Risk factors of early thyroid dysfunction after definitive radiotherapy in nasopharyngeal carcinoma patients.

BACKGROUND: To explore the patterns and risk factors of early thyroid dysfunction in nasopharyngeal carcinoma (NPC) patients within 1 year after intensity-modulated radiation therapy (IMRT). METHODS: Patients with NPC who received definitive IMRT between April 2016 and April 2020 were included. All patients had normal thyroid function before definitive IMRT. The chi-square test, Student's T-test, Mann-Whitney U test, Kaplan-Meier method, receiver operating characteristics curve, and Cox proportional hazard analysis were used for statistical analysis. RESULTS: A total of 132 NPC patients were identified. Of these patients, 56 (42.4%) had hypothyroidism and 17 (12.9%) had hyperthyroidism. The median time to hypothyroidism and hyperthyroidism was 9 months (range, 1-12 months) and 1 month (range, 1-6 months) after definitive IMRT, respectively. In patients with hypothyroidism, 41 (73.2%) had subclinical hypothyroidism and 15 (26.8%) had clinical hypothyroidism. In those with hyperthyroidism, 12 patients (70.6%) had subclinical hyperthyroidism, and five patients (29.4%) had clinical hyperthyroidism. Age, clinical stage, thyroid volume, and V45 were independent risk factors for early radiation-induced hypothyroidism within 1 year after IMRT. Patients aged <47 years, stage III/IV disease, or pre-irradiation thyroid volume < 14 cm3 had higher risks of developing hypothyroidism. CONCLUSION: Primary subclinical hypothyroidism was the most common subtype of early thyroid dysfunction in NPC patients within 1 year after IMRT. Age, clinical stage, thyroid volume, and V45 were independent risk factors for early radiation-induced hypothyroidism in NPC patients.

CircNCOR1 regulates breast cancer radiotherapy efficacy by regulating CDK2 via hsa-miR-638 binding.

BACKGROUND: Despite aggressive local and regional therapy, triple-negative breast cancer (TNBC) is characterized by an increased risk of locoregional recurrence. RNA-sequencing data has identified a large number of circRNAs in primary breast cancers, but the role of specific circRNAs in regulating the radiosensitivity of TNBC is not fully understood. This research aimed to investigate the function of circNCOR1 in the radiosensitivity of TNBC. METHODS: CircRNA high-throughput sequencing was conducted on two breast cancer MDA-MB-231 and BT549 cell lines after 6 Gy radiation. The relationship between circNCOR1, hsa-miR-638, and CDK2 was determined by RNA immunoprecipitation (RIP), FISH and luciferase assays. The proliferation and apoptosis of breast cancer cells were measured by CCK8, flow cytometry, colony formation assays, and western blot. RESULTS: Differential expression of circRNAs was closely related to the proliferation of breast cancer cells after irradiation. Overexpression of circNCOR1 facilitated the proliferation of MDA-MB-231 and BT549 cells and impaired the radiosensitivity of breast cancer cells. Additionally, circNCOR1 acted as a sponge for hsa-miR-638 to regulate the downstream target protein CDK2. Overexpression of hsa-miR-638 promoted apoptosis of breast cancer cells, while overexpression of CDK2 alleviated apoptosis and increased proliferation and clonogenicity. In vivo, overexpression of circNCOR1 partially reversed radiation-induced loosening of tumor structures and enhanced tumor cell proliferation. CONCLUSION: Our results demonstrated that circNCOR1 bounds to hsa-miR-638 and targets CDK2, thereby regulating the radiosensitivity of TNBC.

Survival Outcomes and Treatment Decision by Human Papillomavirus Status Among Patients With Stage IVC Head and Neck Squamous Cell Carcinoma.

PURPOSE: To investigate the influence of human papillomavirus (HPV) status on survival outcomes and treatment decisions for patients with de novo stage IV head and neck squamous cell cancers (HNSCC). METHODS: Patients initially diagnosed with de novo stage IVC HNSCC between 2010 and 2015 were identified from the Surveillance, Epidemiology, and End Results database. Cox multivariable analyses were performed to determine prognostic factors associated with head and neck cancers specific survival (HNCSS) and overall survival (OS). RESULTS: We identified 303 patients who received chemotherapy in this study, including 52.5% of them had HPV-positive disease. HPV-positive HNSCC had better HNCSS (P < 0.001) and OS (P < 0.001) compared to those with HPV-negative disease. The results of Cox multivariable analyses showed that HPV-negative status (P = 0.007), N3 stage (P = 0.004), bone metastases (P < 0.001), and lung metastases (P = 0.003) were associated with worse HNCSS. Similar results were found regarding the OS. The sensitivity analyses indicated that HPV-positive HNSCC patients who were treated with radiotherapy had better survival outcomes. However, no survival benefits were found in those with HPV-positive disease receiving surgery. For HPV-negative patients, no survival benefit was observed among those treated with radiotherapy or surgery. CONCLUSIONS: Approximately half of the stage IVC HNSCC patients are HPV-related. The presence of HPV infection appears to be strongly associated with the survival outcome in patients with de novo stage IV HNSCC. Determination of HPV status may help guide clinicians in prognostic assessment and treatment decision-making in this population.

Ginsenoside Rb1 confers neuroprotection via promotion of glutamate transporters in a mouse model of Parkinson's disease.

Ginsenoside Rb1 has been demonstrated to protect dopaminergic (DA) neurons from death in vitro. However, the neuroprotective effects and underlying mechanism of Rb1 in treating Parkinson's disease (PD) remain uncharacterized. In this study, we explored the effects of Rb1 on the movement disorder and the underlying mechanisms based on the glutamatergic transmission and excitotoxicity in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. Here, for the first time, we report that Rb1 treatment ameliorates motor deficits, prevents DA neuron death, and suppresses α-synuclein expression and astrogliosis in the MPTP mouse model of PD. Rb1 attenuates glutamate excitotoxicity by upregulating glutamate transporter expression and function, and modulating the nigrostriatal and cortico-nigral glutamatergic transmission pathways. Our results demonstrate that Rb1 increases glutamate transporter expression via nuclear translocation of nuclear factor-kappa B, regulates glutamate receptor expression and promotes synaptic protein expression. These results indicate that Rb1 suppresses glutamate excitotoxicity and modulates synaptic transmission to improve the impairments in motor functions of the MPTP model of PD, suggesting that Rb1 may serve as a potential therapeutic agent for PD.

[Effects of Fritillariae Cirrhosae Bulbus on MMP-2,MMP-9 and TIMP-1 in murine asthma model].

To investigate the effects of Fritillariae Cirrhosae Bulbus on airway remodeling and matrix metalloproteinase-2(MMP-2), matrix metalloproteinase-9(MMP-9), tissue inhibitor-1 of metalloproteinase(TIMP-1) of a murine asthma model, and explore its mechanism in treatment of asthma. BALB/C murines were randomly divided into the normal group, model group, high dose group, low dose group, and positive control group. Except for the normal group, all the other groups received ovalbumin(OVA) to establish murine asthma model. After successful modeling, the murines in high dose group and low dose group were orally administered with Fritillariae Cirrhosae Bulbus powder at the dose of 18.0 mg•kg⁻¹ and 9.0 mg•kg⁻¹, respectively; the murines in positive control group were injected intraperitoneally with dexamethasone at the dose of 0.5 mg•kg⁻¹; while the murines in normal group and the model group were orally administered with the same volume of normal saline. All the drugs were given to murines per day for 28 d. The variations of airway responsiveness, variations of the total cell count and leukocyte differential count in bronchoalveolar lavage fluid(BALF), and the variations of thicknesses of bronchial wall and airway smooth muscle of each group were observed. The levels of MMP-2, MMP-9 and TIMP-1 were measured by ELISA; and the expression levels of MMP-2, MMP-9 and TIMP-1 mRNA were detected by RT-PCR. The results showed that as compared with the normal group, the airway responsiveness, the count of total cells, neutrophils, macrophage, lymphocytes, eosinophils in BALF, and the thicknesses of bronchial wall and airway smooth muscle were increased significantly in the model group(P<0.01); as compared with the model group, the above indicators were decreased significantly in the high dose group, low dose group and positive control group (P<0.05 or P<0.01). As compared with the normal group, the levels and expressions of MMP-2, MMP-9 and TIMP-1 mRNA were increased significantly in the model group(P<0.01); while as compared with the model group, these levels were decreased significantly in the high dose group, low dose group and positive control group(P<0.01). In conclusion, Fritillariae Cirrhosae Bulbus can improve airway remodeling in a murine asthma model, and its mechanisms may be related to down-regulating MMP-2, MMP-9 and TIMP-1 levels.

The glycine hinge of transmembrane segment 2 modulates the subcellular localization and gating properties in TREK channels.

TWIK-Related K+ channels (TREK), including TREK-1 and TREK-2, belong to the TREK/TRAAK subclass of two-pore domain K+ (K2P) family. The important functions of transmembrane segment 4 (M4)-glycine hinge in TREK channel gating have been characterized, but the roles of M2-hinge (the equivalent residue of M4-hinge) remain unclear. Here, by characterizing the macroscopic currents, subcellular localization and gating properties of their M2-hinge mutants (G166A for TREK-1 and G196A for TREK-2), we investigated the functions of M2-hinge. G166A displayed decreased whole-cell currents, whereas no current was produced by G196A. Subcellular analysis indicated that both mutants were aggregated near the perinuclear region, and most of them were retented within the endoplasmic reticulum (ER). Next, to explore the roles of M2-hinge in the gating mechanism, we tested the responses of the related M2-hinge mutants to 2-Aminoethoxydiphenyl borate (2-APB) and extracellular pH alteration (ΔpHo). TREK-1mut7-G166A displayed reduced sensitivity to 2-APB activation, but similar sensitivity to ΔpHo, when compared with TREK-1mut7. WT-ΔpCt, a TREK-2 tandom dimer, was used to assess the function of M2-hinge in the cis-type gating of TREK-2. The sensitivities of G196A-ΔpCt to both 2-APB and ΔpHo decreased compared with WT-ΔpCt. Taken together, our results reveal that the M2-hinge of TREK channels control their macroscopic current, subcellular localization and gating process.

Intersubunit Concerted Cooperative and cis-Type Mechanisms Modulate Allosteric Gating in Two-Pore-Domain Potassium Channel TREK-2.

In response to diverse stimuli, two-pore-domain potassium channel TREK-2 regulates cellular excitability, and hence plays a key role in mediating neuropathic pain, mood disorders and ischemia through. Although more and more input modalities are found to achieve their modulations via acting on the channel, the potential role of subunit interaction in these modulations remains to be explored. In the current study, the deletion (lack of proximal C-terminus, ΔpCt) or point mutation (G312A) was introduced into TREK-2 subunits to limit K(+) conductance and used to report subunit stoichiometry. The constructs were then combined with wild type (WT) subunit to produce concatenated dimers with defined composition, and the gating kinetics of these channels to 2-Aminoethoxydiphenyl borate (2-APB) and extracellular pH (pHo) were characterized. Our results show that combination of WT and ΔpCt/G312A subunits reserves similar gating properties to that of WT dimmers, suggesting that the WT subunit exerts dominant and positive effects on the mutated one, and thus the two subunits controls channel gating via a concerted cooperative manner. Further introduction of ΔpCt into the latter subunit of heterodimeric channel G312A-WT or G312A-G312A attenuated their sensitivity to 2-APB and pHo alkalization, implicating that these signals were transduced by a cis-type mechanism. Together, our findings elucidate the mechanisms for how the two subunits control the pore gating of TREK-2, in which both intersubunit concerted cooperative and cis-type manners modulate the allosteric regulations induced by 2-APB and pHo alkalization.

Allosteric coupling between proximal C-terminus and selectivity filter is facilitated by the movement of transmembrane segment 4 in TREK-2 channel.

TREK-2, a member of two-pore-domain potassium channel family, regulates cellular excitability in response to diverse stimuli. However, how such stimuli control channel function remains unclear. Here, by characterizing the responses of cytosolic proximal C-terminus deletant (ΔpCt) and transmembrane segment 4 (M4)-glycine hinge mutant (G312A) to 2-Aminoethoxydiphenyl borate (2-APB), an activator of TREK-2, we show that the transduction initiated from pCt domain is allosterically coupled with the conformation of selectivity filter (SF) via the movements of M4, without depending on the original status of SF. Moreover, ΔpCt and G312A also exhibited blunted responses to extracellular alkalization, a model to induce SF conformational transition. These results suggest that the coupling between pCt domain and SF is bidirectional, and M4 movements are involved in both processes. Further mechanistic exploration reveals that the function of Phe316, a residue close to the C-terminus of M4, is associated with such communications. However, unlike TREK-2, M4-hinge of TREK-1 only controls the transmission from pCt to SF, rather than SF conformational changes triggered by pHo changes. Together, our findings uncover the unique gating properties of TREK-2, and elucidate the mechanisms for how the extracellular and intracellular stimuli harness the pore gating allosterically.

The isoforms generated by alternative translation initiation adopt similar conformation in the selectivity filter in TREK-2

TREK-2 (TWIK-related K+ channel-2), a member of two-pore domain potassium (K2P) channel family, tunes cellular excitability via conducting leak or background currents. In TREK-2, the isoforms generated by alternative translation initiation (ATI) mechanism exhibit large divergence in unitary conductance, but similar in selectivity to K+. Up to now, the structural basis for this similarity in ion selectivity is unknown. Here, we report that externally applied Ba2+ inhibits the currents of TREK-2 in a concentration- and time-dependent manner. The blocking effect is blunted by elevated extracellular K+ or mutation of S4 K+ binding site, which suggests that the inhibitory mechanism of Ba2+ is due to its competitive docking properties within the selectivity filter (SF). Next, we demonstrate that all the ATI isoforms exhibit analogous behaviors upon the application of Ba2+ and alteration of extracellular pH (pHo), which acts on the outer position of the SF. These results strongly support the notion that all the ATI isoforms of TREK-2 possess resembled SF conformation in S4 site and the position defined by pHo, which implicates that neither the role of N-terminus (Nt) nor the unitary conductance is associated with SF conformation. Our findings might help to understand the detail gating mechanism of TREK-2 and K2P channels

The isoforms generated by alternative translation initiation adopt similar conformation in the selectivity filter in TREK-2.

TREK-2 (TWIK-related K(+) channel-2), a member of two-pore domain potassium (K2P) channel family, tunes cellular excitability via conducting leak or background currents. In TREK-2, the isoforms generated by alternative translation initiation (ATI) mechanism exhibit large divergence in unitary conductance, but similar in selectivity to K(+). Up to now, the structural basis for this similarity in ion selectivity is unknown. Here, we report that externally applied Ba(2+) inhibits the currents of TREK-2 in a concentration- and time-dependent manner. The blocking effect is blunted by elevated extracellular K(+) or mutation of S4 K(+) binding site, which suggests that the inhibitory mechanism of Ba(2+) is due to its competitive docking properties within the selectivity filter (SF). Next, we demonstrate that all the ATI isoforms exhibit analogous behaviors upon the application of Ba(2+) and alteration of extracellular pH (pHo), which acts on the outer position of the SF. These results strongly support the notion that all the ATI isoforms of TREK-2 possess resembled SF conformation in S4 site and the position defined by pHo, which implicates that neither the role of N-terminus (Nt) nor the unitary conductance is associated with SF conformation. Our findings might help to understand the detail gating mechanism of TREK-2 and K2P channels.

Mas-related G protein-coupled receptor D is coupled to endogenous calcium-activated chloride channel in Xenopusoocytes

Mas-related G protein-coupled receptor D (MrgD) is expressed almost exclusively in nociceptive primary sensory neurons and the neurons located in stratum granulosum of skin. More and more evidence suggest that MrgD plays an important role in pain sensation and/or transduction. Recent studies have demonstrated that the receptor is also involved in itch sensation in both mouse and human. In the present study, we identified a robust inward current in MrgD-expressing Xenopusoocytes by using â-alanine, a putative ligand of MrgD. The currents were sensitive to inhibitor of Ca2+-activated chloride channels (CaCCs) and intracellular Ca2+ chelator, suggesting they were produced by endogenous CaCCs. Furthermore, it was demonstrated that upon the application of phospholipase C (PLC) inhibitor, or antisense oligonucleotides of inositol trisphosphate receptor (IP3R), the â-alanine-induced currents were dramatically depressed. However, protein kinase C inhibitor did not display any visible effect on CaCC currents. In summary, our data suggest that the activation of MrgD promotes the open of endogenous CaCCs via Gq-PLC-IP3-Ca2+ pathway. The current findings reveal the functional coupling between MrgD and CaCCs in Xenopus oocytes and also provide a facile model to assay the activity of MrgD

Mas-related G protein-coupled receptor D is coupled to endogenous calcium-activated chloride channel in Xenopus oocytes.

Mas-related G protein-coupled receptor D (MrgD) is expressed almost exclusively in nociceptive primary sensory neurons and the neurons located in stratum granulosum of skin. More and more evidence suggest that MrgD plays an important role in pain sensation and/or transduction. Recent studies have demonstrated that the receptor is also involved in itch sensation in both mouse and human. In the present study, we identified a robust inward current in MrgD-expressing Xenopus oocytes by using ß-alanine, a putative ligand of MrgD. The currents were sensitive to inhibitor of Ca(2+)-activated chloride channels (CaCCs) and intracellular Ca(2+) chelator, suggesting they were produced by endogenous CaCCs. Furthermore, it was demonstrated that upon the application of phospholipase C (PLC) inhibitor, or antisense oligonucleotides of inositol trisphosphate receptor (IP3R), the ß-alanine-induced currents were dramatically depressed. However, protein kinase C inhibitor did not display any visible effect on CaCC currents. In summary, our data suggest that the activation of MrgD promotes the open of endogenous CaCCs via G(q)-PLC-IP3-Ca(2+) pathway. The current findings reveal the functional coupling between MrgD and CaCCs in Xenopus oocytes and also provide a facile model to assay the activity of MrgD.

Clostridium botulinum toxin A inhibits contractility in pregnant human myometrium in vitro.

Studies were undertaken to evaluate the effect of Botulinum neurotoxin type-A (BoNTA) preparation on oxytocin-induced contractions of pregnant human myometrium in vitro. Human myometrial tissue was exposed to increasing concentrations (1-50 000 U/mL) of BoNT/A. Isometric contractions were measured using a force displacement transducer. The cumulative effect of BoNT/A on myometrial activity (time to half relaxation [TTR50], frequency, and amplitude) was evaluated. The frequency of myometrial contractions was depressed by 40% from baseline (P < .05) and relaxation time was increased by 30% (P < .05) from baseline within a narrow range of concentrations. There was no significant difference in amplitude. The observed effects were rapidly reversed after complete wash out of the tissue. BoNT/A or its analogues with more specific tissue affinity may be of value as future agents for prevention of unwanted uterine contractile activity associated with preterm labor and fetal surgery.

Effects of collagen matrices by covalent incorporation of heparin and loading with huangqi injection (HI) on anagenetic blood vessel / 中国中药杂志

To investigate effects of collagen matrices by covalent incorporation of heparin and loading with huangqi injection (HI) on anagenetic capillaries, we established the chick chorioallantois model. The collagen matrices by covalent incorporation of heparin and loading with HI were placed and then the eggs were continuously incubated for 3 days. The number of capillaries in the vicinity of samples, the hemoglobin content inside the samples, the dry weight and the macroscopic observation were evaluated. We found the heparinized matrices had comparable angiogenic effects. The number of capillaries, the hemoglobin content, the expression of CD34 increased remarkably (P < 0.01). So we concluded that HI might be considered as an alternative or addition agent to promote the acidification of capillaries.

Effect of compound Puerarin on the collage IV in streptozotocin-induced diabetic nephropathy rats / 中华预防医学杂志

<p><b>OBJECTIVE</b>To observe the effect of compound Puerarin on collagen IV of streptozotocin-induced diabetic rats.</p><p><b>METHODS</b>Diabetic nephropathy rats were induced by intraperitoneal injection of streptozotocin (STZ). Rats were allocated randomly to control group (10), diabetes model group (10), Vitamin C group (10), Puerarin group (10), vitamin C plus Puerarin group (10). The study period lasted for 12 weeks. During and after the treatment, the general state, blood glucose levels, glycosylated hemoglobin, blood urea nitrogen, serum collagen IV, blood urea nitrogen, serum creatinine, urinary albumin excretion rate of the 24-hour, and clearance rate of creatinine collagen IV protein were determined by immunohistochemistoche analysis as well as type the gene expression of collagen IV alpha 1 mRNA were determined by in situ hybridization analysis in the kidney tissue of different groups.</p><p><b>RESULTS</b>(1) Diabetes mellitus and renal function lesion occurred in the four groups. (2) Vitamin C and Puerarin could improve the general conditions of diabetic Rats, decrease blood urea nitrogen [(8.68 +/- 0.43), (7.98 +/- 0.47) and (5.76 +/- 0.82) micromol/L, serum creatinine [(74.68 +/- 8.20), (75.52 +/- 7.98) and (58.66 +/- 6.65) mmol/L], and urinary albumin excretion rate of the 24-hour [(18.40 +/- 0.37), (17.24 +/- 0.30) and (9.97 +/- 1.27) mg/24 h x 10(-3)]; increase clearance rate of creatinine [(0.59 +/- 0.21), (0.61 +/- 0.14) and (0.69 +/- 0.32) ml/min], the expression of collage IV absorbance [(111.56 +/- 14.61), (110.78 +/- 9.69) and (95.44 +/- 9.97) ] in the diabetic Rats were significantly inhibited at the same time.</p><p><b>CONCLUSION</b>The compound Puerarin might have some functions on preventing ren by inhibiting expression of type IV collagen.</p>

Modification of YACs by Homologous Recombination and Transfer of a 330 kb YAC into Mammalian Cells.

YAC clones were modified via homologous recombination by transfecting yeast cells containing YAC with plasmid PRAN4 DNAs. The integration of neo gene into YAC DNA was identified using Southern blotting and PCR methods. A modified YAC that carried 330 kb human DNA was introduced into L929 cells through PEG mediated spheroplast fusion, and G418 resistant colonies were obtained.