMT) family of enzymes, which participates in the endoplasmic reticulum (ER) unfolded protein response (UPR), an important pathway for alleviating ER stress. ER stress and the UPR have been implicated in aging and age-related diseases in several organisms; however, a possible role for PMT1 in determining lifespan has not been previously described. In this study, we report that deletion of PMT1 increases replicative lifespan (RLS) in the budding yeast Saccharomyces cerevisiae, while overexpression of PMT1 (PMT1-OX) reduces RLS. Relative to wild-type and PMT1-OX strains, the pmt1Δ strain had enhanced HAC1 mRNA splicing and elevated expression levels of UPR target genes. Furthermore, the increased RLS of the pmt1Δ strain could be completely abolished by deletion of either IRE1 or HAC1, two upstream modulators of the UPR. The double deletion strains pmt1Δhac1Δ and pmt1Δire1Δ also displayed generally reduced transcription of UPR target genes. Collectively, our results suggest that PMT1 deficiency enhances basal activity of the ER UPR and extends the RLS of yeast mother cells through a mechanism that requires both IRE1 and HAC1.

Clinical presentation of a patient with congenital cutis laxa and abnormal thyroid hormone levels.

We describe a case of generalized cutis laxa (CL) in a 7-year-old female child. At 2 months of age, she was found to have a hoarse voice, and at 3 years, she was much smaller than her peers. Her aging face and short stature caught our attention, and the treatment of the patient was accepted by our hospital. She underwent a thorough examination. X-ray of the wrist bone showed a markedly delayed bone age, and thyroid function tests revealed significantly elevated free triiodothyronine 3 and free thyroxine 4 levels, but thyrotropin was within the normal range. Thyroid dysfunction and CL can be associated with lagged growth and development. Whether her abnormal development was due to thyroid dysfunction or CL could not be ascertained. CL is possibly more complex than it has been supposed so far, and is therefore worth to be further studied.