Table 1.
Characteristics of the included in vitro cell models/studies.
| Author and Year | Wang et al. (2010) | Kim et al. (2014) | Xiong et al. (2015) | Xue et al. (2016) | Lin et al. (2017) | Hao et al. (2019) | Xiong et al. (2019) | Lai et al. (2020) |
|---|---|---|---|---|---|---|---|---|
| Cell lines used | HEI-OC1 (Permissive - 33°C 10% CO2) | HEI-OC1 (Permissive - 33°C 5% CO2) | HEI-OC1 (Permissive - 33°C 10% CO2) | HEI-OC1 (Permissive - 33°C 7% CO2) | HEI-OC1 (Permissive - 33°C 10% CO2) | SK-N-MC and SH-SY5Y cells (37°C 5% CO2) | HEI-OC1 (Permissive - 33°C 10% CO2) | HEI-OC1 (37 °C 5% CO2) |
| Type of SNHL investigated | Ototoxic drug-induced | Ototoxic drug-induced | ARHL | ARHL | Diabetes-related hearing loss | ARHL | ARHL | Ototoxic drug-induced |
| Study design—Experimental | ||||||||
| Control group/s | No treatment/s | No treatment/s | No treatment/s | No treatment/s | Normal glucose (5.5 mmol) | PBS group | No treatment/s | No treatment/s |
| Treatment group/s | t-BHP | -Cisplatin -Cisplatin and β-Lap (at different concentrations)-Cisplatin (+/–) and DHIQ -2 siRNA transfection groups (pre-miR-34a and control)-Cisplatin (+/–) and 4 transfection groups (NQO1, PARP-1, p53 and control)-Cisplatin and β-Lap (+/–) and 4 transfection groups (NQO1, PARP-1, p53 and control) | -4 transfection groups at different concentrations (miR-34a mimic, mimic control, miR-34a inhibitor, inhibitor control)-Resveratrol (0, 2, 5, 10 μM) and 2 transfection (miR-34a mimic and mimic control) groups -H2O2 (+/–) and resveratrol (0, 5, 10 μM) and 2 transfection (miR-34a mimic and mimic control) groups-Resveratrol (+/–) and 2 transfection (miR-34a mimic and mimic control) groups, -resveratrol alone,-5-FU alone and -recevatol + 5-FU group | -H2O2-H2O2 + 5 transfection groups (miR-29b mimic, mimic control, miR-29b inhibitor, plk0.1-SIRT1 and plk0.1-scrample) | -High glucose -High glucose + 8 transfection groups(miR-34a mimic, mimic control; miR-34a-inhibitor, inhibitor control; si-SIRT1 and a negative control; si-HIF-1αand a negative control)-High glucose + 2 transfection groups (pECE-Flag-SIRT1 and si-MOCK/negative control) | -H2O2 + negative control- H2O2 + transfected with MIAT-H2O2 + transfected with anti-miR-29b | - H2O2-UCDA-UCDA+ H2O2- H2O2 + SRT- H2O2 + 4 transfection groups (Parkin, PGC-1α, Drp1 and control/ scrambled siRNA) | -Gentamicin-Gentamicin +1 transfection group (IESC-ex) -Gentamicin +3 transfection groups (IESC-ex, IESC-miR-182-5p-ex and IESC-miR-NC-ex) |
| Dosage(s) (hypoxia inducing agent) | 0, 50, 100, 200 μM | 20 μM | 50 μM | 50 μM | 30 mmol | No data | 1 mM | 2 mM |
| Exposure time | 12 h | up to 24 h | 1 h | 1 h | 48 h | not disclosed | 1 h | not disclosed |
| Harvesting interval(s) | immediately | 0, 6, 12, 18, 24 h | 48, 72 h | 72 h | 48 h | not disclosed | 6, 12, 24 h | not disclosed |
| Techniques used to confirm hypoxia-induction/ROS production | -DCFH-DA assay (Flow cytometric analysis)-Cell viability assay (CCK-8)-Annexin-V FITC, Apoptosis Kit (Flow cytometric analysis) | -Cell proliferation assay (MTT) -Chemiluminescent, PARP Assay Kit -Fluorescent SIRT1 Assay Kit | -Immunocyto-chemistry-Cell viability assay (MTS)-Annexin-V FITC, Apoptosis Kit (Flow cytometric analysis) | - Cell proliferation assay (MTT)-Annexin V-FITC Apoptosis Detection Kit (Flow cytometric analysis)-JC-1 Fluorescence Kit | -Cell viability assay (MTT)-Annexin V-FITC Apoptosis Detection Kit (Flow cytometric analysis) | -Cell proliferation assay (MTT)-Annexin-V FITC, Apoptosis Kit (Flow cytometric analysis) | -Cell viability assay (MTS)-Immunocyto-chemistry (MitoSOX)-JC-1 Florescence Kit (Flow cytometric analysis)-ATP Assay -Western blotting and densitometry - qRT-PCR | -Superoxide dismutase assay kit -Catalase assay kit -Glutathione peroxidase activity -LDH Cytotoxicity Assay Detection Kit |
| MicroRNA investigations | ||||||||
| Samples used to extract RNAs | cell pellets | cell pellets | cell pellets | cell pellets | cell pellets | cell pellets | cell pellets | cell pellets |
| Technique used to determine the gene expression | MiRNA microarray | qRT-PCR | qRT-PCR | qRT-PCR | qRT-PCR | qRT-PCR | qRT-PCR | -qRT-PCR |
| Validation methods | qRT-PCR | Western blotting and densitometry | No data | No data | No data | No data | No data | No data |
| Reported differentially expressed miRNAs / candidate miRNAs | -miR-133a*/-17/-191*/-214/-467b*/-690/-691/ and miR-122/-27b*/-28*/-335–5p/-377/-383/-675–3p/-743b-5p/-871/-874-miR-29a/-203 | miR-34a | miR-34a | miR-29b | miR-34a | miR-29b | miR-34a | miR-182–5p |
| Gene expression studies | ||||||||
| Technique used to determine the gene expression | -mRNA Microarray -TargetScan version 5.1 | No data | qRT-PCR | qRT-PCR | qRT-PCR | qRT-PCR | qRT-PCR | qRT-PCR |
| and Validation methods | qRT-PCR | Western blotting and densitometry | -Western blotting and densitometry-Luciferase assay-Immunocyto-chemistry | Western blotting and densitometry | Western blotting and densitometry | -Western blot, -Luciferase assay | -Western blotting and densitometry -Immunocyto-chemistry | Western blotting and densitometry |
| Reported predicted and/or validated gene(s) | -CCND2, ATF7IP-IGF-1, PIK3R1, PTPN11-FOS, SOS2, PPP3R1, PPM1B, FLNC, PPP5C | SIRT1, PARP-1, p53, NF-kB p65 | SIRT1, p53, acetyl p53, acetyl-FOXO1, 4HNE | SIRT1, PGC-1α | SIRT1, HIF-1α | MIAT, SIRT1, PGC-1α | SIRT1, PINK1, Parkin, PGC-1α, TFAM, COX4, SOD1, TOmm20, 4HNE, LAMP1 | FOXO3, Bcl-2, Bax |
| Reported gene enrichment or functional enrichment pathway | IGF-1 signaling, MAPK signaling | miR-34a-p53-SIRT1-PARP-1 | p53 - mir-34a-SIRT1 | miR-29b-SIRT1-PGC-1α | miR-34a- SIRT1/HIF-1α | MIAT-miR-29b-SIRT1-PGC-1α | miR-34a-SIRT1 | miR-182–5p-FOXO3-Bax-Bcl2 |
Study characteristics of eight primary investigations that fulfilled the study inclusion criteria are summarized. ARHL, age related hearing loss; HEI-OC1, House Ear Institute-Organ of Corti 1; IESC, inner ear stem cells; IESC-ex, exosomes derived from IESCs; NC, negative control; qRT-PCR, quantitative reverse transcription polymerase chain reaction; ROS, reactive oxygen species. NQO1, NADH:quinone oxidoreductase 1; SIRT1, sirtuin 1; PGC-1α, peroxisome proliferator-activated receptor gamma coactivator 1-alpha; HIF-1α, hypoxia-inducible factor 1-alpha; PINK1, PTEN induced kinase 1; PARP-1, poly (ADP-ribose) polymerase 1; MIAT, myocardial infarction associated transcript; 4HNE, 4-hydroxy-2-nonenal; TFAM, mitochondrial transcription factor A; TOmm20, translocase of outer mitochondrial membrane 20; COX4, cytochrome c oxidase subunit 4; SOD1, superoxide dismutase; NF-kB, nuclear factor kappa B; LAMP1, lysosomal-associated membrane protein 1; FOXO1/3, forkhead box protein O 1/3; CCND2, cyclin D2; ATF71P, activating transcription factor 7-interacting protein 1; IGF-1, Insulin-like growth factor 1; PIK3R1, phosphoinositide-3-kinase regulatory subunit 1; PTPN11, tyrosine-protein phosphatase non-receptor type 11; FOS, proto-oncogene, AP-1 transcription factor subunit; SOS2, Ras/Rho guanine nucleotide exchange factor 2; PPP3R1, protein phosphatase 2B regulatory subunit 1; PPM1B, protein phosphatase 1B; FLNC, filamin-C; PPP5C, protein phosphatase 5 catalytic subunit; Bcl2, B-cell lymphoma 2; MAPK, mitogen-activated protein kinase. t-BHP, tertbutyl hydroperoxide, β-Lap, β-lapachone; UCDA, ursodeoxycholic acid; 5-FU, 5-fluorouracil; CCK-8, cell counting kit-8; DCFH-DA, 6-carboxy-2’,7’-dichlorodihydrofluorescein diacetate; FITC, fluorescein isothiocyanate; JC- 1,5,5’,6,6’-tetrachloro-1,1’,3,3’-tetramethyl-benzimidazolylcarbocyanine iodide (mitochondrial dye); MTT, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide; MTS, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carbo xymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium; LDH, Lactate dehydrogenase; ATP, Adenosine triphosphate; *, Some miRNA hairpin precursors give rise to two excised miRNAs, one from each arm. An asterisk has been used to denote the less predominant form by Wang et al. (2010).